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-rw-r--r--src/build-remote/build-remote.cc19
-rw-r--r--src/build-remote/local.mk9
-rw-r--r--src/cpptoml/LICENSE18
-rw-r--r--src/cpptoml/cpptoml.h3457
-rw-r--r--src/libexpr/attr-set.cc16
-rw-r--r--src/libexpr/eval-inline.hh14
-rw-r--r--src/libexpr/eval.cc228
-rw-r--r--src/libexpr/eval.hh8
-rw-r--r--src/libexpr/get-drvs.hh2
-rw-r--r--src/libexpr/lexer.l41
-rw-r--r--src/libexpr/parser.y4
-rw-r--r--src/libexpr/primops.cc75
-rw-r--r--src/libexpr/primops/fetchGit.cc2
-rw-r--r--src/libexpr/primops/fetchMercurial.cc2
-rw-r--r--src/libexpr/primops/fromTOML.cc77
-rw-r--r--src/libexpr/value.hh4
-rw-r--r--src/libmain/stack.cc2
-rw-r--r--src/libstore/binary-cache-store.cc23
-rw-r--r--src/libstore/build.cc457
-rw-r--r--src/libstore/builtins/fetchurl.cc22
-rw-r--r--src/libstore/derivations.cc16
-rw-r--r--src/libstore/derivations.hh4
-rw-r--r--src/libstore/download.cc124
-rw-r--r--src/libstore/download.hh4
-rw-r--r--src/libstore/gc.cc29
-rw-r--r--src/libstore/globals.cc21
-rw-r--r--src/libstore/globals.hh20
-rw-r--r--src/libstore/http-binary-cache-store.cc41
-rw-r--r--src/libstore/legacy-ssh-store.cc68
-rw-r--r--src/libstore/local-store.cc16
-rw-r--r--src/libstore/local-store.hh2
-rw-r--r--src/libstore/optimise-store.cc3
-rw-r--r--src/libstore/parsed-derivations.cc111
-rw-r--r--src/libstore/parsed-derivations.hh35
-rw-r--r--src/libstore/remote-store.cc176
-rw-r--r--src/libstore/remote-store.hh15
-rw-r--r--src/libstore/s3-binary-cache-store.cc166
-rw-r--r--src/libstore/s3.hh4
-rw-r--r--src/libstore/serve-protocol.hh3
-rw-r--r--src/libstore/ssh.cc25
-rw-r--r--src/libstore/ssh.hh1
-rw-r--r--src/libstore/store-api.cc48
-rw-r--r--src/libstore/store-api.hh7
-rw-r--r--src/libutil/archive.cc2
-rw-r--r--src/libutil/compression.cc613
-rw-r--r--src/libutil/compression.hh12
-rw-r--r--src/libutil/json.cc1
-rw-r--r--src/libutil/pool.hh6
-rw-r--r--src/libutil/serialise.cc42
-rw-r--r--src/libutil/serialise.hh8
-rw-r--r--src/libutil/sync.hh4
-rw-r--r--src/libutil/util.cc37
-rw-r--r--src/libutil/util.hh13
-rw-r--r--src/linenoise/ConvertUTF.cpp542
-rwxr-xr-xsrc/linenoise/ConvertUTF.h162
-rw-r--r--src/linenoise/LICENSE66
-rw-r--r--src/linenoise/linenoise.cpp3450
-rw-r--r--src/linenoise/linenoise.h73
-rw-r--r--src/linenoise/wcwidth.cpp315
-rw-r--r--src/nix-build/local.mk9
-rwxr-xr-xsrc/nix-build/nix-build.cc65
-rw-r--r--src/nix-channel/local.mk7
-rwxr-xr-xsrc/nix-channel/nix-channel.cc18
-rw-r--r--src/nix-collect-garbage/local.mk7
-rw-r--r--src/nix-collect-garbage/nix-collect-garbage.cc15
-rw-r--r--src/nix-copy-closure/local.mk7
-rwxr-xr-xsrc/nix-copy-closure/nix-copy-closure.cc13
-rw-r--r--src/nix-daemon/local.mk13
-rw-r--r--src/nix-daemon/nix-daemon.cc31
-rw-r--r--src/nix-env/local.mk7
-rw-r--r--src/nix-env/nix-env.cc22
-rw-r--r--src/nix-instantiate/local.mk7
-rw-r--r--src/nix-instantiate/nix-instantiate.cc36
-rw-r--r--src/nix-prefetch-url/local.mk7
-rw-r--r--src/nix-prefetch-url/nix-prefetch-url.cc75
-rw-r--r--src/nix-store/graphml.cc90
-rw-r--r--src/nix-store/graphml.hh (renamed from src/nix-store/xmlgraph.hh)2
-rw-r--r--src/nix-store/local.mk9
-rw-r--r--src/nix-store/nix-store.cc47
-rw-r--r--src/nix-store/xmlgraph.cc66
-rw-r--r--src/nix/copy.cc8
-rw-r--r--src/nix/doctor.cc124
-rw-r--r--src/nix/edit.cc5
-rw-r--r--src/nix/installables.cc26
-rw-r--r--src/nix/local.mk20
-rw-r--r--src/nix/ls.cc2
-rw-r--r--src/nix/main.cc7
-rw-r--r--src/nix/path-info.cc36
-rw-r--r--src/nix/repl.cc122
-rw-r--r--src/nix/run.cc26
-rw-r--r--src/nix/search.cc32
-rw-r--r--src/nix/upgrade-nix.cc51
-rw-r--r--src/nix/verify.cc2
-rw-r--r--src/nix/why-depends.cc2
94 files changed, 5796 insertions, 5985 deletions
diff --git a/src/build-remote/build-remote.cc b/src/build-remote/build-remote.cc
index 38dbe3e58b26..abf3669b5b35 100644
--- a/src/build-remote/build-remote.cc
+++ b/src/build-remote/build-remote.cc
@@ -17,6 +17,7 @@
 #include "store-api.hh"
 #include "derivations.hh"
 #include "local-store.hh"
+#include "legacy.hh"
 
 using namespace nix;
 using std::cin;
@@ -37,11 +38,9 @@ static AutoCloseFD openSlotLock(const Machine & m, unsigned long long slot)
     return openLockFile(fmt("%s/%s-%d", currentLoad, escapeUri(m.storeUri), slot), true);
 }
 
-int main (int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-
+    {
         logger = makeJSONLogger(*logger);
 
         /* Ensure we don't get any SSH passphrase or host key popups. */
@@ -80,7 +79,7 @@ int main (int argc, char * * argv)
 
         if (machines.empty()) {
             std::cerr << "# decline-permanently\n";
-            return;
+            return 0;
         }
 
         string drvPath;
@@ -90,8 +89,8 @@ int main (int argc, char * * argv)
 
             try {
                 auto s = readString(source);
-                if (s != "try") return;
-            } catch (EndOfFile &) { return; }
+                if (s != "try") return 0;
+            } catch (EndOfFile &) { return 0; }
 
             auto amWilling = readInt(source);
             auto neededSystem = readString(source);
@@ -253,6 +252,8 @@ connected:
             copyPaths(ref<Store>(sshStore), store, missing, NoRepair, NoCheckSigs, NoSubstitute);
         }
 
-        return;
-    });
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("build-remote", _main);
diff --git a/src/build-remote/local.mk b/src/build-remote/local.mk
deleted file mode 100644
index 50b0409d1886..000000000000
--- a/src/build-remote/local.mk
+++ /dev/null
@@ -1,9 +0,0 @@
-programs += build-remote
-
-build-remote_DIR := $(d)
-
-build-remote_INSTALL_DIR := $(libexecdir)/nix
-
-build-remote_LIBS = libmain libformat libstore libutil
-
-build-remote_SOURCES := $(d)/build-remote.cc
diff --git a/src/cpptoml/LICENSE b/src/cpptoml/LICENSE
new file mode 100644
index 000000000000..8802c4fa5a36
--- /dev/null
+++ b/src/cpptoml/LICENSE
@@ -0,0 +1,18 @@
+Copyright (c) 2014 Chase Geigle
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/src/cpptoml/cpptoml.h b/src/cpptoml/cpptoml.h
new file mode 100644
index 000000000000..07de010b1520
--- /dev/null
+++ b/src/cpptoml/cpptoml.h
@@ -0,0 +1,3457 @@
+/**
+ * @file cpptoml.h
+ * @author Chase Geigle
+ * @date May 2013
+ */
+
+#ifndef _CPPTOML_H_
+#define _CPPTOML_H_
+
+#include <algorithm>
+#include <cassert>
+#include <clocale>
+#include <cstdint>
+#include <cstring>
+#include <fstream>
+#include <iomanip>
+#include <map>
+#include <memory>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#if __cplusplus > 201103L
+#define CPPTOML_DEPRECATED(reason) [[deprecated(reason)]]
+#elif defined(__clang__)
+#define CPPTOML_DEPRECATED(reason) __attribute__((deprecated(reason)))
+#elif defined(__GNUG__)
+#define CPPTOML_DEPRECATED(reason) __attribute__((deprecated))
+#elif defined(_MSC_VER)
+#if _MSC_VER < 1910
+#define CPPTOML_DEPRECATED(reason) __declspec(deprecated)
+#else
+#define CPPTOML_DEPRECATED(reason) [[deprecated(reason)]]
+#endif
+#endif
+
+namespace cpptoml
+{
+class writer; // forward declaration
+class base;   // forward declaration
+#if defined(CPPTOML_USE_MAP)
+// a std::map will ensure that entries a sorted, albeit at a slight
+// performance penalty relative to the (default) unordered_map
+using string_to_base_map = std::map<std::string, std::shared_ptr<base>>;
+#else
+// by default an unordered_map is used for best performance as the
+// toml specification does not require entries to be sorted
+using string_to_base_map
+    = std::unordered_map<std::string, std::shared_ptr<base>>;
+#endif
+
+// if defined, `base` will retain type information in form of an enum class
+// such that static_cast can be used instead of dynamic_cast
+// #define CPPTOML_NO_RTTI
+
+template <class T>
+class option
+{
+  public:
+    option() : empty_{true}
+    {
+        // nothing
+    }
+
+    option(T value) : empty_{false}, value_(std::move(value))
+    {
+        // nothing
+    }
+
+    explicit operator bool() const
+    {
+        return !empty_;
+    }
+
+    const T& operator*() const
+    {
+        return value_;
+    }
+
+    const T* operator->() const
+    {
+        return &value_;
+    }
+
+    const T& value_or(const T& alternative) const
+    {
+        if (!empty_)
+            return value_;
+        return alternative;
+    }
+
+  private:
+    bool empty_;
+    T value_;
+};
+
+struct local_date
+{
+    int year = 0;
+    int month = 0;
+    int day = 0;
+};
+
+struct local_time
+{
+    int hour = 0;
+    int minute = 0;
+    int second = 0;
+    int microsecond = 0;
+};
+
+struct zone_offset
+{
+    int hour_offset = 0;
+    int minute_offset = 0;
+};
+
+struct local_datetime : local_date, local_time
+{
+};
+
+struct offset_datetime : local_datetime, zone_offset
+{
+    static inline struct offset_datetime from_zoned(const struct tm& t)
+    {
+        offset_datetime dt;
+        dt.year = t.tm_year + 1900;
+        dt.month = t.tm_mon + 1;
+        dt.day = t.tm_mday;
+        dt.hour = t.tm_hour;
+        dt.minute = t.tm_min;
+        dt.second = t.tm_sec;
+
+        char buf[16];
+        strftime(buf, 16, "%z", &t);
+
+        int offset = std::stoi(buf);
+        dt.hour_offset = offset / 100;
+        dt.minute_offset = offset % 100;
+        return dt;
+    }
+
+    CPPTOML_DEPRECATED("from_local has been renamed to from_zoned")
+    static inline struct offset_datetime from_local(const struct tm& t)
+    {
+        return from_zoned(t);
+    }
+
+    static inline struct offset_datetime from_utc(const struct tm& t)
+    {
+        offset_datetime dt;
+        dt.year = t.tm_year + 1900;
+        dt.month = t.tm_mon + 1;
+        dt.day = t.tm_mday;
+        dt.hour = t.tm_hour;
+        dt.minute = t.tm_min;
+        dt.second = t.tm_sec;
+        return dt;
+    }
+};
+
+CPPTOML_DEPRECATED("datetime has been renamed to offset_datetime")
+typedef offset_datetime datetime;
+
+class fill_guard
+{
+  public:
+    fill_guard(std::ostream& os) : os_(os), fill_{os.fill()}
+    {
+        // nothing
+    }
+
+    ~fill_guard()
+    {
+        os_.fill(fill_);
+    }
+
+  private:
+    std::ostream& os_;
+    std::ostream::char_type fill_;
+};
+
+inline std::ostream& operator<<(std::ostream& os, const local_date& dt)
+{
+    fill_guard g{os};
+    os.fill('0');
+
+    using std::setw;
+    os << setw(4) << dt.year << "-" << setw(2) << dt.month << "-" << setw(2)
+       << dt.day;
+
+    return os;
+}
+
+inline std::ostream& operator<<(std::ostream& os, const local_time& ltime)
+{
+    fill_guard g{os};
+    os.fill('0');
+
+    using std::setw;
+    os << setw(2) << ltime.hour << ":" << setw(2) << ltime.minute << ":"
+       << setw(2) << ltime.second;
+
+    if (ltime.microsecond > 0)
+    {
+        os << ".";
+        int power = 100000;
+        for (int curr_us = ltime.microsecond; curr_us; power /= 10)
+        {
+            auto num = curr_us / power;
+            os << num;
+            curr_us -= num * power;
+        }
+    }
+
+    return os;
+}
+
+inline std::ostream& operator<<(std::ostream& os, const zone_offset& zo)
+{
+    fill_guard g{os};
+    os.fill('0');
+
+    using std::setw;
+
+    if (zo.hour_offset != 0 || zo.minute_offset != 0)
+    {
+        if (zo.hour_offset > 0)
+        {
+            os << "+";
+        }
+        else
+        {
+            os << "-";
+        }
+        os << setw(2) << std::abs(zo.hour_offset) << ":" << setw(2)
+           << std::abs(zo.minute_offset);
+    }
+    else
+    {
+        os << "Z";
+    }
+
+    return os;
+}
+
+inline std::ostream& operator<<(std::ostream& os, const local_datetime& dt)
+{
+    return os << static_cast<const local_date&>(dt) << "T"
+              << static_cast<const local_time&>(dt);
+}
+
+inline std::ostream& operator<<(std::ostream& os, const offset_datetime& dt)
+{
+    return os << static_cast<const local_datetime&>(dt)
+              << static_cast<const zone_offset&>(dt);
+}
+
+template <class T, class... Ts>
+struct is_one_of;
+
+template <class T, class V>
+struct is_one_of<T, V> : std::is_same<T, V>
+{
+};
+
+template <class T, class V, class... Ts>
+struct is_one_of<T, V, Ts...>
+{
+    const static bool value
+        = std::is_same<T, V>::value || is_one_of<T, Ts...>::value;
+};
+
+template <class T>
+class value;
+
+template <class T>
+struct valid_value
+    : is_one_of<T, std::string, int64_t, double, bool, local_date, local_time,
+                local_datetime, offset_datetime>
+{
+};
+
+template <class T, class Enable = void>
+struct value_traits;
+
+template <class T>
+struct valid_value_or_string_convertible
+{
+
+    const static bool value = valid_value<typename std::decay<T>::type>::value
+                              || std::is_convertible<T, std::string>::value;
+};
+
+template <class T>
+struct value_traits<T, typename std::
+                           enable_if<valid_value_or_string_convertible<T>::
+                                         value>::type>
+{
+    using value_type = typename std::
+        conditional<valid_value<typename std::decay<T>::type>::value,
+                    typename std::decay<T>::type, std::string>::type;
+
+    using type = value<value_type>;
+
+    static value_type construct(T&& val)
+    {
+        return value_type(val);
+    }
+};
+
+template <class T>
+struct value_traits<T,
+                    typename std::
+                        enable_if<!valid_value_or_string_convertible<T>::value
+                                  && std::is_floating_point<
+                                         typename std::decay<T>::type>::value>::
+                            type>
+{
+    using value_type = typename std::decay<T>::type;
+
+    using type = value<double>;
+
+    static value_type construct(T&& val)
+    {
+        return value_type(val);
+    }
+};
+
+template <class T>
+struct value_traits<T,
+                    typename std::
+                        enable_if<!valid_value_or_string_convertible<T>::value
+                                  && std::is_signed<typename std::decay<T>::
+                                                        type>::value>::type>
+{
+    using value_type = int64_t;
+
+    using type = value<int64_t>;
+
+    static value_type construct(T&& val)
+    {
+        if (val < (std::numeric_limits<int64_t>::min)())
+            throw std::underflow_error{"constructed value cannot be "
+                                       "represented by a 64-bit signed "
+                                       "integer"};
+
+        if (val > (std::numeric_limits<int64_t>::max)())
+            throw std::overflow_error{"constructed value cannot be represented "
+                                      "by a 64-bit signed integer"};
+
+        return static_cast<int64_t>(val);
+    }
+};
+
+template <class T>
+struct value_traits<T,
+                    typename std::
+                        enable_if<!valid_value_or_string_convertible<T>::value
+                                  && std::is_unsigned<typename std::decay<T>::
+                                                          type>::value>::type>
+{
+    using value_type = int64_t;
+
+    using type = value<int64_t>;
+
+    static value_type construct(T&& val)
+    {
+        if (val > static_cast<uint64_t>((std::numeric_limits<int64_t>::max)()))
+            throw std::overflow_error{"constructed value cannot be represented "
+                                      "by a 64-bit signed integer"};
+
+        return static_cast<int64_t>(val);
+    }
+};
+
+class array;
+class table;
+class table_array;
+
+template <class T>
+struct array_of_trait
+{
+    using return_type = option<std::vector<T>>;
+};
+
+template <>
+struct array_of_trait<array>
+{
+    using return_type = option<std::vector<std::shared_ptr<array>>>;
+};
+
+template <class T>
+inline std::shared_ptr<typename value_traits<T>::type> make_value(T&& val);
+inline std::shared_ptr<array> make_array();
+template <class T>
+inline std::shared_ptr<T> make_element();
+inline std::shared_ptr<table> make_table();
+inline std::shared_ptr<table_array> make_table_array();
+
+#if defined(CPPTOML_NO_RTTI)
+/// Base type used to store underlying data type explicitly if RTTI is disabled
+enum class base_type
+{
+    NONE,
+    STRING,
+    LOCAL_TIME,
+    LOCAL_DATE,
+    LOCAL_DATETIME,
+    OFFSET_DATETIME,
+    INT,
+    FLOAT,
+    BOOL,
+    TABLE,
+    ARRAY,
+    TABLE_ARRAY
+};
+
+/// Type traits class to convert C++ types to enum member
+template <class T>
+struct base_type_traits;
+
+template <>
+struct base_type_traits<std::string>
+{
+    static const base_type type = base_type::STRING;
+};
+
+template <>
+struct base_type_traits<local_time>
+{
+    static const base_type type = base_type::LOCAL_TIME;
+};
+
+template <>
+struct base_type_traits<local_date>
+{
+    static const base_type type = base_type::LOCAL_DATE;
+};
+
+template <>
+struct base_type_traits<local_datetime>
+{
+    static const base_type type = base_type::LOCAL_DATETIME;
+};
+
+template <>
+struct base_type_traits<offset_datetime>
+{
+    static const base_type type = base_type::OFFSET_DATETIME;
+};
+
+template <>
+struct base_type_traits<int64_t>
+{
+    static const base_type type = base_type::INT;
+};
+
+template <>
+struct base_type_traits<double>
+{
+    static const base_type type = base_type::FLOAT;
+};
+
+template <>
+struct base_type_traits<bool>
+{
+    static const base_type type = base_type::BOOL;
+};
+
+template <>
+struct base_type_traits<table>
+{
+    static const base_type type = base_type::TABLE;
+};
+
+template <>
+struct base_type_traits<array>
+{
+    static const base_type type = base_type::ARRAY;
+};
+
+template <>
+struct base_type_traits<table_array>
+{
+    static const base_type type = base_type::TABLE_ARRAY;
+};
+#endif
+
+/**
+ * A generic base TOML value used for type erasure.
+ */
+class base : public std::enable_shared_from_this<base>
+{
+  public:
+    virtual ~base() = default;
+
+    virtual std::shared_ptr<base> clone() const = 0;
+
+    /**
+     * Determines if the given TOML element is a value.
+     */
+    virtual bool is_value() const
+    {
+        return false;
+    }
+
+    /**
+     * Determines if the given TOML element is a table.
+     */
+    virtual bool is_table() const
+    {
+        return false;
+    }
+
+    /**
+     * Converts the TOML element into a table.
+     */
+    std::shared_ptr<table> as_table()
+    {
+        if (is_table())
+            return std::static_pointer_cast<table>(shared_from_this());
+        return nullptr;
+    }
+    /**
+     * Determines if the TOML element is an array of "leaf" elements.
+     */
+    virtual bool is_array() const
+    {
+        return false;
+    }
+
+    /**
+     * Converts the TOML element to an array.
+     */
+    std::shared_ptr<array> as_array()
+    {
+        if (is_array())
+            return std::static_pointer_cast<array>(shared_from_this());
+        return nullptr;
+    }
+
+    /**
+     * Determines if the given TOML element is an array of tables.
+     */
+    virtual bool is_table_array() const
+    {
+        return false;
+    }
+
+    /**
+     * Converts the TOML element into a table array.
+     */
+    std::shared_ptr<table_array> as_table_array()
+    {
+        if (is_table_array())
+            return std::static_pointer_cast<table_array>(shared_from_this());
+        return nullptr;
+    }
+
+    /**
+     * Attempts to coerce the TOML element into a concrete TOML value
+     * of type T.
+     */
+    template <class T>
+    std::shared_ptr<value<T>> as();
+
+    template <class T>
+    std::shared_ptr<const value<T>> as() const;
+
+    template <class Visitor, class... Args>
+    void accept(Visitor&& visitor, Args&&... args) const;
+
+#if defined(CPPTOML_NO_RTTI)
+    base_type type() const
+    {
+      return type_;
+    }
+
+  protected:
+    base(const base_type t) : type_(t)
+    {
+        // nothing
+    }
+
+  private:
+    const base_type type_ = base_type::NONE;
+
+#else
+  protected:
+    base()
+    {
+        // nothing
+    }
+#endif
+};
+
+/**
+ * A concrete TOML value representing the "leaves" of the "tree".
+ */
+template <class T>
+class value : public base
+{
+    struct make_shared_enabler
+    {
+        // nothing; this is a private key accessible only to friends
+    };
+
+    template <class U>
+    friend std::shared_ptr<typename value_traits<U>::type>
+    cpptoml::make_value(U&& val);
+
+  public:
+    static_assert(valid_value<T>::value, "invalid value type");
+
+    std::shared_ptr<base> clone() const override;
+
+    value(const make_shared_enabler&, const T& val) : value(val)
+    {
+        // nothing; note that users cannot actually invoke this function
+        // because they lack access to the make_shared_enabler.
+    }
+
+    bool is_value() const override
+    {
+        return true;
+    }
+
+    /**
+     * Gets the data associated with this value.
+     */
+    T& get()
+    {
+        return data_;
+    }
+
+    /**
+     * Gets the data associated with this value. Const version.
+     */
+    const T& get() const
+    {
+        return data_;
+    }
+
+  private:
+    T data_;
+
+    /**
+     * Constructs a value from the given data.
+     */
+#if defined(CPPTOML_NO_RTTI)
+    value(const T& val) : base(base_type_traits<T>::type), data_(val)
+    {
+    }
+#else
+    value(const T& val) : data_(val)
+    {
+    }
+#endif
+
+    value(const value& val) = delete;
+    value& operator=(const value& val) = delete;
+};
+
+template <class T>
+std::shared_ptr<typename value_traits<T>::type> make_value(T&& val)
+{
+    using value_type = typename value_traits<T>::type;
+    using enabler = typename value_type::make_shared_enabler;
+    return std::make_shared<value_type>(
+        enabler{}, value_traits<T>::construct(std::forward<T>(val)));
+}
+
+template <class T>
+inline std::shared_ptr<value<T>> base::as()
+{
+#if defined(CPPTOML_NO_RTTI)
+    if (type() == base_type_traits<T>::type)
+        return std::static_pointer_cast<value<T>>(shared_from_this());
+    else
+        return nullptr;
+#else
+    return std::dynamic_pointer_cast<value<T>>(shared_from_this());
+#endif
+}
+
+// special case value<double> to allow getting an integer parameter as a
+// double value
+template <>
+inline std::shared_ptr<value<double>> base::as()
+{
+#if defined(CPPTOML_NO_RTTI)
+    if (type() == base_type::FLOAT)
+        return std::static_pointer_cast<value<double>>(shared_from_this());
+
+    if (type() == base_type::INT)
+    {
+        auto v = std::static_pointer_cast<value<int64_t>>(shared_from_this());
+        return make_value<double>(static_cast<double>(v->get()));;
+    }
+#else
+    if (auto v = std::dynamic_pointer_cast<value<double>>(shared_from_this()))
+        return v;
+
+    if (auto v = std::dynamic_pointer_cast<value<int64_t>>(shared_from_this()))
+        return make_value<double>(static_cast<double>(v->get()));
+#endif
+
+    return nullptr;
+}
+
+template <class T>
+inline std::shared_ptr<const value<T>> base::as() const
+{
+#if defined(CPPTOML_NO_RTTI)
+    if (type() == base_type_traits<T>::type)
+        return std::static_pointer_cast<const value<T>>(shared_from_this());
+    else
+        return nullptr;
+#else
+    return std::dynamic_pointer_cast<const value<T>>(shared_from_this());
+#endif
+}
+
+// special case value<double> to allow getting an integer parameter as a
+// double value
+template <>
+inline std::shared_ptr<const value<double>> base::as() const
+{
+#if defined(CPPTOML_NO_RTTI)
+    if (type() == base_type::FLOAT)
+        return std::static_pointer_cast<const value<double>>(shared_from_this());
+
+    if (type() == base_type::INT)
+    {
+        auto v = as<int64_t>();
+        // the below has to be a non-const value<double> due to a bug in
+        // libc++: https://llvm.org/bugs/show_bug.cgi?id=18843
+        return make_value<double>(static_cast<double>(v->get()));
+    }
+#else
+    if (auto v
+        = std::dynamic_pointer_cast<const value<double>>(shared_from_this()))
+        return v;
+
+    if (auto v = as<int64_t>())
+    {
+        // the below has to be a non-const value<double> due to a bug in
+        // libc++: https://llvm.org/bugs/show_bug.cgi?id=18843
+        return make_value<double>(static_cast<double>(v->get()));
+    }
+#endif
+
+    return nullptr;
+}
+
+/**
+ * Exception class for array insertion errors.
+ */
+class array_exception : public std::runtime_error
+{
+  public:
+    array_exception(const std::string& err) : std::runtime_error{err}
+    {
+    }
+};
+
+class array : public base
+{
+  public:
+    friend std::shared_ptr<array> make_array();
+
+    std::shared_ptr<base> clone() const override;
+
+    virtual bool is_array() const override
+    {
+        return true;
+    }
+
+    using size_type = std::size_t;
+
+    /**
+     * arrays can be iterated over
+     */
+    using iterator = std::vector<std::shared_ptr<base>>::iterator;
+
+    /**
+     * arrays can be iterated over.  Const version.
+     */
+    using const_iterator = std::vector<std::shared_ptr<base>>::const_iterator;
+
+    iterator begin()
+    {
+        return values_.begin();
+    }
+
+    const_iterator begin() const
+    {
+        return values_.begin();
+    }
+
+    iterator end()
+    {
+        return values_.end();
+    }
+
+    const_iterator end() const
+    {
+        return values_.end();
+    }
+
+    /**
+     * Obtains the array (vector) of base values.
+     */
+    std::vector<std::shared_ptr<base>>& get()
+    {
+        return values_;
+    }
+
+    /**
+     * Obtains the array (vector) of base values. Const version.
+     */
+    const std::vector<std::shared_ptr<base>>& get() const
+    {
+        return values_;
+    }
+
+    std::shared_ptr<base> at(size_t idx) const
+    {
+        return values_.at(idx);
+    }
+
+    /**
+     * Obtains an array of value<T>s. Note that elements may be
+     * nullptr if they cannot be converted to a value<T>.
+     */
+    template <class T>
+    std::vector<std::shared_ptr<value<T>>> array_of() const
+    {
+        std::vector<std::shared_ptr<value<T>>> result(values_.size());
+
+        std::transform(values_.begin(), values_.end(), result.begin(),
+                       [&](std::shared_ptr<base> v) { return v->as<T>(); });
+
+        return result;
+    }
+
+    /**
+     * Obtains a option<vector<T>>. The option will be empty if the array
+     * contains values that are not of type T.
+     */
+    template <class T>
+    inline typename array_of_trait<T>::return_type get_array_of() const
+    {
+        std::vector<T> result;
+        result.reserve(values_.size());
+
+        for (const auto& val : values_)
+        {
+            if (auto v = val->as<T>())
+                result.push_back(v->get());
+            else
+                return {};
+        }
+
+        return {std::move(result)};
+    }
+
+    /**
+     * Obtains an array of arrays. Note that elements may be nullptr
+     * if they cannot be converted to a array.
+     */
+    std::vector<std::shared_ptr<array>> nested_array() const
+    {
+        std::vector<std::shared_ptr<array>> result(values_.size());
+
+        std::transform(values_.begin(), values_.end(), result.begin(),
+                       [&](std::shared_ptr<base> v) -> std::shared_ptr<array> {
+                           if (v->is_array())
+                               return std::static_pointer_cast<array>(v);
+                           return std::shared_ptr<array>{};
+                       });
+
+        return result;
+    }
+
+    /**
+     * Add a value to the end of the array
+     */
+    template <class T>
+    void push_back(const std::shared_ptr<value<T>>& val)
+    {
+        if (values_.empty() || values_[0]->as<T>())
+        {
+            values_.push_back(val);
+        }
+        else
+        {
+            throw array_exception{"Arrays must be homogenous."};
+        }
+    }
+
+    /**
+     * Add an array to the end of the array
+     */
+    void push_back(const std::shared_ptr<array>& val)
+    {
+        if (values_.empty() || values_[0]->is_array())
+        {
+            values_.push_back(val);
+        }
+        else
+        {
+            throw array_exception{"Arrays must be homogenous."};
+        }
+    }
+
+    /**
+     * Convenience function for adding a simple element to the end
+     * of the array.
+     */
+    template <class T>
+    void push_back(T&& val, typename value_traits<T>::type* = 0)
+    {
+        push_back(make_value(std::forward<T>(val)));
+    }
+
+    /**
+     * Insert a value into the array
+     */
+    template <class T>
+    iterator insert(iterator position, const std::shared_ptr<value<T>>& value)
+    {
+        if (values_.empty() || values_[0]->as<T>())
+        {
+            return values_.insert(position, value);
+        }
+        else
+        {
+            throw array_exception{"Arrays must be homogenous."};
+        }
+    }
+
+    /**
+     * Insert an array into the array
+     */
+    iterator insert(iterator position, const std::shared_ptr<array>& value)
+    {
+        if (values_.empty() || values_[0]->is_array())
+        {
+            return values_.insert(position, value);
+        }
+        else
+        {
+            throw array_exception{"Arrays must be homogenous."};
+        }
+    }
+
+    /**
+     * Convenience function for inserting a simple element in the array
+     */
+    template <class T>
+    iterator insert(iterator position, T&& val,
+                    typename value_traits<T>::type* = 0)
+    {
+        return insert(position, make_value(std::forward<T>(val)));
+    }
+
+    /**
+     * Erase an element from the array
+     */
+    iterator erase(iterator position)
+    {
+        return values_.erase(position);
+    }
+
+    /**
+     * Clear the array
+     */
+    void clear()
+    {
+        values_.clear();
+    }
+
+    /**
+     * Reserve space for n values.
+     */
+    void reserve(size_type n)
+    {
+        values_.reserve(n);
+    }
+
+  private:
+#if defined(CPPTOML_NO_RTTI)
+    array() : base(base_type::ARRAY)
+    {
+        // empty
+    }
+#else
+    array() = default;
+#endif
+
+    template <class InputIterator>
+    array(InputIterator begin, InputIterator end) : values_{begin, end}
+    {
+        // nothing
+    }
+
+    array(const array& obj) = delete;
+    array& operator=(const array& obj) = delete;
+
+    std::vector<std::shared_ptr<base>> values_;
+};
+
+inline std::shared_ptr<array> make_array()
+{
+    struct make_shared_enabler : public array
+    {
+        make_shared_enabler()
+        {
+            // nothing
+        }
+    };
+
+    return std::make_shared<make_shared_enabler>();
+}
+
+template <>
+inline std::shared_ptr<array> make_element<array>()
+{
+    return make_array();
+}
+
+/**
+ * Obtains a option<vector<T>>. The option will be empty if the array
+ * contains values that are not of type T.
+ */
+template <>
+inline typename array_of_trait<array>::return_type
+array::get_array_of<array>() const
+{
+    std::vector<std::shared_ptr<array>> result;
+    result.reserve(values_.size());
+
+    for (const auto& val : values_)
+    {
+        if (auto v = val->as_array())
+            result.push_back(v);
+        else
+            return {};
+    }
+
+    return {std::move(result)};
+}
+
+class table;
+
+class table_array : public base
+{
+    friend class table;
+    friend std::shared_ptr<table_array> make_table_array();
+
+  public:
+    std::shared_ptr<base> clone() const override;
+
+    using size_type = std::size_t;
+
+    /**
+     * arrays can be iterated over
+     */
+    using iterator = std::vector<std::shared_ptr<table>>::iterator;
+
+    /**
+     * arrays can be iterated over.  Const version.
+     */
+    using const_iterator = std::vector<std::shared_ptr<table>>::const_iterator;
+
+    iterator begin()
+    {
+        return array_.begin();
+    }
+
+    const_iterator begin() const
+    {
+        return array_.begin();
+    }
+
+    iterator end()
+    {
+        return array_.end();
+    }
+
+    const_iterator end() const
+    {
+        return array_.end();
+    }
+
+    virtual bool is_table_array() const override
+    {
+        return true;
+    }
+
+    std::vector<std::shared_ptr<table>>& get()
+    {
+        return array_;
+    }
+
+    const std::vector<std::shared_ptr<table>>& get() const
+    {
+        return array_;
+    }
+
+    /**
+     * Add a table to the end of the array
+     */
+    void push_back(const std::shared_ptr<table>& val)
+    {
+        array_.push_back(val);
+    }
+
+    /**
+     * Insert a table into the array
+     */
+    iterator insert(iterator position, const std::shared_ptr<table>& value)
+    {
+        return array_.insert(position, value);
+    }
+
+    /**
+     * Erase an element from the array
+     */
+    iterator erase(iterator position)
+    {
+        return array_.erase(position);
+    }
+
+    /**
+     * Clear the array
+     */
+    void clear()
+    {
+        array_.clear();
+    }
+
+    /**
+     * Reserve space for n tables.
+     */
+    void reserve(size_type n)
+    {
+        array_.reserve(n);
+    }
+
+  private:
+#if defined(CPPTOML_NO_RTTI)
+    table_array() : base(base_type::TABLE_ARRAY)
+    {
+        // nothing
+    }
+#else
+    table_array()
+    {
+        // nothing
+    }
+#endif
+
+    table_array(const table_array& obj) = delete;
+    table_array& operator=(const table_array& rhs) = delete;
+
+    std::vector<std::shared_ptr<table>> array_;
+};
+
+inline std::shared_ptr<table_array> make_table_array()
+{
+    struct make_shared_enabler : public table_array
+    {
+        make_shared_enabler()
+        {
+            // nothing
+        }
+    };
+
+    return std::make_shared<make_shared_enabler>();
+}
+
+template <>
+inline std::shared_ptr<table_array> make_element<table_array>()
+{
+    return make_table_array();
+}
+
+// The below are overloads for fetching specific value types out of a value
+// where special casting behavior (like bounds checking) is desired
+
+template <class T>
+typename std::enable_if<!std::is_floating_point<T>::value
+                            && std::is_signed<T>::value,
+                        option<T>>::type
+get_impl(const std::shared_ptr<base>& elem)
+{
+    if (auto v = elem->as<int64_t>())
+    {
+        if (v->get() < (std::numeric_limits<T>::min)())
+            throw std::underflow_error{
+                "T cannot represent the value requested in get"};
+
+        if (v->get() > (std::numeric_limits<T>::max)())
+            throw std::overflow_error{
+                "T cannot represent the value requested in get"};
+
+        return {static_cast<T>(v->get())};
+    }
+    else
+    {
+        return {};
+    }
+}
+
+template <class T>
+typename std::enable_if<!std::is_same<T, bool>::value
+                            && std::is_unsigned<T>::value,
+                        option<T>>::type
+get_impl(const std::shared_ptr<base>& elem)
+{
+    if (auto v = elem->as<int64_t>())
+    {
+        if (v->get() < 0)
+            throw std::underflow_error{"T cannot store negative value in get"};
+
+        if (static_cast<uint64_t>(v->get()) > (std::numeric_limits<T>::max)())
+            throw std::overflow_error{
+                "T cannot represent the value requested in get"};
+
+        return {static_cast<T>(v->get())};
+    }
+    else
+    {
+        return {};
+    }
+}
+
+template <class T>
+typename std::enable_if<!std::is_integral<T>::value
+                            || std::is_same<T, bool>::value,
+                        option<T>>::type
+get_impl(const std::shared_ptr<base>& elem)
+{
+    if (auto v = elem->as<T>())
+    {
+        return {v->get()};
+    }
+    else
+    {
+        return {};
+    }
+}
+
+/**
+ * Represents a TOML keytable.
+ */
+class table : public base
+{
+  public:
+    friend class table_array;
+    friend std::shared_ptr<table> make_table();
+
+    std::shared_ptr<base> clone() const override;
+
+    /**
+     * tables can be iterated over.
+     */
+    using iterator = string_to_base_map::iterator;
+
+    /**
+     * tables can be iterated over. Const version.
+     */
+    using const_iterator = string_to_base_map::const_iterator;
+
+    iterator begin()
+    {
+        return map_.begin();
+    }
+
+    const_iterator begin() const
+    {
+        return map_.begin();
+    }
+
+    iterator end()
+    {
+        return map_.end();
+    }
+
+    const_iterator end() const
+    {
+        return map_.end();
+    }
+
+    bool is_table() const override
+    {
+        return true;
+    }
+
+    bool empty() const
+    {
+        return map_.empty();
+    }
+
+    /**
+     * Determines if this key table contains the given key.
+     */
+    bool contains(const std::string& key) const
+    {
+        return map_.find(key) != map_.end();
+    }
+
+    /**
+     * Determines if this key table contains the given key. Will
+     * resolve "qualified keys". Qualified keys are the full access
+     * path separated with dots like "grandparent.parent.child".
+     */
+    bool contains_qualified(const std::string& key) const
+    {
+        return resolve_qualified(key);
+    }
+
+    /**
+     * Obtains the base for a given key.
+     * @throw std::out_of_range if the key does not exist
+     */
+    std::shared_ptr<base> get(const std::string& key) const
+    {
+        return map_.at(key);
+    }
+
+    /**
+     * Obtains the base for a given key. Will resolve "qualified
+     * keys". Qualified keys are the full access path separated with
+     * dots like "grandparent.parent.child".
+     *
+     * @throw std::out_of_range if the key does not exist
+     */
+    std::shared_ptr<base> get_qualified(const std::string& key) const
+    {
+        std::shared_ptr<base> p;
+        resolve_qualified(key, &p);
+        return p;
+    }
+
+    /**
+     * Obtains a table for a given key, if possible.
+     */
+    std::shared_ptr<table> get_table(const std::string& key) const
+    {
+        if (contains(key) && get(key)->is_table())
+            return std::static_pointer_cast<table>(get(key));
+        return nullptr;
+    }
+
+    /**
+     * Obtains a table for a given key, if possible. Will resolve
+     * "qualified keys".
+     */
+    std::shared_ptr<table> get_table_qualified(const std::string& key) const
+    {
+        if (contains_qualified(key) && get_qualified(key)->is_table())
+            return std::static_pointer_cast<table>(get_qualified(key));
+        return nullptr;
+    }
+
+    /**
+     * Obtains an array for a given key.
+     */
+    std::shared_ptr<array> get_array(const std::string& key) const
+    {
+        if (!contains(key))
+            return nullptr;
+        return get(key)->as_array();
+    }
+
+    /**
+     * Obtains an array for a given key. Will resolve "qualified keys".
+     */
+    std::shared_ptr<array> get_array_qualified(const std::string& key) const
+    {
+        if (!contains_qualified(key))
+            return nullptr;
+        return get_qualified(key)->as_array();
+    }
+
+    /**
+     * Obtains a table_array for a given key, if possible.
+     */
+    std::shared_ptr<table_array> get_table_array(const std::string& key) const
+    {
+        if (!contains(key))
+            return nullptr;
+        return get(key)->as_table_array();
+    }
+
+    /**
+     * Obtains a table_array for a given key, if possible. Will resolve
+     * "qualified keys".
+     */
+    std::shared_ptr<table_array>
+    get_table_array_qualified(const std::string& key) const
+    {
+        if (!contains_qualified(key))
+            return nullptr;
+        return get_qualified(key)->as_table_array();
+    }
+
+    /**
+     * Helper function that attempts to get a value corresponding
+     * to the template parameter from a given key.
+     */
+    template <class T>
+    option<T> get_as(const std::string& key) const
+    {
+        try
+        {
+            return get_impl<T>(get(key));
+        }
+        catch (const std::out_of_range&)
+        {
+            return {};
+        }
+    }
+
+    /**
+     * Helper function that attempts to get a value corresponding
+     * to the template parameter from a given key. Will resolve "qualified
+     * keys".
+     */
+    template <class T>
+    option<T> get_qualified_as(const std::string& key) const
+    {
+        try
+        {
+            return get_impl<T>(get_qualified(key));
+        }
+        catch (const std::out_of_range&)
+        {
+            return {};
+        }
+    }
+
+    /**
+     * Helper function that attempts to get an array of values of a given
+     * type corresponding to the template parameter for a given key.
+     *
+     * If the key doesn't exist, doesn't exist as an array type, or one or
+     * more keys inside the array type are not of type T, an empty option
+     * is returned. Otherwise, an option containing a vector of the values
+     * is returned.
+     */
+    template <class T>
+    inline typename array_of_trait<T>::return_type
+    get_array_of(const std::string& key) const
+    {
+        if (auto v = get_array(key))
+        {
+            std::vector<T> result;
+            result.reserve(v->get().size());
+
+            for (const auto& b : v->get())
+            {
+                if (auto val = b->as<T>())
+                    result.push_back(val->get());
+                else
+                    return {};
+            }
+            return {std::move(result)};
+        }
+
+        return {};
+    }
+
+    /**
+     * Helper function that attempts to get an array of values of a given
+     * type corresponding to the template parameter for a given key. Will
+     * resolve "qualified keys".
+     *
+     * If the key doesn't exist, doesn't exist as an array type, or one or
+     * more keys inside the array type are not of type T, an empty option
+     * is returned. Otherwise, an option containing a vector of the values
+     * is returned.
+     */
+    template <class T>
+    inline typename array_of_trait<T>::return_type
+    get_qualified_array_of(const std::string& key) const
+    {
+        if (auto v = get_array_qualified(key))
+        {
+            std::vector<T> result;
+            result.reserve(v->get().size());
+
+            for (const auto& b : v->get())
+            {
+                if (auto val = b->as<T>())
+                    result.push_back(val->get());
+                else
+                    return {};
+            }
+            return {std::move(result)};
+        }
+
+        return {};
+    }
+
+    /**
+     * Adds an element to the keytable.
+     */
+    void insert(const std::string& key, const std::shared_ptr<base>& value)
+    {
+        map_[key] = value;
+    }
+
+    /**
+     * Convenience shorthand for adding a simple element to the
+     * keytable.
+     */
+    template <class T>
+    void insert(const std::string& key, T&& val,
+                typename value_traits<T>::type* = 0)
+    {
+        insert(key, make_value(std::forward<T>(val)));
+    }
+
+    /**
+     * Removes an element from the table.
+     */
+    void erase(const std::string& key)
+    {
+        map_.erase(key);
+    }
+
+  private:
+#if defined(CPPTOML_NO_RTTI)
+    table() : base(base_type::TABLE)
+    {
+        // nothing
+    }
+#else
+    table()
+    {
+        // nothing
+    }
+#endif
+
+    table(const table& obj) = delete;
+    table& operator=(const table& rhs) = delete;
+
+    std::vector<std::string> split(const std::string& value,
+                                   char separator) const
+    {
+        std::vector<std::string> result;
+        std::string::size_type p = 0;
+        std::string::size_type q;
+        while ((q = value.find(separator, p)) != std::string::npos)
+        {
+            result.emplace_back(value, p, q - p);
+            p = q + 1;
+        }
+        result.emplace_back(value, p);
+        return result;
+    }
+
+    // If output parameter p is specified, fill it with the pointer to the
+    // specified entry and throw std::out_of_range if it couldn't be found.
+    //
+    // Otherwise, just return true if the entry could be found or false
+    // otherwise and do not throw.
+    bool resolve_qualified(const std::string& key,
+                           std::shared_ptr<base>* p = nullptr) const
+    {
+        auto parts = split(key, '.');
+        auto last_key = parts.back();
+        parts.pop_back();
+
+        auto cur_table = this;
+        for (const auto& part : parts)
+        {
+            cur_table = cur_table->get_table(part).get();
+            if (!cur_table)
+            {
+                if (!p)
+                    return false;
+
+                throw std::out_of_range{key + " is not a valid key"};
+            }
+        }
+
+        if (!p)
+            return cur_table->map_.count(last_key) != 0;
+
+        *p = cur_table->map_.at(last_key);
+        return true;
+    }
+
+    string_to_base_map map_;
+};
+
+/**
+ * Helper function that attempts to get an array of arrays for a given
+ * key.
+ *
+ * If the key doesn't exist, doesn't exist as an array type, or one or
+ * more keys inside the array type are not of type T, an empty option
+ * is returned. Otherwise, an option containing a vector of the values
+ * is returned.
+ */
+template <>
+inline typename array_of_trait<array>::return_type
+table::get_array_of<array>(const std::string& key) const
+{
+    if (auto v = get_array(key))
+    {
+        std::vector<std::shared_ptr<array>> result;
+        result.reserve(v->get().size());
+
+        for (const auto& b : v->get())
+        {
+            if (auto val = b->as_array())
+                result.push_back(val);
+            else
+                return {};
+        }
+
+        return {std::move(result)};
+    }
+
+    return {};
+}
+
+/**
+ * Helper function that attempts to get an array of arrays for a given
+ * key. Will resolve "qualified keys".
+ *
+ * If the key doesn't exist, doesn't exist as an array type, or one or
+ * more keys inside the array type are not of type T, an empty option
+ * is returned. Otherwise, an option containing a vector of the values
+ * is returned.
+ */
+template <>
+inline typename array_of_trait<array>::return_type
+table::get_qualified_array_of<array>(const std::string& key) const
+{
+    if (auto v = get_array_qualified(key))
+    {
+        std::vector<std::shared_ptr<array>> result;
+        result.reserve(v->get().size());
+
+        for (const auto& b : v->get())
+        {
+            if (auto val = b->as_array())
+                result.push_back(val);
+            else
+                return {};
+        }
+
+        return {std::move(result)};
+    }
+
+    return {};
+}
+
+std::shared_ptr<table> make_table()
+{
+    struct make_shared_enabler : public table
+    {
+        make_shared_enabler()
+        {
+            // nothing
+        }
+    };
+
+    return std::make_shared<make_shared_enabler>();
+}
+
+template <>
+inline std::shared_ptr<table> make_element<table>()
+{
+    return make_table();
+}
+
+template <class T>
+std::shared_ptr<base> value<T>::clone() const
+{
+    return make_value(data_);
+}
+
+inline std::shared_ptr<base> array::clone() const
+{
+    auto result = make_array();
+    result->reserve(values_.size());
+    for (const auto& ptr : values_)
+        result->values_.push_back(ptr->clone());
+    return result;
+}
+
+inline std::shared_ptr<base> table_array::clone() const
+{
+    auto result = make_table_array();
+    result->reserve(array_.size());
+    for (const auto& ptr : array_)
+        result->array_.push_back(ptr->clone()->as_table());
+    return result;
+}
+
+inline std::shared_ptr<base> table::clone() const
+{
+    auto result = make_table();
+    for (const auto& pr : map_)
+        result->insert(pr.first, pr.second->clone());
+    return result;
+}
+
+/**
+ * Exception class for all TOML parsing errors.
+ */
+class parse_exception : public std::runtime_error
+{
+  public:
+    parse_exception(const std::string& err) : std::runtime_error{err}
+    {
+    }
+
+    parse_exception(const std::string& err, std::size_t line_number)
+        : std::runtime_error{err + " at line " + std::to_string(line_number)}
+    {
+    }
+};
+
+inline bool is_number(char c)
+{
+    return c >= '0' && c <= '9';
+}
+
+/**
+ * Helper object for consuming expected characters.
+ */
+template <class OnError>
+class consumer
+{
+  public:
+    consumer(std::string::iterator& it, const std::string::iterator& end,
+             OnError&& on_error)
+        : it_(it), end_(end), on_error_(std::forward<OnError>(on_error))
+    {
+        // nothing
+    }
+
+    void operator()(char c)
+    {
+        if (it_ == end_ || *it_ != c)
+            on_error_();
+        ++it_;
+    }
+
+    template <std::size_t N>
+    void operator()(const char (&str)[N])
+    {
+        std::for_each(std::begin(str), std::end(str) - 1,
+                      [&](char c) { (*this)(c); });
+    }
+
+    int eat_digits(int len)
+    {
+        int val = 0;
+        for (int i = 0; i < len; ++i)
+        {
+            if (!is_number(*it_) || it_ == end_)
+                on_error_();
+            val = 10 * val + (*it_++ - '0');
+        }
+        return val;
+    }
+
+    void error()
+    {
+        on_error_();
+    }
+
+  private:
+    std::string::iterator& it_;
+    const std::string::iterator& end_;
+    OnError on_error_;
+};
+
+template <class OnError>
+consumer<OnError> make_consumer(std::string::iterator& it,
+                                const std::string::iterator& end,
+                                OnError&& on_error)
+{
+    return consumer<OnError>(it, end, std::forward<OnError>(on_error));
+}
+
+// replacement for std::getline to handle incorrectly line-ended files
+// https://stackoverflow.com/questions/6089231/getting-std-ifstream-to-handle-lf-cr-and-crlf
+namespace detail
+{
+inline std::istream& getline(std::istream& input, std::string& line)
+{
+    line.clear();
+
+    std::istream::sentry sentry{input, true};
+    auto sb = input.rdbuf();
+
+    while (true)
+    {
+        auto c = sb->sbumpc();
+        if (c == '\r')
+        {
+            if (sb->sgetc() == '\n')
+                c = sb->sbumpc();
+        }
+
+        if (c == '\n')
+            return input;
+
+        if (c == std::istream::traits_type::eof())
+        {
+            if (line.empty())
+                input.setstate(std::ios::eofbit);
+            return input;
+        }
+
+        line.push_back(static_cast<char>(c));
+    }
+}
+}
+
+/**
+ * The parser class.
+ */
+class parser
+{
+  public:
+    /**
+     * Parsers are constructed from streams.
+     */
+    parser(std::istream& stream) : input_(stream)
+    {
+        // nothing
+    }
+
+    parser& operator=(const parser& parser) = delete;
+
+    /**
+     * Parses the stream this parser was created on until EOF.
+     * @throw parse_exception if there are errors in parsing
+     */
+    std::shared_ptr<table> parse()
+    {
+        std::shared_ptr<table> root = make_table();
+
+        table* curr_table = root.get();
+
+        while (detail::getline(input_, line_))
+        {
+            line_number_++;
+            auto it = line_.begin();
+            auto end = line_.end();
+            consume_whitespace(it, end);
+            if (it == end || *it == '#')
+                continue;
+            if (*it == '[')
+            {
+                curr_table = root.get();
+                parse_table(it, end, curr_table);
+            }
+            else
+            {
+                parse_key_value(it, end, curr_table);
+                consume_whitespace(it, end);
+                eol_or_comment(it, end);
+            }
+        }
+        return root;
+    }
+
+  private:
+#if defined _MSC_VER
+    __declspec(noreturn)
+#elif defined __GNUC__
+    __attribute__((noreturn))
+#endif
+        void throw_parse_exception(const std::string& err)
+    {
+        throw parse_exception{err, line_number_};
+    }
+
+    void parse_table(std::string::iterator& it,
+                     const std::string::iterator& end, table*& curr_table)
+    {
+        // remove the beginning keytable marker
+        ++it;
+        if (it == end)
+            throw_parse_exception("Unexpected end of table");
+        if (*it == '[')
+            parse_table_array(it, end, curr_table);
+        else
+            parse_single_table(it, end, curr_table);
+    }
+
+    void parse_single_table(std::string::iterator& it,
+                            const std::string::iterator& end,
+                            table*& curr_table)
+    {
+        if (it == end || *it == ']')
+            throw_parse_exception("Table name cannot be empty");
+
+        std::string full_table_name;
+        bool inserted = false;
+        while (it != end && *it != ']')
+        {
+            auto part = parse_key(it, end,
+                                  [](char c) { return c == '.' || c == ']'; });
+
+            if (part.empty())
+                throw_parse_exception("Empty component of table name");
+
+            if (!full_table_name.empty())
+                full_table_name += ".";
+            full_table_name += part;
+
+            if (curr_table->contains(part))
+            {
+                auto b = curr_table->get(part);
+                if (b->is_table())
+                    curr_table = static_cast<table*>(b.get());
+                else if (b->is_table_array())
+                    curr_table = std::static_pointer_cast<table_array>(b)
+                                     ->get()
+                                     .back()
+                                     .get();
+                else
+                    throw_parse_exception("Key " + full_table_name
+                                          + "already exists as a value");
+            }
+            else
+            {
+                inserted = true;
+                curr_table->insert(part, make_table());
+                curr_table = static_cast<table*>(curr_table->get(part).get());
+            }
+            consume_whitespace(it, end);
+            if (it != end && *it == '.')
+                ++it;
+            consume_whitespace(it, end);
+        }
+
+        if (it == end)
+            throw_parse_exception(
+                "Unterminated table declaration; did you forget a ']'?");
+
+        // table already existed
+        if (!inserted)
+        {
+            auto is_value
+                = [](const std::pair<const std::string&,
+                                     const std::shared_ptr<base>&>& p) {
+                      return p.second->is_value();
+                  };
+
+            // if there are any values, we can't add values to this table
+            // since it has already been defined. If there aren't any
+            // values, then it was implicitly created by something like
+            // [a.b]
+            if (curr_table->empty() || std::any_of(curr_table->begin(),
+                                                   curr_table->end(), is_value))
+            {
+                throw_parse_exception("Redefinition of table "
+                                      + full_table_name);
+            }
+        }
+
+        ++it;
+        consume_whitespace(it, end);
+        eol_or_comment(it, end);
+    }
+
+    void parse_table_array(std::string::iterator& it,
+                           const std::string::iterator& end, table*& curr_table)
+    {
+        ++it;
+        if (it == end || *it == ']')
+            throw_parse_exception("Table array name cannot be empty");
+
+        std::string full_ta_name;
+        while (it != end && *it != ']')
+        {
+            auto part = parse_key(it, end,
+                                  [](char c) { return c == '.' || c == ']'; });
+
+            if (part.empty())
+                throw_parse_exception("Empty component of table array name");
+
+            if (!full_ta_name.empty())
+                full_ta_name += ".";
+            full_ta_name += part;
+
+            consume_whitespace(it, end);
+            if (it != end && *it == '.')
+                ++it;
+            consume_whitespace(it, end);
+
+            if (curr_table->contains(part))
+            {
+                auto b = curr_table->get(part);
+
+                // if this is the end of the table array name, add an
+                // element to the table array that we just looked up
+                if (it != end && *it == ']')
+                {
+                    if (!b->is_table_array())
+                        throw_parse_exception("Key " + full_ta_name
+                                              + " is not a table array");
+                    auto v = b->as_table_array();
+                    v->get().push_back(make_table());
+                    curr_table = v->get().back().get();
+                }
+                // otherwise, just keep traversing down the key name
+                else
+                {
+                    if (b->is_table())
+                        curr_table = static_cast<table*>(b.get());
+                    else if (b->is_table_array())
+                        curr_table = std::static_pointer_cast<table_array>(b)
+                                         ->get()
+                                         .back()
+                                         .get();
+                    else
+                        throw_parse_exception("Key " + full_ta_name
+                                              + " already exists as a value");
+                }
+            }
+            else
+            {
+                // if this is the end of the table array name, add a new
+                // table array and a new table inside that array for us to
+                // add keys to next
+                if (it != end && *it == ']')
+                {
+                    curr_table->insert(part, make_table_array());
+                    auto arr = std::static_pointer_cast<table_array>(
+                        curr_table->get(part));
+                    arr->get().push_back(make_table());
+                    curr_table = arr->get().back().get();
+                }
+                // otherwise, create the implicitly defined table and move
+                // down to it
+                else
+                {
+                    curr_table->insert(part, make_table());
+                    curr_table
+                        = static_cast<table*>(curr_table->get(part).get());
+                }
+            }
+        }
+
+        // consume the last "]]"
+        if (it == end)
+            throw_parse_exception("Unterminated table array name");
+        ++it;
+        if (it == end)
+            throw_parse_exception("Unterminated table array name");
+        ++it;
+
+        consume_whitespace(it, end);
+        eol_or_comment(it, end);
+    }
+
+    void parse_key_value(std::string::iterator& it, std::string::iterator& end,
+                         table* curr_table)
+    {
+        auto key = parse_key(it, end, [](char c) { return c == '='; });
+        if (curr_table->contains(key))
+            throw_parse_exception("Key " + key + " already present");
+        if (it == end || *it != '=')
+            throw_parse_exception("Value must follow after a '='");
+        ++it;
+        consume_whitespace(it, end);
+        curr_table->insert(key, parse_value(it, end));
+        consume_whitespace(it, end);
+    }
+
+    template <class Function>
+    std::string parse_key(std::string::iterator& it,
+                          const std::string::iterator& end, Function&& fun)
+    {
+        consume_whitespace(it, end);
+        if (*it == '"')
+        {
+            return parse_quoted_key(it, end);
+        }
+        else
+        {
+            auto bke = std::find_if(it, end, std::forward<Function>(fun));
+            return parse_bare_key(it, bke);
+        }
+    }
+
+    std::string parse_bare_key(std::string::iterator& it,
+                               const std::string::iterator& end)
+    {
+        if (it == end)
+        {
+            throw_parse_exception("Bare key missing name");
+        }
+
+        auto key_end = end;
+        --key_end;
+        consume_backwards_whitespace(key_end, it);
+        ++key_end;
+        std::string key{it, key_end};
+
+        if (std::find(it, key_end, '#') != key_end)
+        {
+            throw_parse_exception("Bare key " + key + " cannot contain #");
+        }
+
+        if (std::find_if(it, key_end,
+                         [](char c) { return c == ' ' || c == '\t'; })
+            != key_end)
+        {
+            throw_parse_exception("Bare key " + key
+                                  + " cannot contain whitespace");
+        }
+
+        if (std::find_if(it, key_end,
+                         [](char c) { return c == '[' || c == ']'; })
+            != key_end)
+        {
+            throw_parse_exception("Bare key " + key
+                                  + " cannot contain '[' or ']'");
+        }
+
+        it = end;
+        return key;
+    }
+
+    std::string parse_quoted_key(std::string::iterator& it,
+                                 const std::string::iterator& end)
+    {
+        return string_literal(it, end, '"');
+    }
+
+    enum class parse_type
+    {
+        STRING = 1,
+        LOCAL_TIME,
+        LOCAL_DATE,
+        LOCAL_DATETIME,
+        OFFSET_DATETIME,
+        INT,
+        FLOAT,
+        BOOL,
+        ARRAY,
+        INLINE_TABLE
+    };
+
+    std::shared_ptr<base> parse_value(std::string::iterator& it,
+                                      std::string::iterator& end)
+    {
+        parse_type type = determine_value_type(it, end);
+        switch (type)
+        {
+            case parse_type::STRING:
+                return parse_string(it, end);
+            case parse_type::LOCAL_TIME:
+                return parse_time(it, end);
+            case parse_type::LOCAL_DATE:
+            case parse_type::LOCAL_DATETIME:
+            case parse_type::OFFSET_DATETIME:
+                return parse_date(it, end);
+            case parse_type::INT:
+            case parse_type::FLOAT:
+                return parse_number(it, end);
+            case parse_type::BOOL:
+                return parse_bool(it, end);
+            case parse_type::ARRAY:
+                return parse_array(it, end);
+            case parse_type::INLINE_TABLE:
+                return parse_inline_table(it, end);
+            default:
+                throw_parse_exception("Failed to parse value");
+        }
+    }
+
+    parse_type determine_value_type(const std::string::iterator& it,
+                                    const std::string::iterator& end)
+    {
+        if(it == end)
+        {
+            throw_parse_exception("Failed to parse value type");
+        }
+        if (*it == '"' || *it == '\'')
+        {
+            return parse_type::STRING;
+        }
+        else if (is_time(it, end))
+        {
+            return parse_type::LOCAL_TIME;
+        }
+        else if (auto dtype = date_type(it, end))
+        {
+            return *dtype;
+        }
+        else if (is_number(*it) || *it == '-' || *it == '+')
+        {
+            return determine_number_type(it, end);
+        }
+        else if (*it == 't' || *it == 'f')
+        {
+            return parse_type::BOOL;
+        }
+        else if (*it == '[')
+        {
+            return parse_type::ARRAY;
+        }
+        else if (*it == '{')
+        {
+            return parse_type::INLINE_TABLE;
+        }
+        throw_parse_exception("Failed to parse value type");
+    }
+
+    parse_type determine_number_type(const std::string::iterator& it,
+                                     const std::string::iterator& end)
+    {
+        // determine if we are an integer or a float
+        auto check_it = it;
+        if (*check_it == '-' || *check_it == '+')
+            ++check_it;
+        while (check_it != end && is_number(*check_it))
+            ++check_it;
+        if (check_it != end && *check_it == '.')
+        {
+            ++check_it;
+            while (check_it != end && is_number(*check_it))
+                ++check_it;
+            return parse_type::FLOAT;
+        }
+        else
+        {
+            return parse_type::INT;
+        }
+    }
+
+    std::shared_ptr<value<std::string>> parse_string(std::string::iterator& it,
+                                                     std::string::iterator& end)
+    {
+        auto delim = *it;
+        assert(delim == '"' || delim == '\'');
+
+        // end is non-const here because we have to be able to potentially
+        // parse multiple lines in a string, not just one
+        auto check_it = it;
+        ++check_it;
+        if (check_it != end && *check_it == delim)
+        {
+            ++check_it;
+            if (check_it != end && *check_it == delim)
+            {
+                it = ++check_it;
+                return parse_multiline_string(it, end, delim);
+            }
+        }
+        return make_value<std::string>(string_literal(it, end, delim));
+    }
+
+    std::shared_ptr<value<std::string>>
+    parse_multiline_string(std::string::iterator& it,
+                           std::string::iterator& end, char delim)
+    {
+        std::stringstream ss;
+
+        auto is_ws = [](char c) { return c == ' ' || c == '\t'; };
+
+        bool consuming = false;
+        std::shared_ptr<value<std::string>> ret;
+
+        auto handle_line
+            = [&](std::string::iterator& local_it,
+                  std::string::iterator& local_end) {
+                  if (consuming)
+                  {
+                      local_it = std::find_if_not(local_it, local_end, is_ws);
+
+                      // whole line is whitespace
+                      if (local_it == local_end)
+                          return;
+                  }
+
+                  consuming = false;
+
+                  while (local_it != local_end)
+                  {
+                      // handle escaped characters
+                      if (delim == '"' && *local_it == '\\')
+                      {
+                          auto check = local_it;
+                          // check if this is an actual escape sequence or a
+                          // whitespace escaping backslash
+                          ++check;
+                          consume_whitespace(check, local_end);
+                          if (check == local_end)
+                          {
+                              consuming = true;
+                              break;
+                          }
+
+                          ss << parse_escape_code(local_it, local_end);
+                          continue;
+                      }
+
+                      // if we can end the string
+                      if (std::distance(local_it, local_end) >= 3)
+                      {
+                          auto check = local_it;
+                          // check for """
+                          if (*check++ == delim && *check++ == delim
+                              && *check++ == delim)
+                          {
+                              local_it = check;
+                              ret = make_value<std::string>(ss.str());
+                              break;
+                          }
+                      }
+
+                      ss << *local_it++;
+                  }
+              };
+
+        // handle the remainder of the current line
+        handle_line(it, end);
+        if (ret)
+            return ret;
+
+        // start eating lines
+        while (detail::getline(input_, line_))
+        {
+            ++line_number_;
+
+            it = line_.begin();
+            end = line_.end();
+
+            handle_line(it, end);
+
+            if (ret)
+                return ret;
+
+            if (!consuming)
+                ss << std::endl;
+        }
+
+        throw_parse_exception("Unterminated multi-line basic string");
+    }
+
+    std::string string_literal(std::string::iterator& it,
+                               const std::string::iterator& end, char delim)
+    {
+        ++it;
+        std::string val;
+        while (it != end)
+        {
+            // handle escaped characters
+            if (delim == '"' && *it == '\\')
+            {
+                val += parse_escape_code(it, end);
+            }
+            else if (*it == delim)
+            {
+                ++it;
+                consume_whitespace(it, end);
+                return val;
+            }
+            else
+            {
+                val += *it++;
+            }
+        }
+        throw_parse_exception("Unterminated string literal");
+    }
+
+    std::string parse_escape_code(std::string::iterator& it,
+                                  const std::string::iterator& end)
+    {
+        ++it;
+        if (it == end)
+            throw_parse_exception("Invalid escape sequence");
+        char value;
+        if (*it == 'b')
+        {
+            value = '\b';
+        }
+        else if (*it == 't')
+        {
+            value = '\t';
+        }
+        else if (*it == 'n')
+        {
+            value = '\n';
+        }
+        else if (*it == 'f')
+        {
+            value = '\f';
+        }
+        else if (*it == 'r')
+        {
+            value = '\r';
+        }
+        else if (*it == '"')
+        {
+            value = '"';
+        }
+        else if (*it == '\\')
+        {
+            value = '\\';
+        }
+        else if (*it == 'u' || *it == 'U')
+        {
+            return parse_unicode(it, end);
+        }
+        else
+        {
+            throw_parse_exception("Invalid escape sequence");
+        }
+        ++it;
+        return std::string(1, value);
+    }
+
+    std::string parse_unicode(std::string::iterator& it,
+                              const std::string::iterator& end)
+    {
+        bool large = *it++ == 'U';
+        auto codepoint = parse_hex(it, end, large ? 0x10000000 : 0x1000);
+
+        if ((codepoint > 0xd7ff && codepoint < 0xe000) || codepoint > 0x10ffff)
+        {
+            throw_parse_exception(
+                "Unicode escape sequence is not a Unicode scalar value");
+        }
+
+        std::string result;
+        // See Table 3-6 of the Unicode standard
+        if (codepoint <= 0x7f)
+        {
+            // 1-byte codepoints: 00000000 0xxxxxxx
+            // repr: 0xxxxxxx
+            result += static_cast<char>(codepoint & 0x7f);
+        }
+        else if (codepoint <= 0x7ff)
+        {
+            // 2-byte codepoints: 00000yyy yyxxxxxx
+            // repr: 110yyyyy 10xxxxxx
+            //
+            // 0x1f = 00011111
+            // 0xc0 = 11000000
+            //
+            result += static_cast<char>(0xc0 | ((codepoint >> 6) & 0x1f));
+            //
+            // 0x80 = 10000000
+            // 0x3f = 00111111
+            //
+            result += static_cast<char>(0x80 | (codepoint & 0x3f));
+        }
+        else if (codepoint <= 0xffff)
+        {
+            // 3-byte codepoints: zzzzyyyy yyxxxxxx
+            // repr: 1110zzzz 10yyyyyy 10xxxxxx
+            //
+            // 0xe0 = 11100000
+            // 0x0f = 00001111
+            //
+            result += static_cast<char>(0xe0 | ((codepoint >> 12) & 0x0f));
+            result += static_cast<char>(0x80 | ((codepoint >> 6) & 0x1f));
+            result += static_cast<char>(0x80 | (codepoint & 0x3f));
+        }
+        else
+        {
+            // 4-byte codepoints: 000uuuuu zzzzyyyy yyxxxxxx
+            // repr: 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx
+            //
+            // 0xf0 = 11110000
+            // 0x07 = 00000111
+            //
+            result += static_cast<char>(0xf0 | ((codepoint >> 18) & 0x07));
+            result += static_cast<char>(0x80 | ((codepoint >> 12) & 0x3f));
+            result += static_cast<char>(0x80 | ((codepoint >> 6) & 0x3f));
+            result += static_cast<char>(0x80 | (codepoint & 0x3f));
+        }
+        return result;
+    }
+
+    uint32_t parse_hex(std::string::iterator& it,
+                       const std::string::iterator& end, uint32_t place)
+    {
+        uint32_t value = 0;
+        while (place > 0)
+        {
+            if (it == end)
+                throw_parse_exception("Unexpected end of unicode sequence");
+
+            if (!is_hex(*it))
+                throw_parse_exception("Invalid unicode escape sequence");
+
+            value += place * hex_to_digit(*it++);
+            place /= 16;
+        }
+        return value;
+    }
+
+    bool is_hex(char c)
+    {
+        return is_number(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
+    }
+
+    uint32_t hex_to_digit(char c)
+    {
+        if (is_number(c))
+            return static_cast<uint32_t>(c - '0');
+        return 10 + static_cast<uint32_t>(
+                        c - ((c >= 'a' && c <= 'f') ? 'a' : 'A'));
+    }
+
+    std::shared_ptr<base> parse_number(std::string::iterator& it,
+                                       const std::string::iterator& end)
+    {
+        auto check_it = it;
+        auto check_end = find_end_of_number(it, end);
+
+        auto eat_sign = [&]() {
+            if (check_it != end && (*check_it == '-' || *check_it == '+'))
+                ++check_it;
+        };
+
+        eat_sign();
+
+        auto eat_numbers = [&]() {
+            auto beg = check_it;
+            while (check_it != end && is_number(*check_it))
+            {
+                ++check_it;
+                if (check_it != end && *check_it == '_')
+                {
+                    ++check_it;
+                    if (check_it == end || !is_number(*check_it))
+                        throw_parse_exception("Malformed number");
+                }
+            }
+
+            if (check_it == beg)
+                throw_parse_exception("Malformed number");
+        };
+
+        auto check_no_leading_zero = [&]() {
+            if (check_it != end && *check_it == '0' && check_it + 1 != check_end
+                && check_it[1] != '.')
+            {
+                throw_parse_exception("Numbers may not have leading zeros");
+            }
+        };
+
+        check_no_leading_zero();
+        eat_numbers();
+
+        if (check_it != end
+            && (*check_it == '.' || *check_it == 'e' || *check_it == 'E'))
+        {
+            bool is_exp = *check_it == 'e' || *check_it == 'E';
+
+            ++check_it;
+            if (check_it == end)
+                throw_parse_exception("Floats must have trailing digits");
+
+            auto eat_exp = [&]() {
+                eat_sign();
+                check_no_leading_zero();
+                eat_numbers();
+            };
+
+            if (is_exp)
+                eat_exp();
+            else
+                eat_numbers();
+
+            if (!is_exp && check_it != end
+                && (*check_it == 'e' || *check_it == 'E'))
+            {
+                ++check_it;
+                eat_exp();
+            }
+
+            return parse_float(it, check_it);
+        }
+        else
+        {
+            return parse_int(it, check_it);
+        }
+    }
+
+    std::shared_ptr<value<int64_t>> parse_int(std::string::iterator& it,
+                                              const std::string::iterator& end)
+    {
+        std::string v{it, end};
+        v.erase(std::remove(v.begin(), v.end(), '_'), v.end());
+        it = end;
+        try
+        {
+            return make_value<int64_t>(std::stoll(v));
+        }
+        catch (const std::invalid_argument& ex)
+        {
+            throw_parse_exception("Malformed number (invalid argument: "
+                                  + std::string{ex.what()} + ")");
+        }
+        catch (const std::out_of_range& ex)
+        {
+            throw_parse_exception("Malformed number (out of range: "
+                                  + std::string{ex.what()} + ")");
+        }
+    }
+
+    std::shared_ptr<value<double>> parse_float(std::string::iterator& it,
+                                               const std::string::iterator& end)
+    {
+        std::string v{it, end};
+        v.erase(std::remove(v.begin(), v.end(), '_'), v.end());
+        it = end;
+        char decimal_point = std::localeconv()->decimal_point[0];
+        std::replace(v.begin(), v.end(), '.', decimal_point);
+        try
+        {
+            return make_value<double>(std::stod(v));
+        }
+        catch (const std::invalid_argument& ex)
+        {
+            throw_parse_exception("Malformed number (invalid argument: "
+                                  + std::string{ex.what()} + ")");
+        }
+        catch (const std::out_of_range& ex)
+        {
+            throw_parse_exception("Malformed number (out of range: "
+                                  + std::string{ex.what()} + ")");
+        }
+    }
+
+    std::shared_ptr<value<bool>> parse_bool(std::string::iterator& it,
+                                            const std::string::iterator& end)
+    {
+        auto eat = make_consumer(it, end, [this]() {
+            throw_parse_exception("Attempted to parse invalid boolean value");
+        });
+
+        if (*it == 't')
+        {
+            eat("true");
+            return make_value<bool>(true);
+        }
+        else if (*it == 'f')
+        {
+            eat("false");
+            return make_value<bool>(false);
+        }
+
+        eat.error();
+        return nullptr;
+    }
+
+    std::string::iterator find_end_of_number(std::string::iterator it,
+                                             std::string::iterator end)
+    {
+        return std::find_if(it, end, [](char c) {
+            return !is_number(c) && c != '_' && c != '.' && c != 'e' && c != 'E'
+                   && c != '-' && c != '+';
+        });
+    }
+
+    std::string::iterator find_end_of_date(std::string::iterator it,
+                                           std::string::iterator end)
+    {
+        return std::find_if(it, end, [](char c) {
+            return !is_number(c) && c != 'T' && c != 'Z' && c != ':' && c != '-'
+                   && c != '+' && c != '.';
+        });
+    }
+
+    std::string::iterator find_end_of_time(std::string::iterator it,
+                                           std::string::iterator end)
+    {
+        return std::find_if(it, end, [](char c) {
+            return !is_number(c) && c != ':' && c != '.';
+        });
+    }
+
+    local_time read_time(std::string::iterator& it,
+                         const std::string::iterator& end)
+    {
+        auto time_end = find_end_of_time(it, end);
+
+        auto eat = make_consumer(
+            it, time_end, [&]() { throw_parse_exception("Malformed time"); });
+
+        local_time ltime;
+
+        ltime.hour = eat.eat_digits(2);
+        eat(':');
+        ltime.minute = eat.eat_digits(2);
+        eat(':');
+        ltime.second = eat.eat_digits(2);
+
+        int power = 100000;
+        if (it != time_end && *it == '.')
+        {
+            ++it;
+            while (it != time_end && is_number(*it))
+            {
+                ltime.microsecond += power * (*it++ - '0');
+                power /= 10;
+            }
+        }
+
+        if (it != time_end)
+            throw_parse_exception("Malformed time");
+
+        return ltime;
+    }
+
+    std::shared_ptr<value<local_time>>
+    parse_time(std::string::iterator& it, const std::string::iterator& end)
+    {
+        return make_value(read_time(it, end));
+    }
+
+    std::shared_ptr<base> parse_date(std::string::iterator& it,
+                                     const std::string::iterator& end)
+    {
+        auto date_end = find_end_of_date(it, end);
+
+        auto eat = make_consumer(
+            it, date_end, [&]() { throw_parse_exception("Malformed date"); });
+
+        local_date ldate;
+        ldate.year = eat.eat_digits(4);
+        eat('-');
+        ldate.month = eat.eat_digits(2);
+        eat('-');
+        ldate.day = eat.eat_digits(2);
+
+        if (it == date_end)
+            return make_value(ldate);
+
+        eat('T');
+
+        local_datetime ldt;
+        static_cast<local_date&>(ldt) = ldate;
+        static_cast<local_time&>(ldt) = read_time(it, date_end);
+
+        if (it == date_end)
+            return make_value(ldt);
+
+        offset_datetime dt;
+        static_cast<local_datetime&>(dt) = ldt;
+
+        int hoff = 0;
+        int moff = 0;
+        if (*it == '+' || *it == '-')
+        {
+            auto plus = *it == '+';
+            ++it;
+
+            hoff = eat.eat_digits(2);
+            dt.hour_offset = (plus) ? hoff : -hoff;
+            eat(':');
+            moff = eat.eat_digits(2);
+            dt.minute_offset = (plus) ? moff : -moff;
+        }
+        else if (*it == 'Z')
+        {
+            ++it;
+        }
+
+        if (it != date_end)
+            throw_parse_exception("Malformed date");
+
+        return make_value(dt);
+    }
+
+    std::shared_ptr<base> parse_array(std::string::iterator& it,
+                                      std::string::iterator& end)
+    {
+        // this gets ugly because of the "homogeneity" restriction:
+        // arrays can either be of only one type, or contain arrays
+        // (each of those arrays could be of different types, though)
+        //
+        // because of the latter portion, we don't really have a choice
+        // but to represent them as arrays of base values...
+        ++it;
+
+        // ugh---have to read the first value to determine array type...
+        skip_whitespace_and_comments(it, end);
+
+        // edge case---empty array
+        if (*it == ']')
+        {
+            ++it;
+            return make_array();
+        }
+
+        auto val_end = std::find_if(
+            it, end, [](char c) { return c == ',' || c == ']' || c == '#'; });
+        parse_type type = determine_value_type(it, val_end);
+        switch (type)
+        {
+            case parse_type::STRING:
+                return parse_value_array<std::string>(it, end);
+            case parse_type::LOCAL_TIME:
+                return parse_value_array<local_time>(it, end);
+            case parse_type::LOCAL_DATE:
+                return parse_value_array<local_date>(it, end);
+            case parse_type::LOCAL_DATETIME:
+                return parse_value_array<local_datetime>(it, end);
+            case parse_type::OFFSET_DATETIME:
+                return parse_value_array<offset_datetime>(it, end);
+            case parse_type::INT:
+                return parse_value_array<int64_t>(it, end);
+            case parse_type::FLOAT:
+                return parse_value_array<double>(it, end);
+            case parse_type::BOOL:
+                return parse_value_array<bool>(it, end);
+            case parse_type::ARRAY:
+                return parse_object_array<array>(&parser::parse_array, '[', it,
+                                                 end);
+            case parse_type::INLINE_TABLE:
+                return parse_object_array<table_array>(
+                    &parser::parse_inline_table, '{', it, end);
+            default:
+                throw_parse_exception("Unable to parse array");
+        }
+    }
+
+    template <class Value>
+    std::shared_ptr<array> parse_value_array(std::string::iterator& it,
+                                             std::string::iterator& end)
+    {
+        auto arr = make_array();
+        while (it != end && *it != ']')
+        {
+            auto value = parse_value(it, end);
+            if (auto v = value->as<Value>())
+                arr->get().push_back(value);
+            else
+                throw_parse_exception("Arrays must be homogeneous");
+            skip_whitespace_and_comments(it, end);
+            if (*it != ',')
+                break;
+            ++it;
+            skip_whitespace_and_comments(it, end);
+        }
+        if (it != end)
+            ++it;
+        return arr;
+    }
+
+    template <class Object, class Function>
+    std::shared_ptr<Object> parse_object_array(Function&& fun, char delim,
+                                               std::string::iterator& it,
+                                               std::string::iterator& end)
+    {
+        auto arr = make_element<Object>();
+
+        while (it != end && *it != ']')
+        {
+            if (*it != delim)
+                throw_parse_exception("Unexpected character in array");
+
+            arr->get().push_back(((*this).*fun)(it, end));
+            skip_whitespace_and_comments(it, end);
+
+            if (*it != ',')
+                break;
+
+            ++it;
+            skip_whitespace_and_comments(it, end);
+        }
+
+        if (it == end || *it != ']')
+            throw_parse_exception("Unterminated array");
+
+        ++it;
+        return arr;
+    }
+
+    std::shared_ptr<table> parse_inline_table(std::string::iterator& it,
+                                              std::string::iterator& end)
+    {
+        auto tbl = make_table();
+        do
+        {
+            ++it;
+            if (it == end)
+                throw_parse_exception("Unterminated inline table");
+
+            consume_whitespace(it, end);
+            parse_key_value(it, end, tbl.get());
+            consume_whitespace(it, end);
+        } while (*it == ',');
+
+        if (it == end || *it != '}')
+            throw_parse_exception("Unterminated inline table");
+
+        ++it;
+        consume_whitespace(it, end);
+
+        return tbl;
+    }
+
+    void skip_whitespace_and_comments(std::string::iterator& start,
+                                      std::string::iterator& end)
+    {
+        consume_whitespace(start, end);
+        while (start == end || *start == '#')
+        {
+            if (!detail::getline(input_, line_))
+                throw_parse_exception("Unclosed array");
+            line_number_++;
+            start = line_.begin();
+            end = line_.end();
+            consume_whitespace(start, end);
+        }
+    }
+
+    void consume_whitespace(std::string::iterator& it,
+                            const std::string::iterator& end)
+    {
+        while (it != end && (*it == ' ' || *it == '\t'))
+            ++it;
+    }
+
+    void consume_backwards_whitespace(std::string::iterator& back,
+                                      const std::string::iterator& front)
+    {
+        while (back != front && (*back == ' ' || *back == '\t'))
+            --back;
+    }
+
+    void eol_or_comment(const std::string::iterator& it,
+                        const std::string::iterator& end)
+    {
+        if (it != end && *it != '#')
+            throw_parse_exception("Unidentified trailing character '"
+                                  + std::string{*it}
+                                  + "'---did you forget a '#'?");
+    }
+
+    bool is_time(const std::string::iterator& it,
+                 const std::string::iterator& end)
+    {
+        auto time_end = find_end_of_time(it, end);
+        auto len = std::distance(it, time_end);
+
+        if (len < 8)
+            return false;
+
+        if (it[2] != ':' || it[5] != ':')
+            return false;
+
+        if (len > 8)
+            return it[8] == '.' && len > 9;
+
+        return true;
+    }
+
+    option<parse_type> date_type(const std::string::iterator& it,
+                                 const std::string::iterator& end)
+    {
+        auto date_end = find_end_of_date(it, end);
+        auto len = std::distance(it, date_end);
+
+        if (len < 10)
+            return {};
+
+        if (it[4] != '-' || it[7] != '-')
+            return {};
+
+        if (len >= 19 && it[10] == 'T' && is_time(it + 11, date_end))
+        {
+            // datetime type
+            auto time_end = find_end_of_time(it + 11, date_end);
+            if (time_end == date_end)
+                return {parse_type::LOCAL_DATETIME};
+            else
+                return {parse_type::OFFSET_DATETIME};
+        }
+        else if (len == 10)
+        {
+            // just a regular date
+            return {parse_type::LOCAL_DATE};
+        }
+
+        return {};
+    }
+
+    std::istream& input_;
+    std::string line_;
+    std::size_t line_number_ = 0;
+};
+
+/**
+ * Utility function to parse a file as a TOML file. Returns the root table.
+ * Throws a parse_exception if the file cannot be opened.
+ */
+inline std::shared_ptr<table> parse_file(const std::string& filename)
+{
+#if defined(BOOST_NOWIDE_FSTREAM_INCLUDED_HPP)
+    boost::nowide::ifstream file{filename.c_str()};
+#elif defined(NOWIDE_FSTREAM_INCLUDED_HPP)
+    nowide::ifstream file{filename.c_str()};
+#else
+    std::ifstream file{filename};
+#endif
+    if (!file.is_open())
+        throw parse_exception{filename + " could not be opened for parsing"};
+    parser p{file};
+    return p.parse();
+}
+
+template <class... Ts>
+struct value_accept;
+
+template <>
+struct value_accept<>
+{
+    template <class Visitor, class... Args>
+    static void accept(const base&, Visitor&&, Args&&...)
+    {
+        // nothing
+    }
+};
+
+template <class T, class... Ts>
+struct value_accept<T, Ts...>
+{
+    template <class Visitor, class... Args>
+    static void accept(const base& b, Visitor&& visitor, Args&&... args)
+    {
+        if (auto v = b.as<T>())
+        {
+            visitor.visit(*v, std::forward<Args>(args)...);
+        }
+        else
+        {
+            value_accept<Ts...>::accept(b, std::forward<Visitor>(visitor),
+                                        std::forward<Args>(args)...);
+        }
+    }
+};
+
+/**
+ * base implementation of accept() that calls visitor.visit() on the concrete
+ * class.
+ */
+template <class Visitor, class... Args>
+void base::accept(Visitor&& visitor, Args&&... args) const
+{
+    if (is_value())
+    {
+        using value_acceptor
+            = value_accept<std::string, int64_t, double, bool, local_date,
+                           local_time, local_datetime, offset_datetime>;
+        value_acceptor::accept(*this, std::forward<Visitor>(visitor),
+                               std::forward<Args>(args)...);
+    }
+    else if (is_table())
+    {
+        visitor.visit(static_cast<const table&>(*this),
+                      std::forward<Args>(args)...);
+    }
+    else if (is_array())
+    {
+        visitor.visit(static_cast<const array&>(*this),
+                      std::forward<Args>(args)...);
+    }
+    else if (is_table_array())
+    {
+        visitor.visit(static_cast<const table_array&>(*this),
+                      std::forward<Args>(args)...);
+    }
+}
+
+/**
+ * Writer that can be passed to accept() functions of cpptoml objects and
+ * will output valid TOML to a stream.
+ */
+class toml_writer
+{
+  public:
+    /**
+     * Construct a toml_writer that will write to the given stream
+     */
+    toml_writer(std::ostream& s, const std::string& indent_space = "\t")
+        : stream_(s), indent_(indent_space), has_naked_endline_(false)
+    {
+        // nothing
+    }
+
+  public:
+    /**
+     * Output a base value of the TOML tree.
+     */
+    template <class T>
+    void visit(const value<T>& v, bool = false)
+    {
+        write(v);
+    }
+
+    /**
+     * Output a table element of the TOML tree
+     */
+    void visit(const table& t, bool in_array = false)
+    {
+        write_table_header(in_array);
+        std::vector<std::string> values;
+        std::vector<std::string> tables;
+
+        for (const auto& i : t)
+        {
+            if (i.second->is_table() || i.second->is_table_array())
+            {
+                tables.push_back(i.first);
+            }
+            else
+            {
+                values.push_back(i.first);
+            }
+        }
+
+        for (unsigned int i = 0; i < values.size(); ++i)
+        {
+            path_.push_back(values[i]);
+
+            if (i > 0)
+                endline();
+
+            write_table_item_header(*t.get(values[i]));
+            t.get(values[i])->accept(*this, false);
+            path_.pop_back();
+        }
+
+        for (unsigned int i = 0; i < tables.size(); ++i)
+        {
+            path_.push_back(tables[i]);
+
+            if (values.size() > 0 || i > 0)
+                endline();
+
+            write_table_item_header(*t.get(tables[i]));
+            t.get(tables[i])->accept(*this, false);
+            path_.pop_back();
+        }
+
+        endline();
+    }
+
+    /**
+     * Output an array element of the TOML tree
+     */
+    void visit(const array& a, bool = false)
+    {
+        write("[");
+
+        for (unsigned int i = 0; i < a.get().size(); ++i)
+        {
+            if (i > 0)
+                write(", ");
+
+            if (a.get()[i]->is_array())
+            {
+                a.get()[i]->as_array()->accept(*this, true);
+            }
+            else
+            {
+                a.get()[i]->accept(*this, true);
+            }
+        }
+
+        write("]");
+    }
+
+    /**
+     * Output a table_array element of the TOML tree
+     */
+    void visit(const table_array& t, bool = false)
+    {
+        for (unsigned int j = 0; j < t.get().size(); ++j)
+        {
+            if (j > 0)
+                endline();
+
+            t.get()[j]->accept(*this, true);
+        }
+
+        endline();
+    }
+
+    /**
+     * Escape a string for output.
+     */
+    static std::string escape_string(const std::string& str)
+    {
+        std::string res;
+        for (auto it = str.begin(); it != str.end(); ++it)
+        {
+            if (*it == '\b')
+            {
+                res += "\\b";
+            }
+            else if (*it == '\t')
+            {
+                res += "\\t";
+            }
+            else if (*it == '\n')
+            {
+                res += "\\n";
+            }
+            else if (*it == '\f')
+            {
+                res += "\\f";
+            }
+            else if (*it == '\r')
+            {
+                res += "\\r";
+            }
+            else if (*it == '"')
+            {
+                res += "\\\"";
+            }
+            else if (*it == '\\')
+            {
+                res += "\\\\";
+            }
+            else if ((const uint32_t)*it <= 0x001f)
+            {
+                res += "\\u";
+                std::stringstream ss;
+                ss << std::hex << static_cast<uint32_t>(*it);
+                res += ss.str();
+            }
+            else
+            {
+                res += *it;
+            }
+        }
+        return res;
+    }
+
+  protected:
+    /**
+     * Write out a string.
+     */
+    void write(const value<std::string>& v)
+    {
+        write("\"");
+        write(escape_string(v.get()));
+        write("\"");
+    }
+
+    /**
+     * Write out a double.
+     */
+    void write(const value<double>& v)
+    {
+        std::ios::fmtflags flags{stream_.flags()};
+
+        stream_ << std::showpoint;
+        write(v.get());
+
+        stream_.flags(flags);
+    }
+
+    /**
+     * Write out an integer, local_date, local_time, local_datetime, or
+     * offset_datetime.
+     */
+    template <class T>
+    typename std::enable_if<is_one_of<T, int64_t, local_date, local_time,
+                                      local_datetime,
+                                      offset_datetime>::value>::type
+    write(const value<T>& v)
+    {
+        write(v.get());
+    }
+
+    /**
+     * Write out a boolean.
+     */
+    void write(const value<bool>& v)
+    {
+        write((v.get() ? "true" : "false"));
+    }
+
+    /**
+     * Write out the header of a table.
+     */
+    void write_table_header(bool in_array = false)
+    {
+        if (!path_.empty())
+        {
+            indent();
+
+            write("[");
+
+            if (in_array)
+            {
+                write("[");
+            }
+
+            for (unsigned int i = 0; i < path_.size(); ++i)
+            {
+                if (i > 0)
+                {
+                    write(".");
+                }
+
+                if (path_[i].find_first_not_of("ABCDEFGHIJKLMNOPQRSTUVWXYZabcde"
+                                               "fghijklmnopqrstuvwxyz0123456789"
+                                               "_-")
+                    == std::string::npos)
+                {
+                    write(path_[i]);
+                }
+                else
+                {
+                    write("\"");
+                    write(escape_string(path_[i]));
+                    write("\"");
+                }
+            }
+
+            if (in_array)
+            {
+                write("]");
+            }
+
+            write("]");
+            endline();
+        }
+    }
+
+    /**
+     * Write out the identifier for an item in a table.
+     */
+    void write_table_item_header(const base& b)
+    {
+        if (!b.is_table() && !b.is_table_array())
+        {
+            indent();
+
+            if (path_.back().find_first_not_of("ABCDEFGHIJKLMNOPQRSTUVWXYZabcde"
+                                               "fghijklmnopqrstuvwxyz0123456789"
+                                               "_-")
+                == std::string::npos)
+            {
+                write(path_.back());
+            }
+            else
+            {
+                write("\"");
+                write(escape_string(path_.back()));
+                write("\"");
+            }
+
+            write(" = ");
+        }
+    }
+
+  private:
+    /**
+     * Indent the proper number of tabs given the size of
+     * the path.
+     */
+    void indent()
+    {
+        for (std::size_t i = 1; i < path_.size(); ++i)
+            write(indent_);
+    }
+
+    /**
+     * Write a value out to the stream.
+     */
+    template <class T>
+    void write(const T& v)
+    {
+        stream_ << v;
+        has_naked_endline_ = false;
+    }
+
+    /**
+     * Write an endline out to the stream
+     */
+    void endline()
+    {
+        if (!has_naked_endline_)
+        {
+            stream_ << "\n";
+            has_naked_endline_ = true;
+        }
+    }
+
+  private:
+    std::ostream& stream_;
+    const std::string indent_;
+    std::vector<std::string> path_;
+    bool has_naked_endline_;
+};
+
+inline std::ostream& operator<<(std::ostream& stream, const base& b)
+{
+    toml_writer writer{stream};
+    b.accept(writer);
+    return stream;
+}
+
+template <class T>
+std::ostream& operator<<(std::ostream& stream, const value<T>& v)
+{
+    toml_writer writer{stream};
+    v.accept(writer);
+    return stream;
+}
+
+inline std::ostream& operator<<(std::ostream& stream, const table& t)
+{
+    toml_writer writer{stream};
+    t.accept(writer);
+    return stream;
+}
+
+inline std::ostream& operator<<(std::ostream& stream, const table_array& t)
+{
+    toml_writer writer{stream};
+    t.accept(writer);
+    return stream;
+}
+
+inline std::ostream& operator<<(std::ostream& stream, const array& a)
+{
+    toml_writer writer{stream};
+    a.accept(writer);
+    return stream;
+}
+}
+#endif
diff --git a/src/libexpr/attr-set.cc b/src/libexpr/attr-set.cc
index 0474865c6d7d..0785897d2513 100644
--- a/src/libexpr/attr-set.cc
+++ b/src/libexpr/attr-set.cc
@@ -1,5 +1,5 @@
 #include "attr-set.hh"
-#include "eval.hh"
+#include "eval-inline.hh"
 
 #include <algorithm>
 
@@ -7,20 +7,6 @@
 namespace nix {
 
 
-/* Note: Various places expect the allocated memory to be zeroed. */
-static void * allocBytes(size_t n)
-{
-    void * p;
-#if HAVE_BOEHMGC
-    p = GC_malloc(n);
-#else
-    p = calloc(n, 1);
-#endif
-    if (!p) throw std::bad_alloc();
-    return p;
-}
-
-
 /* Allocate a new array of attributes for an attribute set with a specific
    capacity. The space is implicitly reserved after the Bindings
    structure. */
diff --git a/src/libexpr/eval-inline.hh b/src/libexpr/eval-inline.hh
index 8cc50e561354..c27116e3b448 100644
--- a/src/libexpr/eval-inline.hh
+++ b/src/libexpr/eval-inline.hh
@@ -78,4 +78,18 @@ inline void EvalState::forceList(Value & v, const Pos & pos)
         throwTypeError("value is %1% while a list was expected, at %2%", v, pos);
 }
 
+/* Note: Various places expect the allocated memory to be zeroed. */
+inline void * allocBytes(size_t n)
+{
+    void * p;
+#if HAVE_BOEHMGC
+    p = GC_MALLOC(n);
+#else
+    p = calloc(n, 1);
+#endif
+    if (!p) throw std::bad_alloc();
+    return p;
+}
+
+
 }
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 517952164a97..ab407e56907c 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -6,27 +6,26 @@
 #include "globals.hh"
 #include "eval-inline.hh"
 #include "download.hh"
+#include "json.hh"
 
 #include <algorithm>
 #include <cstring>
 #include <unistd.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include <iostream>
+#include <fstream>
+
+#include <sys/time.h>
+#include <sys/resource.h>
 
 #if HAVE_BOEHMGC
 
 #include <gc/gc.h>
 #include <gc/gc_cpp.h>
 
-#define NEW new (UseGC)
-
-#else
-
-#define NEW new
-
 #endif
 
-
 namespace nix {
 
 
@@ -34,7 +33,7 @@ static char * dupString(const char * s)
 {
     char * t;
 #if HAVE_BOEHMGC
-    t = GC_strdup(s);
+    t = GC_STRDUP(s);
 #else
     t = strdup(s);
 #endif
@@ -43,20 +42,6 @@ static char * dupString(const char * s)
 }
 
 
-/* Note: Various places expect the allocated memory to be zeroed. */
-static void * allocBytes(size_t n)
-{
-    void * p;
-#if HAVE_BOEHMGC
-    p = GC_malloc(n);
-#else
-    p = calloc(n, 1);
-#endif
-    if (!p) throw std::bad_alloc();
-    return p;
-}
-
-
 static void printValue(std::ostream & str, std::set<const Value *> & active, const Value & v)
 {
     checkInterrupt();
@@ -199,8 +184,15 @@ void initGC()
 
 #if HAVE_BOEHMGC
     /* Initialise the Boehm garbage collector. */
+
+    /* Don't look for interior pointers. This reduces the odds of
+       misdetection a bit. */
     GC_set_all_interior_pointers(0);
 
+    /* We don't have any roots in data segments, so don't scan from
+       there. */
+    GC_set_no_dls(1);
+
     GC_INIT();
 
     GC_set_oom_fn(oomHandler);
@@ -346,7 +338,6 @@ EvalState::EvalState(const Strings & _searchPath, ref<Store> store)
 
 EvalState::~EvalState()
 {
-    fileEvalCache.clear();
 }
 
 
@@ -360,19 +351,25 @@ Path EvalState::checkSourcePath(const Path & path_)
 
     bool found = false;
 
+    /* First canonicalize the path without symlinks, so we make sure an
+     * attacker can't append ../../... to a path that would be in allowedPaths
+     * and thus leak symlink targets.
+     */
+    Path abspath = canonPath(path_);
+
     for (auto & i : *allowedPaths) {
-        if (isDirOrInDir(path_, i)) {
+        if (isDirOrInDir(abspath, i)) {
             found = true;
             break;
         }
     }
 
     if (!found)
-        throw RestrictedPathError("access to path '%1%' is forbidden in restricted mode", path_);
+        throw RestrictedPathError("access to path '%1%' is forbidden in restricted mode", abspath);
 
     /* Resolve symlinks. */
-    debug(format("checking access to '%s'") % path_);
-    Path path = canonPath(path_, true);
+    debug(format("checking access to '%s'") % abspath);
+    Path path = canonPath(abspath, true);
 
     for (auto & i : *allowedPaths) {
         if (isDirOrInDir(path, i)) {
@@ -451,7 +448,7 @@ Value * EvalState::addPrimOp(const string & name,
     string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name;
     Symbol sym = symbols.create(name2);
     v->type = tPrimOp;
-    v->primOp = NEW PrimOp(primOp, arity, sym);
+    v->primOp = new PrimOp(primOp, arity, sym);
     staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl;
     baseEnv.values[baseEnvDispl++] = v;
     baseEnv.values[0]->attrs->push_back(Attr(sym, v));
@@ -589,10 +586,19 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval)
 }
 
 
+std::atomic<uint64_t> nrValuesFreed{0};
+
+void finalizeValue(void * obj, void * data)
+{
+    nrValuesFreed++;
+}
+
 Value * EvalState::allocValue()
 {
     nrValues++;
-    return (Value *) allocBytes(sizeof(Value));
+    auto v = (Value *) allocBytes(sizeof(Value));
+    //GC_register_finalizer_no_order(v, finalizeValue, nullptr, nullptr, nullptr);
+    return v;
 }
 
 
@@ -725,7 +731,17 @@ void EvalState::evalFile(const Path & path_, Value & v)
     }
 
     printTalkative("evaluating file '%1%'", path2);
-    Expr * e = parseExprFromFile(checkSourcePath(path2));
+    Expr * e = nullptr;
+
+    auto j = fileParseCache.find(path2);
+    if (j != fileParseCache.end())
+        e = j->second;
+
+    if (!e)
+        e = parseExprFromFile(checkSourcePath(path2));
+
+    fileParseCache[path2] = e;
+
     try {
         eval(e, v);
     } catch (Error & e) {
@@ -1068,6 +1084,8 @@ void EvalState::callPrimOp(Value & fun, Value & arg, Value & v, const Pos & pos)
 
 void EvalState::callFunction(Value & fun, Value & arg, Value & v, const Pos & pos)
 {
+    forceValue(fun, pos);
+
     if (fun.type == tPrimOp || fun.type == tPrimOpApp) {
         callPrimOp(fun, arg, v, pos);
         return;
@@ -1083,10 +1101,8 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v, const Pos & po
         auto & fun2 = *allocValue();
         fun2 = fun;
         /* !!! Should we use the attr pos here? */
-        forceValue(*found->value, pos);
         Value v2;
         callFunction(*found->value, fun2, v2, pos);
-        forceValue(v2, pos);
         return callFunction(v2, arg, v, pos);
       }
     }
@@ -1173,7 +1189,6 @@ void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res)
     if (fun.type == tAttrs) {
         auto found = fun.attrs->find(sFunctor);
         if (found != fun.attrs->end()) {
-            forceValue(*found->value);
             Value * v = allocValue();
             callFunction(*found->value, fun, *v, noPos);
             forceValue(*v);
@@ -1557,7 +1572,6 @@ string EvalState::coerceToString(const Pos & pos, Value & v, PathSet & context,
     if (v.type == tAttrs) {
         auto i = v.attrs->find(sToString);
         if (i != v.attrs->end()) {
-            forceValue(*i->value, pos);
             Value v1;
             callFunction(*i->value, v, v1, pos);
             return coerceToString(pos, v1, context, coerceMore, copyToStore);
@@ -1711,12 +1725,9 @@ bool EvalState::eqValues(Value & v1, Value & v2)
     }
 }
 
-
 void EvalState::printStats()
 {
     bool showStats = getEnv("NIX_SHOW_STATS", "0") != "0";
-    Verbosity v = showStats ? lvlInfo : lvlDebug;
-    printMsg(v, "evaluation statistics:");
 
     struct rusage buf;
     getrusage(RUSAGE_SELF, &buf);
@@ -1727,62 +1738,101 @@ void EvalState::printStats()
     uint64_t bValues = nrValues * sizeof(Value);
     uint64_t bAttrsets = nrAttrsets * sizeof(Bindings) + nrAttrsInAttrsets * sizeof(Attr);
 
-    printMsg(v, format("  time elapsed: %1%") % cpuTime);
-    printMsg(v, format("  size of a value: %1%") % sizeof(Value));
-    printMsg(v, format("  size of an attr: %1%") % sizeof(Attr));
-    printMsg(v, format("  environments allocated count: %1%") % nrEnvs);
-    printMsg(v, format("  environments allocated bytes: %1%") % bEnvs);
-    printMsg(v, format("  list elements count: %1%") % nrListElems);
-    printMsg(v, format("  list elements bytes: %1%") % bLists);
-    printMsg(v, format("  list concatenations: %1%") % nrListConcats);
-    printMsg(v, format("  values allocated count: %1%") % nrValues);
-    printMsg(v, format("  values allocated bytes: %1%") % bValues);
-    printMsg(v, format("  sets allocated: %1% (%2% bytes)") % nrAttrsets % bAttrsets);
-    printMsg(v, format("  right-biased unions: %1%") % nrOpUpdates);
-    printMsg(v, format("  values copied in right-biased unions: %1%") % nrOpUpdateValuesCopied);
-    printMsg(v, format("  symbols in symbol table: %1%") % symbols.size());
-    printMsg(v, format("  size of symbol table: %1%") % symbols.totalSize());
-    printMsg(v, format("  number of thunks: %1%") % nrThunks);
-    printMsg(v, format("  number of thunks avoided: %1%") % nrAvoided);
-    printMsg(v, format("  number of attr lookups: %1%") % nrLookups);
-    printMsg(v, format("  number of primop calls: %1%") % nrPrimOpCalls);
-    printMsg(v, format("  number of function calls: %1%") % nrFunctionCalls);
-    printMsg(v, format("  total allocations: %1% bytes") % (bEnvs + bLists + bValues + bAttrsets));
-
 #if HAVE_BOEHMGC
     GC_word heapSize, totalBytes;
     GC_get_heap_usage_safe(&heapSize, 0, 0, 0, &totalBytes);
-    printMsg(v, format("  current Boehm heap size: %1% bytes") % heapSize);
-    printMsg(v, format("  total Boehm heap allocations: %1% bytes") % totalBytes);
 #endif
-
-    if (countCalls) {
-        v = lvlInfo;
-
-        printMsg(v, format("calls to %1% primops:") % primOpCalls.size());
-        typedef std::multimap<size_t, Symbol> PrimOpCalls_;
-        PrimOpCalls_ primOpCalls_;
-        for (auto & i : primOpCalls)
-            primOpCalls_.insert(std::pair<size_t, Symbol>(i.second, i.first));
-        for (auto i = primOpCalls_.rbegin(); i != primOpCalls_.rend(); ++i)
-            printMsg(v, format("%1$10d %2%") % i->first % i->second);
-
-        printMsg(v, format("calls to %1% functions:") % functionCalls.size());
-        typedef std::multimap<size_t, ExprLambda *> FunctionCalls_;
-        FunctionCalls_ functionCalls_;
-        for (auto & i : functionCalls)
-            functionCalls_.insert(std::pair<size_t, ExprLambda *>(i.second, i.first));
-        for (auto i = functionCalls_.rbegin(); i != functionCalls_.rend(); ++i)
-            printMsg(v, format("%1$10d %2%") % i->first % i->second->showNamePos());
-
-        printMsg(v, format("evaluations of %1% attributes:") % attrSelects.size());
-        typedef std::multimap<size_t, Pos> AttrSelects_;
-        AttrSelects_ attrSelects_;
-        for (auto & i : attrSelects)
-            attrSelects_.insert(std::pair<size_t, Pos>(i.second, i.first));
-        for (auto i = attrSelects_.rbegin(); i != attrSelects_.rend(); ++i)
-            printMsg(v, format("%1$10d %2%") % i->first % i->second);
-
+    if (showStats) {
+        auto outPath = getEnv("NIX_SHOW_STATS_PATH","-");
+        std::fstream fs;
+        if (outPath != "-")
+            fs.open(outPath, std::fstream::out);
+        JSONObject topObj(outPath == "-" ? std::cerr : fs, true);
+        topObj.attr("cpuTime",cpuTime);
+        {
+            auto envs = topObj.object("envs");
+            envs.attr("number", nrEnvs);
+            envs.attr("elements", nrValuesInEnvs);
+            envs.attr("bytes", bEnvs);
+        }
+        {
+            auto lists = topObj.object("list");
+            lists.attr("elements", nrListElems);
+            lists.attr("bytes", bLists);
+            lists.attr("concats", nrListConcats);
+        }
+        {
+            auto values = topObj.object("values");
+            values.attr("number", nrValues);
+            values.attr("bytes", bValues);
+        }
+        {
+            auto syms = topObj.object("symbols");
+            syms.attr("number", symbols.size());
+            syms.attr("bytes", symbols.totalSize());
+        }
+        {
+            auto sets = topObj.object("sets");
+            sets.attr("number", nrAttrsets);
+            sets.attr("bytes", bAttrsets);
+            sets.attr("elements", nrAttrsInAttrsets);
+        }
+        {
+            auto sizes = topObj.object("sizes");
+            sizes.attr("Env", sizeof(Env));
+            sizes.attr("Value", sizeof(Value));
+            sizes.attr("Bindings", sizeof(Bindings));
+            sizes.attr("Attr", sizeof(Attr));
+        }
+        topObj.attr("nrOpUpdates", nrOpUpdates);
+        topObj.attr("nrOpUpdateValuesCopied", nrOpUpdateValuesCopied);
+        topObj.attr("nrThunks", nrThunks);
+        topObj.attr("nrAvoided", nrAvoided);
+        topObj.attr("nrLookups", nrLookups);
+        topObj.attr("nrPrimOpCalls", nrPrimOpCalls);
+        topObj.attr("nrFunctionCalls", nrFunctionCalls);
+#if HAVE_BOEHMGC
+        {
+            auto gc = topObj.object("gc");
+            gc.attr("heapSize", heapSize);
+            gc.attr("totalBytes", totalBytes);
+        }
+#endif
+        if (countCalls) {
+            {
+                auto obj = topObj.object("primops");
+                for (auto & i : primOpCalls)
+                    obj.attr(i.first, i.second);
+            }
+            {
+                auto list = topObj.list("functions");
+                for (auto & i : functionCalls) {
+                    auto obj = list.object();
+                    if (i.first->name.set())
+                        obj.attr("name", (const string &) i.first->name);
+                    else
+                        obj.attr("name", nullptr);
+                    if (i.first->pos) {
+                        obj.attr("file", (const string &) i.first->pos.file);
+                        obj.attr("line", i.first->pos.line);
+                        obj.attr("column", i.first->pos.column);
+                    }
+                    obj.attr("count", i.second);
+                }
+            }
+            {
+                auto list = topObj.list("attributes");
+                for (auto & i : attrSelects) {
+                    auto obj = list.object();
+                    if (i.first) {
+                        obj.attr("file", (const string &) i.first.file);
+                        obj.attr("line", i.first.line);
+                        obj.attr("column", i.first.column);
+                    }
+                    obj.attr("count", i.second);
+                }
+            }
+        }
     }
 }
 
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 146f21255034..d0f298e168e9 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -90,6 +90,14 @@ public:
 private:
     SrcToStore srcToStore;
 
+    /* A cache from path names to parse trees. */
+#if HAVE_BOEHMGC
+    typedef std::map<Path, Expr *, std::less<Path>, traceable_allocator<std::pair<const Path, Expr *> > > FileParseCache;
+#else
+    typedef std::map<Path, Expr *> FileParseCache;
+#endif
+    FileParseCache fileParseCache;
+
     /* A cache from path names to values. */
 #if HAVE_BOEHMGC
     typedef std::map<Path, Value, std::less<Path>, traceable_allocator<std::pair<const Path, Value> > > FileEvalCache;
diff --git a/src/libexpr/get-drvs.hh b/src/libexpr/get-drvs.hh
index 4d9128e3f448..daaa635fe1b1 100644
--- a/src/libexpr/get-drvs.hh
+++ b/src/libexpr/get-drvs.hh
@@ -44,7 +44,7 @@ public:
     string queryDrvPath() const;
     string queryOutPath() const;
     string queryOutputName() const;
-    /** Return the list of outputs. The "outputs to install" are determined by `mesa.outputsToInstall`. */
+    /** Return the list of outputs. The "outputs to install" are determined by `meta.outputsToInstall`. */
     Outputs queryOutputs(bool onlyOutputsToInstall = false);
 
     StringSet queryMetaNames();
diff --git a/src/libexpr/lexer.l b/src/libexpr/lexer.l
index 29ca327c1e4e..c34e5c383923 100644
--- a/src/libexpr/lexer.l
+++ b/src/libexpr/lexer.l
@@ -6,12 +6,14 @@
 %option nounput noyy_top_state
 
 
+%s DEFAULT
 %x STRING
 %x IND_STRING
-%x INSIDE_DOLLAR_CURLY
 
 
 %{
+#include <boost/lexical_cast.hpp>
+
 #include "nixexpr.hh"
 #include "parser-tab.hh"
 
@@ -97,8 +99,6 @@ URI         [a-zA-Z][a-zA-Z0-9\+\-\.]*\:[a-zA-Z0-9\%\/\?\:\@\&\=\+\$\,\-\_\.\!\~
 
 %%
 
-<INITIAL,INSIDE_DOLLAR_CURLY>{
-
 
 if          { return IF; }
 then        { return THEN; }
@@ -124,9 +124,11 @@ or          { return OR_KW; }
 
 {ID}        { yylval->id = strdup(yytext); return ID; }
 {INT}       { errno = 0;
-              yylval->n = strtol(yytext, 0, 10);
-              if (errno != 0)
+              try {
+                  yylval->n = boost::lexical_cast<int64_t>(yytext);
+              } catch (const boost::bad_lexical_cast &) {
                   throw ParseError(format("invalid integer '%1%'") % yytext);
+              }
               return INT;
             }
 {FLOAT}     { errno = 0;
@@ -136,17 +138,19 @@ or          { return OR_KW; }
               return FLOAT;
             }
 
-\$\{        { PUSH_STATE(INSIDE_DOLLAR_CURLY); return DOLLAR_CURLY; }
-}
+\$\{        { PUSH_STATE(DEFAULT); return DOLLAR_CURLY; }
 
-\}                           { return '}'; }
-<INSIDE_DOLLAR_CURLY>\}      { POP_STATE(); return '}'; }
-\{                           { return '{'; }
-<INSIDE_DOLLAR_CURLY>\{      { PUSH_STATE(INSIDE_DOLLAR_CURLY); return '{'; }
+\}          { /* State INITIAL only exists at the bottom of the stack and is
+                 used as a marker. DEFAULT replaces it everywhere else.
+                 Popping when in INITIAL state causes an empty stack exception,
+                 so don't */
+              if (YYSTATE != INITIAL)
+                POP_STATE();
+              return '}';
+            }
+\{          { PUSH_STATE(DEFAULT); return '{'; }
 
-<INITIAL,INSIDE_DOLLAR_CURLY>\" {
-                PUSH_STATE(STRING); return '"';
-              }
+\"          { PUSH_STATE(STRING); return '"'; }
 <STRING>([^\$\"\\]|\$[^\{\"\\]|\\{ANY}|\$\\{ANY})*\$/\" |
 <STRING>([^\$\"\\]|\$[^\{\"\\]|\\{ANY}|\$\\{ANY})+ {
                 /* It is impossible to match strings ending with '$' with one
@@ -155,7 +159,7 @@ or          { return OR_KW; }
                 yylval->e = unescapeStr(data->symbols, yytext, yyleng);
                 return STR;
               }
-<STRING>\$\{  { PUSH_STATE(INSIDE_DOLLAR_CURLY); return DOLLAR_CURLY; }
+<STRING>\$\{  { PUSH_STATE(DEFAULT); return DOLLAR_CURLY; }
 <STRING>\"    { POP_STATE(); return '"'; }
 <STRING>\$|\\|\$\\ {
                 /* This can only occur when we reach EOF, otherwise the above
@@ -165,7 +169,7 @@ or          { return OR_KW; }
                 return STR;
               }
 
-<INITIAL,INSIDE_DOLLAR_CURLY>\'\'(\ *\n)?     { PUSH_STATE(IND_STRING); return IND_STRING_OPEN; }
+\'\'(\ *\n)?     { PUSH_STATE(IND_STRING); return IND_STRING_OPEN; }
 <IND_STRING>([^\$\']|\$[^\{\']|\'[^\'\$])+ {
                    yylval->e = new ExprIndStr(yytext);
                    return IND_STR;
@@ -183,14 +187,13 @@ or          { return OR_KW; }
                    yylval->e = unescapeStr(data->symbols, yytext + 2, yyleng - 2);
                    return IND_STR;
                  }
-<IND_STRING>\$\{ { PUSH_STATE(INSIDE_DOLLAR_CURLY); return DOLLAR_CURLY; }
+<IND_STRING>\$\{ { PUSH_STATE(DEFAULT); return DOLLAR_CURLY; }
 <IND_STRING>\'\' { POP_STATE(); return IND_STRING_CLOSE; }
 <IND_STRING>\'   {
                    yylval->e = new ExprIndStr("'");
                    return IND_STR;
                  }
 
-<INITIAL,INSIDE_DOLLAR_CURLY>{
 
 {PATH}      { if (yytext[yyleng-1] == '/')
                   throw ParseError("path '%s' has a trailing slash", yytext);
@@ -215,7 +218,5 @@ or          { return OR_KW; }
               return (unsigned char) yytext[0];
             }
 
-}
-
 %%
 
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index eee48887dc22..cbd576d7d126 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -273,11 +273,11 @@ void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * err
 %token IND_STRING_OPEN IND_STRING_CLOSE
 %token ELLIPSIS
 
-%nonassoc IMPL
+%right IMPL
 %left OR
 %left AND
 %nonassoc EQ NEQ
-%left '<' '>' LEQ GEQ
+%nonassoc '<' '>' LEQ GEQ
 %right UPDATE
 %left NOT
 %left '+' '-'
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 3a6c4035b8b8..7372134e2c9b 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -866,7 +866,7 @@ static void prim_baseNameOf(EvalState & state, const Pos & pos, Value * * args,
 static void prim_dirOf(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
     PathSet context;
-    Path dir = dirOf(state.coerceToPath(pos, *args[0], context));
+    Path dir = dirOf(state.coerceToString(pos, *args[0], context, false, false));
     if (args[0]->type == tPath) mkPath(v, dir.c_str()); else mkString(v, dir, context);
 }
 
@@ -1356,6 +1356,24 @@ static void prim_functionArgs(EvalState & state, const Pos & pos, Value * * args
 }
 
 
+/* Apply a function to every element of an attribute set. */
+static void prim_mapAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
+{
+    state.forceAttrs(*args[1], pos);
+
+    state.mkAttrs(v, args[1]->attrs->size());
+
+    for (auto & i : *args[1]->attrs) {
+        Value * vName = state.allocValue();
+        Value * vFun2 = state.allocValue();
+        mkString(*vName, i.name);
+        mkApp(*vFun2, *args[0], *vName);
+        mkApp(*state.allocAttr(v, i.name), *vFun2, *i.value);
+    }
+}
+
+
+
 /*************************************************************
  * Lists
  *************************************************************/
@@ -1410,7 +1428,6 @@ static void prim_tail(EvalState & state, const Pos & pos, Value * * args, Value
 /* Apply a function to every element of a list. */
 static void prim_map(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
-    state.forceFunction(*args[0], pos);
     state.forceList(*args[1], pos);
 
     state.mkList(v, args[1]->listSize());
@@ -1489,19 +1506,20 @@ static void prim_foldlStrict(EvalState & state, const Pos & pos, Value * * args,
     state.forceFunction(*args[0], pos);
     state.forceList(*args[2], pos);
 
-    Value * vCur = args[1];
+    if (args[2]->listSize()) {
+        Value * vCur = args[1];
 
-    if (args[2]->listSize())
         for (unsigned int n = 0; n < args[2]->listSize(); ++n) {
             Value vTmp;
             state.callFunction(*args[0], *vCur, vTmp, pos);
             vCur = n == args[2]->listSize() - 1 ? &v : state.allocValue();
             state.callFunction(vTmp, *args[2]->listElems()[n], *vCur, pos);
         }
-    else
-        v = *vCur;
-
-    state.forceValue(v);
+        state.forceValue(v);
+    } else {
+        state.forceValue(*args[1]);
+        v = *args[1];
+    }
 }
 
 
@@ -1538,7 +1556,6 @@ static void prim_all(EvalState & state, const Pos & pos, Value * * args, Value &
 
 static void prim_genList(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
-    state.forceFunction(*args[0], pos);
     auto len = state.forceInt(*args[1], pos);
 
     if (len < 0)
@@ -1627,6 +1644,35 @@ static void prim_partition(EvalState & state, const Pos & pos, Value * * args, V
 }
 
 
+/* concatMap = f: list: concatLists (map f list); */
+/* C++-version is to avoid allocating `mkApp', call `f' eagerly */
+static void prim_concatMap(EvalState & state, const Pos & pos, Value * * args, Value & v)
+{
+    state.forceFunction(*args[0], pos);
+    state.forceList(*args[1], pos);
+    auto nrLists = args[1]->listSize();
+
+    Value lists[nrLists];
+    size_t len = 0;
+
+    for (unsigned int n = 0; n < nrLists; ++n) {
+        Value * vElem = args[1]->listElems()[n];
+        state.callFunction(*args[0], *vElem, lists[n], pos);
+        state.forceList(lists[n], pos);
+        len += lists[n].listSize();
+    }
+
+    state.mkList(v, len);
+    auto out = v.listElems();
+    for (unsigned int n = 0, pos = 0; n < nrLists; ++n) {
+        auto l = lists[n].listSize();
+        if (l)
+            memcpy(out + pos, lists[n].listElems(), l * sizeof(Value *));
+        pos += l;
+    }
+}
+
+
 /*************************************************************
  * Integer arithmetic
  *************************************************************/
@@ -1634,6 +1680,8 @@ static void prim_partition(EvalState & state, const Pos & pos, Value * * args, V
 
 static void prim_add(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
+    state.forceValue(*args[0], pos);
+    state.forceValue(*args[1], pos);
     if (args[0]->type == tFloat || args[1]->type == tFloat)
         mkFloat(v, state.forceFloat(*args[0], pos) + state.forceFloat(*args[1], pos));
     else
@@ -1643,6 +1691,8 @@ static void prim_add(EvalState & state, const Pos & pos, Value * * args, Value &
 
 static void prim_sub(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
+    state.forceValue(*args[0], pos);
+    state.forceValue(*args[1], pos);
     if (args[0]->type == tFloat || args[1]->type == tFloat)
         mkFloat(v, state.forceFloat(*args[0], pos) - state.forceFloat(*args[1], pos));
     else
@@ -1652,6 +1702,8 @@ static void prim_sub(EvalState & state, const Pos & pos, Value * * args, Value &
 
 static void prim_mul(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
+    state.forceValue(*args[0], pos);
+    state.forceValue(*args[1], pos);
     if (args[0]->type == tFloat || args[1]->type == tFloat)
         mkFloat(v, state.forceFloat(*args[0], pos) * state.forceFloat(*args[1], pos));
     else
@@ -1661,6 +1713,9 @@ static void prim_mul(EvalState & state, const Pos & pos, Value * * args, Value &
 
 static void prim_div(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
+    state.forceValue(*args[0], pos);
+    state.forceValue(*args[1], pos);
+
     NixFloat f2 = state.forceFloat(*args[1], pos);
     if (f2 == 0) throw EvalError(format("division by zero, at %1%") % pos);
 
@@ -2212,6 +2267,7 @@ void EvalState::createBaseEnv()
     addPrimOp("__intersectAttrs", 2, prim_intersectAttrs);
     addPrimOp("__catAttrs", 2, prim_catAttrs);
     addPrimOp("__functionArgs", 1, prim_functionArgs);
+    addPrimOp("__mapAttrs", 2, prim_mapAttrs);
 
     // Lists
     addPrimOp("__isList", 1, prim_isList);
@@ -2229,6 +2285,7 @@ void EvalState::createBaseEnv()
     addPrimOp("__genList", 2, prim_genList);
     addPrimOp("__sort", 2, prim_sort);
     addPrimOp("__partition", 2, prim_partition);
+    addPrimOp("__concatMap", 2, prim_concatMap);
 
     // Integer arithmetic
     addPrimOp("__add", 2, prim_add);
diff --git a/src/libexpr/primops/fetchGit.cc b/src/libexpr/primops/fetchGit.cc
index 7aa98e0bfab3..0c6539959bf6 100644
--- a/src/libexpr/primops/fetchGit.cc
+++ b/src/libexpr/primops/fetchGit.cc
@@ -219,8 +219,6 @@ static void prim_fetchGit(EvalState & state, const Pos & pos, Value * * args, Va
     } else
         url = state.coerceToString(pos, *args[0], context, false, false);
 
-    if (!isUri(url)) url = absPath(url);
-
     // FIXME: git externals probably can be used to bypass the URI
     // whitelist. Ah well.
     state.checkURI(url);
diff --git a/src/libexpr/primops/fetchMercurial.cc b/src/libexpr/primops/fetchMercurial.cc
index 9d35f6d0d6d7..97cda2458c9b 100644
--- a/src/libexpr/primops/fetchMercurial.cc
+++ b/src/libexpr/primops/fetchMercurial.cc
@@ -184,8 +184,6 @@ static void prim_fetchMercurial(EvalState & state, const Pos & pos, Value * * ar
     } else
         url = state.coerceToString(pos, *args[0], context, false, false);
 
-    if (!isUri(url)) url = absPath(url);
-
     // FIXME: git externals probably can be used to bypass the URI
     // whitelist. Ah well.
     state.checkURI(url);
diff --git a/src/libexpr/primops/fromTOML.cc b/src/libexpr/primops/fromTOML.cc
new file mode 100644
index 000000000000..4128de05d0cf
--- /dev/null
+++ b/src/libexpr/primops/fromTOML.cc
@@ -0,0 +1,77 @@
+#include "primops.hh"
+#include "eval-inline.hh"
+
+#include "cpptoml/cpptoml.h"
+
+namespace nix {
+
+static void prim_fromTOML(EvalState & state, const Pos & pos, Value * * args, Value & v)
+{
+    using namespace cpptoml;
+
+    auto toml = state.forceStringNoCtx(*args[0], pos);
+
+    std::istringstream tomlStream(toml);
+
+    std::function<void(Value &, std::shared_ptr<base>)> visit;
+
+    visit = [&](Value & v, std::shared_ptr<base> t) {
+
+        if (auto t2 = t->as_table()) {
+
+            size_t size = 0;
+            for (auto & i : *t2) { (void) i; size++; }
+
+            state.mkAttrs(v, size);
+
+            for (auto & i : *t2) {
+                auto & v2 = *state.allocAttr(v, state.symbols.create(i.first));
+
+                if (auto i2 = i.second->as_table_array()) {
+                    size_t size2 = i2->get().size();
+                    state.mkList(v2, size2);
+                    for (size_t j = 0; j < size2; ++j)
+                        visit(*(v2.listElems()[j] = state.allocValue()), i2->get()[j]);
+                }
+                else
+                    visit(v2, i.second);
+            }
+
+            v.attrs->sort();
+        }
+
+        else if (auto t2 = t->as_array()) {
+            size_t size = t2->get().size();
+
+            state.mkList(v, size);
+
+            for (size_t i = 0; i < size; ++i)
+                visit(*(v.listElems()[i] = state.allocValue()), t2->get()[i]);
+        }
+
+        else if (t->is_value()) {
+            if (auto val = t->as<int64_t>())
+                mkInt(v, val->get());
+            else if (auto val = t->as<NixFloat>())
+                mkFloat(v, val->get());
+            else if (auto val = t->as<bool>())
+                mkBool(v, val->get());
+            else if (auto val = t->as<std::string>())
+                mkString(v, val->get());
+            else
+                throw EvalError("unsupported value type in TOML");
+        }
+
+        else abort();
+    };
+
+    try {
+        visit(v, parser(tomlStream).parse());
+    } catch (std::runtime_error & e) {
+        throw EvalError("while parsing a TOML string at %s: %s", pos, e.what());
+    }
+}
+
+static RegisterPrimOp r("fromTOML", 1, prim_fromTOML);
+
+}
diff --git a/src/libexpr/value.hh b/src/libexpr/value.hh
index 66b41a158400..e1ec87d3b84c 100644
--- a/src/libexpr/value.hh
+++ b/src/libexpr/value.hh
@@ -43,8 +43,8 @@ class XMLWriter;
 class JSONPlaceholder;
 
 
-typedef long NixInt;
-typedef float NixFloat;
+typedef int64_t NixInt;
+typedef double NixFloat;
 
 /* External values must descend from ExternalValueBase, so that
  * type-agnostic nix functions (e.g. showType) can be implemented
diff --git a/src/libmain/stack.cc b/src/libmain/stack.cc
index 13896aeecb6e..e6224de7d28f 100644
--- a/src/libmain/stack.cc
+++ b/src/libmain/stack.cc
@@ -63,7 +63,7 @@ void detectStackOverflow()
     act.sa_sigaction = sigsegvHandler;
     act.sa_flags = SA_SIGINFO | SA_ONSTACK;
     if (sigaction(SIGSEGV, &act, 0))
-        throw SysError("resetting SIGCHLD");
+        throw SysError("resetting SIGSEGV");
 #endif
 }
 
diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index 76c0a1a891b8..4527ee6ba660 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -217,17 +217,6 @@ void BinaryCacheStore::narFromPath(const Path & storePath, Sink & sink)
 {
     auto info = queryPathInfo(storePath).cast<const NarInfo>();
 
-    auto source = sinkToSource([this, url{info->url}](Sink & sink) {
-        try {
-            getFile(url, sink);
-        } catch (NoSuchBinaryCacheFile & e) {
-            throw SubstituteGone(e.what());
-        }
-    });
-
-    stats.narRead++;
-    //stats.narReadCompressedBytes += nar->size(); // FIXME
-
     uint64_t narSize = 0;
 
     LambdaSink wrapperSink([&](const unsigned char * data, size_t len) {
@@ -235,8 +224,18 @@ void BinaryCacheStore::narFromPath(const Path & storePath, Sink & sink)
         narSize += len;
     });
 
-    decompress(info->compression, *source, wrapperSink);
+    auto decompressor = makeDecompressionSink(info->compression, wrapperSink);
 
+    try {
+        getFile(info->url, *decompressor);
+    } catch (NoSuchBinaryCacheFile & e) {
+        throw SubstituteGone(e.what());
+    }
+
+    decompressor->finish();
+
+    stats.narRead++;
+    //stats.narReadCompressedBytes += nar->size(); // FIXME
     stats.narReadBytes += narSize;
 }
 
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 8eb19205970d..9c408e29c06c 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -11,6 +11,7 @@
 #include "compression.hh"
 #include "json.hh"
 #include "nar-info.hh"
+#include "parsed-derivations.hh"
 
 #include <algorithm>
 #include <iostream>
@@ -20,6 +21,7 @@
 #include <future>
 #include <chrono>
 #include <regex>
+#include <queue>
 
 #include <limits.h>
 #include <sys/time.h>
@@ -29,7 +31,9 @@
 #include <sys/utsname.h>
 #include <sys/select.h>
 #include <sys/resource.h>
+#include <sys/socket.h>
 #include <fcntl.h>
+#include <netdb.h>
 #include <unistd.h>
 #include <errno.h>
 #include <cstring>
@@ -738,6 +742,8 @@ private:
     /* The derivation stored at drvPath. */
     std::unique_ptr<BasicDerivation> drv;
 
+    std::unique_ptr<ParsedDerivation> parsedDrv;
+
     /* The remainder is state held during the build. */
 
     /* Locks on the output paths. */
@@ -852,7 +858,7 @@ private:
        building multiple times. Since this contains the hash, it
        allows us to compare whether two rounds produced the same
        result. */
-    ValidPathInfos prevInfos;
+    std::map<Path, ValidPathInfo> prevInfos;
 
     const uid_t sandboxUid = 1000;
     const gid_t sandboxGid = 100;
@@ -933,6 +939,11 @@ private:
        as valid. */
     void registerOutputs();
 
+    /* Check that an output meets the requirements specified by the
+       'outputChecks' attribute (or the legacy
+       '{allowed,disallowed}{References,Requisites}' attributes). */
+    void checkOutputs(const std::map<std::string, ValidPathInfo> & outputs);
+
     /* Open a log file and a pipe to it. */
     Path openLogFile();
 
@@ -1137,6 +1148,8 @@ void DerivationGoal::haveDerivation()
         return;
     }
 
+    parsedDrv = std::make_unique<ParsedDerivation>(drvPath, *drv);
+
     /* We are first going to try to create the invalid output paths
        through substitutes.  If that doesn't work, we'll build
        them. */
@@ -1393,7 +1406,7 @@ void DerivationGoal::tryToBuild()
     /* Don't do a remote build if the derivation has the attribute
        `preferLocalBuild' set.  Also, check and repair modes are only
        supported for local builds. */
-    bool buildLocally = buildMode != bmNormal || drv->willBuildLocally();
+    bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally();
 
     auto started = [&]() {
         auto msg = fmt(
@@ -1639,19 +1652,13 @@ HookReply DerivationGoal::tryBuildHook()
 
     try {
 
-        /* Tell the hook about system features (beyond the system type)
-           required from the build machine.  (The hook could parse the
-           drv file itself, but this is easier.) */
-        Strings features = tokenizeString<Strings>(get(drv->env, "requiredSystemFeatures"));
-        for (auto & i : features) checkStoreName(i); /* !!! abuse */
-
         /* Send the request to the hook. */
         worker.hook->sink
             << "try"
             << (worker.getNrLocalBuilds() < settings.maxBuildJobs ? 1 : 0)
             << drv->platform
             << drvPath
-            << features;
+            << parsedDrv->getRequiredSystemFeatures();
         worker.hook->sink.flush();
 
         /* Read the first line of input, which should be a word indicating
@@ -1777,35 +1784,40 @@ static std::once_flag dns_resolve_flag;
 static void preloadNSS() {
     /* builtin:fetchurl can trigger a DNS lookup, which with glibc can trigger a dynamic library load of
        one of the glibc NSS libraries in a sandboxed child, which will fail unless the library's already
-       been loaded in the parent. So we force a download of an invalid URL to force the NSS machinery to
+       been loaded in the parent. So we force a lookup of an invalid domain to force the NSS machinery to
        load its lookup libraries in the parent before any child gets a chance to. */
     std::call_once(dns_resolve_flag, []() {
-        DownloadRequest request("http://this.pre-initializes.the.dns.resolvers.invalid");
-        request.tries = 1; // We only need to do it once, and this also suppresses an annoying warning
-        try { getDownloader()->download(request); } catch (...) {}
+        struct addrinfo *res = NULL;
+
+        if (getaddrinfo("this.pre-initializes.the.dns.resolvers.invalid.", "http", NULL, &res) != 0) {
+            if (res) freeaddrinfo(res);
+        }
     });
 }
 
 void DerivationGoal::startBuilder()
 {
     /* Right platform? */
-    if (!drv->canBuildLocally()) {
-        throw Error(
-            format("a '%1%' is required to build '%3%', but I am a '%2%'")
-            % drv->platform % settings.thisSystem % drvPath);
-    }
+    if (!parsedDrv->canBuildLocally())
+        throw Error("a '%s' with features {%s} is required to build '%s', but I am a '%s' with features {%s}",
+            drv->platform,
+            concatStringsSep(", ", parsedDrv->getRequiredSystemFeatures()),
+            drvPath,
+            settings.thisSystem,
+            concatStringsSep(", ", settings.systemFeatures));
 
     if (drv->isBuiltin())
         preloadNSS();
 
 #if __APPLE__
-    additionalSandboxProfile = get(drv->env, "__sandboxProfile");
+    additionalSandboxProfile = parsedDrv->getStringAttr("__sandboxProfile").value_or("");
 #endif
 
     /* Are we doing a chroot build? */
     {
+        auto noChroot = parsedDrv->getBoolAttr("__noChroot");
         if (settings.sandboxMode == smEnabled) {
-            if (get(drv->env, "__noChroot") == "1")
+            if (noChroot)
                 throw Error(format("derivation '%1%' has '__noChroot' set, "
                     "but that's not allowed when 'sandbox' is 'true'") % drvPath);
 #if __APPLE__
@@ -1818,7 +1830,7 @@ void DerivationGoal::startBuilder()
         else if (settings.sandboxMode == smDisabled)
             useChroot = false;
         else if (settings.sandboxMode == smRelaxed)
-            useChroot = !fixedOutput && get(drv->env, "__noChroot") != "1";
+            useChroot = !fixedOutput && !noChroot;
     }
 
     if (worker.store.storeDir != worker.store.realStoreDir) {
@@ -1869,7 +1881,7 @@ void DerivationGoal::startBuilder()
     writeStructuredAttrs();
 
     /* Handle exportReferencesGraph(), if set. */
-    if (!drv->env.count("__json")) {
+    if (!parsedDrv->getStructuredAttrs()) {
         /* The `exportReferencesGraph' feature allows the references graph
            to be passed to a builder.  This attribute should be a list of
            pairs [name1 path1 name2 path2 ...].  The references graph of
@@ -1934,7 +1946,7 @@ void DerivationGoal::startBuilder()
         PathSet allowedPaths = settings.allowedImpureHostPrefixes;
 
         /* This works like the above, except on a per-derivation level */
-        Strings impurePaths = tokenizeString<Strings>(get(drv->env, "__impureHostDeps"));
+        auto impurePaths = parsedDrv->getStringsAttr("__impureHostDeps").value_or(Strings());
 
         for (auto & i : impurePaths) {
             bool found = false;
@@ -2003,7 +2015,7 @@ void DerivationGoal::startBuilder()
 
         /* Create /etc/hosts with localhost entry. */
         if (!fixedOutput)
-            writeFile(chrootRootDir + "/etc/hosts", "127.0.0.1 localhost\n");
+            writeFile(chrootRootDir + "/etc/hosts", "127.0.0.1 localhost\n::1 localhost\n");
 
         /* Make the closure of the inputs available in the chroot,
            rather than the whole Nix store.  This prevents any access
@@ -2181,6 +2193,7 @@ void DerivationGoal::startBuilder()
         userNamespaceSync.create();
 
         options.allowVfork = false;
+        options.restoreMountNamespace = false;
 
         Pid helper = startProcess([&]() {
 
@@ -2247,6 +2260,7 @@ void DerivationGoal::startBuilder()
 #endif
     {
         options.allowVfork = !buildUser && !drv->isBuiltin();
+        options.restoreMountNamespace = false;
         pid = startProcess([&]() {
             runChild();
         }, options);
@@ -2302,7 +2316,7 @@ void DerivationGoal::initEnv()
        passAsFile is ignored in structure mode because it's not
        needed (attributes are not passed through the environment, so
        there is no size constraint). */
-    if (!drv->env.count("__json")) {
+    if (!parsedDrv->getStructuredAttrs()) {
 
         StringSet passAsFile = tokenizeString<StringSet>(get(drv->env, "passAsFile"));
         int fileNr = 0;
@@ -2349,8 +2363,8 @@ void DerivationGoal::initEnv()
        fixed-output derivations is by definition pure (since we
        already know the cryptographic hash of the output). */
     if (fixedOutput) {
-        Strings varNames = tokenizeString<Strings>(get(drv->env, "impureEnvVars"));
-        for (auto & i : varNames) env[i] = getEnv(i);
+        for (auto & i : parsedDrv->getStringsAttr("impureEnvVars").value_or(Strings()))
+            env[i] = getEnv(i);
     }
 
     /* Currently structured log messages piggyback on stderr, but we
@@ -2365,111 +2379,103 @@ static std::regex shVarName("[A-Za-z_][A-Za-z0-9_]*");
 
 void DerivationGoal::writeStructuredAttrs()
 {
-    auto jsonAttr = drv->env.find("__json");
-    if (jsonAttr == drv->env.end()) return;
-
-    try {
-
-        auto jsonStr = rewriteStrings(jsonAttr->second, inputRewrites);
+    auto & structuredAttrs = parsedDrv->getStructuredAttrs();
+    if (!structuredAttrs) return;
 
-        auto json = nlohmann::json::parse(jsonStr);
+    auto json = *structuredAttrs;
 
-        /* Add an "outputs" object containing the output paths. */
-        nlohmann::json outputs;
-        for (auto & i : drv->outputs)
-            outputs[i.first] = rewriteStrings(i.second.path, inputRewrites);
-        json["outputs"] = outputs;
-
-        /* Handle exportReferencesGraph. */
-        auto e = json.find("exportReferencesGraph");
-        if (e != json.end() && e->is_object()) {
-            for (auto i = e->begin(); i != e->end(); ++i) {
-                std::ostringstream str;
-                {
-                    JSONPlaceholder jsonRoot(str, true);
-                    PathSet storePaths;
-                    for (auto & p : *i)
-                        storePaths.insert(p.get<std::string>());
-                    worker.store.pathInfoToJSON(jsonRoot,
-                        exportReferences(storePaths), false, true);
-                }
-                json[i.key()] = nlohmann::json::parse(str.str()); // urgh
+    /* Add an "outputs" object containing the output paths. */
+    nlohmann::json outputs;
+    for (auto & i : drv->outputs)
+        outputs[i.first] = rewriteStrings(i.second.path, inputRewrites);
+    json["outputs"] = outputs;
+
+    /* Handle exportReferencesGraph. */
+    auto e = json.find("exportReferencesGraph");
+    if (e != json.end() && e->is_object()) {
+        for (auto i = e->begin(); i != e->end(); ++i) {
+            std::ostringstream str;
+            {
+                JSONPlaceholder jsonRoot(str, true);
+                PathSet storePaths;
+                for (auto & p : *i)
+                    storePaths.insert(p.get<std::string>());
+                worker.store.pathInfoToJSON(jsonRoot,
+                    exportReferences(storePaths), false, true);
             }
+            json[i.key()] = nlohmann::json::parse(str.str()); // urgh
         }
+    }
 
-        writeFile(tmpDir + "/.attrs.json", json.dump());
+    writeFile(tmpDir + "/.attrs.json", rewriteStrings(json.dump(), inputRewrites));
 
-        /* As a convenience to bash scripts, write a shell file that
-           maps all attributes that are representable in bash -
-           namely, strings, integers, nulls, Booleans, and arrays and
-           objects consisting entirely of those values. (So nested
-           arrays or objects are not supported.) */
+    /* As a convenience to bash scripts, write a shell file that
+       maps all attributes that are representable in bash -
+       namely, strings, integers, nulls, Booleans, and arrays and
+       objects consisting entirely of those values. (So nested
+       arrays or objects are not supported.) */
 
-        auto handleSimpleType = [](const nlohmann::json & value) -> std::experimental::optional<std::string> {
-            if (value.is_string())
-                return shellEscape(value);
+    auto handleSimpleType = [](const nlohmann::json & value) -> std::experimental::optional<std::string> {
+        if (value.is_string())
+            return shellEscape(value);
 
-            if (value.is_number()) {
-                auto f = value.get<float>();
-                if (std::ceil(f) == f)
-                    return std::to_string(value.get<int>());
-            }
-
-            if (value.is_null())
-                return std::string("''");
+        if (value.is_number()) {
+            auto f = value.get<float>();
+            if (std::ceil(f) == f)
+                return std::to_string(value.get<int>());
+        }
 
-            if (value.is_boolean())
-                return value.get<bool>() ? std::string("1") : std::string("");
+        if (value.is_null())
+            return std::string("''");
 
-            return {};
-        };
+        if (value.is_boolean())
+            return value.get<bool>() ? std::string("1") : std::string("");
 
-        std::string jsonSh;
+        return {};
+    };
 
-        for (auto i = json.begin(); i != json.end(); ++i) {
+    std::string jsonSh;
 
-            if (!std::regex_match(i.key(), shVarName)) continue;
+    for (auto i = json.begin(); i != json.end(); ++i) {
 
-            auto & value = i.value();
+        if (!std::regex_match(i.key(), shVarName)) continue;
 
-            auto s = handleSimpleType(value);
-            if (s)
-                jsonSh += fmt("declare %s=%s\n", i.key(), *s);
+        auto & value = i.value();
 
-            else if (value.is_array()) {
-                std::string s2;
-                bool good = true;
+        auto s = handleSimpleType(value);
+        if (s)
+            jsonSh += fmt("declare %s=%s\n", i.key(), *s);
 
-                for (auto i = value.begin(); i != value.end(); ++i) {
-                    auto s3 = handleSimpleType(i.value());
-                    if (!s3) { good = false; break; }
-                    s2 += *s3; s2 += ' ';
-                }
+        else if (value.is_array()) {
+            std::string s2;
+            bool good = true;
 
-                if (good)
-                    jsonSh += fmt("declare -a %s=(%s)\n", i.key(), s2);
+            for (auto i = value.begin(); i != value.end(); ++i) {
+                auto s3 = handleSimpleType(i.value());
+                if (!s3) { good = false; break; }
+                s2 += *s3; s2 += ' ';
             }
 
-            else if (value.is_object()) {
-                std::string s2;
-                bool good = true;
+            if (good)
+                jsonSh += fmt("declare -a %s=(%s)\n", i.key(), s2);
+        }
 
-                for (auto i = value.begin(); i != value.end(); ++i) {
-                    auto s3 = handleSimpleType(i.value());
-                    if (!s3) { good = false; break; }
-                    s2 += fmt("[%s]=%s ", shellEscape(i.key()), *s3);
-                }
+        else if (value.is_object()) {
+            std::string s2;
+            bool good = true;
 
-                if (good)
-                    jsonSh += fmt("declare -A %s=(%s)\n", i.key(), s2);
+            for (auto i = value.begin(); i != value.end(); ++i) {
+                auto s3 = handleSimpleType(i.value());
+                if (!s3) { good = false; break; }
+                s2 += fmt("[%s]=%s ", shellEscape(i.key()), *s3);
             }
-        }
 
-        writeFile(tmpDir + "/.attrs.sh", jsonSh);
-
-    } catch (std::exception & e) {
-        throw Error("cannot process __json attribute of '%s': %s", drvPath, e.what());
+            if (good)
+                jsonSh += fmt("declare -A %s=(%s)\n", i.key(), s2);
+        }
     }
+
+    writeFile(tmpDir + "/.attrs.sh", rewriteStrings(jsonSh, inputRewrites));
 }
 
 
@@ -2624,7 +2630,7 @@ void DerivationGoal::runChild()
                 createDirs(chrootRootDir + "/dev/shm");
                 createDirs(chrootRootDir + "/dev/pts");
                 ss.push_back("/dev/full");
-                if (pathExists("/dev/kvm"))
+                if (settings.systemFeatures.get().count("kvm") && pathExists("/dev/kvm"))
                     ss.push_back("/dev/kvm");
                 ss.push_back("/dev/null");
                 ss.push_back("/dev/random");
@@ -2913,7 +2919,7 @@ void DerivationGoal::runChild()
 
             writeFile(sandboxFile, sandboxProfile);
 
-            bool allowLocalNetworking = get(drv->env, "__darwinAllowLocalNetworking") == "1";
+            bool allowLocalNetworking = parsedDrv->getBoolAttr("__darwinAllowLocalNetworking");
 
             /* The tmpDir in scope points at the temporary build directory for our derivation. Some packages try different mechanisms
                to find temporary directories, so we want to open up a broader place for them to dump their files, if needed. */
@@ -2985,10 +2991,9 @@ void DerivationGoal::runChild()
 /* Parse a list of reference specifiers.  Each element must either be
    a store path, or the symbolic name of the output of the derivation
    (such as `out'). */
-PathSet parseReferenceSpecifiers(Store & store, const BasicDerivation & drv, string attr)
+PathSet parseReferenceSpecifiers(Store & store, const BasicDerivation & drv, const Strings & paths)
 {
     PathSet result;
-    Paths paths = tokenizeString<Paths>(attr);
     for (auto & i : paths) {
         if (store.isStorePath(i))
             result.insert(i);
@@ -3013,7 +3018,7 @@ void DerivationGoal::registerOutputs()
         if (allValid) return;
     }
 
-    ValidPathInfos infos;
+    std::map<std::string, ValidPathInfo> infos;
 
     /* Set of inodes seen during calls to canonicalisePathMetaData()
        for this build's outputs.  This needs to be shared between
@@ -3117,7 +3122,7 @@ void DerivationGoal::registerOutputs()
                the derivation to its content-addressed location. */
             Hash h2 = recursive ? hashPath(h.type, actualPath).first : hashFile(h.type, actualPath);
 
-            Path dest = worker.store.makeFixedOutputPath(recursive, h2, drv->env["name"]);
+            Path dest = worker.store.makeFixedOutputPath(recursive, h2, storePathToName(path));
 
             if (h != h2) {
 
@@ -3198,48 +3203,6 @@ void DerivationGoal::registerOutputs()
                 debug(format("referenced input: '%1%'") % i);
         }
 
-        /* Enforce `allowedReferences' and friends. */
-        auto checkRefs = [&](const string & attrName, bool allowed, bool recursive) {
-            if (drv->env.find(attrName) == drv->env.end()) return;
-
-            PathSet spec = parseReferenceSpecifiers(worker.store, *drv, get(drv->env, attrName));
-
-            PathSet used;
-            if (recursive) {
-                /* Our requisites are the union of the closures of our references. */
-                for (auto & i : references)
-                    /* Don't call computeFSClosure on ourselves. */
-                    if (path != i)
-                        worker.store.computeFSClosure(i, used);
-            } else
-                used = references;
-
-            PathSet badPaths;
-
-            for (auto & i : used)
-                if (allowed) {
-                    if (spec.find(i) == spec.end())
-                        badPaths.insert(i);
-                } else {
-                    if (spec.find(i) != spec.end())
-                        badPaths.insert(i);
-                }
-
-            if (!badPaths.empty()) {
-                string badPathsStr;
-                for (auto & i : badPaths) {
-                    badPathsStr += "\n\t";
-                    badPathsStr += i;
-                }
-                throw BuildError(format("output '%1%' is not allowed to refer to the following paths:%2%") % actualPath % badPathsStr);
-            }
-        };
-
-        checkRefs("allowedReferences", true, false);
-        checkRefs("allowedRequisites", true, true);
-        checkRefs("disallowedReferences", false, false);
-        checkRefs("disallowedRequisites", false, true);
-
         if (curRound == nrRounds) {
             worker.store.optimisePath(actualPath); // FIXME: combine with scanForReferences()
             worker.markContentsGood(path);
@@ -3255,11 +3218,14 @@ void DerivationGoal::registerOutputs()
 
         if (!info.references.empty()) info.ca.clear();
 
-        infos.push_back(info);
+        infos[i.first] = info;
     }
 
     if (buildMode == bmCheck) return;
 
+    /* Apply output checks. */
+    checkOutputs(infos);
+
     /* Compare the result with the previous round, and report which
        path is different, if any.*/
     if (curRound > 1 && prevInfos != infos) {
@@ -3267,16 +3233,16 @@ void DerivationGoal::registerOutputs()
         for (auto i = prevInfos.begin(), j = infos.begin(); i != prevInfos.end(); ++i, ++j)
             if (!(*i == *j)) {
                 result.isNonDeterministic = true;
-                Path prev = i->path + checkSuffix;
+                Path prev = i->second.path + checkSuffix;
                 bool prevExists = keepPreviousRound && pathExists(prev);
                 auto msg = prevExists
-                    ? fmt("output '%1%' of '%2%' differs from '%3%' from previous round", i->path, drvPath, prev)
-                    : fmt("output '%1%' of '%2%' differs from previous round", i->path, drvPath);
+                    ? fmt("output '%1%' of '%2%' differs from '%3%' from previous round", i->second.path, drvPath, prev)
+                    : fmt("output '%1%' of '%2%' differs from previous round", i->second.path, drvPath);
 
                 auto diffHook = settings.diffHook;
                 if (prevExists && diffHook != "" && runDiffHook) {
                     try {
-                        auto diff = runProgram(diffHook, true, {prev, i->path});
+                        auto diff = runProgram(diffHook, true, {prev, i->second.path});
                         if (diff != "")
                             printError(chomp(diff));
                     } catch (Error & error) {
@@ -3321,7 +3287,11 @@ void DerivationGoal::registerOutputs()
     /* Register each output path as valid, and register the sets of
        paths referenced by each of them.  If there are cycles in the
        outputs, this will fail. */
-    worker.store.registerValidPaths(infos);
+    {
+        ValidPathInfos infos2;
+        for (auto & i : infos) infos2.push_back(i.second);
+        worker.store.registerValidPaths(infos2);
+    }
 
     /* In case of a fixed-output derivation hash mismatch, throw an
        exception now that we have registered the output as valid. */
@@ -3330,6 +3300,158 @@ void DerivationGoal::registerOutputs()
 }
 
 
+void DerivationGoal::checkOutputs(const std::map<Path, ValidPathInfo> & outputs)
+{
+    std::map<Path, const ValidPathInfo &> outputsByPath;
+    for (auto & output : outputs)
+        outputsByPath.emplace(output.second.path, output.second);
+
+    for (auto & output : outputs) {
+        auto & outputName = output.first;
+        auto & info = output.second;
+
+        struct Checks
+        {
+            bool ignoreSelfRefs = false;
+            std::experimental::optional<uint64_t> maxSize, maxClosureSize;
+            std::experimental::optional<Strings> allowedReferences, allowedRequisites, disallowedReferences, disallowedRequisites;
+        };
+
+        /* Compute the closure and closure size of some output. This
+           is slightly tricky because some of its references (namely
+           other outputs) may not be valid yet. */
+        auto getClosure = [&](const Path & path)
+        {
+            uint64_t closureSize = 0;
+            PathSet pathsDone;
+            std::queue<Path> pathsLeft;
+            pathsLeft.push(path);
+
+            while (!pathsLeft.empty()) {
+                auto path = pathsLeft.front();
+                pathsLeft.pop();
+                if (!pathsDone.insert(path).second) continue;
+
+                auto i = outputsByPath.find(path);
+                if (i != outputsByPath.end()) {
+                    closureSize += i->second.narSize;
+                    for (auto & ref : i->second.references)
+                        pathsLeft.push(ref);
+                } else {
+                    auto info = worker.store.queryPathInfo(path);
+                    closureSize += info->narSize;
+                    for (auto & ref : info->references)
+                        pathsLeft.push(ref);
+                }
+            }
+
+            return std::make_pair(pathsDone, closureSize);
+        };
+
+        auto applyChecks = [&](const Checks & checks)
+        {
+            if (checks.maxSize && info.narSize > *checks.maxSize)
+                throw BuildError("path '%s' is too large at %d bytes; limit is %d bytes",
+                    info.path, info.narSize, *checks.maxSize);
+
+            if (checks.maxClosureSize) {
+                uint64_t closureSize = getClosure(info.path).second;
+                if (closureSize > *checks.maxClosureSize)
+                    throw BuildError("closure of path '%s' is too large at %d bytes; limit is %d bytes",
+                        info.path, closureSize, *checks.maxClosureSize);
+            }
+
+            auto checkRefs = [&](const std::experimental::optional<Strings> & value, bool allowed, bool recursive)
+            {
+                if (!value) return;
+
+                PathSet spec = parseReferenceSpecifiers(worker.store, *drv, *value);
+
+                PathSet used = recursive ? getClosure(info.path).first : info.references;
+
+                if (recursive && checks.ignoreSelfRefs)
+                    used.erase(info.path);
+
+                PathSet badPaths;
+
+                for (auto & i : used)
+                    if (allowed) {
+                        if (!spec.count(i))
+                            badPaths.insert(i);
+                    } else {
+                        if (spec.count(i))
+                            badPaths.insert(i);
+                    }
+
+                if (!badPaths.empty()) {
+                    string badPathsStr;
+                    for (auto & i : badPaths) {
+                        badPathsStr += "\n  ";
+                        badPathsStr += i;
+                    }
+                    throw BuildError("output '%s' is not allowed to refer to the following paths:%s", info.path, badPathsStr);
+                }
+            };
+
+            checkRefs(checks.allowedReferences, true, false);
+            checkRefs(checks.allowedRequisites, true, true);
+            checkRefs(checks.disallowedReferences, false, false);
+            checkRefs(checks.disallowedRequisites, false, true);
+        };
+
+        if (auto structuredAttrs = parsedDrv->getStructuredAttrs()) {
+            auto outputChecks = structuredAttrs->find("outputChecks");
+            if (outputChecks != structuredAttrs->end()) {
+                auto output = outputChecks->find(outputName);
+
+                if (output != outputChecks->end()) {
+                    Checks checks;
+
+                    auto maxSize = output->find("maxSize");
+                    if (maxSize != output->end())
+                        checks.maxSize = maxSize->get<uint64_t>();
+
+                    auto maxClosureSize = output->find("maxClosureSize");
+                    if (maxClosureSize != output->end())
+                        checks.maxClosureSize = maxClosureSize->get<uint64_t>();
+
+                    auto get = [&](const std::string & name) -> std::experimental::optional<Strings> {
+                        auto i = output->find(name);
+                        if (i != output->end()) {
+                            Strings res;
+                            for (auto j = i->begin(); j != i->end(); ++j) {
+                                if (!j->is_string())
+                                    throw Error("attribute '%s' of derivation '%s' must be a list of strings", name, drvPath);
+                                res.push_back(j->get<std::string>());
+                            }
+                            checks.disallowedRequisites = res;
+                            return res;
+                        }
+                        return {};
+                    };
+
+                    checks.allowedReferences = get("allowedReferences");
+                    checks.allowedRequisites = get("allowedRequisites");
+                    checks.disallowedReferences = get("disallowedReferences");
+                    checks.disallowedRequisites = get("disallowedRequisites");
+
+                    applyChecks(checks);
+                }
+            }
+        } else {
+            // legacy non-structured-attributes case
+            Checks checks;
+            checks.ignoreSelfRefs = true;
+            checks.allowedReferences = parsedDrv->getStringsAttr("allowedReferences");
+            checks.allowedRequisites = parsedDrv->getStringsAttr("allowedRequisites");
+            checks.disallowedReferences = parsedDrv->getStringsAttr("disallowedReferences");
+            checks.disallowedRequisites = parsedDrv->getStringsAttr("disallowedRequisites");
+            applyChecks(checks);
+        }
+    }
+}
+
+
 Path DerivationGoal::openLogFile()
 {
     logSize = 0;
@@ -3678,6 +3800,19 @@ void SubstitutionGoal::tryNext()
     } catch (InvalidPath &) {
         tryNext();
         return;
+    } catch (SubstituterDisabled &) {
+        if (settings.tryFallback) {
+            tryNext();
+            return;
+        }
+        throw;
+    } catch (Error & e) {
+        if (settings.tryFallback) {
+            printError(e.what());
+            tryNext();
+            return;
+        }
+        throw;
     }
 
     /* Update the total expected download size. */
diff --git a/src/libstore/builtins/fetchurl.cc b/src/libstore/builtins/fetchurl.cc
index 1f4abd374f54..92aec63a0379 100644
--- a/src/libstore/builtins/fetchurl.cc
+++ b/src/libstore/builtins/fetchurl.cc
@@ -24,6 +24,7 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
 
     Path storePath = getAttr("out");
     auto mainUrl = getAttr("url");
+    bool unpack = get(drv.env, "unpack", "") == "1";
 
     /* Note: have to use a fresh downloader here because we're in
        a forked process. */
@@ -39,21 +40,16 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
             request.verifyTLS = false;
             request.decompress = false;
 
-            downloader->download(std::move(request), sink);
+            auto decompressor = makeDecompressionSink(
+                unpack && hasSuffix(mainUrl, ".xz") ? "xz" : "none", sink);
+            downloader->download(std::move(request), *decompressor);
+            decompressor->finish();
         });
 
-        if (get(drv.env, "unpack", "") == "1") {
-
-            if (hasSuffix(mainUrl, ".xz")) {
-                auto source2 = sinkToSource([&](Sink & sink) {
-                    decompress("xz", *source, sink);
-                });
-                restorePath(storePath, *source2);
-            } else
-                restorePath(storePath, *source);
-
-        } else
-              writeFile(storePath, *source);
+        if (unpack)
+            restorePath(storePath, *source);
+        else
+            writeFile(storePath, *source);
 
         auto executable = drv.env.find("executable");
         if (executable != drv.env.end() && executable->second == "1") {
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 74b861281ee0..3961126fff9c 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -36,12 +36,6 @@ Path BasicDerivation::findOutput(const string & id) const
 }
 
 
-bool BasicDerivation::willBuildLocally() const
-{
-    return get(env, "preferLocalBuild") == "1" && canBuildLocally();
-}
-
-
 bool BasicDerivation::substitutesAllowed() const
 {
     return get(env, "allowSubstitutes", "1") == "1";
@@ -54,14 +48,6 @@ bool BasicDerivation::isBuiltin() const
 }
 
 
-bool BasicDerivation::canBuildLocally() const
-{
-    return platform == settings.thisSystem
-        || settings.extraPlatforms.get().count(platform) > 0
-        || isBuiltin();
-}
-
-
 Path writeDerivation(ref<Store> store,
     const Derivation & drv, const string & name, RepairFlag repair)
 {
@@ -342,7 +328,7 @@ Hash hashDerivationModulo(Store & store, Derivation drv)
         Hash h = drvHashes[i.first];
         if (!h) {
             assert(store.isValidPath(i.first));
-            Derivation drv2 = readDerivation(i.first);
+            Derivation drv2 = readDerivation(store.toRealPath(i.first));
             h = hashDerivationModulo(store, drv2);
             drvHashes[i.first] = h;
         }
diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh
index 7b97730d3bf2..9753e796db5f 100644
--- a/src/libstore/derivations.hh
+++ b/src/libstore/derivations.hh
@@ -56,14 +56,10 @@ struct BasicDerivation
        the given derivation. */
     Path findOutput(const string & id) const;
 
-    bool willBuildLocally() const;
-
     bool substitutesAllowed() const;
 
     bool isBuiltin() const;
 
-    bool canBuildLocally() const;
-
     /* Return true iff this is a fixed-output derivation. */
     bool isFixedOutput() const;
 
diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index 29bb56ea1277..7773d903265b 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -58,16 +58,6 @@ std::string resolveUri(const std::string & uri)
         return uri;
 }
 
-ref<std::string> decodeContent(const std::string & encoding, ref<std::string> data)
-{
-    if (encoding == "")
-        return data;
-    else if (encoding == "br")
-        return decompress(encoding, *data);
-    else
-        throw Error("unsupported Content-Encoding '%s'", encoding);
-}
-
 struct CurlDownloader : public Downloader
 {
     CURLM * curlm = 0;
@@ -106,6 +96,12 @@ struct CurlDownloader : public Downloader
                 fmt(request.data ? "uploading '%s'" : "downloading '%s'", request.uri),
                 {request.uri}, request.parentAct)
             , callback(callback)
+            , finalSink([this](const unsigned char * data, size_t len) {
+                if (this->request.dataCallback)
+                    this->request.dataCallback((char *) data, len);
+                else
+                    this->result.data->append((char *) data, len);
+              })
         {
             if (!request.expectedETag.empty())
                 requestHeaders = curl_slist_append(requestHeaders, ("If-None-Match: " + request.expectedETag).c_str());
@@ -129,22 +125,40 @@ struct CurlDownloader : public Downloader
             }
         }
 
-        template<class T>
-        void fail(const T & e)
+        void failEx(std::exception_ptr ex)
         {
             assert(!done);
             done = true;
-            callback.rethrow(std::make_exception_ptr(e));
+            callback.rethrow(ex);
+        }
+
+        template<class T>
+        void fail(const T & e)
+        {
+            failEx(std::make_exception_ptr(e));
         }
 
+        LambdaSink finalSink;
+        std::shared_ptr<CompressionSink> decompressionSink;
+
+        std::exception_ptr writeException;
+
         size_t writeCallback(void * contents, size_t size, size_t nmemb)
         {
-            size_t realSize = size * nmemb;
-            if (request.dataCallback)
-                request.dataCallback((char *) contents, realSize);
-            else
-                result.data->append((char *) contents, realSize);
-            return realSize;
+            try {
+                size_t realSize = size * nmemb;
+                result.bodySize += realSize;
+
+                if (!decompressionSink)
+                    decompressionSink = makeDecompressionSink(encoding, finalSink);
+
+                (*decompressionSink)((unsigned char *) contents, realSize);
+
+                return realSize;
+            } catch (...) {
+                writeException = std::current_exception();
+                return 0;
+            }
         }
 
         static size_t writeCallbackWrapper(void * contents, size_t size, size_t nmemb, void * userp)
@@ -162,6 +176,7 @@ struct CurlDownloader : public Downloader
                 auto ss = tokenizeString<vector<string>>(line, " ");
                 status = ss.size() >= 2 ? ss[1] : "";
                 result.data = std::make_shared<std::string>();
+                result.bodySize = 0;
                 encoding = "";
             } else {
                 auto i = line.find(':');
@@ -244,6 +259,7 @@ struct CurlDownloader : public Downloader
 
             curl_easy_setopt(req, CURLOPT_URL, request.uri.c_str());
             curl_easy_setopt(req, CURLOPT_FOLLOWLOCATION, 1L);
+            curl_easy_setopt(req, CURLOPT_MAXREDIRS, 10);
             curl_easy_setopt(req, CURLOPT_NOSIGNAL, 1);
             curl_easy_setopt(req, CURLOPT_USERAGENT,
                 ("curl/" LIBCURL_VERSION " Nix/" + nixVersion +
@@ -295,6 +311,7 @@ struct CurlDownloader : public Downloader
             curl_easy_setopt(req, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 
             result.data = std::make_shared<std::string>();
+            result.bodySize = 0;
         }
 
         void finish(CURLcode code)
@@ -308,29 +325,35 @@ struct CurlDownloader : public Downloader
                 result.effectiveUrl = effectiveUrlCStr;
 
             debug("finished %s of '%s'; curl status = %d, HTTP status = %d, body = %d bytes",
-                request.verb(), request.uri, code, httpStatus, result.data ? result.data->size() : 0);
+                request.verb(), request.uri, code, httpStatus, result.bodySize);
+
+            if (decompressionSink)
+                decompressionSink->finish();
 
             if (code == CURLE_WRITE_ERROR && result.etag == request.expectedETag) {
                 code = CURLE_OK;
                 httpStatus = 304;
             }
 
-            if (code == CURLE_OK &&
+            if (writeException)
+                failEx(writeException);
+
+            else if (code == CURLE_OK &&
                 (httpStatus == 200 || httpStatus == 201 || httpStatus == 204 || httpStatus == 304 || httpStatus == 226 /* FTP */ || httpStatus == 0 /* other protocol */))
             {
                 result.cached = httpStatus == 304;
                 done = true;
 
                 try {
-                    if (request.decompress)
-                        result.data = decodeContent(encoding, ref<std::string>(result.data));
-                    act.progress(result.data->size(), result.data->size());
+                    act.progress(result.bodySize, result.bodySize);
                     callback(std::move(result));
                 } catch (...) {
                     done = true;
                     callback.rethrow();
                 }
-            } else {
+            }
+
+            else {
                 // We treat most errors as transient, but won't retry when hopeless
                 Error err = Transient;
 
@@ -364,6 +387,8 @@ struct CurlDownloader : public Downloader
                         case CURLE_INTERFACE_FAILED:
                         case CURLE_UNKNOWN_OPTION:
                         case CURLE_SSL_CACERT_BADFILE:
+                        case CURLE_TOO_MANY_REDIRECTS:
+                        case CURLE_WRITE_ERROR:
                             err = Misc;
                             break;
                         default: // Shut up warnings
@@ -597,7 +622,7 @@ struct CurlDownloader : public Downloader
             // FIXME: do this on a worker thread
             try {
 #ifdef ENABLE_S3
-                S3Helper s3Helper("", Aws::Region::US_EAST_1); // FIXME: make configurable
+                S3Helper s3Helper("", Aws::Region::US_EAST_1, ""); // FIXME: make configurable
                 auto slash = request.uri.find('/', 5);
                 if (slash == std::string::npos)
                     throw nix::Error("bad S3 URI '%s'", request.uri);
@@ -686,11 +711,12 @@ void Downloader::download(DownloadRequest && request, Sink & sink)
 
         /* If the buffer is full, then go to sleep until the calling
            thread wakes us up (i.e. when it has removed data from the
-           buffer). Note: this does stall the download thread. */
-        while (state->data.size() > 1024 * 1024) {
-            if (state->quit) return;
+           buffer). We don't wait forever to prevent stalling the
+           download thread. (Hopefully sleeping will throttle the
+           sender.) */
+        if (state->data.size() > 1024 * 1024) {
             debug("download buffer is full; going to sleep");
-            state.wait(state->request);
+            state.wait_for(state->request, std::chrono::seconds(10));
         }
 
         /* Append data to the buffer and wake up the calling
@@ -712,28 +738,36 @@ void Downloader::download(DownloadRequest && request, Sink & sink)
             state->request.notify_one();
         }});
 
-    auto state(_state->lock());
-
     while (true) {
         checkInterrupt();
 
-        if (state->quit) {
-            if (state->exc) std::rethrow_exception(state->exc);
-            break;
-        }
+        std::string chunk;
 
-        /* If no data is available, then wait for the download thread
-           to wake us up. */
-        if (state->data.empty())
-            state.wait(state->avail);
+        /* Grab data if available, otherwise wait for the download
+           thread to wake us up. */
+        {
+            auto state(_state->lock());
+
+            while (state->data.empty()) {
+
+                if (state->quit) {
+                    if (state->exc) std::rethrow_exception(state->exc);
+                    return;
+                }
+
+                state.wait(state->avail);
+            }
+
+            chunk = std::move(state->data);
 
-        /* If data is available, then flush it to the sink and wake up
-           the download thread if it's blocked on a full buffer. */
-        if (!state->data.empty()) {
-            sink((unsigned char *) state->data.data(), state->data.size());
-            state->data.clear();
             state->request.notify_one();
         }
+
+        /* Flush the data to the sink and wake up the download thread
+           if it's blocked on a full buffer. We don't hold the state
+           lock while doing this to prevent blocking the download
+           thread if sink() takes a long time. */
+        sink((unsigned char *) chunk.data(), chunk.size());
     }
 }
 
diff --git a/src/libstore/download.hh b/src/libstore/download.hh
index da55df7a6e71..f0228f7d053a 100644
--- a/src/libstore/download.hh
+++ b/src/libstore/download.hh
@@ -38,6 +38,7 @@ struct DownloadResult
     std::string etag;
     std::string effectiveUrl;
     std::shared_ptr<std::string> data;
+    uint64_t bodySize = 0;
 };
 
 class Store;
@@ -87,7 +88,4 @@ public:
 
 bool isUri(const string & s);
 
-/* Decode data according to the Content-Encoding header. */
-ref<std::string> decodeContent(const std::string & encoding, ref<std::string> data);
-
 }
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index ba49749d830a..b415d5421476 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -7,6 +7,7 @@
 #include <queue>
 #include <algorithm>
 #include <regex>
+#include <random>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -365,7 +366,7 @@ try_again:
     char buf[bufsiz];
     auto res = readlink(file.c_str(), buf, bufsiz);
     if (res == -1) {
-        if (errno == ENOENT || errno == EACCES)
+        if (errno == ENOENT || errno == EACCES || errno == ESRCH)
             return;
         throw SysError("reading symlink");
     }
@@ -425,25 +426,28 @@ PathSet LocalStore::findRuntimeRoots()
                         readProcLink((format("%1%/%2%") % fdStr % fd_ent->d_name).str(), paths);
                     }
                 }
-                if (errno)
+                if (errno) {
+                    if (errno == ESRCH)
+                        continue;
                     throw SysError(format("iterating /proc/%1%/fd") % ent->d_name);
-                fdDir.reset();
-
-                auto mapLines =
-                    tokenizeString<std::vector<string>>(readFile((format("/proc/%1%/maps") % ent->d_name).str(), true), "\n");
-                for (const auto& line : mapLines) {
-                    auto match = std::smatch{};
-                    if (std::regex_match(line, match, mapRegex))
-                        paths.emplace(match[1]);
                 }
+                fdDir.reset();
 
                 try {
+                    auto mapLines =
+                        tokenizeString<std::vector<string>>(readFile((format("/proc/%1%/maps") % ent->d_name).str(), true), "\n");
+                    for (const auto& line : mapLines) {
+                        auto match = std::smatch{};
+                        if (std::regex_match(line, match, mapRegex))
+                            paths.emplace(match[1]);
+                    }
+
                     auto envString = readFile((format("/proc/%1%/environ") % ent->d_name).str(), true);
                     auto env_end = std::sregex_iterator{};
                     for (auto i = std::sregex_iterator{envString.begin(), envString.end(), storePathRegex}; i != env_end; ++i)
                         paths.emplace(i->str());
                 } catch (SysError & e) {
-                    if (errno == ENOENT || errno == EACCES)
+                    if (errno == ENOENT || errno == EACCES || errno == ESRCH)
                         continue;
                     throw;
                 }
@@ -829,7 +833,8 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
                alphabetically first (e.g. /nix/store/000...).  This
                matters when using --max-freed etc. */
             vector<Path> entries_(entries.begin(), entries.end());
-            random_shuffle(entries_.begin(), entries_.end());
+            std::mt19937 gen(1);
+            std::shuffle(entries_.begin(), entries_.end(), gen);
 
             for (auto & i : entries_)
                 tryToDelete(state, i);
diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index d95db56726cb..1c2c08715a14 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -78,7 +78,11 @@ void loadConfFile()
        ~/.nix/nix.conf or the command line. */
     globalConfig.resetOverriden();
 
-    globalConfig.applyConfigFile(getConfigDir() + "/nix/nix.conf");
+    auto dirs = getConfigDirs();
+    // Iterate over them in reverse so that the ones appearing first in the path take priority
+    for (auto dir = dirs.rbegin(); dir != dirs.rend(); dir++) {
+        globalConfig.applyConfigFile(*dir + "/nix/nix.conf");
+    }
 }
 
 unsigned int Settings::getDefaultCores()
@@ -86,6 +90,21 @@ unsigned int Settings::getDefaultCores()
     return std::max(1U, std::thread::hardware_concurrency());
 }
 
+StringSet Settings::getDefaultSystemFeatures()
+{
+    /* For backwards compatibility, accept some "features" that are
+       used in Nixpkgs to route builds to certain machines but don't
+       actually require anything special on the machines. */
+    StringSet features{"nixos-test", "benchmark", "big-parallel"};
+
+    #if __linux__
+    if (access("/dev/kvm", R_OK | W_OK) == 0)
+        features.insert("kvm");
+    #endif
+
+    return features;
+}
+
 const string nixVersion = PACKAGE_VERSION;
 
 template<> void BaseSetting<SandboxMode>::set(const std::string & str)
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index f589078dbb98..53efc6a90fb6 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -32,6 +32,8 @@ class Settings : public Config {
 
     unsigned int getDefaultCores();
 
+    StringSet getDefaultSystemFeatures();
+
 public:
 
     Settings();
@@ -80,9 +82,9 @@ public:
     /* Whether to show build log output in real time. */
     bool verboseBuild = true;
 
-    /* If verboseBuild is false, the number of lines of the tail of
-       the log to show if a build fails. */
-    size_t logLines = 10;
+    Setting<size_t> logLines{this, 10, "log-lines",
+        "If verbose-build is false, the number of lines of the tail of "
+        "the log to show if a build fails."};
 
     MaxBuildJobsSetting maxBuildJobs{this, 1, "max-jobs",
         "Maximum number of parallel build jobs. \"auto\" means use number of cores.",
@@ -193,7 +195,13 @@ public:
     Setting<bool> showTrace{this, false, "show-trace",
         "Whether to show a stack trace on evaluation errors."};
 
-    Setting<SandboxMode> sandboxMode{this, smDisabled, "sandbox",
+    Setting<SandboxMode> sandboxMode{this,
+        #if __linux__
+          smEnabled
+        #else
+          smDisabled
+        #endif
+        , "sandbox",
         "Whether to enable sandboxed builds. Can be \"true\", \"false\" or \"relaxed\".",
         {"build-use-chroot", "build-use-sandbox"}};
 
@@ -261,6 +269,10 @@ public:
         "These may be supported natively (e.g. armv7 on some aarch64 CPUs "
         "or using hacks like qemu-user."};
 
+    Setting<StringSet> systemFeatures{this, getDefaultSystemFeatures(),
+        "system-features",
+        "Optional features that this system implements (like \"kvm\")."};
+
     Setting<Strings> substituters{this,
         nixStore == "/nix/store" ? Strings{"https://cache.nixos.org/"} : Strings(),
         "substituters",
diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index ab524d523cf2..8da0e2f9d82a 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -13,6 +13,14 @@ private:
 
     Path cacheUri;
 
+    struct State
+    {
+        bool enabled = true;
+        std::chrono::steady_clock::time_point disabledUntil;
+    };
+
+    Sync<State> _state;
+
 public:
 
     HttpBinaryCacheStore(
@@ -46,8 +54,33 @@ public:
 
 protected:
 
+    void maybeDisable()
+    {
+        auto state(_state.lock());
+        if (state->enabled && settings.tryFallback) {
+            int t = 60;
+            printError("disabling binary cache '%s' for %s seconds", getUri(), t);
+            state->enabled = false;
+            state->disabledUntil = std::chrono::steady_clock::now() + std::chrono::seconds(t);
+        }
+    }
+
+    void checkEnabled()
+    {
+        auto state(_state.lock());
+        if (state->enabled) return;
+        if (std::chrono::steady_clock::now() > state->disabledUntil) {
+            state->enabled = true;
+            debug("re-enabling binary cache '%s'", getUri());
+            return;
+        }
+        throw SubstituterDisabled("substituter '%s' is disabled", getUri());
+    }
+
     bool fileExists(const std::string & path) override
     {
+        checkEnabled();
+
         try {
             DownloadRequest request(cacheUri + "/" + path);
             request.head = true;
@@ -59,6 +92,7 @@ protected:
                bucket is unlistable, so treat 403 as 404. */
             if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
                 return false;
+            maybeDisable();
             throw;
         }
     }
@@ -86,12 +120,14 @@ protected:
 
     void getFile(const std::string & path, Sink & sink) override
     {
+        checkEnabled();
         auto request(makeRequest(path));
         try {
             getDownloader()->download(std::move(request), sink);
         } catch (DownloadError & e) {
             if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
                 throw NoSuchBinaryCacheFile("file '%s' does not exist in binary cache '%s'", path, getUri());
+            maybeDisable();
             throw;
         }
     }
@@ -99,15 +135,18 @@ protected:
     void getFile(const std::string & path,
         Callback<std::shared_ptr<std::string>> callback) override
     {
+        checkEnabled();
+
         auto request(makeRequest(path));
 
         getDownloader()->enqueueDownload(request,
-            {[callback](std::future<DownloadResult> result) {
+            {[callback, this](std::future<DownloadResult> result) {
                 try {
                     callback(result.get().data);
                 } catch (DownloadError & e) {
                     if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
                         return callback(std::shared_ptr<std::string>());
+                    maybeDisable();
                     callback.rethrow();
                 } catch (...) {
                     callback.rethrow();
diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index 02d91ded04cd..26e1851981db 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -17,6 +17,7 @@ struct LegacySSHStore : public Store
     const Setting<Path> sshKey{this, "", "ssh-key", "path to an SSH private key"};
     const Setting<bool> compress{this, false, "compress", "whether to compress the connection"};
     const Setting<Path> remoteProgram{this, "nix-store", "remote-program", "path to the nix-store executable on the remote system"};
+    const Setting<std::string> remoteStore{this, "", "remote-store", "URI of the store on the remote system"};
 
     // Hack for getting remote build log output.
     const Setting<int> logFD{this, -1, "log-fd", "file descriptor to which SSH's stderr is connected"};
@@ -27,6 +28,7 @@ struct LegacySSHStore : public Store
         FdSink to;
         FdSource from;
         int remoteVersion;
+        bool good = true;
     };
 
     std::string host;
@@ -41,7 +43,7 @@ struct LegacySSHStore : public Store
         , connections(make_ref<Pool<Connection>>(
             std::max(1, (int) maxConnections),
             [this]() { return openConnection(); },
-            [](const ref<Connection> & r) { return true; }
+            [](const ref<Connection> & r) { return r->good; }
             ))
         , master(
             host,
@@ -56,7 +58,9 @@ struct LegacySSHStore : public Store
     ref<Connection> openConnection()
     {
         auto conn = make_ref<Connection>();
-        conn->sshConn = master.startCommand(fmt("%s --serve --write", remoteProgram));
+        conn->sshConn = master.startCommand(
+            fmt("%s --serve --write", remoteProgram)
+            + (remoteStore.get() == "" ? "" : " --store " + shellEscape(remoteStore.get())));
         conn->to = FdSink(conn->sshConn->in.get());
         conn->from = FdSource(conn->sshConn->out.get());
 
@@ -127,18 +131,48 @@ struct LegacySSHStore : public Store
 
         auto conn(connections->get());
 
-        conn->to
-            << cmdImportPaths
-            << 1;
-        copyNAR(source, conn->to);
-        conn->to
-            << exportMagic
-            << info.path
-            << info.references
-            << info.deriver
-            << 0
-            << 0;
-        conn->to.flush();
+        if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 5) {
+
+            conn->to
+                << cmdAddToStoreNar
+                << info.path
+                << info.deriver
+                << info.narHash.to_string(Base16, false)
+                << info.references
+                << info.registrationTime
+                << info.narSize
+                << info.ultimate
+                << info.sigs
+                << info.ca;
+            try {
+                copyNAR(source, conn->to);
+            } catch (...) {
+                conn->good = false;
+                throw;
+            }
+            conn->to.flush();
+
+        } else {
+
+            conn->to
+                << cmdImportPaths
+                << 1;
+            try {
+                copyNAR(source, conn->to);
+            } catch (...) {
+                conn->good = false;
+                throw;
+            }
+            conn->to
+                << exportMagic
+                << info.path
+                << info.references
+                << info.deriver
+                << 0
+                << 0;
+            conn->to.flush();
+
+        }
 
         if (readInt(conn->from) != 1)
             throw Error("failed to add path '%s' to remote host '%s', info.path, host");
@@ -269,6 +303,12 @@ struct LegacySSHStore : public Store
     {
         auto conn(connections->get());
     }
+
+    unsigned int getProtocol() override
+    {
+        auto conn(connections->get());
+        return conn->remoteVersion;
+    }
 };
 
 static RegisterStoreImplementation regStore([](
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 3b2ba65f3b46..e1cb423d151f 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -366,6 +366,8 @@ void LocalStore::makeStoreWritable()
         throw SysError("getting info about the Nix store mount point");
 
     if (stat.f_flag & ST_RDONLY) {
+        saveMountNamespace();
+
         if (unshare(CLONE_NEWNS) == -1)
             throw SysError("setting up a private mount namespace");
 
@@ -450,7 +452,7 @@ static void canonicalisePathMetaData_(const Path & path, uid_t fromUid, InodesSe
     ssize_t eaSize = llistxattr(path.c_str(), nullptr, 0);
 
     if (eaSize < 0) {
-        if (errno != ENOTSUP)
+        if (errno != ENOTSUP && errno != ENODATA)
             throw SysError("querying extended attributes of '%s'", path);
     } else if (eaSize > 0) {
         std::vector<char> eaBuf(eaSize);
@@ -880,6 +882,12 @@ void LocalStore::querySubstitutablePathInfos(const PathSet & paths,
                     narInfo ? narInfo->fileSize : 0,
                     info->narSize};
             } catch (InvalidPath) {
+            } catch (SubstituterDisabled) {
+            } catch (Error & e) {
+                if (settings.tryFallback)
+                    printError(e.what());
+                else
+                    throw;
             }
         }
     }
@@ -1332,6 +1340,12 @@ void LocalStore::verifyPath(const Path & path, const PathSet & store,
 }
 
 
+unsigned int LocalStore::getProtocol()
+{
+    return PROTOCOL_VERSION;
+}
+
+
 #if defined(FS_IOC_SETFLAGS) && defined(FS_IOC_GETFLAGS) && defined(FS_IMMUTABLE_FL)
 
 static void makeMutable(const Path & path)
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 746bdbeed793..fce963433a5e 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -209,6 +209,8 @@ public:
 
     void registerValidPaths(const ValidPathInfos & infos);
 
+    unsigned int getProtocol() override;
+
     void vacuumDB();
 
     /* Repair the contents of the given path by redownloading it using
diff --git a/src/libstore/optimise-store.cc b/src/libstore/optimise-store.cc
index 7840167d7772..991512f21795 100644
--- a/src/libstore/optimise-store.cc
+++ b/src/libstore/optimise-store.cc
@@ -104,8 +104,7 @@ void LocalStore::optimisePath_(Activity * act, OptimiseStats & stats,
        *.app/Contents/Resources/\*.lproj seem to be the only paths affected. See
        https://github.com/NixOS/nix/issues/1443 for more discussion. */
 
-    if (std::regex_search(path, std::regex("\\.app/Contents/PkgInfo$")) ||
-        std::regex_search(path, std::regex("\\.app/Contents/Resources/.+\\.lproj$")))
+    if (std::regex_search(path, std::regex("\\.app/Contents/.+$")))
     {
         debug(format("'%1%' is not allowed to be linked in macOS") % path);
         return;
diff --git a/src/libstore/parsed-derivations.cc b/src/libstore/parsed-derivations.cc
new file mode 100644
index 000000000000..dc3286482736
--- /dev/null
+++ b/src/libstore/parsed-derivations.cc
@@ -0,0 +1,111 @@
+#include "parsed-derivations.hh"
+
+namespace nix {
+
+ParsedDerivation::ParsedDerivation(const Path & drvPath, BasicDerivation & drv)
+    : drvPath(drvPath), drv(drv)
+{
+    /* Parse the __json attribute, if any. */
+    auto jsonAttr = drv.env.find("__json");
+    if (jsonAttr != drv.env.end()) {
+        try {
+            structuredAttrs = nlohmann::json::parse(jsonAttr->second);
+        } catch (std::exception & e) {
+            throw Error("cannot process __json attribute of '%s': %s", drvPath, e.what());
+        }
+    }
+}
+
+std::experimental::optional<std::string> ParsedDerivation::getStringAttr(const std::string & name) const
+{
+    if (structuredAttrs) {
+        auto i = structuredAttrs->find(name);
+        if (i == structuredAttrs->end())
+            return {};
+        else {
+            if (!i->is_string())
+                throw Error("attribute '%s' of derivation '%s' must be a string", name, drvPath);
+            return i->get<std::string>();
+        }
+    } else {
+        auto i = drv.env.find(name);
+        if (i == drv.env.end())
+            return {};
+        else
+            return i->second;
+    }
+}
+
+bool ParsedDerivation::getBoolAttr(const std::string & name, bool def) const
+{
+    if (structuredAttrs) {
+        auto i = structuredAttrs->find(name);
+        if (i == structuredAttrs->end())
+            return def;
+        else {
+            if (!i->is_boolean())
+                throw Error("attribute '%s' of derivation '%s' must be a Boolean", name, drvPath);
+            return i->get<bool>();
+        }
+    } else {
+        auto i = drv.env.find(name);
+        if (i == drv.env.end())
+            return def;
+        else
+            return i->second == "1";
+    }
+}
+
+std::experimental::optional<Strings> ParsedDerivation::getStringsAttr(const std::string & name) const
+{
+    if (structuredAttrs) {
+        auto i = structuredAttrs->find(name);
+        if (i == structuredAttrs->end())
+            return {};
+        else {
+            if (!i->is_array())
+                throw Error("attribute '%s' of derivation '%s' must be a list of strings", name, drvPath);
+            Strings res;
+            for (auto j = i->begin(); j != i->end(); ++j) {
+                if (!j->is_string())
+                    throw Error("attribute '%s' of derivation '%s' must be a list of strings", name, drvPath);
+                res.push_back(j->get<std::string>());
+            }
+            return res;
+        }
+    } else {
+        auto i = drv.env.find(name);
+        if (i == drv.env.end())
+            return {};
+        else
+            return tokenizeString<Strings>(i->second);
+    }
+}
+
+StringSet ParsedDerivation::getRequiredSystemFeatures() const
+{
+    StringSet res;
+    for (auto & i : getStringsAttr("requiredSystemFeatures").value_or(Strings()))
+        res.insert(i);
+    return res;
+}
+
+bool ParsedDerivation::canBuildLocally() const
+{
+    if (drv.platform != settings.thisSystem.get()
+        && !settings.extraPlatforms.get().count(drv.platform)
+        && !drv.isBuiltin())
+        return false;
+
+    for (auto & feature : getRequiredSystemFeatures())
+        if (!settings.systemFeatures.get().count(feature)) return false;
+
+    return true;
+}
+
+bool ParsedDerivation::willBuildLocally() const
+{
+    return getBoolAttr("preferLocalBuild") && canBuildLocally();
+}
+
+}
diff --git a/src/libstore/parsed-derivations.hh b/src/libstore/parsed-derivations.hh
new file mode 100644
index 000000000000..0a82c146172b
--- /dev/null
+++ b/src/libstore/parsed-derivations.hh
@@ -0,0 +1,35 @@
+#include "derivations.hh"
+
+#include <nlohmann/json.hpp>
+
+namespace nix {
+
+class ParsedDerivation
+{
+    Path drvPath;
+    BasicDerivation & drv;
+    std::experimental::optional<nlohmann::json> structuredAttrs;
+
+public:
+
+    ParsedDerivation(const Path & drvPath, BasicDerivation & drv);
+
+    const std::experimental::optional<nlohmann::json> & getStructuredAttrs() const
+    {
+        return structuredAttrs;
+    }
+
+    std::experimental::optional<std::string> getStringAttr(const std::string & name) const;
+
+    bool getBoolAttr(const std::string & name, bool def = false) const;
+
+    std::experimental::optional<Strings> getStringsAttr(const std::string & name) const;
+
+    StringSet getRequiredSystemFeatures() const;
+
+    bool canBuildLocally() const;
+
+    bool willBuildLocally() const;
+};
+
+}
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index ea86ef052f53..def140cfbe18 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -161,7 +161,8 @@ void RemoteStore::initConnection(Connection & conn)
         if (GET_PROTOCOL_MINOR(conn.daemonVersion) >= 11)
             conn.to << false;
 
-        conn.processStderr();
+        auto ex = conn.processStderr();
+        if (ex) std::rethrow_exception(ex);
     }
     catch (Error & e) {
         throw Error("cannot open connection to remote store '%s': %s", getUri(), e.what());
@@ -195,22 +196,68 @@ void RemoteStore::setOptions(Connection & conn)
             conn.to << i.first << i.second.value;
     }
 
-    conn.processStderr();
+    auto ex = conn.processStderr();
+    if (ex) std::rethrow_exception(ex);
+}
+
+
+/* A wrapper around Pool<RemoteStore::Connection>::Handle that marks
+   the connection as bad (causing it to be closed) if a non-daemon
+   exception is thrown before the handle is closed. Such an exception
+   causes a deviation from the expected protocol and therefore a
+   desynchronization between the client and daemon. */
+struct ConnectionHandle
+{
+    Pool<RemoteStore::Connection>::Handle handle;
+    bool daemonException = false;
+
+    ConnectionHandle(Pool<RemoteStore::Connection>::Handle && handle)
+        : handle(std::move(handle))
+    { }
+
+    ConnectionHandle(ConnectionHandle && h)
+        : handle(std::move(h.handle))
+    { }
+
+    ~ConnectionHandle()
+    {
+        if (!daemonException && std::uncaught_exception()) {
+            handle.markBad();
+            debug("closing daemon connection because of an exception");
+        }
+    }
+
+    RemoteStore::Connection * operator -> () { return &*handle; }
+
+    void processStderr(Sink * sink = 0, Source * source = 0)
+    {
+        auto ex = handle->processStderr(sink, source);
+        if (ex) {
+            daemonException = true;
+            std::rethrow_exception(ex);
+        }
+    }
+};
+
+
+ConnectionHandle RemoteStore::getConnection()
+{
+    return ConnectionHandle(connections->get());
 }
 
 
 bool RemoteStore::isValidPathUncached(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopIsValidPath << path;
-    conn->processStderr();
+    conn.processStderr();
     return readInt(conn->from);
 }
 
 
 PathSet RemoteStore::queryValidPaths(const PathSet & paths, SubstituteFlag maybeSubstitute)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 12) {
         PathSet res;
         for (auto & i : paths)
@@ -218,7 +265,7 @@ PathSet RemoteStore::queryValidPaths(const PathSet & paths, SubstituteFlag maybe
         return res;
     } else {
         conn->to << wopQueryValidPaths << paths;
-        conn->processStderr();
+        conn.processStderr();
         return readStorePaths<PathSet>(*this, conn->from);
     }
 }
@@ -226,27 +273,27 @@ PathSet RemoteStore::queryValidPaths(const PathSet & paths, SubstituteFlag maybe
 
 PathSet RemoteStore::queryAllValidPaths()
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopQueryAllValidPaths;
-    conn->processStderr();
+    conn.processStderr();
     return readStorePaths<PathSet>(*this, conn->from);
 }
 
 
 PathSet RemoteStore::querySubstitutablePaths(const PathSet & paths)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 12) {
         PathSet res;
         for (auto & i : paths) {
             conn->to << wopHasSubstitutes << i;
-            conn->processStderr();
+            conn.processStderr();
             if (readInt(conn->from)) res.insert(i);
         }
         return res;
     } else {
         conn->to << wopQuerySubstitutablePaths << paths;
-        conn->processStderr();
+        conn.processStderr();
         return readStorePaths<PathSet>(*this, conn->from);
     }
 }
@@ -257,14 +304,14 @@ void RemoteStore::querySubstitutablePathInfos(const PathSet & paths,
 {
     if (paths.empty()) return;
 
-    auto conn(connections->get());
+    auto conn(getConnection());
 
     if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 12) {
 
         for (auto & i : paths) {
             SubstitutablePathInfo info;
             conn->to << wopQuerySubstitutablePathInfo << i;
-            conn->processStderr();
+            conn.processStderr();
             unsigned int reply = readInt(conn->from);
             if (reply == 0) continue;
             info.deriver = readString(conn->from);
@@ -278,7 +325,7 @@ void RemoteStore::querySubstitutablePathInfos(const PathSet & paths,
     } else {
 
         conn->to << wopQuerySubstitutablePathInfos << paths;
-        conn->processStderr();
+        conn.processStderr();
         size_t count = readNum<size_t>(conn->from);
         for (size_t n = 0; n < count; n++) {
             Path path = readStorePath(*this, conn->from);
@@ -300,10 +347,10 @@ void RemoteStore::queryPathInfoUncached(const Path & path,
     try {
         std::shared_ptr<ValidPathInfo> info;
         {
-            auto conn(connections->get());
+            auto conn(getConnection());
             conn->to << wopQueryPathInfo << path;
             try {
-                conn->processStderr();
+                conn.processStderr();
             } catch (Error & e) {
                 // Ugly backwards compatibility hack.
                 if (e.msg().find("is not valid") != std::string::npos)
@@ -335,9 +382,9 @@ void RemoteStore::queryPathInfoUncached(const Path & path,
 void RemoteStore::queryReferrers(const Path & path,
     PathSet & referrers)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopQueryReferrers << path;
-    conn->processStderr();
+    conn.processStderr();
     PathSet referrers2 = readStorePaths<PathSet>(*this, conn->from);
     referrers.insert(referrers2.begin(), referrers2.end());
 }
@@ -345,36 +392,36 @@ void RemoteStore::queryReferrers(const Path & path,
 
 PathSet RemoteStore::queryValidDerivers(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopQueryValidDerivers << path;
-    conn->processStderr();
+    conn.processStderr();
     return readStorePaths<PathSet>(*this, conn->from);
 }
 
 
 PathSet RemoteStore::queryDerivationOutputs(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopQueryDerivationOutputs << path;
-    conn->processStderr();
+    conn.processStderr();
     return readStorePaths<PathSet>(*this, conn->from);
 }
 
 
 PathSet RemoteStore::queryDerivationOutputNames(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopQueryDerivationOutputNames << path;
-    conn->processStderr();
+    conn.processStderr();
     return readStrings<PathSet>(conn->from);
 }
 
 
 Path RemoteStore::queryPathFromHashPart(const string & hashPart)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopQueryPathFromHashPart << hashPart;
-    conn->processStderr();
+    conn.processStderr();
     Path path = readString(conn->from);
     if (!path.empty()) assertStorePath(path);
     return path;
@@ -384,7 +431,7 @@ Path RemoteStore::queryPathFromHashPart(const string & hashPart)
 void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
     RepairFlag repair, CheckSigsFlag checkSigs, std::shared_ptr<FSAccessor> accessor)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
 
     if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 18) {
         conn->to << wopImportPaths;
@@ -403,7 +450,7 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
                 ;
         });
 
-        conn->processStderr(0, source2.get());
+        conn.processStderr(0, source2.get());
 
         auto importedPaths = readStorePaths<PathSet>(*this, conn->from);
         assert(importedPaths.size() <= 1);
@@ -417,7 +464,7 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
                  << repair << !checkSigs;
         bool tunnel = GET_PROTOCOL_MINOR(conn->daemonVersion) >= 21;
         if (!tunnel) copyNAR(source, conn->to);
-        conn->processStderr(0, tunnel ? &source : nullptr);
+        conn.processStderr(0, tunnel ? &source : nullptr);
     }
 }
 
@@ -427,7 +474,7 @@ Path RemoteStore::addToStore(const string & name, const Path & _srcPath,
 {
     if (repair) throw Error("repairing is not supported when building through the Nix daemon");
 
-    auto conn(connections->get());
+    auto conn(getConnection());
 
     Path srcPath(absPath(_srcPath));
 
@@ -445,13 +492,13 @@ Path RemoteStore::addToStore(const string & name, const Path & _srcPath,
             dumpPath(srcPath, conn->to, filter);
         }
         conn->to.warn = false;
-        conn->processStderr();
+        conn.processStderr();
     } catch (SysError & e) {
         /* Daemon closed while we were sending the path. Probably OOM
            or I/O error. */
         if (e.errNo == EPIPE)
             try {
-                conn->processStderr();
+                conn.processStderr();
             } catch (EndOfFile & e) { }
         throw;
     }
@@ -465,17 +512,17 @@ Path RemoteStore::addTextToStore(const string & name, const string & s,
 {
     if (repair) throw Error("repairing is not supported when building through the Nix daemon");
 
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopAddTextToStore << name << s << references;
 
-    conn->processStderr();
+    conn.processStderr();
     return readStorePath(*this, conn->from);
 }
 
 
 void RemoteStore::buildPaths(const PathSet & drvPaths, BuildMode buildMode)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopBuildPaths;
     if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 13) {
         conn->to << drvPaths;
@@ -494,7 +541,7 @@ void RemoteStore::buildPaths(const PathSet & drvPaths, BuildMode buildMode)
             drvPaths2.insert(string(i, 0, i.find('!')));
         conn->to << drvPaths2;
     }
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
@@ -502,9 +549,9 @@ void RemoteStore::buildPaths(const PathSet & drvPaths, BuildMode buildMode)
 BuildResult RemoteStore::buildDerivation(const Path & drvPath, const BasicDerivation & drv,
     BuildMode buildMode)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopBuildDerivation << drvPath << drv << buildMode;
-    conn->processStderr();
+    conn.processStderr();
     BuildResult res;
     unsigned int status;
     conn->from >> status >> res.errorMsg;
@@ -515,45 +562,45 @@ BuildResult RemoteStore::buildDerivation(const Path & drvPath, const BasicDeriva
 
 void RemoteStore::ensurePath(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopEnsurePath << path;
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
 
 void RemoteStore::addTempRoot(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopAddTempRoot << path;
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
 
 void RemoteStore::addIndirectRoot(const Path & path)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopAddIndirectRoot << path;
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
 
 void RemoteStore::syncWithGC()
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopSyncWithGC;
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
 
 Roots RemoteStore::findRoots()
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopFindRoots;
-    conn->processStderr();
+    conn.processStderr();
     size_t count = readNum<size_t>(conn->from);
     Roots result;
     while (count--) {
@@ -567,7 +614,7 @@ Roots RemoteStore::findRoots()
 
 void RemoteStore::collectGarbage(const GCOptions & options, GCResults & results)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
 
     conn->to
         << wopCollectGarbage << options.action << options.pathsToDelete << options.ignoreLiveness
@@ -575,7 +622,7 @@ void RemoteStore::collectGarbage(const GCOptions & options, GCResults & results)
         /* removed options */
         << 0 << 0 << 0;
 
-    conn->processStderr();
+    conn.processStderr();
 
     results.paths = readStrings<PathSet>(conn->from);
     results.bytesFreed = readLongLong(conn->from);
@@ -590,27 +637,27 @@ void RemoteStore::collectGarbage(const GCOptions & options, GCResults & results)
 
 void RemoteStore::optimiseStore()
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopOptimiseStore;
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
 
 bool RemoteStore::verifyStore(bool checkContents, RepairFlag repair)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopVerifyStore << checkContents << repair;
-    conn->processStderr();
+    conn.processStderr();
     return readInt(conn->from);
 }
 
 
 void RemoteStore::addSignatures(const Path & storePath, const StringSet & sigs)
 {
-    auto conn(connections->get());
+    auto conn(getConnection());
     conn->to << wopAddSignatures << storePath << sigs;
-    conn->processStderr();
+    conn.processStderr();
     readInt(conn->from);
 }
 
@@ -620,13 +667,13 @@ void RemoteStore::queryMissing(const PathSet & targets,
     unsigned long long & downloadSize, unsigned long long & narSize)
 {
     {
-        auto conn(connections->get());
+        auto conn(getConnection());
         if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 19)
             // Don't hold the connection handle in the fallback case
             // to prevent a deadlock.
             goto fallback;
         conn->to << wopQueryMissing << targets;
-        conn->processStderr();
+        conn.processStderr();
         willBuild = readStorePaths<PathSet>(*this, conn->from);
         willSubstitute = readStorePaths<PathSet>(*this, conn->from);
         unknown = readStorePaths<PathSet>(*this, conn->from);
@@ -642,7 +689,14 @@ void RemoteStore::queryMissing(const PathSet & targets,
 
 void RemoteStore::connect()
 {
+    auto conn(getConnection());
+}
+
+
+unsigned int RemoteStore::getProtocol()
+{
     auto conn(connections->get());
+    return conn->daemonVersion;
 }
 
 
@@ -679,7 +733,7 @@ static Logger::Fields readFields(Source & from)
 }
 
 
-void RemoteStore::Connection::processStderr(Sink * sink, Source * source)
+std::exception_ptr RemoteStore::Connection::processStderr(Sink * sink, Source * source)
 {
     to.flush();
 
@@ -704,7 +758,7 @@ void RemoteStore::Connection::processStderr(Sink * sink, Source * source)
         else if (msg == STDERR_ERROR) {
             string error = readString(from);
             unsigned int status = readInt(from);
-            throw Error(status, error);
+            return std::make_exception_ptr(Error(status, error));
         }
 
         else if (msg == STDERR_NEXT)
@@ -738,6 +792,8 @@ void RemoteStore::Connection::processStderr(Sink * sink, Source * source)
         else
             throw Error("got unknown message type %x from Nix daemon", msg);
     }
+
+    return nullptr;
 }
 
 static std::string uriScheme = "unix://";
diff --git a/src/libstore/remote-store.hh b/src/libstore/remote-store.hh
index b488e34ce263..4f554b5980e8 100644
--- a/src/libstore/remote-store.hh
+++ b/src/libstore/remote-store.hh
@@ -14,6 +14,7 @@ class Pid;
 struct FdSink;
 struct FdSource;
 template<typename T> class Pool;
+struct ConnectionHandle;
 
 
 /* FIXME: RemoteStore is a misnomer - should be something like
@@ -97,12 +98,15 @@ public:
 
     void connect() override;
 
+    unsigned int getProtocol() override;
+
     void flushBadConnections();
 
 protected:
 
     struct Connection
     {
+        AutoCloseFD fd;
         FdSink to;
         FdSource from;
         unsigned int daemonVersion;
@@ -110,7 +114,7 @@ protected:
 
         virtual ~Connection();
 
-        void processStderr(Sink * sink = 0, Source * source = 0);
+        std::exception_ptr processStderr(Sink * sink = 0, Source * source = 0);
     };
 
     ref<Connection> openConnectionWrapper();
@@ -123,6 +127,10 @@ protected:
 
     virtual void setOptions(Connection & conn);
 
+    ConnectionHandle getConnection();
+
+    friend struct ConnectionHandle;
+
 private:
 
     std::atomic_bool failed{false};
@@ -140,11 +148,6 @@ public:
 
 private:
 
-    struct Connection : RemoteStore::Connection
-    {
-        AutoCloseFD fd;
-    };
-
     ref<RemoteStore::Connection> openConnection() override;
     std::experimental::optional<std::string> path;
 };
diff --git a/src/libstore/s3-binary-cache-store.cc b/src/libstore/s3-binary-cache-store.cc
index 26144ccb40cc..4f1e23198ffe 100644
--- a/src/libstore/s3-binary-cache-store.cc
+++ b/src/libstore/s3-binary-cache-store.cc
@@ -19,8 +19,6 @@
 #include <aws/core/utils/logging/LogMacros.h>
 #include <aws/core/utils/threading/Executor.h>
 #include <aws/s3/S3Client.h>
-#include <aws/s3/model/CreateBucketRequest.h>
-#include <aws/s3/model/GetBucketLocationRequest.h>
 #include <aws/s3/model/GetObjectRequest.h>
 #include <aws/s3/model/HeadObjectRequest.h>
 #include <aws/s3/model/ListObjectsRequest.h>
@@ -84,8 +82,8 @@ static void initAWS()
     });
 }
 
-S3Helper::S3Helper(const std::string & profile, const std::string & region)
-    : config(makeConfig(region))
+S3Helper::S3Helper(const std::string & profile, const std::string & region, const std::string & endpoint)
+    : config(makeConfig(region, endpoint))
     , client(make_ref<Aws::S3::S3Client>(
             profile == ""
             ? std::dynamic_pointer_cast<Aws::Auth::AWSCredentialsProvider>(
@@ -99,7 +97,7 @@ S3Helper::S3Helper(const std::string & profile, const std::string & region)
 #else
             Aws::Client::AWSAuthV4Signer::PayloadSigningPolicy::Never,
 #endif
-            false))
+            endpoint.empty()))
 {
 }
 
@@ -116,11 +114,14 @@ class RetryStrategy : public Aws::Client::DefaultRetryStrategy
     }
 };
 
-ref<Aws::Client::ClientConfiguration> S3Helper::makeConfig(const string & region)
+ref<Aws::Client::ClientConfiguration> S3Helper::makeConfig(const string & region, const string & endpoint)
 {
     initAWS();
     auto res = make_ref<Aws::Client::ClientConfiguration>();
     res->region = region;
+    if (!endpoint.empty()) {
+        res->endpointOverride = endpoint;
+    }
     res->requestTimeoutMs = 600 * 1000;
     res->retryStrategy = std::make_shared<RetryStrategy>();
     res->caFile = settings.caFile;
@@ -150,10 +151,8 @@ S3Helper::DownloadResult S3Helper::getObject(
         auto result = checkAws(fmt("AWS error fetching '%s'", key),
             client->GetObject(request));
 
-        res.data = decodeContent(
-            result.GetContentEncoding(),
-            make_ref<std::string>(
-                dynamic_cast<std::stringstream &>(result.GetBody()).str()));
+        res.data = decompress(result.GetContentEncoding(),
+            dynamic_cast<std::stringstream &>(result.GetBody()).str());
 
     } catch (S3Error & e) {
         if (e.err != Aws::S3::S3Errors::NO_SUCH_KEY) throw;
@@ -170,9 +169,12 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
 {
     const Setting<std::string> profile{this, "", "profile", "The name of the AWS configuration profile to use."};
     const Setting<std::string> region{this, Aws::Region::US_EAST_1, "region", {"aws-region"}};
+    const Setting<std::string> endpoint{this, "", "endpoint", "An optional override of the endpoint to use when talking to S3."};
     const Setting<std::string> narinfoCompression{this, "", "narinfo-compression", "compression method for .narinfo files"};
     const Setting<std::string> lsCompression{this, "", "ls-compression", "compression method for .ls files"};
     const Setting<std::string> logCompression{this, "", "log-compression", "compression method for log/* files"};
+    const Setting<bool> multipartUpload{
+        this, false, "multipart-upload", "whether to use multi-part uploads"};
     const Setting<uint64_t> bufferSize{
         this, 5 * 1024 * 1024, "buffer-size", "size (in bytes) of each part in multi-part uploads"};
 
@@ -186,7 +188,7 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
         const Params & params, const std::string & bucketName)
         : S3BinaryCacheStore(params)
         , bucketName(bucketName)
-        , s3Helper(profile, region)
+        , s3Helper(profile, region, endpoint)
     {
         diskCache = getNarInfoDiskCache();
     }
@@ -200,32 +202,6 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
     {
         if (!diskCache->cacheExists(getUri(), wantMassQuery_, priority)) {
 
-            /* Create the bucket if it doesn't already exists. */
-            // FIXME: HeadBucket would be more appropriate, but doesn't return
-            // an easily parsed 404 message.
-            auto res = s3Helper.client->GetBucketLocation(
-                Aws::S3::Model::GetBucketLocationRequest().WithBucket(bucketName));
-
-            if (!res.IsSuccess()) {
-                if (res.GetError().GetErrorType() != Aws::S3::S3Errors::NO_SUCH_BUCKET)
-                    throw Error(format("AWS error checking bucket '%s': %s") % bucketName % res.GetError().GetMessage());
-
-                printInfo("creating S3 bucket '%s'...", bucketName);
-
-                // Stupid S3 bucket locations.
-                auto bucketConfig = Aws::S3::Model::CreateBucketConfiguration();
-                if (s3Helper.config->region != "us-east-1")
-                    bucketConfig.SetLocationConstraint(
-                        Aws::S3::Model::BucketLocationConstraintMapper::GetBucketLocationConstraintForName(
-                            s3Helper.config->region));
-
-                checkAws(format("AWS error creating bucket '%s'") % bucketName,
-                    s3Helper.client->CreateBucket(
-                        Aws::S3::Model::CreateBucketRequest()
-                        .WithBucket(bucketName)
-                        .WithCreateBucketConfiguration(bucketConfig)));
-            }
-
             BinaryCacheStore::init();
 
             diskCache->createCache(getUri(), storeDir, wantMassQuery_, priority);
@@ -273,6 +249,9 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
         return true;
     }
 
+    std::shared_ptr<TransferManager> transferManager;
+    std::once_flag transferManagerCreated;
+
     void uploadFile(const std::string & path, const std::string & data,
         const std::string & mimeType,
         const std::string & contentEncoding)
@@ -284,60 +263,73 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
         static std::shared_ptr<Aws::Utils::Threading::PooledThreadExecutor>
             executor = std::make_shared<Aws::Utils::Threading::PooledThreadExecutor>(maxThreads);
 
-        TransferManagerConfiguration transferConfig(executor.get());
-
-        transferConfig.s3Client = s3Helper.client;
-        transferConfig.bufferSize = bufferSize;
-
-        if (contentEncoding != "")
-            transferConfig.createMultipartUploadTemplate.SetContentEncoding(
-                contentEncoding);
-
-        transferConfig.uploadProgressCallback =
-            [&](const TransferManager *transferManager,
-                const std::shared_ptr<const TransferHandle>
-                    &transferHandle) {
-              //FIXME: find a way to properly abort the multipart upload.
-              checkInterrupt();
-              debug("upload progress ('%s'): '%d' of '%d' bytes",
-                             path,
-                             transferHandle->GetBytesTransferred(),
-                             transferHandle->GetBytesTotalSize());
-            };
+        std::call_once(transferManagerCreated, [&]()
+        {
+            if (multipartUpload) {
+                TransferManagerConfiguration transferConfig(executor.get());
+
+                transferConfig.s3Client = s3Helper.client;
+                transferConfig.bufferSize = bufferSize;
+
+                transferConfig.uploadProgressCallback =
+                    [](const TransferManager *transferManager,
+                        const std::shared_ptr<const TransferHandle>
+                        &transferHandle)
+                    {
+                        //FIXME: find a way to properly abort the multipart upload.
+                        //checkInterrupt();
+                        debug("upload progress ('%s'): '%d' of '%d' bytes",
+                            transferHandle->GetKey(),
+                            transferHandle->GetBytesTransferred(),
+                            transferHandle->GetBytesTotalSize());
+                    };
+
+                transferManager = TransferManager::Create(transferConfig);
+            }
+        });
 
-        transferConfig.transferStatusUpdatedCallback =
-            [&](const TransferManager *,
-                const std::shared_ptr<const TransferHandle>
-                    &transferHandle) {
-              switch (transferHandle->GetStatus()) {
-                  case TransferStatus::COMPLETED:
-                      printTalkative("upload of '%s' completed", path);
-                      stats.put++;
-                      stats.putBytes += data.size();
-                      break;
-                  case TransferStatus::IN_PROGRESS:
-                      break;
-                  case TransferStatus::FAILED:
-                      throw Error("AWS error: failed to upload 's3://%s/%s'",
-                                  bucketName, path);
-                      break;
-                  default:
-                      throw Error("AWS error: transfer status of 's3://%s/%s' "
-                                  "in unexpected state",
-                                  bucketName, path);
-              };
-            };
+        auto now1 = std::chrono::steady_clock::now();
 
-        std::shared_ptr<TransferManager> transferManager =
-            TransferManager::Create(transferConfig);
+        if (transferManager) {
 
-        auto now1 = std::chrono::steady_clock::now();
+            if (contentEncoding != "")
+                throw Error("setting a content encoding is not supported with S3 multi-part uploads");
+
+            std::shared_ptr<TransferHandle> transferHandle =
+                transferManager->UploadFile(
+                    stream, bucketName, path, mimeType,
+                    Aws::Map<Aws::String, Aws::String>(),
+                    nullptr /*, contentEncoding */);
 
-        std::shared_ptr<TransferHandle> transferHandle =
-            transferManager->UploadFile(stream, bucketName, path, mimeType,
-                                        Aws::Map<Aws::String, Aws::String>());
+            transferHandle->WaitUntilFinished();
 
-        transferHandle->WaitUntilFinished();
+            if (transferHandle->GetStatus() == TransferStatus::FAILED)
+                throw Error("AWS error: failed to upload 's3://%s/%s': %s",
+                    bucketName, path, transferHandle->GetLastError().GetMessage());
+
+            if (transferHandle->GetStatus() != TransferStatus::COMPLETED)
+                throw Error("AWS error: transfer status of 's3://%s/%s' in unexpected state",
+                    bucketName, path);
+
+        } else {
+
+            auto request =
+                Aws::S3::Model::PutObjectRequest()
+                .WithBucket(bucketName)
+                .WithKey(path);
+
+            request.SetContentType(mimeType);
+
+            if (contentEncoding != "")
+                request.SetContentEncoding(contentEncoding);
+
+            auto stream = std::make_shared<istringstream_nocopy>(data);
+
+            request.SetBody(stream);
+
+            auto result = checkAws(fmt("AWS error uploading '%s'", path),
+                s3Helper.client->PutObject(request));
+        }
 
         auto now2 = std::chrono::steady_clock::now();
 
@@ -349,6 +341,8 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
                   bucketName % path % data.size() % duration);
 
         stats.putTimeMs += duration;
+        stats.putBytes += data.size();
+        stats.put++;
     }
 
     void upsertFile(const std::string & path, const std::string & data,
diff --git a/src/libstore/s3.hh b/src/libstore/s3.hh
index 4f996400343c..95d612b66335 100644
--- a/src/libstore/s3.hh
+++ b/src/libstore/s3.hh
@@ -14,9 +14,9 @@ struct S3Helper
     ref<Aws::Client::ClientConfiguration> config;
     ref<Aws::S3::S3Client> client;
 
-    S3Helper(const std::string & profile, const std::string & region);
+    S3Helper(const std::string & profile, const std::string & region, const std::string & endpoint);
 
-    ref<Aws::Client::ClientConfiguration> makeConfig(const std::string & region);
+    ref<Aws::Client::ClientConfiguration> makeConfig(const std::string & region, const std::string & endpoint);
 
     struct DownloadResult
     {
diff --git a/src/libstore/serve-protocol.hh b/src/libstore/serve-protocol.hh
index f67d1e2580a5..9fae6d5349f1 100644
--- a/src/libstore/serve-protocol.hh
+++ b/src/libstore/serve-protocol.hh
@@ -5,7 +5,7 @@ namespace nix {
 #define SERVE_MAGIC_1 0x390c9deb
 #define SERVE_MAGIC_2 0x5452eecb
 
-#define SERVE_PROTOCOL_VERSION 0x204
+#define SERVE_PROTOCOL_VERSION 0x205
 #define GET_PROTOCOL_MAJOR(x) ((x) & 0xff00)
 #define GET_PROTOCOL_MINOR(x) ((x) & 0x00ff)
 
@@ -18,6 +18,7 @@ typedef enum {
     cmdBuildPaths = 6,
     cmdQueryClosure = 7,
     cmdBuildDerivation = 8,
+    cmdAddToStoreNar = 9,
 } ServeCommand;
 
 }
diff --git a/src/libstore/ssh.cc b/src/libstore/ssh.cc
index 033c580936ad..cf133b57cb20 100644
--- a/src/libstore/ssh.cc
+++ b/src/libstore/ssh.cc
@@ -1,11 +1,13 @@
 #include "ssh.hh"
+#include "affinity.hh"
 
 namespace nix {
 
 SSHMaster::SSHMaster(const std::string & host, const std::string & keyFile, bool useMaster, bool compress, int logFD)
     : host(host)
+    , fakeSSH(host == "localhost")
     , keyFile(keyFile)
-    , useMaster(useMaster)
+    , useMaster(useMaster && !fakeSSH)
     , compress(compress)
     , logFD(logFD)
 {
@@ -33,7 +35,9 @@ std::unique_ptr<SSHMaster::Connection> SSHMaster::startCommand(const std::string
 
     auto conn = std::make_unique<Connection>();
     conn->sshPid = startProcess([&]() {
+        restoreAffinity();
         restoreSignals();
+        restoreMountNamespace();
 
         close(in.writeSide.get());
         close(out.readSide.get());
@@ -45,12 +49,19 @@ std::unique_ptr<SSHMaster::Connection> SSHMaster::startCommand(const std::string
         if (logFD != -1 && dup2(logFD, STDERR_FILENO) == -1)
             throw SysError("duping over stderr");
 
-        Strings args = { "ssh", host.c_str(), "-x", "-a" };
-        addCommonSSHOpts(args);
-        if (socketPath != "")
-            args.insert(args.end(), {"-S", socketPath});
-        if (verbosity >= lvlChatty)
-            args.push_back("-v");
+        Strings args;
+
+        if (fakeSSH) {
+            args = { "bash", "-c" };
+        } else {
+            args = { "ssh", host.c_str(), "-x", "-a" };
+            addCommonSSHOpts(args);
+            if (socketPath != "")
+                args.insert(args.end(), {"-S", socketPath});
+            if (verbosity >= lvlChatty)
+                args.push_back("-v");
+        }
+
         args.push_back(command);
         execvp(args.begin()->c_str(), stringsToCharPtrs(args).data());
 
diff --git a/src/libstore/ssh.hh b/src/libstore/ssh.hh
index 1268e6d00054..4f0f0bd29f9f 100644
--- a/src/libstore/ssh.hh
+++ b/src/libstore/ssh.hh
@@ -10,6 +10,7 @@ class SSHMaster
 private:
 
     const std::string host;
+    bool fakeSSH;
     const std::string keyFile;
     const bool useMaster;
     const bool compress;
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 9b0b7d6327e0..dc54c735fdb1 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -320,6 +320,8 @@ ref<const ValidPathInfo> Store::queryPathInfo(const Path & storePath)
 void Store::queryPathInfo(const Path & storePath,
     Callback<ref<ValidPathInfo>> callback)
 {
+    assertStorePath(storePath);
+
     auto hashPart = storePathToHash(storePath);
 
     try {
@@ -586,15 +588,19 @@ void copyStorePath(ref<Store> srcStore, ref<Store> dstStore,
 
     uint64_t total = 0;
 
-    // FIXME
-#if 0
     if (!info->narHash) {
+        StringSink sink;
+        srcStore->narFromPath({storePath}, sink);
         auto info2 = make_ref<ValidPathInfo>(*info);
         info2->narHash = hashString(htSHA256, *sink.s);
         if (!info->narSize) info2->narSize = sink.s->size();
+        if (info->ultimate) info2->ultimate = false;
         info = info2;
+
+        StringSource source(*sink.s);
+        dstStore->addToStore(*info, source, repair, checkSigs);
+        return;
     }
-#endif
 
     if (info->ultimate) {
         auto info2 = make_ref<ValidPathInfo>(*info);
@@ -609,6 +615,8 @@ void copyStorePath(ref<Store> srcStore, ref<Store> dstStore,
             act.progress(total, info->narSize);
         });
         srcStore->narFromPath({storePath}, wrapperSink);
+    }, [&]() {
+        throw EndOfFile("NAR for '%s' fetched from '%s' is incomplete", storePath, srcStore->getUri());
     });
 
     dstStore->addToStore(*info, *source, repair, checkSigs);
@@ -629,11 +637,12 @@ void copyPaths(ref<Store> srcStore, ref<Store> dstStore, const PathSet & storePa
     Activity act(*logger, lvlInfo, actCopyPaths, fmt("copying %d paths", missing.size()));
 
     std::atomic<size_t> nrDone{0};
+    std::atomic<size_t> nrFailed{0};
     std::atomic<uint64_t> bytesExpected{0};
     std::atomic<uint64_t> nrRunning{0};
 
     auto showProgress = [&]() {
-        act.progress(nrDone, missing.size(), nrRunning);
+        act.progress(nrDone, missing.size(), nrRunning, nrFailed);
     };
 
     ThreadPool pool;
@@ -662,7 +671,16 @@ void copyPaths(ref<Store> srcStore, ref<Store> dstStore, const PathSet & storePa
             if (!dstStore->isValidPath(storePath)) {
                 MaintainCount<decltype(nrRunning)> mc(nrRunning);
                 showProgress();
-                copyStorePath(srcStore, dstStore, storePath, repair, checkSigs);
+                try {
+                    copyStorePath(srcStore, dstStore, storePath, repair, checkSigs);
+                } catch (Error &e) {
+                    nrFailed++;
+                    if (!settings.keepGoing)
+                        throw e;
+                    logger->log(lvlError, format("could not copy %s: %s") % storePath % e.what());
+                    showProgress();
+                    return;
+                }
             }
 
             nrDone++;
@@ -834,8 +852,24 @@ ref<Store> openStore(const std::string & uri_,
     if (q != std::string::npos) {
         for (auto s : tokenizeString<Strings>(uri.substr(q + 1), "&")) {
             auto e = s.find('=');
-            if (e != std::string::npos)
-                params[s.substr(0, e)] = s.substr(e + 1);
+            if (e != std::string::npos) {
+                auto value = s.substr(e + 1);
+                std::string decoded;
+                for (size_t i = 0; i < value.size(); ) {
+                    if (value[i] == '%') {
+                        if (i + 2 >= value.size())
+                            throw Error("invalid URI parameter '%s'", value);
+                        try {
+                            decoded += std::stoul(std::string(value, i + 1, 2), 0, 16);
+                            i += 3;
+                        } catch (...) {
+                            throw Error("invalid URI parameter '%s'", value);
+                        }
+                    } else
+                        decoded += value[i++];
+                }
+                params[s.substr(0, e)] = decoded;
+            }
         }
         uri = uri_.substr(0, q);
     }
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 7c5b495a4482..106b2be5e6b2 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -23,6 +23,7 @@ MakeError(BuildError, Error) /* denotes a permanent build failure */
 MakeError(InvalidPath, Error)
 MakeError(Unsupported, Error)
 MakeError(SubstituteGone, Error)
+MakeError(SubstituterDisabled, Error)
 
 
 struct BasicDerivation;
@@ -598,6 +599,12 @@ public:
        a notion of connection. Otherwise this is a no-op. */
     virtual void connect() { };
 
+    /* Get the protocol version of this store or it's connection. */
+    virtual unsigned int getProtocol()
+    {
+        return 0;
+    };
+
     /* Get the priority of the store, used to order substituters. In
        particular, binary caches can specify a priority field in their
        "nix-cache-info" file. Lower value means higher priority. */
diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc
index 1be8934a2eba..bb68e82886d0 100644
--- a/src/libutil/archive.cc
+++ b/src/libutil/archive.cc
@@ -283,7 +283,7 @@ void parseDump(ParseSink & sink, Source & source)
 {
     string version;
     try {
-        version = readString(source);
+        version = readString(source, narVersionMagic1.size());
     } catch (SerialisationError & e) {
         /* This generally means the integer at the start couldn't be
            decoded.  Ignore and throw the exception below. */
diff --git a/src/libutil/compression.cc b/src/libutil/compression.cc
index e1782f8c4bd9..0dd84e32034a 100644
--- a/src/libutil/compression.cc
+++ b/src/libutil/compression.cc
@@ -8,246 +8,265 @@
 #include <cstdio>
 #include <cstring>
 
-#if HAVE_BROTLI
 #include <brotli/decode.h>
 #include <brotli/encode.h>
-#endif // HAVE_BROTLI
 
 #include <iostream>
 
 namespace nix {
 
-static const size_t bufSize = 32 * 1024;
-
-static void decompressNone(Source & source, Sink & sink)
+// Don't feed brotli too much at once.
+struct ChunkedCompressionSink : CompressionSink
 {
-    std::vector<unsigned char> buf(bufSize);
-    while (true) {
-        size_t n;
-        try {
-            n = source.read(buf.data(), buf.size());
-        } catch (EndOfFile &) {
-            break;
+    uint8_t outbuf[32 * 1024];
+
+    void write(const unsigned char * data, size_t len) override
+    {
+        const size_t CHUNK_SIZE = sizeof(outbuf) << 2;
+        while (len) {
+            size_t n = std::min(CHUNK_SIZE, len);
+            writeInternal(data, n);
+            data += n;
+            len -= n;
         }
-        sink(buf.data(), n);
     }
-}
 
-static void decompressXZ(Source & source, Sink & sink)
+    virtual void writeInternal(const unsigned char * data, size_t len) = 0;
+};
+
+struct NoneSink : CompressionSink
 {
-    lzma_stream strm(LZMA_STREAM_INIT);
-
-    lzma_ret ret = lzma_stream_decoder(
-        &strm, UINT64_MAX, LZMA_CONCATENATED);
-    if (ret != LZMA_OK)
-        throw CompressionError("unable to initialise lzma decoder");
-
-    Finally free([&]() { lzma_end(&strm); });
-
-    lzma_action action = LZMA_RUN;
-    std::vector<uint8_t> inbuf(bufSize), outbuf(bufSize);
-    strm.next_in = nullptr;
-    strm.avail_in = 0;
-    strm.next_out = outbuf.data();
-    strm.avail_out = outbuf.size();
-    bool eof = false;
-
-    while (true) {
-        checkInterrupt();
-
-        if (strm.avail_in == 0 && !eof) {
-            strm.next_in = inbuf.data();
-            try {
-                strm.avail_in = source.read((unsigned char *) strm.next_in, inbuf.size());
-            } catch (EndOfFile &) {
-                eof = true;
-            }
-        }
+    Sink & nextSink;
+    NoneSink(Sink & nextSink) : nextSink(nextSink) { }
+    void finish() override { flush(); }
+    void write(const unsigned char * data, size_t len) override { nextSink(data, len); }
+};
 
-        if (strm.avail_in == 0)
-            action = LZMA_FINISH;
+struct XzDecompressionSink : CompressionSink
+{
+    Sink & nextSink;
+    uint8_t outbuf[BUFSIZ];
+    lzma_stream strm = LZMA_STREAM_INIT;
+    bool finished = false;
 
-        lzma_ret ret = lzma_code(&strm, action);
+    XzDecompressionSink(Sink & nextSink) : nextSink(nextSink)
+    {
+        lzma_ret ret = lzma_stream_decoder(
+            &strm, UINT64_MAX, LZMA_CONCATENATED);
+        if (ret != LZMA_OK)
+            throw CompressionError("unable to initialise lzma decoder");
 
-        if (strm.avail_out < outbuf.size()) {
-            sink((unsigned char *) outbuf.data(), outbuf.size() - strm.avail_out);
-            strm.next_out = outbuf.data();
-            strm.avail_out = outbuf.size();
-        }
+        strm.next_out = outbuf;
+        strm.avail_out = sizeof(outbuf);
+    }
 
-        if (ret == LZMA_STREAM_END) return;
+    ~XzDecompressionSink()
+    {
+        lzma_end(&strm);
+    }
 
-        if (ret != LZMA_OK)
-            throw CompressionError("error %d while decompressing xz file", ret);
+    void finish() override
+    {
+        CompressionSink::flush();
+        write(nullptr, 0);
     }
-}
 
-static void decompressBzip2(Source & source, Sink & sink)
-{
-    bz_stream strm;
-    memset(&strm, 0, sizeof(strm));
-
-    int ret = BZ2_bzDecompressInit(&strm, 0, 0);
-    if (ret != BZ_OK)
-        throw CompressionError("unable to initialise bzip2 decoder");
-
-    Finally free([&]() { BZ2_bzDecompressEnd(&strm); });
-
-    std::vector<char> inbuf(bufSize), outbuf(bufSize);
-    strm.next_in = nullptr;
-    strm.avail_in = 0;
-    strm.next_out = outbuf.data();
-    strm.avail_out = outbuf.size();
-    bool eof = false;
-
-    while (true) {
-        checkInterrupt();
-
-        if (strm.avail_in == 0 && !eof) {
-            strm.next_in = inbuf.data();
-            try {
-                strm.avail_in = source.read((unsigned char *) strm.next_in, inbuf.size());
-            } catch (EndOfFile &) {
-                eof = true;
-            }
-        }
+    void write(const unsigned char * data, size_t len) override
+    {
+        strm.next_in = data;
+        strm.avail_in = len;
+
+        while (!finished && (!data || strm.avail_in)) {
+            checkInterrupt();
 
-        int ret = BZ2_bzDecompress(&strm);
+            lzma_ret ret = lzma_code(&strm, data ? LZMA_RUN : LZMA_FINISH);
+            if (ret != LZMA_OK && ret != LZMA_STREAM_END)
+                throw CompressionError("error %d while decompressing xz file", ret);
 
-        if (strm.avail_in == 0 && strm.avail_out == outbuf.size() && eof)
-            throw CompressionError("bzip2 data ends prematurely");
+            finished = ret == LZMA_STREAM_END;
 
-        if (strm.avail_out < outbuf.size()) {
-            sink((unsigned char *) outbuf.data(), outbuf.size() - strm.avail_out);
-            strm.next_out = outbuf.data();
-            strm.avail_out = outbuf.size();
+            if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) {
+                nextSink(outbuf, sizeof(outbuf) - strm.avail_out);
+                strm.next_out = outbuf;
+                strm.avail_out = sizeof(outbuf);
+            }
         }
+    }
+};
 
-        if (ret == BZ_STREAM_END) return;
+struct BzipDecompressionSink : ChunkedCompressionSink
+{
+    Sink & nextSink;
+    bz_stream strm;
+    bool finished = false;
 
+    BzipDecompressionSink(Sink & nextSink) : nextSink(nextSink)
+    {
+        memset(&strm, 0, sizeof(strm));
+        int ret = BZ2_bzDecompressInit(&strm, 0, 0);
         if (ret != BZ_OK)
-            throw CompressionError("error while decompressing bzip2 file");
+            throw CompressionError("unable to initialise bzip2 decoder");
+
+        strm.next_out = (char *) outbuf;
+        strm.avail_out = sizeof(outbuf);
     }
-}
 
-static void decompressBrotli(Source & source, Sink & sink)
-{
-#if !HAVE_BROTLI
-    RunOptions options(BROTLI, {"-d"});
-    options.standardIn = &source;
-    options.standardOut = &sink;
-    runProgram2(options);
-#else
-    auto *s = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr);
-    if (!s)
-        throw CompressionError("unable to initialize brotli decoder");
-
-    Finally free([s]() { BrotliDecoderDestroyInstance(s); });
-
-    std::vector<uint8_t> inbuf(bufSize), outbuf(bufSize);
-    const uint8_t * next_in = nullptr;
-    size_t avail_in = 0;
-    bool eof = false;
-
-    while (true) {
-        checkInterrupt();
-
-        if (avail_in == 0 && !eof) {
-            next_in = inbuf.data();
-            try {
-                avail_in = source.read((unsigned char *) next_in, inbuf.size());
-            } catch (EndOfFile &) {
-                eof = true;
+    ~BzipDecompressionSink()
+    {
+        BZ2_bzDecompressEnd(&strm);
+    }
+
+    void finish() override
+    {
+        flush();
+        write(nullptr, 0);
+    }
+
+    void writeInternal(const unsigned char * data, size_t len) override
+    {
+        assert(len <= std::numeric_limits<decltype(strm.avail_in)>::max());
+
+        strm.next_in = (char *) data;
+        strm.avail_in = len;
+
+        while (strm.avail_in) {
+            checkInterrupt();
+
+            int ret = BZ2_bzDecompress(&strm);
+            if (ret != BZ_OK && ret != BZ_STREAM_END)
+                throw CompressionError("error while decompressing bzip2 file");
+
+            finished = ret == BZ_STREAM_END;
+
+            if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) {
+                nextSink(outbuf, sizeof(outbuf) - strm.avail_out);
+                strm.next_out = (char *) outbuf;
+                strm.avail_out = sizeof(outbuf);
             }
         }
+    }
+};
 
-        uint8_t * next_out = outbuf.data();
-        size_t avail_out = outbuf.size();
-
-        auto ret = BrotliDecoderDecompressStream(s,
-                &avail_in, &next_in,
-                &avail_out, &next_out,
-                nullptr);
-
-        switch (ret) {
-        case BROTLI_DECODER_RESULT_ERROR:
-            throw CompressionError("error while decompressing brotli file");
-        case BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT:
-            if (eof)
-                throw CompressionError("incomplete or corrupt brotli file");
-            break;
-        case BROTLI_DECODER_RESULT_SUCCESS:
-            if (avail_in != 0)
-                throw CompressionError("unexpected input after brotli decompression");
-            break;
-        case BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT:
-            // I'm not sure if this can happen, but abort if this happens with empty buffer
-            if (avail_out == outbuf.size())
-                throw CompressionError("brotli decompression requires larger buffer");
-            break;
-        }
+struct BrotliDecompressionSink : ChunkedCompressionSink
+{
+    Sink & nextSink;
+    BrotliDecoderState * state;
+    bool finished = false;
 
-        // Always ensure we have full buffer for next invocation
-        if (avail_out < outbuf.size())
-            sink((unsigned char *) outbuf.data(), outbuf.size() - avail_out);
+    BrotliDecompressionSink(Sink & nextSink) : nextSink(nextSink)
+    {
+        state = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr);
+        if (!state)
+            throw CompressionError("unable to initialize brotli decoder");
+    }
 
-        if (ret == BROTLI_DECODER_RESULT_SUCCESS) return;
+    ~BrotliDecompressionSink()
+    {
+        BrotliDecoderDestroyInstance(state);
     }
-#endif // HAVE_BROTLI
-}
+
+    void finish() override
+    {
+        flush();
+        writeInternal(nullptr, 0);
+    }
+
+    void writeInternal(const unsigned char * data, size_t len) override
+    {
+        const uint8_t * next_in = data;
+        size_t avail_in = len;
+        uint8_t * next_out = outbuf;
+        size_t avail_out = sizeof(outbuf);
+
+        while (!finished && (!data || avail_in)) {
+            checkInterrupt();
+
+            if (!BrotliDecoderDecompressStream(state,
+                    &avail_in, &next_in,
+                    &avail_out, &next_out,
+                    nullptr))
+                throw CompressionError("error while decompressing brotli file");
+
+            if (avail_out < sizeof(outbuf) || avail_in == 0) {
+                nextSink(outbuf, sizeof(outbuf) - avail_out);
+                next_out = outbuf;
+                avail_out = sizeof(outbuf);
+            }
+
+            finished = BrotliDecoderIsFinished(state);
+        }
+    }
+};
 
 ref<std::string> decompress(const std::string & method, const std::string & in)
 {
-    StringSource source(in);
-    StringSink sink;
-    decompress(method, source, sink);
-    return sink.s;
+    StringSink ssink;
+    auto sink = makeDecompressionSink(method, ssink);
+    (*sink)(in);
+    sink->finish();
+    return ssink.s;
 }
 
-void decompress(const std::string & method, Source & source, Sink & sink)
+ref<CompressionSink> makeDecompressionSink(const std::string & method, Sink & nextSink)
 {
-    if (method == "none")
-        return decompressNone(source, sink);
+    if (method == "none" || method == "")
+        return make_ref<NoneSink>(nextSink);
     else if (method == "xz")
-        return decompressXZ(source, sink);
+        return make_ref<XzDecompressionSink>(nextSink);
     else if (method == "bzip2")
-        return decompressBzip2(source, sink);
+        return make_ref<BzipDecompressionSink>(nextSink);
     else if (method == "br")
-        return decompressBrotli(source, sink);
+        return make_ref<BrotliDecompressionSink>(nextSink);
     else
         throw UnknownCompressionMethod("unknown compression method '%s'", method);
 }
 
-struct NoneSink : CompressionSink
-{
-    Sink & nextSink;
-    NoneSink(Sink & nextSink) : nextSink(nextSink) { }
-    void finish() override { flush(); }
-    void write(const unsigned char * data, size_t len) override { nextSink(data, len); }
-};
-
-struct XzSink : CompressionSink
+struct XzCompressionSink : CompressionSink
 {
     Sink & nextSink;
     uint8_t outbuf[BUFSIZ];
     lzma_stream strm = LZMA_STREAM_INIT;
     bool finished = false;
 
-    template <typename F>
-    XzSink(Sink & nextSink, F&& initEncoder) : nextSink(nextSink) {
-        lzma_ret ret = initEncoder();
+    XzCompressionSink(Sink & nextSink, bool parallel) : nextSink(nextSink)
+    {
+        lzma_ret ret;
+        bool done = false;
+
+        if (parallel) {
+#ifdef HAVE_LZMA_MT
+            lzma_mt mt_options = {};
+            mt_options.flags = 0;
+            mt_options.timeout = 300; // Using the same setting as the xz cmd line
+            mt_options.preset = LZMA_PRESET_DEFAULT;
+            mt_options.filters = NULL;
+            mt_options.check = LZMA_CHECK_CRC64;
+            mt_options.threads = lzma_cputhreads();
+            mt_options.block_size = 0;
+            if (mt_options.threads == 0)
+                mt_options.threads = 1;
+            // FIXME: maybe use lzma_stream_encoder_mt_memusage() to control the
+            // number of threads.
+            ret = lzma_stream_encoder_mt(&strm, &mt_options);
+            done = true;
+#else
+            printMsg(lvlError, "warning: parallel XZ compression requested but not supported, falling back to single-threaded compression");
+#endif
+        }
+
+        if (!done)
+            ret = lzma_easy_encoder(&strm, 6, LZMA_CHECK_CRC64);
+
         if (ret != LZMA_OK)
             throw CompressionError("unable to initialise lzma encoder");
+
         // FIXME: apply the x86 BCJ filter?
 
         strm.next_out = outbuf;
         strm.avail_out = sizeof(outbuf);
     }
-    XzSink(Sink & nextSink) : XzSink(nextSink, [this]() {
-        return lzma_easy_encoder(&strm, 6, LZMA_CHECK_CRC64);
-    }) {}
 
-    ~XzSink()
+    ~XzCompressionSink()
     {
         lzma_end(&strm);
     }
@@ -255,43 +274,25 @@ struct XzSink : CompressionSink
     void finish() override
     {
         CompressionSink::flush();
-
-        assert(!finished);
-        finished = true;
-
-        while (true) {
-            checkInterrupt();
-
-            lzma_ret ret = lzma_code(&strm, LZMA_FINISH);
-            if (ret != LZMA_OK && ret != LZMA_STREAM_END)
-                throw CompressionError("error while flushing xz file");
-
-            if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
-                nextSink(outbuf, sizeof(outbuf) - strm.avail_out);
-                strm.next_out = outbuf;
-                strm.avail_out = sizeof(outbuf);
-            }
-
-            if (ret == LZMA_STREAM_END) break;
-        }
+        write(nullptr, 0);
     }
 
     void write(const unsigned char * data, size_t len) override
     {
-        assert(!finished);
-
         strm.next_in = data;
         strm.avail_in = len;
 
-        while (strm.avail_in) {
+        while (!finished && (!data || strm.avail_in)) {
             checkInterrupt();
 
-            lzma_ret ret = lzma_code(&strm, LZMA_RUN);
-            if (ret != LZMA_OK)
-                throw CompressionError("error while compressing xz file");
+            lzma_ret ret = lzma_code(&strm, data ? LZMA_RUN : LZMA_FINISH);
+            if (ret != LZMA_OK && ret != LZMA_STREAM_END)
+                throw CompressionError("error %d while compressing xz file", ret);
+
+            finished = ret == LZMA_STREAM_END;
 
-            if (strm.avail_out == 0) {
-                nextSink(outbuf, sizeof(outbuf));
+            if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) {
+                nextSink(outbuf, sizeof(outbuf) - strm.avail_out);
                 strm.next_out = outbuf;
                 strm.avail_out = sizeof(outbuf);
             }
@@ -299,46 +300,24 @@ struct XzSink : CompressionSink
     }
 };
 
-#ifdef HAVE_LZMA_MT
-struct ParallelXzSink : public XzSink
-{
-  ParallelXzSink(Sink &nextSink) : XzSink(nextSink, [this]() {
-        lzma_mt mt_options = {};
-        mt_options.flags = 0;
-        mt_options.timeout = 300; // Using the same setting as the xz cmd line
-        mt_options.preset = LZMA_PRESET_DEFAULT;
-        mt_options.filters = NULL;
-        mt_options.check = LZMA_CHECK_CRC64;
-        mt_options.threads = lzma_cputhreads();
-        mt_options.block_size = 0;
-        if (mt_options.threads == 0)
-            mt_options.threads = 1;
-        // FIXME: maybe use lzma_stream_encoder_mt_memusage() to control the
-        // number of threads.
-        return lzma_stream_encoder_mt(&strm, &mt_options);
-  }) {}
-};
-#endif
-
-struct BzipSink : CompressionSink
+struct BzipCompressionSink : ChunkedCompressionSink
 {
     Sink & nextSink;
-    char outbuf[BUFSIZ];
     bz_stream strm;
     bool finished = false;
 
-    BzipSink(Sink & nextSink) : nextSink(nextSink)
+    BzipCompressionSink(Sink & nextSink) : nextSink(nextSink)
     {
         memset(&strm, 0, sizeof(strm));
         int ret = BZ2_bzCompressInit(&strm, 9, 0, 30);
         if (ret != BZ_OK)
             throw CompressionError("unable to initialise bzip2 encoder");
 
-        strm.next_out = outbuf;
+        strm.next_out = (char *) outbuf;
         strm.avail_out = sizeof(outbuf);
     }
 
-    ~BzipSink()
+    ~BzipCompressionSink()
     {
         BZ2_bzCompressEnd(&strm);
     }
@@ -346,114 +325,49 @@ struct BzipSink : CompressionSink
     void finish() override
     {
         flush();
-
-        assert(!finished);
-        finished = true;
-
-        while (true) {
-            checkInterrupt();
-
-            int ret = BZ2_bzCompress(&strm, BZ_FINISH);
-            if (ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
-                throw CompressionError("error while flushing bzip2 file");
-
-            if (strm.avail_out == 0 || ret == BZ_STREAM_END) {
-                nextSink((unsigned char *) outbuf, sizeof(outbuf) - strm.avail_out);
-                strm.next_out = outbuf;
-                strm.avail_out = sizeof(outbuf);
-            }
-
-            if (ret == BZ_STREAM_END) break;
-        }
-    }
-
-    void write(const unsigned char * data, size_t len) override
-    {
-        /* Bzip2's 'avail_in' parameter is an unsigned int, so we need
-           to split the input into chunks of at most 4 GiB. */
-        while (len) {
-            auto n = std::min((size_t) std::numeric_limits<decltype(strm.avail_in)>::max(), len);
-            writeInternal(data, n);
-            data += n;
-            len -= n;
-        }
+        writeInternal(nullptr, 0);
     }
 
-    void writeInternal(const unsigned char * data, size_t len)
+    void writeInternal(const unsigned char * data, size_t len) override
     {
-        assert(!finished);
         assert(len <= std::numeric_limits<decltype(strm.avail_in)>::max());
 
         strm.next_in = (char *) data;
         strm.avail_in = len;
 
-        while (strm.avail_in) {
+        while (!finished && (!data || strm.avail_in)) {
             checkInterrupt();
 
-            int ret = BZ2_bzCompress(&strm, BZ_RUN);
-            if (ret != BZ_OK)
-                CompressionError("error while compressing bzip2 file");
+            int ret = BZ2_bzCompress(&strm, data ? BZ_RUN : BZ_FINISH);
+            if (ret != BZ_RUN_OK && ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
+                throw CompressionError("error %d while compressing bzip2 file", ret);
 
-            if (strm.avail_out == 0) {
-                nextSink((unsigned char *) outbuf, sizeof(outbuf));
-                strm.next_out = outbuf;
+            finished = ret == BZ_STREAM_END;
+
+            if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) {
+                nextSink(outbuf, sizeof(outbuf) - strm.avail_out);
+                strm.next_out = (char *) outbuf;
                 strm.avail_out = sizeof(outbuf);
             }
         }
     }
 };
 
-struct LambdaCompressionSink : CompressionSink
-{
-    Sink & nextSink;
-    std::string data;
-    using CompressFnTy = std::function<std::string(const std::string&)>;
-    CompressFnTy compressFn;
-    LambdaCompressionSink(Sink& nextSink, CompressFnTy compressFn)
-        : nextSink(nextSink)
-        , compressFn(std::move(compressFn))
-    {
-    };
-
-    void finish() override
-    {
-        flush();
-        nextSink(compressFn(data));
-    }
-
-    void write(const unsigned char * data, size_t len) override
-    {
-        checkInterrupt();
-        this->data.append((const char *) data, len);
-    }
-};
-
-struct BrotliCmdSink : LambdaCompressionSink
-{
-    BrotliCmdSink(Sink& nextSink)
-        : LambdaCompressionSink(nextSink, [](const std::string& data) {
-            return runProgram(BROTLI, true, {}, data);
-        })
-    {
-    }
-};
-
-#if HAVE_BROTLI
-struct BrotliSink : CompressionSink
+struct BrotliCompressionSink : ChunkedCompressionSink
 {
     Sink & nextSink;
     uint8_t outbuf[BUFSIZ];
     BrotliEncoderState *state;
     bool finished = false;
 
-    BrotliSink(Sink & nextSink) : nextSink(nextSink)
+    BrotliCompressionSink(Sink & nextSink) : nextSink(nextSink)
     {
         state = BrotliEncoderCreateInstance(nullptr, nullptr, nullptr);
         if (!state)
             throw CompressionError("unable to initialise brotli encoder");
     }
 
-    ~BrotliSink()
+    ~BrotliCompressionSink()
     {
         BrotliEncoderDestroyInstance(state);
     }
@@ -461,94 +375,47 @@ struct BrotliSink : CompressionSink
     void finish() override
     {
         flush();
-        assert(!finished);
-
-        const uint8_t *next_in = nullptr;
-        size_t avail_in = 0;
-        uint8_t *next_out = outbuf;
-        size_t avail_out = sizeof(outbuf);
-        while (!finished) {
-            checkInterrupt();
-
-            if (!BrotliEncoderCompressStream(state,
-                        BROTLI_OPERATION_FINISH,
-                        &avail_in, &next_in,
-                        &avail_out, &next_out,
-                        nullptr))
-                throw CompressionError("error while finishing brotli file");
-
-            finished = BrotliEncoderIsFinished(state);
-            if (avail_out == 0 || finished) {
-                nextSink(outbuf, sizeof(outbuf) - avail_out);
-                next_out = outbuf;
-                avail_out = sizeof(outbuf);
-            }
-        }
+        writeInternal(nullptr, 0);
     }
 
-    void write(const unsigned char * data, size_t len) override
+    void writeInternal(const unsigned char * data, size_t len) override
     {
-        // Don't feed brotli too much at once
-        const size_t CHUNK_SIZE = sizeof(outbuf) << 2;
-        while (len) {
-          size_t n = std::min(CHUNK_SIZE, len);
-          writeInternal(data, n);
-          data += n;
-          len -= n;
-        }
-    }
-
-    void writeInternal(const unsigned char * data, size_t len)
-    {
-        assert(!finished);
-
-        const uint8_t *next_in = data;
+        const uint8_t * next_in = data;
         size_t avail_in = len;
-        uint8_t *next_out = outbuf;
+        uint8_t * next_out = outbuf;
         size_t avail_out = sizeof(outbuf);
 
-        while (avail_in > 0) {
+        while (!finished && (!data || avail_in)) {
             checkInterrupt();
 
             if (!BrotliEncoderCompressStream(state,
-                      BROTLI_OPERATION_PROCESS,
-                      &avail_in, &next_in,
-                      &avail_out, &next_out,
-                      nullptr))
-                throw CompressionError("error while compressing brotli file");
+                    data ? BROTLI_OPERATION_PROCESS : BROTLI_OPERATION_FINISH,
+                    &avail_in, &next_in,
+                    &avail_out, &next_out,
+                    nullptr))
+                throw CompressionError("error while compressing brotli compression");
 
             if (avail_out < sizeof(outbuf) || avail_in == 0) {
                 nextSink(outbuf, sizeof(outbuf) - avail_out);
                 next_out = outbuf;
                 avail_out = sizeof(outbuf);
             }
+
+            finished = BrotliEncoderIsFinished(state);
         }
     }
 };
-#endif // HAVE_BROTLI
 
 ref<CompressionSink> makeCompressionSink(const std::string & method, Sink & nextSink, const bool parallel)
 {
-    if (parallel) {
-#ifdef HAVE_LZMA_MT
-        if (method == "xz")
-            return make_ref<ParallelXzSink>(nextSink);
-#endif
-        printMsg(lvlError, format("Warning: parallel compression requested but not supported for method '%1%', falling back to single-threaded compression") % method);
-    }
-
     if (method == "none")
         return make_ref<NoneSink>(nextSink);
     else if (method == "xz")
-        return make_ref<XzSink>(nextSink);
+        return make_ref<XzCompressionSink>(nextSink, parallel);
     else if (method == "bzip2")
-        return make_ref<BzipSink>(nextSink);
+        return make_ref<BzipCompressionSink>(nextSink);
     else if (method == "br")
-#if HAVE_BROTLI
-        return make_ref<BrotliSink>(nextSink);
-#else
-        return make_ref<BrotliCmdSink>(nextSink);
-#endif
+        return make_ref<BrotliCompressionSink>(nextSink);
     else
         throw UnknownCompressionMethod(format("unknown compression method '%s'") % method);
 }
diff --git a/src/libutil/compression.hh b/src/libutil/compression.hh
index f7a3e3fbd32e..dd666a4e19fd 100644
--- a/src/libutil/compression.hh
+++ b/src/libutil/compression.hh
@@ -8,17 +8,17 @@
 
 namespace nix {
 
-ref<std::string> decompress(const std::string & method, const std::string & in);
-
-void decompress(const std::string & method, Source & source, Sink & sink);
-
-ref<std::string> compress(const std::string & method, const std::string & in, const bool parallel = false);
-
 struct CompressionSink : BufferedSink
 {
     virtual void finish() = 0;
 };
 
+ref<std::string> decompress(const std::string & method, const std::string & in);
+
+ref<CompressionSink> makeDecompressionSink(const std::string & method, Sink & nextSink);
+
+ref<std::string> compress(const std::string & method, const std::string & in, const bool parallel = false);
+
 ref<CompressionSink> makeCompressionSink(const std::string & method, Sink & nextSink, const bool parallel = false);
 
 MakeError(UnknownCompressionMethod, Error);
diff --git a/src/libutil/json.cc b/src/libutil/json.cc
index 813b257016e4..0a6fb65f0605 100644
--- a/src/libutil/json.cc
+++ b/src/libutil/json.cc
@@ -31,6 +31,7 @@ template<> void toJSON<unsigned long>(std::ostream & str, const unsigned long &
 template<> void toJSON<long long>(std::ostream & str, const long long & n) { str << n; }
 template<> void toJSON<unsigned long long>(std::ostream & str, const unsigned long long & n) { str << n; }
 template<> void toJSON<float>(std::ostream & str, const float & n) { str << n; }
+template<> void toJSON<double>(std::ostream & str, const double & n) { str << n; }
 
 template<> void toJSON<std::string>(std::ostream & str, const std::string & s)
 {
diff --git a/src/libutil/pool.hh b/src/libutil/pool.hh
index 0b142b0597c7..d49067bb95dc 100644
--- a/src/libutil/pool.hh
+++ b/src/libutil/pool.hh
@@ -97,6 +97,7 @@ public:
     private:
         Pool & pool;
         std::shared_ptr<R> r;
+        bool bad = false;
 
         friend Pool;
 
@@ -112,7 +113,8 @@ public:
             if (!r) return;
             {
                 auto state_(pool.state.lock());
-                state_->idle.push_back(ref<R>(r));
+                if (!bad)
+                    state_->idle.push_back(ref<R>(r));
                 assert(state_->inUse);
                 state_->inUse--;
             }
@@ -121,6 +123,8 @@ public:
 
         R * operator -> () { return &*r; }
         R & operator * () { return *r; }
+
+        void markBad() { bad = true; }
     };
 
     Handle get()
diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc
index 21803edd056a..0e75eeec2bfe 100644
--- a/src/libutil/serialise.cc
+++ b/src/libutil/serialise.cc
@@ -157,21 +157,25 @@ size_t StringSource::read(unsigned char * data, size_t len)
 }
 
 
-std::unique_ptr<Source> sinkToSource(std::function<void(Sink &)> fun)
+#if BOOST_VERSION >= 106300 && BOOST_VERSION < 106600
+#error Coroutines are broken in this version of Boost!
+#endif
+
+std::unique_ptr<Source> sinkToSource(
+    std::function<void(Sink &)> fun,
+    std::function<void()> eof)
 {
     struct SinkToSource : Source
     {
         typedef boost::coroutines2::coroutine<std::string> coro_t;
 
-        coro_t::pull_type coro;
+        std::function<void(Sink &)> fun;
+        std::function<void()> eof;
+        std::experimental::optional<coro_t::pull_type> coro;
+        bool started = false;
 
-        SinkToSource(std::function<void(Sink &)> fun)
-            : coro([&](coro_t::push_type & yield) {
-                LambdaSink sink([&](const unsigned char * data, size_t len) {
-                    if (len) yield(std::string((const char *) data, len));
-                });
-                fun(sink);
-            })
+        SinkToSource(std::function<void(Sink &)> fun, std::function<void()> eof)
+            : fun(fun), eof(eof)
         {
         }
 
@@ -181,11 +185,18 @@ std::unique_ptr<Source> sinkToSource(std::function<void(Sink &)> fun)
         size_t read(unsigned char * data, size_t len) override
         {
             if (!coro)
-                throw EndOfFile("coroutine has finished");
+                coro = coro_t::pull_type([&](coro_t::push_type & yield) {
+                    LambdaSink sink([&](const unsigned char * data, size_t len) {
+                            if (len) yield(std::string((const char *) data, len));
+                        });
+                    fun(sink);
+                });
+
+            if (!*coro) { eof(); abort(); }
 
             if (pos == cur.size()) {
-                if (!cur.empty()) coro();
-                cur = coro.get();
+                if (!cur.empty()) (*coro)();
+                cur = coro->get();
                 pos = 0;
             }
 
@@ -197,7 +208,7 @@ std::unique_ptr<Source> sinkToSource(std::function<void(Sink &)> fun)
         }
     };
 
-    return std::make_unique<SinkToSource>(fun);
+    return std::make_unique<SinkToSource>(fun, eof);
 }
 
 
@@ -261,16 +272,17 @@ void readPadding(size_t len, Source & source)
 size_t readString(unsigned char * buf, size_t max, Source & source)
 {
     auto len = readNum<size_t>(source);
-    if (len > max) throw Error("string is too long");
+    if (len > max) throw SerialisationError("string is too long");
     source(buf, len);
     readPadding(len, source);
     return len;
 }
 
 
-string readString(Source & source)
+string readString(Source & source, size_t max)
 {
     auto len = readNum<size_t>(source);
+    if (len > max) throw SerialisationError("string is too long");
     std::string res(len, 0);
     source((unsigned char*) res.data(), len);
     readPadding(len, source);
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 14b62fdb6774..969e4dff383d 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -214,7 +214,11 @@ struct LambdaSource : Source
 
 /* Convert a function that feeds data into a Sink into a Source. The
    Source executes the function as a coroutine. */
-std::unique_ptr<Source> sinkToSource(std::function<void(Sink &)> fun);
+std::unique_ptr<Source> sinkToSource(
+    std::function<void(Sink &)> fun,
+    std::function<void()> eof = []() {
+        throw EndOfFile("coroutine has finished");
+    });
 
 
 void writePadding(size_t len, Sink & sink);
@@ -280,7 +284,7 @@ inline uint64_t readLongLong(Source & source)
 
 void readPadding(size_t len, Source & source);
 size_t readString(unsigned char * buf, size_t max, Source & source);
-string readString(Source & source);
+string readString(Source & source, size_t max = std::numeric_limits<size_t>::max());
 template<class T> T readStrings(Source & source);
 
 Source & operator >> (Source & in, string & s);
diff --git a/src/libutil/sync.hh b/src/libutil/sync.hh
index 3b2710f6fd30..e1d591d77a84 100644
--- a/src/libutil/sync.hh
+++ b/src/libutil/sync.hh
@@ -57,11 +57,11 @@ public:
         }
 
         template<class Rep, class Period>
-        void wait_for(std::condition_variable & cv,
+        std::cv_status wait_for(std::condition_variable & cv,
             const std::chrono::duration<Rep, Period> & duration)
         {
             assert(s);
-            cv.wait_for(lk, duration);
+            return cv.wait_for(lk, duration);
         }
 
         template<class Rep, class Period, class Predicate>
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 6bc64ae75a42..e12c4b258c25 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -167,7 +167,7 @@ Path dirOf(const Path & path)
 {
     Path::size_type pos = path.rfind('/');
     if (pos == string::npos)
-        throw Error(format("invalid file name '%1%'") % path);
+        return ".";
     return pos == 0 ? "/" : Path(path, 0, pos);
 }
 
@@ -468,7 +468,7 @@ static Lazy<Path> getHome2([]() {
         std::vector<char> buf(16384);
         struct passwd pwbuf;
         struct passwd * pw;
-        if (getpwuid_r(getuid(), &pwbuf, buf.data(), buf.size(), &pw) != 0
+        if (getpwuid_r(geteuid(), &pwbuf, buf.data(), buf.size(), &pw) != 0
             || !pw || !pw->pw_dir || !pw->pw_dir[0])
             throw Error("cannot determine user's home directory");
         homeDir = pw->pw_dir;
@@ -496,6 +496,15 @@ Path getConfigDir()
     return configDir;
 }
 
+std::vector<Path> getConfigDirs()
+{
+    Path configHome = getConfigDir();
+    string configDirs = getEnv("XDG_CONFIG_DIRS");
+    std::vector<Path> result = tokenizeString<std::vector<string>>(configDirs, ":");
+    result.insert(result.begin(), configHome);
+    return result;
+}
+
 
 Path getDataDir()
 {
@@ -927,6 +936,8 @@ pid_t startProcess(std::function<void()> fun, const ProcessOptions & options)
                 throw SysError("setting death signal");
 #endif
             restoreAffinity();
+            if (options.restoreMountNamespace)
+                restoreMountNamespace();
             fun();
         } catch (std::exception & e) {
             try {
@@ -1495,4 +1506,26 @@ std::unique_ptr<InterruptCallback> createInterruptCallback(std::function<void()>
     return std::unique_ptr<InterruptCallback>(res.release());
 }
 
+static AutoCloseFD fdSavedMountNamespace;
+
+void saveMountNamespace()
+{
+#if __linux__
+    std::once_flag done;
+    std::call_once(done, []() {
+        fdSavedMountNamespace = open("/proc/self/ns/mnt", O_RDONLY);
+        if (!fdSavedMountNamespace)
+            throw SysError("saving parent mount namespace");
+    });
+#endif
+}
+
+void restoreMountNamespace()
+{
+#if __linux__
+    if (fdSavedMountNamespace && setns(fdSavedMountNamespace.get(), CLONE_NEWNS) == -1)
+        throw SysError("restoring parent mount namespace");
+#endif
+}
+
 }
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index fc25d27758c7..d67bddc138c8 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -131,6 +131,9 @@ Path getCacheDir();
 /* Return $XDG_CONFIG_HOME or $HOME/.config. */
 Path getConfigDir();
 
+/* Return the directories to search for user configuration files */
+std::vector<Path> getConfigDirs();
+
 /* Return $XDG_DATA_HOME or $HOME/.local/share. */
 Path getDataDir();
 
@@ -247,6 +250,7 @@ struct ProcessOptions
     bool dieWithParent = true;
     bool runExitHandlers = false;
     bool allowVfork = true;
+    bool restoreMountNamespace = true;
 };
 
 pid_t startProcess(std::function<void()> fun, const ProcessOptions & options = ProcessOptions());
@@ -511,4 +515,13 @@ typedef std::function<bool(const Path & path)> PathFilter;
 extern PathFilter defaultPathFilter;
 
 
+/* Save the current mount namespace. Ignored if called more than
+   once. */
+void saveMountNamespace();
+
+/* Restore the mount namespace saved by saveMountNamespace(). Ignored
+   if saveMountNamespace() was never called. */
+void restoreMountNamespace();
+
+
 }
diff --git a/src/linenoise/ConvertUTF.cpp b/src/linenoise/ConvertUTF.cpp
deleted file mode 100644
index f7e5915d5e8f..000000000000
--- a/src/linenoise/ConvertUTF.cpp
+++ /dev/null
@@ -1,542 +0,0 @@
-/*
- * Copyright 2001-2004 Unicode, Inc.
- * 
- * Disclaimer
- * 
- * This source code is provided as is by Unicode, Inc. No claims are
- * made as to fitness for any particular purpose. No warranties of any
- * kind are expressed or implied. The recipient agrees to determine
- * applicability of information provided. If this file has been
- * purchased on magnetic or optical media from Unicode, Inc., the
- * sole remedy for any claim will be exchange of defective media
- * within 90 days of receipt.
- * 
- * Limitations on Rights to Redistribute This Code
- * 
- * Unicode, Inc. hereby grants the right to freely use the information
- * supplied in this file in the creation of products supporting the
- * Unicode Standard, and to make copies of this file in any form
- * for internal or external distribution as long as this notice
- * remains attached.
- */
-
-/* ---------------------------------------------------------------------
-
-    Conversions between UTF32, UTF-16, and UTF-8. Source code file.
-    Author: Mark E. Davis, 1994.
-    Rev History: Rick McGowan, fixes & updates May 2001.
-    Sept 2001: fixed const & error conditions per
-        mods suggested by S. Parent & A. Lillich.
-    June 2002: Tim Dodd added detection and handling of incomplete
-        source sequences, enhanced error detection, added casts
-        to eliminate compiler warnings.
-    July 2003: slight mods to back out aggressive FFFE detection.
-    Jan 2004: updated switches in from-UTF8 conversions.
-    Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions.
-
-    See the header file "ConvertUTF.h" for complete documentation.
-
------------------------------------------------------------------------- */
-
-#include "ConvertUTF.h"
-#ifdef CVTUTF_DEBUG
-#include <stdio.h>
-#endif
-
-namespace linenoise_ng {
-
-static const int halfShift  = 10; /* used for shifting by 10 bits */
-
-static const UTF32 halfBase = 0x0010000UL;
-static const UTF32 halfMask = 0x3FFUL;
-
-#define UNI_SUR_HIGH_START  (UTF32)0xD800
-#define UNI_SUR_HIGH_END    (UTF32)0xDBFF
-#define UNI_SUR_LOW_START   (UTF32)0xDC00
-#define UNI_SUR_LOW_END     (UTF32)0xDFFF
-#define false      0
-#define true        1
-
-/* --------------------------------------------------------------------- */
-
-ConversionResult ConvertUTF32toUTF16 (
-        const UTF32** sourceStart, const UTF32* sourceEnd, 
-        char16_t** targetStart, char16_t* targetEnd, ConversionFlags flags) {
-    ConversionResult result = conversionOK;
-    const UTF32* source = *sourceStart;
-    char16_t* target = *targetStart;
-    while (source < sourceEnd) {
-        UTF32 ch;
-        if (target >= targetEnd) {
-            result = targetExhausted; break;
-        }
-        ch = *source++;
-        if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
-            /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */
-            if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
-                if (flags == strictConversion) {
-                    --source; /* return to the illegal value itself */
-                    result = sourceIllegal;
-                    break;
-                } else {
-                    *target++ = UNI_REPLACEMENT_CHAR;
-                }
-            } else {
-                *target++ = (UTF16)ch; /* normal case */
-            }
-        } else if (ch > UNI_MAX_LEGAL_UTF32) {
-            if (flags == strictConversion) {
-                result = sourceIllegal;
-            } else {
-                *target++ = UNI_REPLACEMENT_CHAR;
-            }
-        } else {
-            /* target is a character in range 0xFFFF - 0x10FFFF. */
-            if (target + 1 >= targetEnd) {
-                --source; /* Back up source pointer! */
-                result = targetExhausted; break;
-            }
-            ch -= halfBase;
-            *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
-            *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
-        }
-    }
-    *sourceStart = source;
-    *targetStart = target;
-    return result;
-}
-
-/* --------------------------------------------------------------------- */
-
-ConversionResult ConvertUTF16toUTF32 (
-        const UTF16** sourceStart, const UTF16* sourceEnd, 
-        UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
-    ConversionResult result = conversionOK;
-    const UTF16* source = *sourceStart;
-    UTF32* target = *targetStart;
-    UTF32 ch, ch2;
-    while (source < sourceEnd) {
-        const UTF16* oldSource = source; /*  In case we have to back up because of target overflow. */
-        ch = *source++;
-        /* If we have a surrogate pair, convert to UTF32 first. */
-        if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
-            /* If the 16 bits following the high surrogate are in the source buffer... */
-            if (source < sourceEnd) {
-                ch2 = *source;
-                /* If it's a low surrogate, convert to UTF32. */
-                if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
-                    ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
-                        + (ch2 - UNI_SUR_LOW_START) + halfBase;
-                    ++source;
-                } else if (flags == strictConversion) { /* it's an unpaired high surrogate */
-                    --source; /* return to the illegal value itself */
-                    result = sourceIllegal;
-                    break;
-                }
-            } else { /* We don't have the 16 bits following the high surrogate. */
-                --source; /* return to the high surrogate */
-                result = sourceExhausted;
-                break;
-            }
-        } else if (flags == strictConversion) {
-            /* UTF-16 surrogate values are illegal in UTF-32 */
-            if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
-                --source; /* return to the illegal value itself */
-                result = sourceIllegal;
-                break;
-            }
-        }
-        if (target >= targetEnd) {
-            source = oldSource; /* Back up source pointer! */
-            result = targetExhausted; break;
-        }
-        *target++ = ch;
-    }
-    *sourceStart = source;
-    *targetStart = target;
-#ifdef CVTUTF_DEBUG
-if (result == sourceIllegal) {
-    fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2);
-    fflush(stderr);
-}
-#endif
-    return result;
-}
-
-/* --------------------------------------------------------------------- */
-
-/*
- * Index into the table below with the first byte of a UTF-8 sequence to
- * get the number of trailing bytes that are supposed to follow it.
- * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is
- * left as-is for anyone who may want to do such conversion, which was
- * allowed in earlier algorithms.
- */
-static const char trailingBytesForUTF8[256] = {
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
-    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
-};
-
-/*
- * Magic values subtracted from a buffer value during UTF8 conversion.
- * This table contains as many values as there might be trailing bytes
- * in a UTF-8 sequence.
- */
-static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, 
-                     0x03C82080UL, 0xFA082080UL, 0x82082080UL };
-
-/*
- * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
- * into the first byte, depending on how many bytes follow.  There are
- * as many entries in this table as there are UTF-8 sequence types.
- * (I.e., one byte sequence, two byte... etc.). Remember that sequencs
- * for *legal* UTF-8 will be 4 or fewer bytes total.
- */
-static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
-
-/* --------------------------------------------------------------------- */
-
-/* The interface converts a whole buffer to avoid function-call overhead.
- * Constants have been gathered. Loops & conditionals have been removed as
- * much as possible for efficiency, in favor of drop-through switches.
- * (See "Note A" at the bottom of the file for equivalent code.)
- * If your compiler supports it, the "isLegalUTF8" call can be turned
- * into an inline function.
- */
-
-/* --------------------------------------------------------------------- */
-
-ConversionResult ConvertUTF16toUTF8 (
-        const UTF16** sourceStart, const UTF16* sourceEnd, 
-        UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
-    ConversionResult result = conversionOK;
-    const UTF16* source = *sourceStart;
-    UTF8* target = *targetStart;
-    while (source < sourceEnd) {
-        UTF32 ch;
-        unsigned short bytesToWrite = 0;
-        const UTF32 byteMask = 0xBF;
-        const UTF32 byteMark = 0x80; 
-        const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */
-        ch = *source++;
-        /* If we have a surrogate pair, convert to UTF32 first. */
-        if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
-            /* If the 16 bits following the high surrogate are in the source buffer... */
-            if (source < sourceEnd) {
-                UTF32 ch2 = *source;
-                /* If it's a low surrogate, convert to UTF32. */
-                if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
-                    ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
-                        + (ch2 - UNI_SUR_LOW_START) + halfBase;
-                    ++source;
-                } else if (flags == strictConversion) { /* it's an unpaired high surrogate */
-                    --source; /* return to the illegal value itself */
-                    result = sourceIllegal;
-                    break;
-                }
-            } else { /* We don't have the 16 bits following the high surrogate. */
-                --source; /* return to the high surrogate */
-                result = sourceExhausted;
-                break;
-            }
-        } else if (flags == strictConversion) {
-            /* UTF-16 surrogate values are illegal in UTF-32 */
-            if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
-                --source; /* return to the illegal value itself */
-                result = sourceIllegal;
-                break;
-            }
-        }
-        /* Figure out how many bytes the result will require */
-        if (ch < (UTF32)0x80) {      bytesToWrite = 1;
-        } else if (ch < (UTF32)0x800) {     bytesToWrite = 2;
-        } else if (ch < (UTF32)0x10000) {   bytesToWrite = 3;
-        } else if (ch < (UTF32)0x110000) {  bytesToWrite = 4;
-        } else {                            bytesToWrite = 3;
-                                            ch = UNI_REPLACEMENT_CHAR;
-        }
-
-        target += bytesToWrite;
-        if (target > targetEnd) {
-            source = oldSource; /* Back up source pointer! */
-            target -= bytesToWrite; result = targetExhausted; break;
-        }
-        switch (bytesToWrite) { /* note: everything falls through. */
-            case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
-            case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
-            case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
-            case 1: *--target =  (UTF8)(ch | firstByteMark[bytesToWrite]);
-        }
-        target += bytesToWrite;
-    }
-    *sourceStart = source;
-    *targetStart = target;
-    return result;
-}
-
-/* --------------------------------------------------------------------- */
-
-/*
- * Utility routine to tell whether a sequence of bytes is legal UTF-8.
- * This must be called with the length pre-determined by the first byte.
- * If not calling this from ConvertUTF8to*, then the length can be set by:
- *  length = trailingBytesForUTF8[*source]+1;
- * and the sequence is illegal right away if there aren't that many bytes
- * available.
- * If presented with a length > 4, this returns false.  The Unicode
- * definition of UTF-8 goes up to 4-byte sequences.
- */
-
-static Boolean isLegalUTF8(const UTF8 *source, int length) {
-    UTF8 a;
-    const UTF8 *srcptr = source+length;
-    switch (length) {
-    default: return false;
-        /* Everything else falls through when "true"... */
-    case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
-    case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
-    case 2: if ((a = (*--srcptr)) > 0xBF) return false;
-
-        switch (*source) {
-            /* no fall-through in this inner switch */
-            case 0xE0: if (a < 0xA0) return false; break;
-            case 0xED: if (a > 0x9F) return false; break;
-            case 0xF0: if (a < 0x90) return false; break;
-            case 0xF4: if (a > 0x8F) return false; break;
-            default:   if (a < 0x80) return false;
-        }
-
-    case 1: if (*source >= 0x80 && *source < 0xC2) return false;
-    }
-    if (*source > 0xF4) return false;
-    return true;
-}
-
-/* --------------------------------------------------------------------- */
-
-/*
- * Exported function to return whether a UTF-8 sequence is legal or not.
- * This is not used here; it's just exported.
- */
-Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) {
-    int length = trailingBytesForUTF8[*source]+1;
-    if (source+length > sourceEnd) {
-        return false;
-    }
-    return isLegalUTF8(source, length);
-}
-
-/* --------------------------------------------------------------------- */
-
-ConversionResult ConvertUTF8toUTF16 (
-        const UTF8** sourceStart, const UTF8* sourceEnd, 
-        UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
-    ConversionResult result = conversionOK;
-    const UTF8* source = *sourceStart;
-    UTF16* target = *targetStart;
-    while (source < sourceEnd) {
-        UTF32 ch = 0;
-        unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
-        if (source + extraBytesToRead >= sourceEnd) {
-            result = sourceExhausted; break;
-        }
-        /* Do this check whether lenient or strict */
-        if (! isLegalUTF8(source, extraBytesToRead+1)) {
-            result = sourceIllegal;
-            break;
-        }
-        /*
-         * The cases all fall through. See "Note A" below.
-         */
-        switch (extraBytesToRead) {
-            case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
-            case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
-            case 3: ch += *source++; ch <<= 6;
-            case 2: ch += *source++; ch <<= 6;
-            case 1: ch += *source++; ch <<= 6;
-            case 0: ch += *source++;
-        }
-        ch -= offsetsFromUTF8[extraBytesToRead];
-
-        if (target >= targetEnd) {
-            source -= (extraBytesToRead+1); /* Back up source pointer! */
-            result = targetExhausted; break;
-        }
-        if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
-            /* UTF-16 surrogate values are illegal in UTF-32 */
-            if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
-                if (flags == strictConversion) {
-                    source -= (extraBytesToRead+1); /* return to the illegal value itself */
-                    result = sourceIllegal;
-                    break;
-                } else {
-                    *target++ = UNI_REPLACEMENT_CHAR;
-                }
-            } else {
-                *target++ = (UTF16)ch; /* normal case */
-            }
-        } else if (ch > UNI_MAX_UTF16) {
-            if (flags == strictConversion) {
-                result = sourceIllegal;
-                source -= (extraBytesToRead+1); /* return to the start */
-                break; /* Bail out; shouldn't continue */
-            } else {
-                *target++ = UNI_REPLACEMENT_CHAR;
-            }
-        } else {
-            /* target is a character in range 0xFFFF - 0x10FFFF. */
-            if (target + 1 >= targetEnd) {
-                source -= (extraBytesToRead+1); /* Back up source pointer! */
-                result = targetExhausted; break;
-            }
-            ch -= halfBase;
-            *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
-            *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
-        }
-    }
-    *sourceStart = source;
-    *targetStart = target;
-    return result;
-}
-
-/* --------------------------------------------------------------------- */
-
-ConversionResult ConvertUTF32toUTF8 (
-        const UTF32** sourceStart, const UTF32* sourceEnd, 
-        UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
-    ConversionResult result = conversionOK;
-    const UTF32* source = *sourceStart;
-    UTF8* target = *targetStart;
-    while (source < sourceEnd) {
-        UTF32 ch;
-        unsigned short bytesToWrite = 0;
-        const UTF32 byteMask = 0xBF;
-        const UTF32 byteMark = 0x80; 
-        ch = *source++;
-        if (flags == strictConversion ) {
-            /* UTF-16 surrogate values are illegal in UTF-32 */
-            if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
-                --source; /* return to the illegal value itself */
-                result = sourceIllegal;
-                break;
-            }
-        }
-        /*
-         * Figure out how many bytes the result will require. Turn any
-         * illegally large UTF32 things (> Plane 17) into replacement chars.
-         */
-        if (ch < (UTF32)0x80) {      bytesToWrite = 1;
-        } else if (ch < (UTF32)0x800) {     bytesToWrite = 2;
-        } else if (ch < (UTF32)0x10000) {   bytesToWrite = 3;
-        } else if (ch <= UNI_MAX_LEGAL_UTF32) {  bytesToWrite = 4;
-        } else {                            bytesToWrite = 3;
-                                            ch = UNI_REPLACEMENT_CHAR;
-                                            result = sourceIllegal;
-        }
-        
-        target += bytesToWrite;
-        if (target > targetEnd) {
-            --source; /* Back up source pointer! */
-            target -= bytesToWrite; result = targetExhausted; break;
-        }
-        switch (bytesToWrite) { /* note: everything falls through. */
-            case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
-            case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
-            case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
-            case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]);
-        }
-        target += bytesToWrite;
-    }
-    *sourceStart = source;
-    *targetStart = target;
-    return result;
-}
-
-/* --------------------------------------------------------------------- */
-
-ConversionResult ConvertUTF8toUTF32 (
-        const UTF8** sourceStart, const UTF8* sourceEnd, 
-        UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
-    ConversionResult result = conversionOK;
-    const UTF8* source = *sourceStart;
-    UTF32* target = *targetStart;
-    while (source < sourceEnd) {
-        UTF32 ch = 0;
-        unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
-        if (source + extraBytesToRead >= sourceEnd) {
-            result = sourceExhausted; break;
-        }
-        /* Do this check whether lenient or strict */
-        if (! isLegalUTF8(source, extraBytesToRead+1)) {
-            result = sourceIllegal;
-            break;
-        }
-        /*
-         * The cases all fall through. See "Note A" below.
-         */
-        switch (extraBytesToRead) {
-            case 5: ch += *source++; ch <<= 6;
-            case 4: ch += *source++; ch <<= 6;
-            case 3: ch += *source++; ch <<= 6;
-            case 2: ch += *source++; ch <<= 6;
-            case 1: ch += *source++; ch <<= 6;
-            case 0: ch += *source++;
-        }
-        ch -= offsetsFromUTF8[extraBytesToRead];
-
-        if (target >= targetEnd) {
-            source -= (extraBytesToRead+1); /* Back up the source pointer! */
-            result = targetExhausted; break;
-        }
-        if (ch <= UNI_MAX_LEGAL_UTF32) {
-            /*
-             * UTF-16 surrogate values are illegal in UTF-32, and anything
-             * over Plane 17 (> 0x10FFFF) is illegal.
-             */
-            if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
-                if (flags == strictConversion) {
-                    source -= (extraBytesToRead+1); /* return to the illegal value itself */
-                    result = sourceIllegal;
-                    break;
-                } else {
-                    *target++ = UNI_REPLACEMENT_CHAR;
-                }
-            } else {
-                *target++ = ch;
-            }
-        } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */
-            result = sourceIllegal;
-            *target++ = UNI_REPLACEMENT_CHAR;
-        }
-    }
-    *sourceStart = source;
-    *targetStart = target;
-    return result;
-}
-
-}
-
-/* ---------------------------------------------------------------------
-
-    Note A.
-    The fall-through switches in UTF-8 reading code save a
-    temp variable, some decrements & conditionals.  The switches
-    are equivalent to the following loop:
-        {
-            int tmpBytesToRead = extraBytesToRead+1;
-            do {
-                ch += *source++;
-                --tmpBytesToRead;
-                if (tmpBytesToRead) ch <<= 6;
-            } while (tmpBytesToRead > 0);
-        }
-    In UTF-8 writing code, the switches on "bytesToWrite" are
-    similarly unrolled loops.
-
-   --------------------------------------------------------------------- */
diff --git a/src/linenoise/ConvertUTF.h b/src/linenoise/ConvertUTF.h
deleted file mode 100755
index 8a296235dcd9..000000000000
--- a/src/linenoise/ConvertUTF.h
+++ /dev/null
@@ -1,162 +0,0 @@
-/*
- * Copyright 2001-2004 Unicode, Inc.
- * 
- * Disclaimer
- * 
- * This source code is provided as is by Unicode, Inc. No claims are
- * made as to fitness for any particular purpose. No warranties of any
- * kind are expressed or implied. The recipient agrees to determine
- * applicability of information provided. If this file has been
- * purchased on magnetic or optical media from Unicode, Inc., the
- * sole remedy for any claim will be exchange of defective media
- * within 90 days of receipt.
- * 
- * Limitations on Rights to Redistribute This Code
- * 
- * Unicode, Inc. hereby grants the right to freely use the information
- * supplied in this file in the creation of products supporting the
- * Unicode Standard, and to make copies of this file in any form
- * for internal or external distribution as long as this notice
- * remains attached.
- */
-
-/* ---------------------------------------------------------------------
-
-    Conversions between UTF32, UTF-16, and UTF-8.  Header file.
-
-    Several funtions are included here, forming a complete set of
-    conversions between the three formats.  UTF-7 is not included
-    here, but is handled in a separate source file.
-
-    Each of these routines takes pointers to input buffers and output
-    buffers.  The input buffers are const.
-
-    Each routine converts the text between *sourceStart and sourceEnd,
-    putting the result into the buffer between *targetStart and
-    targetEnd. Note: the end pointers are *after* the last item: e.g. 
-    *(sourceEnd - 1) is the last item.
-
-    The return result indicates whether the conversion was successful,
-    and if not, whether the problem was in the source or target buffers.
-    (Only the first encountered problem is indicated.)
-
-    After the conversion, *sourceStart and *targetStart are both
-    updated to point to the end of last text successfully converted in
-    the respective buffers.
-
-    Input parameters:
-        sourceStart - pointer to a pointer to the source buffer.
-                The contents of this are modified on return so that
-                it points at the next thing to be converted.
-        targetStart - similarly, pointer to pointer to the target buffer.
-        sourceEnd, targetEnd - respectively pointers to the ends of the
-                two buffers, for overflow checking only.
-
-    These conversion functions take a ConversionFlags argument. When this
-    flag is set to strict, both irregular sequences and isolated surrogates
-    will cause an error.  When the flag is set to lenient, both irregular
-    sequences and isolated surrogates are converted.
-
-    Whether the flag is strict or lenient, all illegal sequences will cause
-    an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
-    or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
-    must check for illegal sequences.
-
-    When the flag is set to lenient, characters over 0x10FFFF are converted
-    to the replacement character; otherwise (when the flag is set to strict)
-    they constitute an error.
-
-    Output parameters:
-        The value "sourceIllegal" is returned from some routines if the input
-        sequence is malformed.  When "sourceIllegal" is returned, the source
-        value will point to the illegal value that caused the problem. E.g.,
-        in UTF-8 when a sequence is malformed, it points to the start of the
-        malformed sequence.  
-
-    Author: Mark E. Davis, 1994.
-    Rev History: Rick McGowan, fixes & updates May 2001.
-                 Fixes & updates, Sept 2001.
-
------------------------------------------------------------------------- */
-
-/* ---------------------------------------------------------------------
-    The following 4 definitions are compiler-specific.
-    The C standard does not guarantee that wchar_t has at least
-    16 bits, so wchar_t is no less portable than unsigned short!
-    All should be unsigned values to avoid sign extension during
-    bit mask & shift operations.
------------------------------------------------------------------------- */
-
-#if 0
-typedef unsigned long  UTF32; /* at least 32 bits */
-typedef unsigned short UTF16; /* at least 16 bits */
-typedef unsigned char  UTF8;  /* typically 8 bits */
-#endif
-
-#include <stdint.h>
-#include <string>
-
-namespace linenoise_ng {
-
-typedef uint32_t         UTF32;
-typedef uint16_t         UTF16;
-typedef uint8_t          UTF8;
-typedef unsigned char    Boolean; /* 0 or 1 */
-
-/* Some fundamental constants */
-#define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD
-#define UNI_MAX_BMP (UTF32)0x0000FFFF
-#define UNI_MAX_UTF16 (UTF32)0x0010FFFF
-#define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF
-#define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF
-
-typedef enum {
-        conversionOK,           /* conversion successful */
-        sourceExhausted,        /* partial character in source, but hit end */
-        targetExhausted,        /* insuff. room in target for conversion */
-        sourceIllegal           /* source sequence is illegal/malformed */
-} ConversionResult;
-
-typedef enum {
-        strictConversion = 0,
-        lenientConversion
-} ConversionFlags;
-
-// /* This is for C++ and does no harm in C */
-// #ifdef __cplusplus
-// extern "C" {
-// #endif
-
-ConversionResult ConvertUTF8toUTF16 (
-                const UTF8** sourceStart, const UTF8* sourceEnd, 
-                UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
-
-ConversionResult ConvertUTF16toUTF8 (
-                const UTF16** sourceStart, const UTF16* sourceEnd, 
-                UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
-                
-ConversionResult ConvertUTF8toUTF32 (
-                const UTF8** sourceStart, const UTF8* sourceEnd, 
-                UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
-
-ConversionResult ConvertUTF32toUTF8 (
-                const UTF32** sourceStart, const UTF32* sourceEnd, 
-                UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
-                
-ConversionResult ConvertUTF16toUTF32 (
-                const UTF16** sourceStart, const UTF16* sourceEnd, 
-                UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
-
-ConversionResult ConvertUTF32toUTF16 (
-                const UTF32** sourceStart, const UTF32* sourceEnd, 
-                char16_t** targetStart, char16_t* targetEnd, ConversionFlags flags);
-
-Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd);
-
-// #ifdef __cplusplus
-// }
-// #endif
-
-}
-
-/* --------------------------------------------------------------------- */
diff --git a/src/linenoise/LICENSE b/src/linenoise/LICENSE
deleted file mode 100644
index b7c58c445860..000000000000
--- a/src/linenoise/LICENSE
+++ /dev/null
@@ -1,66 +0,0 @@
-linenoise.cpp
-=============
-
-Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
-Copyright (c) 2010, Pieter Noordhuis <pcnoordhuis at gmail dot com>
-
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-  * Redistributions of source code must retain the above copyright notice,
-    this list of conditions and the following disclaimer.
-  * Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in the
-    documentation and/or other materials provided with the distribution.
-  * Neither the name of Redis nor the names of its contributors may be used
-    to endorse or promote products derived from this software without
-    specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGE.
-
-
-wcwidth.cpp
-===========
-
-Markus Kuhn -- 2007-05-26 (Unicode 5.0)
-
-Permission to use, copy, modify, and distribute this software
-for any purpose and without fee is hereby granted. The author
-disclaims all warranties with regard to this software.
-
-
-
-ConvertUTF.cpp
-==============
-
-Copyright 2001-2004 Unicode, Inc.
- 
-Disclaimer
- 
-This source code is provided as is by Unicode, Inc. No claims are
-made as to fitness for any particular purpose. No warranties of any
-kind are expressed or implied. The recipient agrees to determine
-applicability of information provided. If this file has been
-purchased on magnetic or optical media from Unicode, Inc., the
-sole remedy for any claim will be exchange of defective media
-within 90 days of receipt.
- 
-Limitations on Rights to Redistribute This Code
- 
-Unicode, Inc. hereby grants the right to freely use the information
-supplied in this file in the creation of products supporting the
-Unicode Standard, and to make copies of this file in any form
-for internal or external distribution as long as this notice
-remains attached.
diff --git a/src/linenoise/linenoise.cpp b/src/linenoise/linenoise.cpp
deleted file mode 100644
index c57505d2fa97..000000000000
--- a/src/linenoise/linenoise.cpp
+++ /dev/null
@@ -1,3450 +0,0 @@
-/* linenoise.c -- guerrilla line editing library against the idea that a
- * line editing lib needs to be 20,000 lines of C code.
- *
- * Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
- * Copyright (c) 2010, Pieter Noordhuis <pcnoordhuis at gmail dot com>
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *   * Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *   * Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- *   * Neither the name of Redis nor the names of its contributors may be used
- *     to endorse or promote products derived from this software without
- *     specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- * line editing lib needs to be 20,000 lines of C code.
- *
- * You can find the latest source code at:
- *
- *   http://github.com/antirez/linenoise
- *
- * Does a number of crazy assumptions that happen to be true in 99.9999% of
- * the 2010 UNIX computers around.
- *
- * References:
- * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
- * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
- *
- * Todo list:
- * - Switch to gets() if $TERM is something we can't support.
- * - Filter bogus Ctrl+<char> combinations.
- * - Win32 support
- *
- * Bloat:
- * - Completion?
- * - History search like Ctrl+r in readline?
- *
- * List of escape sequences used by this program, we do everything just
- * with three sequences. In order to be so cheap we may have some
- * flickering effect with some slow terminal, but the lesser sequences
- * the more compatible.
- *
- * CHA (Cursor Horizontal Absolute)
- *    Sequence: ESC [ n G
- *    Effect: moves cursor to column n (1 based)
- *
- * EL (Erase Line)
- *    Sequence: ESC [ n K
- *    Effect: if n is 0 or missing, clear from cursor to end of line
- *    Effect: if n is 1, clear from beginning of line to cursor
- *    Effect: if n is 2, clear entire line
- *
- * CUF (Cursor Forward)
- *    Sequence: ESC [ n C
- *    Effect: moves cursor forward of n chars
- *
- * The following are used to clear the screen: ESC [ H ESC [ 2 J
- * This is actually composed of two sequences:
- *
- * cursorhome
- *    Sequence: ESC [ H
- *    Effect: moves the cursor to upper left corner
- *
- * ED2 (Clear entire screen)
- *    Sequence: ESC [ 2 J
- *    Effect: clear the whole screen
- *
- */
-
-#ifdef _WIN32
-
-#include <conio.h>
-#include <windows.h>
-#include <io.h>
-
-#if defined(_MSC_VER) && _MSC_VER < 1900
-#define snprintf _snprintf  // Microsoft headers use underscores in some names
-#endif
-
-#if !defined GNUC
-#define strcasecmp _stricmp
-#endif
-
-#define strdup _strdup
-#define isatty _isatty
-#define write _write
-#define STDIN_FILENO 0
-
-#else /* _WIN32 */
-
-#include <signal.h>
-#include <termios.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-#include <sys/ioctl.h>
-#include <cctype>
-#include <wctype.h>
-
-#endif /* _WIN32 */
-
-#include <stdio.h>
-#include <errno.h>
-#include <fcntl.h>
-
-#include "linenoise.h"
-#include "ConvertUTF.h"
-
-#include <string>
-#include <vector>
-#include <memory>
-
-using std::string;
-using std::vector;
-using std::unique_ptr;
-using namespace linenoise_ng;
-
-typedef unsigned char char8_t;
-
-static ConversionResult copyString8to32(char32_t* dst, size_t dstSize,
-                                        size_t& dstCount, const char* src) {
-  const UTF8* sourceStart = reinterpret_cast<const UTF8*>(src);
-  const UTF8* sourceEnd = sourceStart + strlen(src);
-  UTF32* targetStart = reinterpret_cast<UTF32*>(dst);
-  UTF32* targetEnd = targetStart + dstSize;
-
-  ConversionResult res = ConvertUTF8toUTF32(
-      &sourceStart, sourceEnd, &targetStart, targetEnd, lenientConversion);
-
-  if (res == conversionOK) {
-    dstCount = targetStart - reinterpret_cast<UTF32*>(dst);
-
-    if (dstCount < dstSize) {
-      *targetStart = 0;
-    }
-  }
-
-  return res;
-}
-
-static ConversionResult copyString8to32(char32_t* dst, size_t dstSize,
-                                        size_t& dstCount, const char8_t* src) {
-  return copyString8to32(dst, dstSize, dstCount,
-                         reinterpret_cast<const char*>(src));
-}
-
-static size_t strlen32(const char32_t* str) {
-  const char32_t* ptr = str;
-
-  while (*ptr) {
-    ++ptr;
-  }
-
-  return ptr - str;
-}
-
-static size_t strlen8(const char8_t* str) {
-  return strlen(reinterpret_cast<const char*>(str));
-}
-
-static char8_t* strdup8(const char* src) {
-  return reinterpret_cast<char8_t*>(strdup(src));
-}
-
-#ifdef _WIN32
-static const int FOREGROUND_WHITE =
-    FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
-static const int BACKGROUND_WHITE =
-    BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE;
-static const int INTENSITY = FOREGROUND_INTENSITY | BACKGROUND_INTENSITY;
-
-class WinAttributes {
- public:
-  WinAttributes() {
-    CONSOLE_SCREEN_BUFFER_INFO info;
-    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &info);
-    _defaultAttribute = info.wAttributes & INTENSITY;
-    _defaultColor = info.wAttributes & FOREGROUND_WHITE;
-    _defaultBackground = info.wAttributes & BACKGROUND_WHITE;
-
-    _consoleAttribute = _defaultAttribute;
-    _consoleColor = _defaultColor | _defaultBackground;
-  }
-
- public:
-  int _defaultAttribute;
-  int _defaultColor;
-  int _defaultBackground;
-
-  int _consoleAttribute;
-  int _consoleColor;
-};
-
-static WinAttributes WIN_ATTR;
-
-static void copyString32to16(char16_t* dst, size_t dstSize, size_t* dstCount,
-                             const char32_t* src, size_t srcSize) {
-  const UTF32* sourceStart = reinterpret_cast<const UTF32*>(src);
-  const UTF32* sourceEnd = sourceStart + srcSize;
-  char16_t* targetStart = reinterpret_cast<char16_t*>(dst);
-  char16_t* targetEnd = targetStart + dstSize;
-
-  ConversionResult res = ConvertUTF32toUTF16(
-      &sourceStart, sourceEnd, &targetStart, targetEnd, lenientConversion);
-
-  if (res == conversionOK) {
-    *dstCount = targetStart - reinterpret_cast<char16_t*>(dst);
-
-    if (*dstCount < dstSize) {
-      *targetStart = 0;
-    }
-  }
-}
-#endif
-
-static void copyString32to8(char* dst, size_t dstSize, size_t* dstCount,
-                            const char32_t* src, size_t srcSize) {
-  const UTF32* sourceStart = reinterpret_cast<const UTF32*>(src);
-  const UTF32* sourceEnd = sourceStart + srcSize;
-  UTF8* targetStart = reinterpret_cast<UTF8*>(dst);
-  UTF8* targetEnd = targetStart + dstSize;
-
-  ConversionResult res = ConvertUTF32toUTF8(
-      &sourceStart, sourceEnd, &targetStart, targetEnd, lenientConversion);
-
-  if (res == conversionOK) {
-    *dstCount = targetStart - reinterpret_cast<UTF8*>(dst);
-
-    if (*dstCount < dstSize) {
-      *targetStart = 0;
-    }
-  }
-}
-
-static void copyString32to8(char* dst, size_t dstLen, const char32_t* src) {
-  size_t dstCount = 0;
-  copyString32to8(dst, dstLen, &dstCount, src, strlen32(src));
-}
-
-static void copyString32(char32_t* dst, const char32_t* src, size_t len) {
-  while (0 < len && *src) {
-    *dst++ = *src++;
-    --len;
-  }
-
-  *dst = 0;
-}
-
-static int strncmp32(const char32_t* left, const char32_t* right, size_t len) {
-  while (0 < len && *left) {
-    if (*left != *right) {
-      return *left - *right;
-    }
-
-    ++left;
-    ++right;
-    --len;
-  }
-
-  return 0;
-}
-
-#ifdef _WIN32
-#include <iostream>
-
-static size_t OutputWin(char16_t* text16, char32_t* text32, size_t len32) {
-  size_t count16 = 0;
-
-  copyString32to16(text16, len32, &count16, text32, len32);
-  WriteConsoleW(GetStdHandle(STD_OUTPUT_HANDLE), text16,
-                static_cast<DWORD>(count16), nullptr, nullptr);
-
-  return count16;
-}
-
-static char32_t* HandleEsc(char32_t* p, char32_t* end) {
-  if (*p == '[') {
-    int code = 0;
-
-    for (++p; p < end; ++p) {
-      char32_t c = *p;
-
-      if ('0' <= c && c <= '9') {
-        code = code * 10 + (c - '0');
-      } else if (c == 'm' || c == ';') {
-        switch (code) {
-          case 0:
-            WIN_ATTR._consoleAttribute = WIN_ATTR._defaultAttribute;
-            WIN_ATTR._consoleColor =
-                WIN_ATTR._defaultColor | WIN_ATTR._defaultBackground;
-            break;
-
-          case 1:  // BOLD
-          case 5:  // BLINK
-            WIN_ATTR._consoleAttribute =
-                (WIN_ATTR._defaultAttribute ^ FOREGROUND_INTENSITY) & INTENSITY;
-            break;
-
-          case 30:
-            WIN_ATTR._consoleColor = BACKGROUND_WHITE;
-            break;
-
-          case 31:
-            WIN_ATTR._consoleColor =
-                FOREGROUND_RED | WIN_ATTR._defaultBackground;
-            break;
-
-          case 32:
-            WIN_ATTR._consoleColor =
-                FOREGROUND_GREEN | WIN_ATTR._defaultBackground;
-            break;
-
-          case 33:
-            WIN_ATTR._consoleColor =
-                FOREGROUND_RED | FOREGROUND_GREEN | WIN_ATTR._defaultBackground;
-            break;
-
-          case 34:
-            WIN_ATTR._consoleColor =
-                FOREGROUND_BLUE | WIN_ATTR._defaultBackground;
-            break;
-
-          case 35:
-            WIN_ATTR._consoleColor =
-                FOREGROUND_BLUE | FOREGROUND_RED | WIN_ATTR._defaultBackground;
-            break;
-
-          case 36:
-            WIN_ATTR._consoleColor = FOREGROUND_BLUE | FOREGROUND_GREEN |
-                                     WIN_ATTR._defaultBackground;
-            break;
-
-          case 37:
-            WIN_ATTR._consoleColor = FOREGROUND_GREEN | FOREGROUND_RED |
-                                     FOREGROUND_BLUE |
-                                     WIN_ATTR._defaultBackground;
-            break;
-        }
-
-        code = 0;
-      }
-
-      if (*p == 'm') {
-        ++p;
-        break;
-      }
-    }
-  } else {
-    ++p;
-  }
-
-  auto handle = GetStdHandle(STD_OUTPUT_HANDLE);
-  SetConsoleTextAttribute(handle,
-                          WIN_ATTR._consoleAttribute | WIN_ATTR._consoleColor);
-
-  return p;
-}
-
-static size_t WinWrite32(char16_t* text16, char32_t* text32, size_t len32) {
-  char32_t* p = text32;
-  char32_t* q = p;
-  char32_t* e = text32 + len32;
-  size_t count16 = 0;
-
-  while (p < e) {
-    if (*p == 27) {
-      if (q < p) {
-        count16 += OutputWin(text16, q, p - q);
-      }
-
-      q = p = HandleEsc(p + 1, e);
-    } else {
-      ++p;
-    }
-  }
-
-  if (q < p) {
-    count16 += OutputWin(text16, q, p - q);
-  }
-
-  return count16;
-}
-#endif
-
-static int write32(int fd, char32_t* text32, int len32) {
-#ifdef _WIN32
-  if (isatty(fd)) {
-    size_t len16 = 2 * len32 + 1;
-    unique_ptr<char16_t[]> text16(new char16_t[len16]);
-    size_t count16 = WinWrite32(text16.get(), text32, len32);
-
-    return static_cast<int>(count16);
-  } else {
-    size_t len8 = 4 * len32 + 1;
-    unique_ptr<char[]> text8(new char[len8]);
-    size_t count8 = 0;
-
-    copyString32to8(text8.get(), len8, &count8, text32, len32);
-
-    return write(fd, text8.get(), static_cast<unsigned int>(count8));
-  }
-#else
-  size_t len8 = 4 * len32 + 1;
-  unique_ptr<char[]> text8(new char[len8]);
-  size_t count8 = 0;
-
-  copyString32to8(text8.get(), len8, &count8, text32, len32);
-
-  return write(fd, text8.get(), count8);
-#endif
-}
-
-class Utf32String {
- public:
-  Utf32String() : _length(0), _data(nullptr) { 
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[1](); 
-  }
-
-  explicit Utf32String(const char* src) : _length(0), _data(nullptr) {
-    size_t len = strlen(src);
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[len + 1]();
-    copyString8to32(_data, len + 1, _length, src);
-  }
-
-  explicit Utf32String(const char8_t* src) : _length(0), _data(nullptr) {
-    size_t len = strlen(reinterpret_cast<const char*>(src));
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[len + 1]();
-    copyString8to32(_data, len + 1, _length, src);
-  }
-
-  explicit Utf32String(const char32_t* src) : _length(0), _data(nullptr) {
-    for (_length = 0; src[_length] != 0; ++_length) {
-    }
-
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[_length + 1]();
-    memcpy(_data, src, _length * sizeof(char32_t));
-  }
-
-  explicit Utf32String(const char32_t* src, int len) : _length(len), _data(nullptr) {
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[len + 1]();
-    memcpy(_data, src, len * sizeof(char32_t));
-  }
-
-  explicit Utf32String(int len) : _length(0), _data(nullptr) { 
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[len](); 
-  }
-
-  explicit Utf32String(const Utf32String& that) : _length(that._length), _data(nullptr) {
-    // note: parens intentional, _data must be properly initialized
-    _data = new char32_t[_length + 1]();
-    memcpy(_data, that._data, sizeof(char32_t) * _length);
-  }
-
-  Utf32String& operator=(const Utf32String& that) {
-    if (this != &that) {
-      delete[] _data;
-      _data = new char32_t[that._length]();
-      _length = that._length;
-      memcpy(_data, that._data, sizeof(char32_t) * _length);
-    }
-
-    return *this;
-  }
-
-  ~Utf32String() { delete[] _data; }
-
- public:
-  char32_t* get() const { return _data; }
-
-  size_t length() const { return _length; }
-
-  size_t chars() const { return _length; }
-
-  void initFromBuffer() {
-    for (_length = 0; _data[_length] != 0; ++_length) {
-    }
-  }
-
-  const char32_t& operator[](size_t pos) const { return _data[pos]; }
-
-  char32_t& operator[](size_t pos) { return _data[pos]; }
-
- private:
-  size_t _length;
-  char32_t* _data;
-};
-
-class Utf8String {
-  Utf8String(const Utf8String&) = delete;
-  Utf8String& operator=(const Utf8String&) = delete;
-
- public:
-  explicit Utf8String(const Utf32String& src) {
-    size_t len = src.length() * 4 + 1;
-    _data = new char[len];
-    copyString32to8(_data, len, src.get());
-  }
-
-  ~Utf8String() { delete[] _data; }
-
- public:
-  char* get() const { return _data; }
-
- private:
-  char* _data;
-};
-
-struct linenoiseCompletions {
-  vector<Utf32String> completionStrings;
-};
-
-#define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
-#define LINENOISE_MAX_LINE 4096
-
-// make control-characters more readable
-#define ctrlChar(upperCaseASCII) (upperCaseASCII - 0x40)
-
-/**
- * Recompute widths of all characters in a char32_t buffer
- * @param text          input buffer of Unicode characters
- * @param widths        output buffer of character widths
- * @param charCount     number of characters in buffer
- */
-namespace linenoise_ng {
-int mk_wcwidth(char32_t ucs);
-}
-
-static void recomputeCharacterWidths(const char32_t* text, char* widths,
-                                     int charCount) {
-  for (int i = 0; i < charCount; ++i) {
-    widths[i] = mk_wcwidth(text[i]);
-  }
-}
-
-/**
- * Calculate a new screen position given a starting position, screen width and
- * character count
- * @param x             initial x position (zero-based)
- * @param y             initial y position (zero-based)
- * @param screenColumns screen column count
- * @param charCount     character positions to advance
- * @param xOut          returned x position (zero-based)
- * @param yOut          returned y position (zero-based)
- */
-static void calculateScreenPosition(int x, int y, int screenColumns,
-                                    int charCount, int& xOut, int& yOut) {
-  xOut = x;
-  yOut = y;
-  int charsRemaining = charCount;
-  while (charsRemaining > 0) {
-    int charsThisRow = (x + charsRemaining < screenColumns) ? charsRemaining
-                                                            : screenColumns - x;
-    xOut = x + charsThisRow;
-    yOut = y;
-    charsRemaining -= charsThisRow;
-    x = 0;
-    ++y;
-  }
-  if (xOut == screenColumns) {  // we have to special-case line wrap
-    xOut = 0;
-    ++yOut;
-  }
-}
-
-/**
- * Calculate a column width using mk_wcswidth()
- * @param buf32  text to calculate
- * @param len    length of text to calculate
- */
-namespace linenoise_ng {
-int mk_wcswidth(const char32_t* pwcs, size_t n);
-}
-
-static int calculateColumnPosition(char32_t* buf32, int len) {
-  int width = mk_wcswidth(reinterpret_cast<const char32_t*>(buf32), len);
-  if (width == -1)
-    return len;
-  else
-    return width;
-}
-
-static bool isControlChar(char32_t testChar) {
-  return (testChar < ' ') ||                      // C0 controls
-         (testChar >= 0x7F && testChar <= 0x9F);  // DEL and C1 controls
-}
-
-struct PromptBase {            // a convenience struct for grouping prompt info
-  Utf32String promptText;      // our copy of the prompt text, edited
-  char* promptCharWidths;      // character widths from mk_wcwidth()
-  int promptChars;             // chars in promptText
-  int promptBytes;             // bytes in promptText
-  int promptExtraLines;        // extra lines (beyond 1) occupied by prompt
-  int promptIndentation;       // column offset to end of prompt
-  int promptLastLinePosition;  // index into promptText where last line begins
-  int promptPreviousInputLen;  // promptChars of previous input line, for
-                               // clearing
-  int promptCursorRowOffset;   // where the cursor is relative to the start of
-                               // the prompt
-  int promptScreenColumns;     // width of screen in columns
-  int promptPreviousLen;       // help erasing
-  int promptErrorCode;         // error code (invalid UTF-8) or zero
-
-  PromptBase() : promptPreviousInputLen(0) {}
-
-  bool write() {
-    if (write32(1, promptText.get(), promptBytes) == -1) return false;
-
-    return true;
-  }
-};
-
-struct PromptInfo : public PromptBase {
-  PromptInfo(const char* textPtr, int columns) {
-    promptExtraLines = 0;
-    promptLastLinePosition = 0;
-    promptPreviousLen = 0;
-    promptScreenColumns = columns;
-    Utf32String tempUnicode(textPtr);
-
-    // strip control characters from the prompt -- we do allow newline
-    char32_t* pIn = tempUnicode.get();
-    char32_t* pOut = pIn;
-
-    int len = 0;
-    int x = 0;
-
-    bool const strip = (isatty(1) == 0);
-
-    while (*pIn) {
-      char32_t c = *pIn;
-      if ('\n' == c || !isControlChar(c)) {
-        *pOut = c;
-        ++pOut;
-        ++pIn;
-        ++len;
-        if ('\n' == c || ++x >= promptScreenColumns) {
-          x = 0;
-          ++promptExtraLines;
-          promptLastLinePosition = len;
-        }
-      } else if (c == '\x1b') {
-        if (strip) {
-          // jump over control chars
-          ++pIn;
-          if (*pIn == '[') {
-            ++pIn;
-            while (*pIn && ((*pIn == ';') || ((*pIn >= '0' && *pIn <= '9')))) {
-              ++pIn;
-            }
-            if (*pIn == 'm') {
-              ++pIn;
-            }
-          }
-        } else {
-          // copy control chars
-          *pOut = *pIn;
-          ++pOut;
-          ++pIn;
-          if (*pIn == '[') {
-            *pOut = *pIn;
-            ++pOut;
-            ++pIn;
-            while (*pIn && ((*pIn == ';') || ((*pIn >= '0' && *pIn <= '9')))) {
-              *pOut = *pIn;
-              ++pOut;
-              ++pIn;
-            }
-            if (*pIn == 'm') {
-              *pOut = *pIn;
-              ++pOut;
-              ++pIn;
-            }
-          }
-        }
-      } else {
-        ++pIn;
-      }
-    }
-    *pOut = 0;
-    promptChars = len;
-    promptBytes = static_cast<int>(pOut - tempUnicode.get());
-    promptText = tempUnicode;
-
-    promptIndentation = len - promptLastLinePosition;
-    promptCursorRowOffset = promptExtraLines;
-  }
-};
-
-// Used with DynamicPrompt (history search)
-//
-static const Utf32String forwardSearchBasePrompt("(i-search)`");
-static const Utf32String reverseSearchBasePrompt("(reverse-i-search)`");
-static const Utf32String endSearchBasePrompt("': ");
-static Utf32String
-    previousSearchText;  // remembered across invocations of linenoise()
-
-// changing prompt for "(reverse-i-search)`text':" etc.
-//
-struct DynamicPrompt : public PromptBase {
-  Utf32String searchText;  // text we are searching for
-  char* searchCharWidths;  // character widths from mk_wcwidth()
-  int searchTextLen;       // chars in searchText
-  int direction;           // current search direction, 1=forward, -1=reverse
-
-  DynamicPrompt(PromptBase& pi, int initialDirection)
-      : searchTextLen(0), direction(initialDirection) {
-    promptScreenColumns = pi.promptScreenColumns;
-    promptCursorRowOffset = 0;
-    Utf32String emptyString(1);
-    searchText = emptyString;
-    const Utf32String* basePrompt =
-        (direction > 0) ? &forwardSearchBasePrompt : &reverseSearchBasePrompt;
-    size_t promptStartLength = basePrompt->length();
-    promptChars =
-        static_cast<int>(promptStartLength + endSearchBasePrompt.length());
-    promptBytes = promptChars;
-    promptLastLinePosition = promptChars;  // TODO fix this, we are asssuming
-                                           // that the history prompt won't wrap
-                                           // (!)
-    promptPreviousLen = promptChars;
-    Utf32String tempUnicode(promptChars + 1);
-    memcpy(tempUnicode.get(), basePrompt->get(),
-           sizeof(char32_t) * promptStartLength);
-    memcpy(&tempUnicode[promptStartLength], endSearchBasePrompt.get(),
-           sizeof(char32_t) * (endSearchBasePrompt.length() + 1));
-    tempUnicode.initFromBuffer();
-    promptText = tempUnicode;
-    calculateScreenPosition(0, 0, pi.promptScreenColumns, promptChars,
-                            promptIndentation, promptExtraLines);
-  }
-
-  void updateSearchPrompt(void) {
-    const Utf32String* basePrompt =
-        (direction > 0) ? &forwardSearchBasePrompt : &reverseSearchBasePrompt;
-    size_t promptStartLength = basePrompt->length();
-    promptChars = static_cast<int>(promptStartLength + searchTextLen +
-                                   endSearchBasePrompt.length());
-    promptBytes = promptChars;
-    Utf32String tempUnicode(promptChars + 1);
-    memcpy(tempUnicode.get(), basePrompt->get(),
-           sizeof(char32_t) * promptStartLength);
-    memcpy(&tempUnicode[promptStartLength], searchText.get(),
-           sizeof(char32_t) * searchTextLen);
-    size_t endIndex = promptStartLength + searchTextLen;
-    memcpy(&tempUnicode[endIndex], endSearchBasePrompt.get(),
-           sizeof(char32_t) * (endSearchBasePrompt.length() + 1));
-    tempUnicode.initFromBuffer();
-    promptText = tempUnicode;
-  }
-
-  void updateSearchText(const char32_t* textPtr) {
-    Utf32String tempUnicode(textPtr);
-    searchTextLen = static_cast<int>(tempUnicode.chars());
-    searchText = tempUnicode;
-    updateSearchPrompt();
-  }
-};
-
-class KillRing {
-  static const int capacity = 10;
-  int size;
-  int index;
-  char indexToSlot[10];
-  vector<Utf32String> theRing;
-
- public:
-  enum action { actionOther, actionKill, actionYank };
-  action lastAction;
-  size_t lastYankSize;
-
-  KillRing() : size(0), index(0), lastAction(actionOther) {
-    theRing.reserve(capacity);
-  }
-
-  void kill(const char32_t* text, int textLen, bool forward) {
-    if (textLen == 0) {
-      return;
-    }
-    Utf32String killedText(text, textLen);
-    if (lastAction == actionKill && size > 0) {
-      int slot = indexToSlot[0];
-      int currentLen = static_cast<int>(theRing[slot].length());
-      int resultLen = currentLen + textLen;
-      Utf32String temp(resultLen + 1);
-      if (forward) {
-        memcpy(temp.get(), theRing[slot].get(), currentLen * sizeof(char32_t));
-        memcpy(&temp[currentLen], killedText.get(), textLen * sizeof(char32_t));
-      } else {
-        memcpy(temp.get(), killedText.get(), textLen * sizeof(char32_t));
-        memcpy(&temp[textLen], theRing[slot].get(),
-               currentLen * sizeof(char32_t));
-      }
-      temp[resultLen] = 0;
-      temp.initFromBuffer();
-      theRing[slot] = temp;
-    } else {
-      if (size < capacity) {
-        if (size > 0) {
-          memmove(&indexToSlot[1], &indexToSlot[0], size);
-        }
-        indexToSlot[0] = size;
-        size++;
-        theRing.push_back(killedText);
-      } else {
-        int slot = indexToSlot[capacity - 1];
-        theRing[slot] = killedText;
-        memmove(&indexToSlot[1], &indexToSlot[0], capacity - 1);
-        indexToSlot[0] = slot;
-      }
-      index = 0;
-    }
-  }
-
-  Utf32String* yank() { return (size > 0) ? &theRing[indexToSlot[index]] : 0; }
-
-  Utf32String* yankPop() {
-    if (size == 0) {
-      return 0;
-    }
-    ++index;
-    if (index == size) {
-      index = 0;
-    }
-    return &theRing[indexToSlot[index]];
-  }
-};
-
-class InputBuffer {
-  char32_t* buf32;   // input buffer
-  char* charWidths;  // character widths from mk_wcwidth()
-  int buflen;        // buffer size in characters
-  int len;           // length of text in input buffer
-  int pos;           // character position in buffer ( 0 <= pos <= len )
-
-  void clearScreen(PromptBase& pi);
-  int incrementalHistorySearch(PromptBase& pi, int startChar);
-  int completeLine(PromptBase& pi);
-  void refreshLine(PromptBase& pi);
-
- public:
-  InputBuffer(char32_t* buffer, char* widthArray, int bufferLen)
-      : buf32(buffer),
-        charWidths(widthArray),
-        buflen(bufferLen - 1),
-        len(0),
-        pos(0) {
-    buf32[0] = 0;
-  }
-  void preloadBuffer(const char* preloadText) {
-    size_t ucharCount = 0;
-    copyString8to32(buf32, buflen + 1, ucharCount, preloadText);
-    recomputeCharacterWidths(buf32, charWidths, static_cast<int>(ucharCount));
-    len = static_cast<int>(ucharCount);
-    pos = static_cast<int>(ucharCount);
-  }
-  int getInputLine(PromptBase& pi);
-  int length(void) const { return len; }
-};
-
-// Special codes for keyboard input:
-//
-// Between Windows and the various Linux "terminal" programs, there is some
-// pretty diverse behavior in the "scan codes" and escape sequences we are
-// presented with.  So ... we'll translate them all into our own pidgin
-// pseudocode, trying to stay out of the way of UTF-8 and international
-// characters.  Here's the general plan.
-//
-// "User input keystrokes" (key chords, whatever) will be encoded as a single
-// value.
-// The low 21 bits are reserved for Unicode characters.  Popular function-type
-// keys
-// get their own codes in the range 0x10200000 to (if needed) 0x1FE00000,
-// currently
-// just arrow keys, Home, End and Delete.  Keypresses with Ctrl get ORed with
-// 0x20000000, with Alt get ORed with 0x40000000.  So, Ctrl+Alt+Home is encoded
-// as 0x20000000 + 0x40000000 + 0x10A00000 == 0x70A00000.  To keep things
-// complicated,
-// the Alt key is equivalent to prefixing the keystroke with ESC, so ESC
-// followed by
-// D is treated the same as Alt + D ... we'll just use Emacs terminology and
-// call
-// this "Meta".  So, we will encode both ESC followed by D and Alt held down
-// while D
-// is pressed the same, as Meta-D, encoded as 0x40000064.
-//
-// Here are the definitions of our component constants:
-//
-// Maximum unsigned 32-bit value    = 0xFFFFFFFF;   // For reference, max 32-bit
-// value
-// Highest allocated Unicode char   = 0x001FFFFF;   // For reference, max
-// Unicode value
-static const int META = 0x40000000;  // Meta key combination
-static const int CTRL = 0x20000000;  // Ctrl key combination
-// static const int SPECIAL_KEY = 0x10000000;   // Common bit for all special
-// keys
-static const int UP_ARROW_KEY = 0x10200000;  // Special keys
-static const int DOWN_ARROW_KEY = 0x10400000;
-static const int RIGHT_ARROW_KEY = 0x10600000;
-static const int LEFT_ARROW_KEY = 0x10800000;
-static const int HOME_KEY = 0x10A00000;
-static const int END_KEY = 0x10C00000;
-static const int DELETE_KEY = 0x10E00000;
-static const int PAGE_UP_KEY = 0x11000000;
-static const int PAGE_DOWN_KEY = 0x11200000;
-
-static const char* unsupported_term[] = {"dumb", "cons25", "emacs", NULL};
-static linenoiseCompletionCallback* completionCallback = NULL;
-
-#ifdef _WIN32
-static HANDLE console_in, console_out;
-static DWORD oldMode;
-static WORD oldDisplayAttribute;
-#else
-static struct termios orig_termios; /* in order to restore at exit */
-#endif
-
-static KillRing killRing;
-
-static int rawmode = 0; /* for atexit() function to check if restore is needed*/
-static int atexit_registered = 0; /* register atexit just 1 time */
-static int historyMaxLen = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
-static int historyLen = 0;
-static int historyIndex = 0;
-static char8_t** history = NULL;
-
-// used to emulate Windows command prompt on down-arrow after a recall
-// we use -2 as our "not set" value because we add 1 to the previous index on
-// down-arrow,
-// and zero is a valid index (so -1 is a valid "previous index")
-static int historyPreviousIndex = -2;
-static bool historyRecallMostRecent = false;
-
-static void linenoiseAtExit(void);
-
-static bool isUnsupportedTerm(void) {
-  char* term = getenv("TERM");
-  if (term == NULL) return false;
-  for (int j = 0; unsupported_term[j]; ++j)
-    if (!strcasecmp(term, unsupported_term[j])) {
-      return true;
-    }
-  return false;
-}
-
-static void beep() {
-  fprintf(stderr, "\x7");  // ctrl-G == bell/beep
-  fflush(stderr);
-}
-
-void linenoiseHistoryFree(void) {
-  if (history) {
-    for (int j = 0; j < historyLen; ++j) free(history[j]);
-    historyLen = 0;
-    free(history);
-    history = 0;
-  }
-}
-
-static int enableRawMode(void) {
-#ifdef _WIN32
-  if (!console_in) {
-    console_in = GetStdHandle(STD_INPUT_HANDLE);
-    console_out = GetStdHandle(STD_OUTPUT_HANDLE);
-
-    GetConsoleMode(console_in, &oldMode);
-    SetConsoleMode(console_in, oldMode &
-                                   ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT |
-                                     ENABLE_PROCESSED_INPUT));
-  }
-  return 0;
-#else
-  struct termios raw;
-
-  if (!isatty(STDIN_FILENO)) goto fatal;
-  if (!atexit_registered) {
-    atexit(linenoiseAtExit);
-    atexit_registered = 1;
-  }
-  if (tcgetattr(0, &orig_termios) == -1) goto fatal;
-
-  raw = orig_termios; /* modify the original mode */
-  /* input modes: no break, no CR to NL, no parity check, no strip char,
-   * no start/stop output control. */
-  raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
-  /* output modes - disable post processing */
-  // this is wrong, we don't want raw output, it turns newlines into straight
-  // linefeeds
-  // raw.c_oflag &= ~(OPOST);
-  /* control modes - set 8 bit chars */
-  raw.c_cflag |= (CS8);
-  /* local modes - echoing off, canonical off, no extended functions,
-   * no signal chars (^Z,^C) */
-  raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
-  /* control chars - set return condition: min number of bytes and timer.
-   * We want read to return every single byte, without timeout. */
-  raw.c_cc[VMIN] = 1;
-  raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
-
-  /* put terminal in raw mode after flushing */
-  if (tcsetattr(0, TCSADRAIN, &raw) < 0) goto fatal;
-  rawmode = 1;
-  return 0;
-
-fatal:
-  errno = ENOTTY;
-  return -1;
-#endif
-}
-
-static void disableRawMode(void) {
-#ifdef _WIN32
-  SetConsoleMode(console_in, oldMode);
-  console_in = 0;
-  console_out = 0;
-#else
-  if (rawmode && tcsetattr(0, TCSADRAIN, &orig_termios) != -1) rawmode = 0;
-#endif
-}
-
-// At exit we'll try to fix the terminal to the initial conditions
-static void linenoiseAtExit(void) { disableRawMode(); }
-
-static int getScreenColumns(void) {
-  int cols;
-#ifdef _WIN32
-  CONSOLE_SCREEN_BUFFER_INFO inf;
-  GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &inf);
-  cols = inf.dwSize.X;
-#else
-  struct winsize ws;
-  cols = (ioctl(1, TIOCGWINSZ, &ws) == -1) ? 80 : ws.ws_col;
-#endif
-  // cols is 0 in certain circumstances like inside debugger, which creates
-  // further issues
-  return (cols > 0) ? cols : 80;
-}
-
-static int getScreenRows(void) {
-  int rows;
-#ifdef _WIN32
-  CONSOLE_SCREEN_BUFFER_INFO inf;
-  GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &inf);
-  rows = 1 + inf.srWindow.Bottom - inf.srWindow.Top;
-#else
-  struct winsize ws;
-  rows = (ioctl(1, TIOCGWINSZ, &ws) == -1) ? 24 : ws.ws_row;
-#endif
-  return (rows > 0) ? rows : 24;
-}
-
-static void setDisplayAttribute(bool enhancedDisplay, bool error) {
-#ifdef _WIN32
-  if (enhancedDisplay) {
-    CONSOLE_SCREEN_BUFFER_INFO inf;
-    GetConsoleScreenBufferInfo(console_out, &inf);
-    oldDisplayAttribute = inf.wAttributes;
-    BYTE oldLowByte = oldDisplayAttribute & 0xFF;
-    BYTE newLowByte;
-    switch (oldLowByte) {
-      case 0x07:
-        // newLowByte = FOREGROUND_BLUE | FOREGROUND_INTENSITY;  // too dim
-        // newLowByte = FOREGROUND_BLUE;                         // even dimmer
-        newLowByte = FOREGROUND_BLUE |
-                     FOREGROUND_GREEN;  // most similar to xterm appearance
-        break;
-      case 0x70:
-        newLowByte = BACKGROUND_BLUE | BACKGROUND_INTENSITY;
-        break;
-      default:
-        newLowByte = oldLowByte ^ 0xFF;  // default to inverse video
-        break;
-    }
-    inf.wAttributes = (inf.wAttributes & 0xFF00) | newLowByte;
-    SetConsoleTextAttribute(console_out, inf.wAttributes);
-  } else {
-    SetConsoleTextAttribute(console_out, oldDisplayAttribute);
-  }
-#else
-  if (enhancedDisplay) {
-    char const* p = (error ? "\x1b[1;31m" : "\x1b[1;34m");
-    if (write(1, p, 7) == -1)
-      return; /* bright blue (visible with both B&W bg) */
-  } else {
-    if (write(1, "\x1b[0m", 4) == -1) return; /* reset */
-  }
-#endif
-}
-
-/**
- * Display the dynamic incremental search prompt and the current user input
- * line.
- * @param pi   PromptBase struct holding information about the prompt and our
- * screen position
- * @param buf32  input buffer to be displayed
- * @param len  count of characters in the buffer
- * @param pos  current cursor position within the buffer (0 <= pos <= len)
- */
-static void dynamicRefresh(PromptBase& pi, char32_t* buf32, int len, int pos) {
-  // calculate the position of the end of the prompt
-  int xEndOfPrompt, yEndOfPrompt;
-  calculateScreenPosition(0, 0, pi.promptScreenColumns, pi.promptChars,
-                          xEndOfPrompt, yEndOfPrompt);
-  pi.promptIndentation = xEndOfPrompt;
-
-  // calculate the position of the end of the input line
-  int xEndOfInput, yEndOfInput;
-  calculateScreenPosition(xEndOfPrompt, yEndOfPrompt, pi.promptScreenColumns,
-                          calculateColumnPosition(buf32, len), xEndOfInput,
-                          yEndOfInput);
-
-  // calculate the desired position of the cursor
-  int xCursorPos, yCursorPos;
-  calculateScreenPosition(xEndOfPrompt, yEndOfPrompt, pi.promptScreenColumns,
-                          calculateColumnPosition(buf32, pos), xCursorPos,
-                          yCursorPos);
-
-#ifdef _WIN32
-  // position at the start of the prompt, clear to end of previous input
-  CONSOLE_SCREEN_BUFFER_INFO inf;
-  GetConsoleScreenBufferInfo(console_out, &inf);
-  inf.dwCursorPosition.X = 0;
-  inf.dwCursorPosition.Y -= pi.promptCursorRowOffset /*- pi.promptExtraLines*/;
-  SetConsoleCursorPosition(console_out, inf.dwCursorPosition);
-  DWORD count;
-  FillConsoleOutputCharacterA(console_out, ' ',
-                              pi.promptPreviousLen + pi.promptPreviousInputLen,
-                              inf.dwCursorPosition, &count);
-  pi.promptPreviousLen = pi.promptIndentation;
-  pi.promptPreviousInputLen = len;
-
-  // display the prompt
-  if (!pi.write()) return;
-
-  // display the input line
-  if (write32(1, buf32, len) == -1) return;
-
-  // position the cursor
-  GetConsoleScreenBufferInfo(console_out, &inf);
-  inf.dwCursorPosition.X = xCursorPos;  // 0-based on Win32
-  inf.dwCursorPosition.Y -= yEndOfInput - yCursorPos;
-  SetConsoleCursorPosition(console_out, inf.dwCursorPosition);
-#else  // _WIN32
-  char seq[64];
-  int cursorRowMovement = pi.promptCursorRowOffset - pi.promptExtraLines;
-  if (cursorRowMovement > 0) {  // move the cursor up as required
-    snprintf(seq, sizeof seq, "\x1b[%dA", cursorRowMovement);
-    if (write(1, seq, strlen(seq)) == -1) return;
-  }
-  // position at the start of the prompt, clear to end of screen
-  snprintf(seq, sizeof seq, "\x1b[1G\x1b[J");  // 1-based on VT100
-  if (write(1, seq, strlen(seq)) == -1) return;
-
-  // display the prompt
-  if (!pi.write()) return;
-
-  // display the input line
-  if (write32(1, buf32, len) == -1) return;
-
-  // we have to generate our own newline on line wrap
-  if (xEndOfInput == 0 && yEndOfInput > 0)
-    if (write(1, "\n", 1) == -1) return;
-
-  // position the cursor
-  cursorRowMovement = yEndOfInput - yCursorPos;
-  if (cursorRowMovement > 0) {  // move the cursor up as required
-    snprintf(seq, sizeof seq, "\x1b[%dA", cursorRowMovement);
-    if (write(1, seq, strlen(seq)) == -1) return;
-  }
-  // position the cursor within the line
-  snprintf(seq, sizeof seq, "\x1b[%dG", xCursorPos + 1);  // 1-based on VT100
-  if (write(1, seq, strlen(seq)) == -1) return;
-#endif
-
-  pi.promptCursorRowOffset =
-      pi.promptExtraLines + yCursorPos;  // remember row for next pass
-}
-
-/**
- * Refresh the user's input line: the prompt is already onscreen and is not
- * redrawn here
- * @param pi   PromptBase struct holding information about the prompt and our
- * screen position
- */
-void InputBuffer::refreshLine(PromptBase& pi) {
-  // check for a matching brace/bracket/paren, remember its position if found
-  int highlight = -1;
-  bool indicateError = false;
-  if (pos < len) {
-    /* this scans for a brace matching buf32[pos] to highlight */
-    unsigned char part1, part2;
-    int scanDirection = 0;
-    if (strchr("}])", buf32[pos])) {
-      scanDirection = -1; /* backwards */
-      if (buf32[pos] == '}') {
-        part1 = '}'; part2 = '{';
-      } else if (buf32[pos] == ']') {
-        part1 = ']'; part2 = '[';
-      } else {
-        part1 = ')'; part2 = '(';
-      }
-    }
-    else if (strchr("{[(", buf32[pos])) {
-      scanDirection = 1; /* forwards */
-      if (buf32[pos] == '{') {
-        //part1 = '{'; part2 = '}';
-        part1 = '}'; part2 = '{';
-      } else if (buf32[pos] == '[') {
-        //part1 = '['; part2 = ']';
-        part1 = ']'; part2 = '[';
-      } else {
-        //part1 = '('; part2 = ')';
-        part1 = ')'; part2 = '(';
-      }
-    }
-
-    if (scanDirection) {
-      int unmatched = scanDirection;
-      int unmatchedOther = 0;
-      for (int i = pos + scanDirection; i >= 0 && i < len; i += scanDirection) {
-        /* TODO: the right thing when inside a string */
-        if (strchr("}])", buf32[i])) {
-          if (buf32[i] == part1) {
-            --unmatched;
-          } else {
-            --unmatchedOther;
-          }
-        } else if (strchr("{[(", buf32[i])) {
-          if (buf32[i] == part2) {
-            ++unmatched;
-          } else {
-            ++unmatchedOther;
-          }
-        }
-/*
-        if (strchr("}])", buf32[i]))
-          --unmatched;
-        else if (strchr("{[(", buf32[i]))
-          ++unmatched;
-*/
-        if (unmatched == 0) {
-          highlight = i;
-          indicateError = (unmatchedOther != 0);
-          break;
-        }
-      }
-    }
-  }
-
-  // calculate the position of the end of the input line
-  int xEndOfInput, yEndOfInput;
-  calculateScreenPosition(pi.promptIndentation, 0, pi.promptScreenColumns,
-                          calculateColumnPosition(buf32, len), xEndOfInput,
-                          yEndOfInput);
-
-  // calculate the desired position of the cursor
-  int xCursorPos, yCursorPos;
-  calculateScreenPosition(pi.promptIndentation, 0, pi.promptScreenColumns,
-                          calculateColumnPosition(buf32, pos), xCursorPos,
-                          yCursorPos);
-
-#ifdef _WIN32
-  // position at the end of the prompt, clear to end of previous input
-  CONSOLE_SCREEN_BUFFER_INFO inf;
-  GetConsoleScreenBufferInfo(console_out, &inf);
-  inf.dwCursorPosition.X = pi.promptIndentation;  // 0-based on Win32
-  inf.dwCursorPosition.Y -= pi.promptCursorRowOffset - pi.promptExtraLines;
-  SetConsoleCursorPosition(console_out, inf.dwCursorPosition);
-  DWORD count;
-  if (len < pi.promptPreviousInputLen)
-    FillConsoleOutputCharacterA(console_out, ' ', pi.promptPreviousInputLen,
-                                inf.dwCursorPosition, &count);
-  pi.promptPreviousInputLen = len;
-
-  // display the input line
-  if (highlight == -1) {
-    if (write32(1, buf32, len) == -1) return;
-  } else {
-    if (write32(1, buf32, highlight) == -1) return;
-    setDisplayAttribute(true, indicateError); /* bright blue (visible with both B&W bg) */
-    if (write32(1, &buf32[highlight], 1) == -1) return;
-    setDisplayAttribute(false, indicateError);
-    if (write32(1, buf32 + highlight + 1, len - highlight - 1) == -1) return;
-  }
-
-  // position the cursor
-  GetConsoleScreenBufferInfo(console_out, &inf);
-  inf.dwCursorPosition.X = xCursorPos;  // 0-based on Win32
-  inf.dwCursorPosition.Y -= yEndOfInput - yCursorPos;
-  SetConsoleCursorPosition(console_out, inf.dwCursorPosition);
-#else  // _WIN32
-  char seq[64];
-  int cursorRowMovement = pi.promptCursorRowOffset - pi.promptExtraLines;
-  if (cursorRowMovement > 0) {  // move the cursor up as required
-    snprintf(seq, sizeof seq, "\x1b[%dA", cursorRowMovement);
-    if (write(1, seq, strlen(seq)) == -1) return;
-  }
-  // position at the end of the prompt, clear to end of screen
-  snprintf(seq, sizeof seq, "\x1b[%dG\x1b[J",
-           pi.promptIndentation + 1);  // 1-based on VT100
-  if (write(1, seq, strlen(seq)) == -1) return;
-
-  if (highlight == -1) {  // write unhighlighted text
-    if (write32(1, buf32, len) == -1) return;
-  } else {  // highlight the matching brace/bracket/parenthesis
-    if (write32(1, buf32, highlight) == -1) return;
-    setDisplayAttribute(true, indicateError);
-    if (write32(1, &buf32[highlight], 1) == -1) return;
-    setDisplayAttribute(false, indicateError);
-    if (write32(1, buf32 + highlight + 1, len - highlight - 1) == -1) return;
-  }
-
-  // we have to generate our own newline on line wrap
-  if (xEndOfInput == 0 && yEndOfInput > 0)
-    if (write(1, "\n", 1) == -1) return;
-
-  // position the cursor
-  cursorRowMovement = yEndOfInput - yCursorPos;
-  if (cursorRowMovement > 0) {  // move the cursor up as required
-    snprintf(seq, sizeof seq, "\x1b[%dA", cursorRowMovement);
-    if (write(1, seq, strlen(seq)) == -1) return;
-  }
-  // position the cursor within the line
-  snprintf(seq, sizeof seq, "\x1b[%dG", xCursorPos + 1);  // 1-based on VT100
-  if (write(1, seq, strlen(seq)) == -1) return;
-#endif
-
-  pi.promptCursorRowOffset =
-      pi.promptExtraLines + yCursorPos;  // remember row for next pass
-}
-
-#ifndef _WIN32
-
-/**
- * Read a UTF-8 sequence from the non-Windows keyboard and return the Unicode
- * (char32_t) character it
- * encodes
- *
- * @return  char32_t Unicode character
- */
-static char32_t readUnicodeCharacter(void) {
-  static char8_t utf8String[5];
-  static size_t utf8Count = 0;
-  while (true) {
-    char8_t c;
-
-    /* Continue reading if interrupted by signal. */
-    ssize_t nread;
-    do {
-      nread = read(0, &c, 1);
-    } while ((nread == -1) && (errno == EINTR));
-
-    if (nread <= 0) return 0;
-    if (c <= 0x7F) {  // short circuit ASCII
-      utf8Count = 0;
-      return c;
-    } else if (utf8Count < sizeof(utf8String) - 1) {
-      utf8String[utf8Count++] = c;
-      utf8String[utf8Count] = 0;
-      char32_t unicodeChar[2];
-      size_t ucharCount;
-      ConversionResult res =
-          copyString8to32(unicodeChar, 2, ucharCount, utf8String);
-      if (res == conversionOK && ucharCount) {
-        utf8Count = 0;
-        return unicodeChar[0];
-      }
-    } else {
-      utf8Count =
-          0;  // this shouldn't happen: got four bytes but no UTF-8 character
-    }
-  }
-}
-
-namespace EscapeSequenceProcessing {  // move these out of global namespace
-
-// This chunk of code does parsing of the escape sequences sent by various Linux
-// terminals.
-//
-// It handles arrow keys, Home, End and Delete keys by interpreting the
-// sequences sent by
-// gnome terminal, xterm, rxvt, konsole, aterm and yakuake including the Alt and
-// Ctrl key
-// combinations that are understood by linenoise.
-//
-// The parsing uses tables, a bunch of intermediate dispatch routines and a
-// doDispatch
-// loop that reads the tables and sends control to "deeper" routines to continue
-// the
-// parsing.  The starting call to doDispatch( c, initialDispatch ) will
-// eventually return
-// either a character (with optional CTRL and META bits set), or -1 if parsing
-// fails, or
-// zero if an attempt to read from the keyboard fails.
-//
-// This is rather sloppy escape sequence processing, since we're not paying
-// attention to what the
-// actual TERM is set to and are processing all key sequences for all terminals,
-// but it works with
-// the most common keystrokes on the most common terminals.  It's intricate, but
-// the nested 'if'
-// statements required to do it directly would be worse.  This way has the
-// advantage of allowing
-// changes and extensions without having to touch a lot of code.
-
-// This is a typedef for the routine called by doDispatch().  It takes the
-// current character
-// as input, does any required processing including reading more characters and
-// calling other
-// dispatch routines, then eventually returns the final (possibly extended or
-// special) character.
-//
-typedef char32_t (*CharacterDispatchRoutine)(char32_t);
-
-// This structure is used by doDispatch() to hold a list of characters to test
-// for and
-// a list of routines to call if the character matches.  The dispatch routine
-// list is one
-// longer than the character list; the final entry is used if no character
-// matches.
-//
-struct CharacterDispatch {
-  unsigned int len;                    // length of the chars list
-  const char* chars;                   // chars to test
-  CharacterDispatchRoutine* dispatch;  // array of routines to call
-};
-
-// This dispatch routine is given a dispatch table and then farms work out to
-// routines
-// listed in the table based on the character it is called with.  The dispatch
-// routines can
-// read more input characters to decide what should eventually be returned.
-// Eventually,
-// a called routine returns either a character or -1 to indicate parsing
-// failure.
-//
-static char32_t doDispatch(char32_t c, CharacterDispatch& dispatchTable) {
-  for (unsigned int i = 0; i < dispatchTable.len; ++i) {
-    if (static_cast<unsigned char>(dispatchTable.chars[i]) == c) {
-      return dispatchTable.dispatch[i](c);
-    }
-  }
-  return dispatchTable.dispatch[dispatchTable.len](c);
-}
-
-static char32_t thisKeyMetaCtrl =
-    0;  // holds pre-set Meta and/or Ctrl modifiers
-
-// Final dispatch routines -- return something
-//
-static char32_t normalKeyRoutine(char32_t c) { return thisKeyMetaCtrl | c; }
-static char32_t upArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | UP_ARROW_KEY;
-}
-static char32_t downArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | DOWN_ARROW_KEY;
-}
-static char32_t rightArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | RIGHT_ARROW_KEY;
-}
-static char32_t leftArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | LEFT_ARROW_KEY;
-}
-static char32_t homeKeyRoutine(char32_t) { return thisKeyMetaCtrl | HOME_KEY; }
-static char32_t endKeyRoutine(char32_t) { return thisKeyMetaCtrl | END_KEY; }
-static char32_t pageUpKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | PAGE_UP_KEY;
-}
-static char32_t pageDownKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | PAGE_DOWN_KEY;
-}
-static char32_t deleteCharRoutine(char32_t) {
-  return thisKeyMetaCtrl | ctrlChar('H');
-}  // key labeled Backspace
-static char32_t deleteKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | DELETE_KEY;
-}  // key labeled Delete
-static char32_t ctrlUpArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | CTRL | UP_ARROW_KEY;
-}
-static char32_t ctrlDownArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | CTRL | DOWN_ARROW_KEY;
-}
-static char32_t ctrlRightArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | CTRL | RIGHT_ARROW_KEY;
-}
-static char32_t ctrlLeftArrowKeyRoutine(char32_t) {
-  return thisKeyMetaCtrl | CTRL | LEFT_ARROW_KEY;
-}
-static char32_t escFailureRoutine(char32_t) {
-  beep();
-  return -1;
-}
-
-// Handle ESC [ 1 ; 3 (or 5) <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket1Semicolon3or5Routines[] = {
-    upArrowKeyRoutine, downArrowKeyRoutine, rightArrowKeyRoutine,
-    leftArrowKeyRoutine, escFailureRoutine};
-static CharacterDispatch escLeftBracket1Semicolon3or5Dispatch = {
-    4, "ABCD", escLeftBracket1Semicolon3or5Routines};
-
-// Handle ESC [ 1 ; <more stuff> escape sequences
-//
-static char32_t escLeftBracket1Semicolon3Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  thisKeyMetaCtrl |= META;
-  return doDispatch(c, escLeftBracket1Semicolon3or5Dispatch);
-}
-static char32_t escLeftBracket1Semicolon5Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  thisKeyMetaCtrl |= CTRL;
-  return doDispatch(c, escLeftBracket1Semicolon3or5Dispatch);
-}
-static CharacterDispatchRoutine escLeftBracket1SemicolonRoutines[] = {
-    escLeftBracket1Semicolon3Routine, escLeftBracket1Semicolon5Routine,
-    escFailureRoutine};
-static CharacterDispatch escLeftBracket1SemicolonDispatch = {
-    2, "35", escLeftBracket1SemicolonRoutines};
-
-// Handle ESC [ 1 <more stuff> escape sequences
-//
-static char32_t escLeftBracket1SemicolonRoutine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket1SemicolonDispatch);
-}
-static CharacterDispatchRoutine escLeftBracket1Routines[] = {
-    homeKeyRoutine, escLeftBracket1SemicolonRoutine, escFailureRoutine};
-static CharacterDispatch escLeftBracket1Dispatch = {2, "~;",
-                                                    escLeftBracket1Routines};
-
-// Handle ESC [ 3 <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket3Routines[] = {deleteKeyRoutine,
-                                                             escFailureRoutine};
-static CharacterDispatch escLeftBracket3Dispatch = {1, "~",
-                                                    escLeftBracket3Routines};
-
-// Handle ESC [ 4 <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket4Routines[] = {endKeyRoutine,
-                                                             escFailureRoutine};
-static CharacterDispatch escLeftBracket4Dispatch = {1, "~",
-                                                    escLeftBracket4Routines};
-
-// Handle ESC [ 5 <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket5Routines[] = {pageUpKeyRoutine,
-                                                             escFailureRoutine};
-static CharacterDispatch escLeftBracket5Dispatch = {1, "~",
-                                                    escLeftBracket5Routines};
-
-// Handle ESC [ 6 <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket6Routines[] = {pageDownKeyRoutine,
-                                                             escFailureRoutine};
-static CharacterDispatch escLeftBracket6Dispatch = {1, "~",
-                                                    escLeftBracket6Routines};
-
-// Handle ESC [ 7 <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket7Routines[] = {homeKeyRoutine,
-                                                             escFailureRoutine};
-static CharacterDispatch escLeftBracket7Dispatch = {1, "~",
-                                                    escLeftBracket7Routines};
-
-// Handle ESC [ 8 <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracket8Routines[] = {endKeyRoutine,
-                                                             escFailureRoutine};
-static CharacterDispatch escLeftBracket8Dispatch = {1, "~",
-                                                    escLeftBracket8Routines};
-
-// Handle ESC [ <digit> escape sequences
-//
-static char32_t escLeftBracket0Routine(char32_t c) {
-  return escFailureRoutine(c);
-}
-static char32_t escLeftBracket1Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket1Dispatch);
-}
-static char32_t escLeftBracket2Routine(char32_t c) {
-  return escFailureRoutine(c);  // Insert key, unused
-}
-static char32_t escLeftBracket3Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket3Dispatch);
-}
-static char32_t escLeftBracket4Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket4Dispatch);
-}
-static char32_t escLeftBracket5Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket5Dispatch);
-}
-static char32_t escLeftBracket6Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket6Dispatch);
-}
-static char32_t escLeftBracket7Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket7Dispatch);
-}
-static char32_t escLeftBracket8Routine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracket8Dispatch);
-}
-static char32_t escLeftBracket9Routine(char32_t c) {
-  return escFailureRoutine(c);
-}
-
-// Handle ESC [ <more stuff> escape sequences
-//
-static CharacterDispatchRoutine escLeftBracketRoutines[] = {
-    upArrowKeyRoutine,      downArrowKeyRoutine,    rightArrowKeyRoutine,
-    leftArrowKeyRoutine,    homeKeyRoutine,         endKeyRoutine,
-    escLeftBracket0Routine, escLeftBracket1Routine, escLeftBracket2Routine,
-    escLeftBracket3Routine, escLeftBracket4Routine, escLeftBracket5Routine,
-    escLeftBracket6Routine, escLeftBracket7Routine, escLeftBracket8Routine,
-    escLeftBracket9Routine, escFailureRoutine};
-static CharacterDispatch escLeftBracketDispatch = {16, "ABCDHF0123456789",
-                                                   escLeftBracketRoutines};
-
-// Handle ESC O <char> escape sequences
-//
-static CharacterDispatchRoutine escORoutines[] = {
-    upArrowKeyRoutine,       downArrowKeyRoutine,     rightArrowKeyRoutine,
-    leftArrowKeyRoutine,     homeKeyRoutine,          endKeyRoutine,
-    ctrlUpArrowKeyRoutine,   ctrlDownArrowKeyRoutine, ctrlRightArrowKeyRoutine,
-    ctrlLeftArrowKeyRoutine, escFailureRoutine};
-static CharacterDispatch escODispatch = {10, "ABCDHFabcd", escORoutines};
-
-// Initial ESC dispatch -- could be a Meta prefix or the start of an escape
-// sequence
-//
-static char32_t escLeftBracketRoutine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escLeftBracketDispatch);
-}
-static char32_t escORoutine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escODispatch);
-}
-static char32_t setMetaRoutine(char32_t c);  // need forward reference
-static CharacterDispatchRoutine escRoutines[] = {escLeftBracketRoutine,
-                                                 escORoutine, setMetaRoutine};
-static CharacterDispatch escDispatch = {2, "[O", escRoutines};
-
-// Initial dispatch -- we are not in the middle of anything yet
-//
-static char32_t escRoutine(char32_t c) {
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-  return doDispatch(c, escDispatch);
-}
-static CharacterDispatchRoutine initialRoutines[] = {
-    escRoutine, deleteCharRoutine, normalKeyRoutine};
-static CharacterDispatch initialDispatch = {2, "\x1B\x7F", initialRoutines};
-
-// Special handling for the ESC key because it does double duty
-//
-static char32_t setMetaRoutine(char32_t c) {
-  thisKeyMetaCtrl = META;
-  if (c == 0x1B) {  // another ESC, stay in ESC processing mode
-    c = readUnicodeCharacter();
-    if (c == 0) return 0;
-    return doDispatch(c, escDispatch);
-  }
-  return doDispatch(c, initialDispatch);
-}
-
-}  // namespace EscapeSequenceProcessing // move these out of global namespace
-
-#endif  // #ifndef _WIN32
-
-// linenoiseReadChar -- read a keystroke or keychord from the keyboard, and
-// translate it
-// into an encoded "keystroke".  When convenient, extended keys are translated
-// into their
-// simpler Emacs keystrokes, so an unmodified "left arrow" becomes Ctrl-B.
-//
-// A return value of zero means "no input available", and a return value of -1
-// means "invalid key".
-//
-static char32_t linenoiseReadChar(void) {
-#ifdef _WIN32
-
-  INPUT_RECORD rec;
-  DWORD count;
-  int modifierKeys = 0;
-  bool escSeen = false;
-  while (true) {
-    ReadConsoleInputW(console_in, &rec, 1, &count);
-#if 0  // helper for debugging keystrokes, display info in the debug "Output"
-       // window in the debugger
-        {
-            if ( rec.EventType == KEY_EVENT ) {
-                //if ( rec.Event.KeyEvent.uChar.UnicodeChar ) {
-                    char buf[1024];
-                    sprintf(
-                            buf,
-                            "Unicode character 0x%04X, repeat count %d, virtual keycode 0x%04X, "
-                            "virtual scancode 0x%04X, key %s%s%s%s%s\n",
-                            rec.Event.KeyEvent.uChar.UnicodeChar,
-                            rec.Event.KeyEvent.wRepeatCount,
-                            rec.Event.KeyEvent.wVirtualKeyCode,
-                            rec.Event.KeyEvent.wVirtualScanCode,
-                            rec.Event.KeyEvent.bKeyDown ? "down" : "up",
-                                (rec.Event.KeyEvent.dwControlKeyState & LEFT_CTRL_PRESSED)  ?
-                                    " L-Ctrl" : "",
-                                (rec.Event.KeyEvent.dwControlKeyState & RIGHT_CTRL_PRESSED) ?
-                                    " R-Ctrl" : "",
-                                (rec.Event.KeyEvent.dwControlKeyState & LEFT_ALT_PRESSED)   ?
-                                    " L-Alt"  : "",
-                                (rec.Event.KeyEvent.dwControlKeyState & RIGHT_ALT_PRESSED)  ?
-                                    " R-Alt"  : ""
-                           );
-                    OutputDebugStringA( buf );
-                //}
-            }
-        }
-#endif
-    if (rec.EventType != KEY_EVENT) {
-      continue;
-    }
-    // Windows provides for entry of characters that are not on your keyboard by
-    // sending the
-    // Unicode characters as a "key up" with virtual keycode 0x12 (VK_MENU ==
-    // Alt key) ...
-    // accept these characters, otherwise only process characters on "key down"
-    if (!rec.Event.KeyEvent.bKeyDown &&
-        rec.Event.KeyEvent.wVirtualKeyCode != VK_MENU) {
-      continue;
-    }
-    modifierKeys = 0;
-    // AltGr is encoded as ( LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED ), so don't
-    // treat this
-    // combination as either CTRL or META we just turn off those two bits, so it
-    // is still
-    // possible to combine CTRL and/or META with an AltGr key by using
-    // right-Ctrl and/or
-    // left-Alt
-    if ((rec.Event.KeyEvent.dwControlKeyState &
-         (LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED)) ==
-        (LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED)) {
-      rec.Event.KeyEvent.dwControlKeyState &=
-          ~(LEFT_CTRL_PRESSED | RIGHT_ALT_PRESSED);
-    }
-    if (rec.Event.KeyEvent.dwControlKeyState &
-        (RIGHT_CTRL_PRESSED | LEFT_CTRL_PRESSED)) {
-      modifierKeys |= CTRL;
-    }
-    if (rec.Event.KeyEvent.dwControlKeyState &
-        (RIGHT_ALT_PRESSED | LEFT_ALT_PRESSED)) {
-      modifierKeys |= META;
-    }
-    if (escSeen) {
-      modifierKeys |= META;
-    }
-    if (rec.Event.KeyEvent.uChar.UnicodeChar == 0) {
-      switch (rec.Event.KeyEvent.wVirtualKeyCode) {
-        case VK_LEFT:
-          return modifierKeys | LEFT_ARROW_KEY;
-        case VK_RIGHT:
-          return modifierKeys | RIGHT_ARROW_KEY;
-        case VK_UP:
-          return modifierKeys | UP_ARROW_KEY;
-        case VK_DOWN:
-          return modifierKeys | DOWN_ARROW_KEY;
-        case VK_DELETE:
-          return modifierKeys | DELETE_KEY;
-        case VK_HOME:
-          return modifierKeys | HOME_KEY;
-        case VK_END:
-          return modifierKeys | END_KEY;
-        case VK_PRIOR:
-          return modifierKeys | PAGE_UP_KEY;
-        case VK_NEXT:
-          return modifierKeys | PAGE_DOWN_KEY;
-        default:
-          continue;  // in raw mode, ReadConsoleInput shows shift, ctrl ...
-      }              //  ... ignore them
-    } else if (rec.Event.KeyEvent.uChar.UnicodeChar ==
-               ctrlChar('[')) {  // ESC, set flag for later
-      escSeen = true;
-      continue;
-    } else {
-      // we got a real character, return it
-      return modifierKeys | rec.Event.KeyEvent.uChar.UnicodeChar;
-    }
-  }
-
-#else
-  char32_t c;
-  c = readUnicodeCharacter();
-  if (c == 0) return 0;
-
-// If _DEBUG_LINUX_KEYBOARD is set, then ctrl-^ puts us into a keyboard
-// debugging mode
-// where we print out decimal and decoded values for whatever the "terminal"
-// program
-// gives us on different keystrokes.  Hit ctrl-C to exit this mode.
-//
-#define _DEBUG_LINUX_KEYBOARD
-#if defined(_DEBUG_LINUX_KEYBOARD)
-  if (c == ctrlChar('^')) {  // ctrl-^, special debug mode, prints all keys hit,
-                             // ctrl-C to get out
-    printf(
-        "\nEntering keyboard debugging mode (on ctrl-^), press ctrl-C to exit "
-        "this mode\n");
-    while (true) {
-      unsigned char keys[10];
-      int ret = read(0, keys, 10);
-
-      if (ret <= 0) {
-        printf("\nret: %d\n", ret);
-      }
-      for (int i = 0; i < ret; ++i) {
-        char32_t key = static_cast<char32_t>(keys[i]);
-        char* friendlyTextPtr;
-        char friendlyTextBuf[10];
-        const char* prefixText = (key < 0x80) ? "" : "0x80+";
-        char32_t keyCopy = (key < 0x80) ? key : key - 0x80;
-        if (keyCopy >= '!' && keyCopy <= '~') {  // printable
-          friendlyTextBuf[0] = '\'';
-          friendlyTextBuf[1] = keyCopy;
-          friendlyTextBuf[2] = '\'';
-          friendlyTextBuf[3] = 0;
-          friendlyTextPtr = friendlyTextBuf;
-        } else if (keyCopy == ' ') {
-          friendlyTextPtr = const_cast<char*>("space");
-        } else if (keyCopy == 27) {
-          friendlyTextPtr = const_cast<char*>("ESC");
-        } else if (keyCopy == 0) {
-          friendlyTextPtr = const_cast<char*>("NUL");
-        } else if (keyCopy == 127) {
-          friendlyTextPtr = const_cast<char*>("DEL");
-        } else {
-          friendlyTextBuf[0] = '^';
-          friendlyTextBuf[1] = keyCopy + 0x40;
-          friendlyTextBuf[2] = 0;
-          friendlyTextPtr = friendlyTextBuf;
-        }
-        printf("%d x%02X (%s%s)  ", key, key, prefixText, friendlyTextPtr);
-      }
-      printf("\x1b[1G\n");  // go to first column of new line
-
-      // drop out of this loop on ctrl-C
-      if (keys[0] == ctrlChar('C')) {
-        printf("Leaving keyboard debugging mode (on ctrl-C)\n");
-        fflush(stdout);
-        return -2;
-      }
-    }
-  }
-#endif  // _DEBUG_LINUX_KEYBOARD
-
-  EscapeSequenceProcessing::thisKeyMetaCtrl =
-      0;  // no modifiers yet at initialDispatch
-  return EscapeSequenceProcessing::doDispatch(
-      c, EscapeSequenceProcessing::initialDispatch);
-#endif  // #_WIN32
-}
-
-/**
- * Free memory used in a recent command completion session
- *
- * @param lc pointer to a linenoiseCompletions struct
- */
-static void freeCompletions(linenoiseCompletions* lc) {
-  lc->completionStrings.clear();
-}
-
-/**
- * convert {CTRL + 'A'}, {CTRL + 'a'} and {CTRL + ctrlChar( 'A' )} into
- * ctrlChar( 'A' )
- * leave META alone
- *
- * @param c character to clean up
- * @return cleaned-up character
- */
-static int cleanupCtrl(int c) {
-  if (c & CTRL) {
-    int d = c & 0x1FF;
-    if (d >= 'a' && d <= 'z') {
-      c = (c + ('a' - ctrlChar('A'))) & ~CTRL;
-    }
-    if (d >= 'A' && d <= 'Z') {
-      c = (c + ('A' - ctrlChar('A'))) & ~CTRL;
-    }
-    if (d >= ctrlChar('A') && d <= ctrlChar('Z')) {
-      c = c & ~CTRL;
-    }
-  }
-  return c;
-}
-
-// break characters that may precede items to be completed
-static const char breakChars[] = " =+-/\\*?\"'`&<>;|@{([])}";
-
-// maximum number of completions to display without asking
-static const size_t completionCountCutoff = 100;
-
-/**
- * Handle command completion, using a completionCallback() routine to provide
- * possible substitutions
- * This routine handles the mechanics of updating the user's input buffer with
- * possible replacement
- * of text as the user selects a proposed completion string, or cancels the
- * completion attempt.
- * @param pi     PromptBase struct holding information about the prompt and our
- * screen position
- */
-int InputBuffer::completeLine(PromptBase& pi) {
-  linenoiseCompletions lc;
-  char32_t c = 0;
-
-  // completionCallback() expects a parsable entity, so find the previous break
-  // character and
-  // extract a copy to parse.  we also handle the case where tab is hit while
-  // not at end-of-line.
-  int startIndex = pos;
-  while (--startIndex >= 0) {
-    if (strchr(breakChars, buf32[startIndex])) {
-      break;
-    }
-  }
-  ++startIndex;
-  int itemLength = pos - startIndex;
-  Utf32String unicodeCopy(&buf32[startIndex], itemLength);
-  Utf8String parseItem(unicodeCopy);
-
-  // get a list of completions
-  completionCallback(parseItem.get(), &lc);
-
-  // if no completions, we are done
-  if (lc.completionStrings.size() == 0) {
-    beep();
-    freeCompletions(&lc);
-    return 0;
-  }
-
-  // at least one completion
-  int longestCommonPrefix = 0;
-  int displayLength = 0;
-  if (lc.completionStrings.size() == 1) {
-    longestCommonPrefix = static_cast<int>(lc.completionStrings[0].length());
-  } else {
-    bool keepGoing = true;
-    while (keepGoing) {
-      for (size_t j = 0; j < lc.completionStrings.size() - 1; ++j) {
-        char32_t c1 = lc.completionStrings[j][longestCommonPrefix];
-        char32_t c2 = lc.completionStrings[j + 1][longestCommonPrefix];
-        if ((0 == c1) || (0 == c2) || (c1 != c2)) {
-          keepGoing = false;
-          break;
-        }
-      }
-      if (keepGoing) {
-        ++longestCommonPrefix;
-      }
-    }
-  }
-  if (lc.completionStrings.size() != 1) {  // beep if ambiguous
-    beep();
-  }
-
-  // if we can extend the item, extend it and return to main loop
-  if (longestCommonPrefix > itemLength) {
-    displayLength = len + longestCommonPrefix - itemLength;
-    if (displayLength > buflen) {
-      longestCommonPrefix -= displayLength - buflen;  // don't overflow buffer
-      displayLength = buflen;                         // truncate the insertion
-      beep();                                         // and make a noise
-    }
-    Utf32String displayText(displayLength + 1);
-    memcpy(displayText.get(), buf32, sizeof(char32_t) * startIndex);
-    memcpy(&displayText[startIndex], &lc.completionStrings[0][0],
-           sizeof(char32_t) * longestCommonPrefix);
-    int tailIndex = startIndex + longestCommonPrefix;
-    memcpy(&displayText[tailIndex], &buf32[pos],
-           sizeof(char32_t) * (displayLength - tailIndex + 1));
-    copyString32(buf32, displayText.get(), displayLength);
-    pos = startIndex + longestCommonPrefix;
-    len = displayLength;
-    refreshLine(pi);
-    return 0;
-  }
-
-  // we can't complete any further, wait for second tab
-  do {
-    c = linenoiseReadChar();
-    c = cleanupCtrl(c);
-  } while (c == static_cast<char32_t>(-1));
-
-  // if any character other than tab, pass it to the main loop
-  if (c != ctrlChar('I')) {
-    freeCompletions(&lc);
-    return c;
-  }
-
-  // we got a second tab, maybe show list of possible completions
-  bool showCompletions = true;
-  bool onNewLine = false;
-  if (lc.completionStrings.size() > completionCountCutoff) {
-    int savePos =
-        pos;  // move cursor to EOL to avoid overwriting the command line
-    pos = len;
-    refreshLine(pi);
-    pos = savePos;
-    printf("\nDisplay all %u possibilities? (y or n)",
-           static_cast<unsigned int>(lc.completionStrings.size()));
-    fflush(stdout);
-    onNewLine = true;
-    while (c != 'y' && c != 'Y' && c != 'n' && c != 'N' && c != ctrlChar('C')) {
-      do {
-        c = linenoiseReadChar();
-        c = cleanupCtrl(c);
-      } while (c == static_cast<char32_t>(-1));
-    }
-    switch (c) {
-      case 'n':
-      case 'N':
-        showCompletions = false;
-        freeCompletions(&lc);
-        break;
-      case ctrlChar('C'):
-        showCompletions = false;
-        freeCompletions(&lc);
-        if (write(1, "^C", 2) == -1) return -1;  // Display the ^C we got
-        c = 0;
-        break;
-    }
-  }
-
-  // if showing the list, do it the way readline does it
-  bool stopList = false;
-  if (showCompletions) {
-    int longestCompletion = 0;
-    for (size_t j = 0; j < lc.completionStrings.size(); ++j) {
-      itemLength = static_cast<int>(lc.completionStrings[j].length());
-      if (itemLength > longestCompletion) {
-        longestCompletion = itemLength;
-      }
-    }
-    longestCompletion += 2;
-    int columnCount = pi.promptScreenColumns / longestCompletion;
-    if (columnCount < 1) {
-      columnCount = 1;
-    }
-    if (!onNewLine) {  // skip this if we showed "Display all %d possibilities?"
-      int savePos =
-          pos;  // move cursor to EOL to avoid overwriting the command line
-      pos = len;
-      refreshLine(pi);
-      pos = savePos;
-    }
-    size_t pauseRow = getScreenRows() - 1;
-    size_t rowCount =
-        (lc.completionStrings.size() + columnCount - 1) / columnCount;
-    for (size_t row = 0; row < rowCount; ++row) {
-      if (row == pauseRow) {
-        printf("\n--More--");
-        fflush(stdout);
-        c = 0;
-        bool doBeep = false;
-        while (c != ' ' && c != '\r' && c != '\n' && c != 'y' && c != 'Y' &&
-               c != 'n' && c != 'N' && c != 'q' && c != 'Q' &&
-               c != ctrlChar('C')) {
-          if (doBeep) {
-            beep();
-          }
-          doBeep = true;
-          do {
-            c = linenoiseReadChar();
-            c = cleanupCtrl(c);
-          } while (c == static_cast<char32_t>(-1));
-        }
-        switch (c) {
-          case ' ':
-          case 'y':
-          case 'Y':
-            printf("\r        \r");
-            pauseRow += getScreenRows() - 1;
-            break;
-          case '\r':
-          case '\n':
-            printf("\r        \r");
-            ++pauseRow;
-            break;
-          case 'n':
-          case 'N':
-          case 'q':
-          case 'Q':
-            printf("\r        \r");
-            stopList = true;
-            break;
-          case ctrlChar('C'):
-            if (write(1, "^C", 2) == -1) return -1;  // Display the ^C we got
-            stopList = true;
-            break;
-        }
-      } else {
-        printf("\n");
-      }
-      if (stopList) {
-        break;
-      }
-      for (int column = 0; column < columnCount; ++column) {
-        size_t index = (column * rowCount) + row;
-        if (index < lc.completionStrings.size()) {
-          itemLength = static_cast<int>(lc.completionStrings[index].length());
-          fflush(stdout);
-          if (write32(1, lc.completionStrings[index].get(), itemLength) == -1)
-            return -1;
-          if (((column + 1) * rowCount) + row < lc.completionStrings.size()) {
-            for (int k = itemLength; k < longestCompletion; ++k) {
-              printf(" ");
-            }
-          }
-        }
-      }
-    }
-    fflush(stdout);
-    freeCompletions(&lc);
-  }
-
-  // display the prompt on a new line, then redisplay the input buffer
-  if (!stopList || c == ctrlChar('C')) {
-    if (write(1, "\n", 1) == -1) return 0;
-  }
-  if (!pi.write()) return 0;
-#ifndef _WIN32
-  // we have to generate our own newline on line wrap on Linux
-  if (pi.promptIndentation == 0 && pi.promptExtraLines > 0)
-    if (write(1, "\n", 1) == -1) return 0;
-#endif
-  pi.promptCursorRowOffset = pi.promptExtraLines;
-  refreshLine(pi);
-  return 0;
-}
-
-/**
- * Clear the screen ONLY (no redisplay of anything)
- */
-void linenoiseClearScreen(void) {
-#ifdef _WIN32
-  COORD coord = {0, 0};
-  CONSOLE_SCREEN_BUFFER_INFO inf;
-  HANDLE screenHandle = GetStdHandle(STD_OUTPUT_HANDLE);
-  GetConsoleScreenBufferInfo(screenHandle, &inf);
-  SetConsoleCursorPosition(screenHandle, coord);
-  DWORD count;
-  FillConsoleOutputCharacterA(screenHandle, ' ', inf.dwSize.X * inf.dwSize.Y,
-                              coord, &count);
-#else
-  if (write(1, "\x1b[H\x1b[2J", 7) <= 0) return;
-#endif
-}
-
-void InputBuffer::clearScreen(PromptBase& pi) {
-  linenoiseClearScreen();
-  if (!pi.write()) return;
-#ifndef _WIN32
-  // we have to generate our own newline on line wrap on Linux
-  if (pi.promptIndentation == 0 && pi.promptExtraLines > 0)
-    if (write(1, "\n", 1) == -1) return;
-#endif
-  pi.promptCursorRowOffset = pi.promptExtraLines;
-  refreshLine(pi);
-}
-
-/**
- * Incremental history search -- take over the prompt and keyboard as the user
- * types a search
- * string, deletes characters from it, changes direction, and either accepts the
- * found line (for
- * execution orediting) or cancels.
- * @param pi        PromptBase struct holding information about the (old,
- * static) prompt and our
- *                  screen position
- * @param startChar the character that began the search, used to set the initial
- * direction
- */
-int InputBuffer::incrementalHistorySearch(PromptBase& pi, int startChar) {
-  size_t bufferSize;
-  size_t ucharCount = 0;
-
-  // if not already recalling, add the current line to the history list so we
-  // don't have to
-  // special case it
-  if (historyIndex == historyLen - 1) {
-    free(history[historyLen - 1]);
-    bufferSize = sizeof(char32_t) * len + 1;
-    unique_ptr<char[]> tempBuffer(new char[bufferSize]);
-    copyString32to8(tempBuffer.get(), bufferSize, buf32);
-    history[historyLen - 1] = strdup8(tempBuffer.get());
-  }
-  int historyLineLength = len;
-  int historyLinePosition = pos;
-  char32_t emptyBuffer[1];
-  char emptyWidths[1];
-  InputBuffer empty(emptyBuffer, emptyWidths, 1);
-  empty.refreshLine(pi);  // erase the old input first
-  DynamicPrompt dp(pi, (startChar == ctrlChar('R')) ? -1 : 1);
-
-  dp.promptPreviousLen = pi.promptPreviousLen;
-  dp.promptPreviousInputLen = pi.promptPreviousInputLen;
-  dynamicRefresh(dp, buf32, historyLineLength,
-                 historyLinePosition);  // draw user's text with our prompt
-
-  // loop until we get an exit character
-  int c = 0;
-  bool keepLooping = true;
-  bool useSearchedLine = true;
-  bool searchAgain = false;
-  char32_t* activeHistoryLine = 0;
-  while (keepLooping) {
-    c = linenoiseReadChar();
-    c = cleanupCtrl(c);  // convert CTRL + <char> into normal ctrl
-
-    switch (c) {
-      // these characters keep the selected text but do not execute it
-      case ctrlChar('A'):  // ctrl-A, move cursor to start of line
-      case HOME_KEY:
-      case ctrlChar('B'):  // ctrl-B, move cursor left by one character
-      case LEFT_ARROW_KEY:
-      case META + 'b':  // meta-B, move cursor left by one word
-      case META + 'B':
-      case CTRL + LEFT_ARROW_KEY:
-      case META + LEFT_ARROW_KEY:  // Emacs allows Meta, bash & readline don't
-      case ctrlChar('D'):
-      case META + 'd':  // meta-D, kill word to right of cursor
-      case META + 'D':
-      case ctrlChar('E'):  // ctrl-E, move cursor to end of line
-      case END_KEY:
-      case ctrlChar('F'):  // ctrl-F, move cursor right by one character
-      case RIGHT_ARROW_KEY:
-      case META + 'f':  // meta-F, move cursor right by one word
-      case META + 'F':
-      case CTRL + RIGHT_ARROW_KEY:
-      case META + RIGHT_ARROW_KEY:  // Emacs allows Meta, bash & readline don't
-      case META + ctrlChar('H'):
-      case ctrlChar('J'):
-      case ctrlChar('K'):  // ctrl-K, kill from cursor to end of line
-      case ctrlChar('M'):
-      case ctrlChar('N'):  // ctrl-N, recall next line in history
-      case ctrlChar('P'):  // ctrl-P, recall previous line in history
-      case DOWN_ARROW_KEY:
-      case UP_ARROW_KEY:
-      case ctrlChar('T'):  // ctrl-T, transpose characters
-      case ctrlChar(
-          'U'):  // ctrl-U, kill all characters to the left of the cursor
-      case ctrlChar('W'):
-      case META + 'y':  // meta-Y, "yank-pop", rotate popped text
-      case META + 'Y':
-      case 127:
-      case DELETE_KEY:
-      case META + '<':  // start of history
-      case PAGE_UP_KEY:
-      case META + '>':  // end of history
-      case PAGE_DOWN_KEY:
-        keepLooping = false;
-        break;
-
-      // these characters revert the input line to its previous state
-      case ctrlChar('C'):  // ctrl-C, abort this line
-      case ctrlChar('G'):
-      case ctrlChar('L'):  // ctrl-L, clear screen and redisplay line
-        keepLooping = false;
-        useSearchedLine = false;
-        if (c != ctrlChar('L')) {
-          c = -1;  // ctrl-C and ctrl-G just abort the search and do nothing
-                   // else
-        }
-        break;
-
-      // these characters stay in search mode and update the display
-      case ctrlChar('S'):
-      case ctrlChar('R'):
-        if (dp.searchTextLen ==
-            0) {  // if no current search text, recall previous text
-          if (previousSearchText.length()) {
-            dp.updateSearchText(previousSearchText.get());
-          }
-        }
-        if ((dp.direction == 1 && c == ctrlChar('R')) ||
-            (dp.direction == -1 && c == ctrlChar('S'))) {
-          dp.direction = 0 - dp.direction;  // reverse direction
-          dp.updateSearchPrompt();          // change the prompt
-        } else {
-          searchAgain = true;  // same direction, search again
-        }
-        break;
-
-// job control is its own thing
-#ifndef _WIN32
-      case ctrlChar('Z'):  // ctrl-Z, job control
-        disableRawMode();  // Returning to Linux (whatever) shell, leave raw
-                           // mode
-        raise(SIGSTOP);    // Break out in mid-line
-        enableRawMode();   // Back from Linux shell, re-enter raw mode
-        {
-          bufferSize = historyLineLength + 1;
-          unique_ptr<char32_t[]> tempUnicode(new char32_t[bufferSize]);
-          copyString8to32(tempUnicode.get(), bufferSize, ucharCount,
-                          history[historyIndex]);
-          dynamicRefresh(dp, tempUnicode.get(), historyLineLength,
-                         historyLinePosition);
-        }
-        continue;
-        break;
-#endif
-
-      // these characters update the search string, and hence the selected input
-      // line
-      case ctrlChar('H'):  // backspace/ctrl-H, delete char to left of cursor
-        if (dp.searchTextLen > 0) {
-          unique_ptr<char32_t[]> tempUnicode(new char32_t[dp.searchTextLen]);
-          --dp.searchTextLen;
-          dp.searchText[dp.searchTextLen] = 0;
-          copyString32(tempUnicode.get(), dp.searchText.get(),
-                       dp.searchTextLen);
-          dp.updateSearchText(tempUnicode.get());
-        } else {
-          beep();
-        }
-        break;
-
-      case ctrlChar('Y'):  // ctrl-Y, yank killed text
-        break;
-
-      default:
-        if (!isControlChar(c) && c <= 0x0010FFFF) {  // not an action character
-          unique_ptr<char32_t[]> tempUnicode(
-              new char32_t[dp.searchTextLen + 2]);
-          copyString32(tempUnicode.get(), dp.searchText.get(),
-                       dp.searchTextLen);
-          tempUnicode[dp.searchTextLen] = c;
-          tempUnicode[dp.searchTextLen + 1] = 0;
-          dp.updateSearchText(tempUnicode.get());
-        } else {
-          beep();
-        }
-    }  // switch
-
-    // if we are staying in search mode, search now
-    if (keepLooping) {
-      bufferSize = historyLineLength + 1;
-      if (activeHistoryLine) {
-        delete[] activeHistoryLine;
-        activeHistoryLine = nullptr;
-      }
-      activeHistoryLine = new char32_t[bufferSize];
-      copyString8to32(activeHistoryLine, bufferSize, ucharCount,
-                      history[historyIndex]);
-      if (dp.searchTextLen > 0) {
-        bool found = false;
-        int historySearchIndex = historyIndex;
-        int lineLength = static_cast<int>(ucharCount);
-        int lineSearchPos = historyLinePosition;
-        if (searchAgain) {
-          lineSearchPos += dp.direction;
-        }
-        searchAgain = false;
-        while (true) {
-          while ((dp.direction > 0) ? (lineSearchPos < lineLength)
-                                    : (lineSearchPos >= 0)) {
-            if (strncmp32(dp.searchText.get(),
-                          &activeHistoryLine[lineSearchPos],
-                          dp.searchTextLen) == 0) {
-              found = true;
-              break;
-            }
-            lineSearchPos += dp.direction;
-          }
-          if (found) {
-            historyIndex = historySearchIndex;
-            historyLineLength = lineLength;
-            historyLinePosition = lineSearchPos;
-            break;
-          } else if ((dp.direction > 0) ? (historySearchIndex < historyLen - 1)
-                                        : (historySearchIndex > 0)) {
-            historySearchIndex += dp.direction;
-            bufferSize = strlen8(history[historySearchIndex]) + 1;
-            delete[] activeHistoryLine;
-            activeHistoryLine = nullptr;
-            activeHistoryLine = new char32_t[bufferSize];
-            copyString8to32(activeHistoryLine, bufferSize, ucharCount,
-                            history[historySearchIndex]);
-            lineLength = static_cast<int>(ucharCount);
-            lineSearchPos =
-                (dp.direction > 0) ? 0 : (lineLength - dp.searchTextLen);
-          } else {
-            beep();
-            break;
-          }
-        };  // while
-      }
-      if (activeHistoryLine) {
-        delete[] activeHistoryLine;
-        activeHistoryLine = nullptr;
-      }
-      bufferSize = historyLineLength + 1;
-      activeHistoryLine = new char32_t[bufferSize];
-      copyString8to32(activeHistoryLine, bufferSize, ucharCount,
-                      history[historyIndex]);
-      dynamicRefresh(dp, activeHistoryLine, historyLineLength,
-                     historyLinePosition);  // draw user's text with our prompt
-    }
-  }  // while
-
-  // leaving history search, restore previous prompt, maybe make searched line
-  // current
-  PromptBase pb;
-  pb.promptChars = pi.promptIndentation;
-  pb.promptBytes = pi.promptBytes;
-  Utf32String tempUnicode(pb.promptBytes + 1);
-
-  copyString32(tempUnicode.get(), &pi.promptText[pi.promptLastLinePosition],
-               pb.promptBytes - pi.promptLastLinePosition);
-  tempUnicode.initFromBuffer();
-  pb.promptText = tempUnicode;
-  pb.promptExtraLines = 0;
-  pb.promptIndentation = pi.promptIndentation;
-  pb.promptLastLinePosition = 0;
-  pb.promptPreviousInputLen = historyLineLength;
-  pb.promptCursorRowOffset = dp.promptCursorRowOffset;
-  pb.promptScreenColumns = pi.promptScreenColumns;
-  pb.promptPreviousLen = dp.promptChars;
-  if (useSearchedLine && activeHistoryLine) {
-    historyRecallMostRecent = true;
-    copyString32(buf32, activeHistoryLine, buflen + 1);
-    len = historyLineLength;
-    pos = historyLinePosition;
-  }
-  if (activeHistoryLine) {
-    delete[] activeHistoryLine;
-    activeHistoryLine = nullptr;
-  }
-  dynamicRefresh(pb, buf32, len,
-                 pos);  // redraw the original prompt with current input
-  pi.promptPreviousInputLen = len;
-  pi.promptCursorRowOffset = pi.promptExtraLines + pb.promptCursorRowOffset;
-  previousSearchText =
-      dp.searchText;  // save search text for possible reuse on ctrl-R ctrl-R
-  return c;           // pass a character or -1 back to main loop
-}
-
-static bool isCharacterAlphanumeric(char32_t testChar) {
-#ifdef _WIN32
-  return (iswalnum((wint_t)testChar) != 0 ? true : false);
-#else
-  return (iswalnum(testChar) != 0 ? true : false);
-#endif
-}
-
-#ifndef _WIN32
-static bool gotResize = false;
-#endif
-static int keyType = 0;
-
-int InputBuffer::getInputLine(PromptBase& pi) {
-  keyType = 0;
-
-  // The latest history entry is always our current buffer
-  if (len > 0) {
-    size_t bufferSize = sizeof(char32_t) * len + 1;
-    unique_ptr<char[]> tempBuffer(new char[bufferSize]);
-    copyString32to8(tempBuffer.get(), bufferSize, buf32);
-    linenoiseHistoryAdd(tempBuffer.get());
-  } else {
-    linenoiseHistoryAdd("");
-  }
-  historyIndex = historyLen - 1;
-  historyRecallMostRecent = false;
-
-  // display the prompt
-  if (!pi.write()) return -1;
-
-#ifndef _WIN32
-  // we have to generate our own newline on line wrap on Linux
-  if (pi.promptIndentation == 0 && pi.promptExtraLines > 0)
-    if (write(1, "\n", 1) == -1) return -1;
-#endif
-
-  // the cursor starts out at the end of the prompt
-  pi.promptCursorRowOffset = pi.promptExtraLines;
-
-  // kill and yank start in "other" mode
-  killRing.lastAction = KillRing::actionOther;
-
-  // when history search returns control to us, we execute its terminating
-  // keystroke
-  int terminatingKeystroke = -1;
-
-  // if there is already text in the buffer, display it first
-  if (len > 0) {
-    refreshLine(pi);
-  }
-
-  // loop collecting characters, respond to line editing characters
-  while (true) {
-    int c;
-    if (terminatingKeystroke == -1) {
-      c = linenoiseReadChar();  // get a new keystroke
-
-      keyType = 0; 
-      if (c != 0) {
-        // set flag that we got some input
-        if (c == ctrlChar('C')) {
-          keyType = 1;
-        } else if (c == ctrlChar('D')) {
-          keyType = 2;
-        }
-      }
-
-#ifndef _WIN32
-      if (c == 0 && gotResize) {
-        // caught a window resize event
-        // now redraw the prompt and line
-        gotResize = false;
-        pi.promptScreenColumns = getScreenColumns();
-        dynamicRefresh(pi, buf32, len,
-                       pos);  // redraw the original prompt with current input
-        continue;
-      }
-#endif
-    } else {
-      c = terminatingKeystroke;   // use the terminating keystroke from search
-      terminatingKeystroke = -1;  // clear it once we've used it
-    }
-
-    c = cleanupCtrl(c);  // convert CTRL + <char> into normal ctrl
-
-    if (c == 0) {
-      return len;
-    }
-
-    if (c == -1) {
-      refreshLine(pi);
-      continue;
-    }
-
-    if (c == -2) {
-      if (!pi.write()) return -1;
-      refreshLine(pi);
-      continue;
-    }
-
-    // ctrl-I/tab, command completion, needs to be before switch statement
-    if (c == ctrlChar('I') && completionCallback) {
-      killRing.lastAction = KillRing::actionOther;
-      historyRecallMostRecent = false;
-
-      // completeLine does the actual completion and replacement
-      c = completeLine(pi);
-
-      if (c < 0)  // return on error
-        return len;
-
-      if (c == 0)  // read next character when 0
-        continue;
-
-      // deliberate fall-through here, so we use the terminating character
-    }
-
-    switch (c) {
-      case ctrlChar('A'):  // ctrl-A, move cursor to start of line
-      case HOME_KEY:
-        killRing.lastAction = KillRing::actionOther;
-        pos = 0;
-        refreshLine(pi);
-        break;
-
-      case ctrlChar('B'):  // ctrl-B, move cursor left by one character
-      case LEFT_ARROW_KEY:
-        killRing.lastAction = KillRing::actionOther;
-        if (pos > 0) {
-          --pos;
-          refreshLine(pi);
-        }
-        break;
-
-      case META + 'b':  // meta-B, move cursor left by one word
-      case META + 'B':
-      case CTRL + LEFT_ARROW_KEY:
-      case META + LEFT_ARROW_KEY:  // Emacs allows Meta, bash & readline don't
-        killRing.lastAction = KillRing::actionOther;
-        if (pos > 0) {
-          while (pos > 0 && !isCharacterAlphanumeric(buf32[pos - 1])) {
-            --pos;
-          }
-          while (pos > 0 && isCharacterAlphanumeric(buf32[pos - 1])) {
-            --pos;
-          }
-          refreshLine(pi);
-        }
-        break;
-
-      case ctrlChar('C'):  // ctrl-C, abort this line
-        killRing.lastAction = KillRing::actionOther;
-        historyRecallMostRecent = false;
-        errno = EAGAIN;
-        --historyLen;
-        free(history[historyLen]);
-        // we need one last refresh with the cursor at the end of the line
-        // so we don't display the next prompt over the previous input line
-        pos = len;  // pass len as pos for EOL
-        refreshLine(pi);
-        if (write(1, "^C", 2) == -1) return -1;  // Display the ^C we got
-        return -1;
-
-      case META + 'c':  // meta-C, give word initial Cap
-      case META + 'C':
-        killRing.lastAction = KillRing::actionOther;
-        historyRecallMostRecent = false;
-        if (pos < len) {
-          while (pos < len && !isCharacterAlphanumeric(buf32[pos])) {
-            ++pos;
-          }
-          if (pos < len && isCharacterAlphanumeric(buf32[pos])) {
-            if (buf32[pos] >= 'a' && buf32[pos] <= 'z') {
-              buf32[pos] += 'A' - 'a';
-            }
-            ++pos;
-          }
-          while (pos < len && isCharacterAlphanumeric(buf32[pos])) {
-            if (buf32[pos] >= 'A' && buf32[pos] <= 'Z') {
-              buf32[pos] += 'a' - 'A';
-            }
-            ++pos;
-          }
-          refreshLine(pi);
-        }
-        break;
-
-      // ctrl-D, delete the character under the cursor
-      // on an empty line, exit the shell
-      case ctrlChar('D'):
-        killRing.lastAction = KillRing::actionOther;
-        if (len > 0 && pos < len) {
-          historyRecallMostRecent = false;
-          memmove(buf32 + pos, buf32 + pos + 1, sizeof(char32_t) * (len - pos));
-          --len;
-          refreshLine(pi);
-        } else if (len == 0) {
-          --historyLen;
-          free(history[historyLen]);
-          return -1;
-        }
-        break;
-
-      case META + 'd':  // meta-D, kill word to right of cursor
-      case META + 'D':
-        if (pos < len) {
-          historyRecallMostRecent = false;
-          int endingPos = pos;
-          while (endingPos < len &&
-                 !isCharacterAlphanumeric(buf32[endingPos])) {
-            ++endingPos;
-          }
-          while (endingPos < len && isCharacterAlphanumeric(buf32[endingPos])) {
-            ++endingPos;
-          }
-          killRing.kill(&buf32[pos], endingPos - pos, true);
-          memmove(buf32 + pos, buf32 + endingPos,
-                  sizeof(char32_t) * (len - endingPos + 1));
-          len -= endingPos - pos;
-          refreshLine(pi);
-        }
-        killRing.lastAction = KillRing::actionKill;
-        break;
-
-      case ctrlChar('E'):  // ctrl-E, move cursor to end of line
-      case END_KEY:
-        killRing.lastAction = KillRing::actionOther;
-        pos = len;
-        refreshLine(pi);
-        break;
-
-      case ctrlChar('F'):  // ctrl-F, move cursor right by one character
-      case RIGHT_ARROW_KEY:
-        killRing.lastAction = KillRing::actionOther;
-        if (pos < len) {
-          ++pos;
-          refreshLine(pi);
-        }
-        break;
-
-      case META + 'f':  // meta-F, move cursor right by one word
-      case META + 'F':
-      case CTRL + RIGHT_ARROW_KEY:
-      case META + RIGHT_ARROW_KEY:  // Emacs allows Meta, bash & readline don't
-        killRing.lastAction = KillRing::actionOther;
-        if (pos < len) {
-          while (pos < len && !isCharacterAlphanumeric(buf32[pos])) {
-            ++pos;
-          }
-          while (pos < len && isCharacterAlphanumeric(buf32[pos])) {
-            ++pos;
-          }
-          refreshLine(pi);
-        }
-        break;
-
-      case ctrlChar('H'):  // backspace/ctrl-H, delete char to left of cursor
-        killRing.lastAction = KillRing::actionOther;
-        if (pos > 0) {
-          historyRecallMostRecent = false;
-          memmove(buf32 + pos - 1, buf32 + pos,
-                  sizeof(char32_t) * (1 + len - pos));
-          --pos;
-          --len;
-          refreshLine(pi);
-        }
-        break;
-
-      // meta-Backspace, kill word to left of cursor
-      case META + ctrlChar('H'):
-        if (pos > 0) {
-          historyRecallMostRecent = false;
-          int startingPos = pos;
-          while (pos > 0 && !isCharacterAlphanumeric(buf32[pos - 1])) {
-            --pos;
-          }
-          while (pos > 0 && isCharacterAlphanumeric(buf32[pos - 1])) {
-            --pos;
-          }
-          killRing.kill(&buf32[pos], startingPos - pos, false);
-          memmove(buf32 + pos, buf32 + startingPos,
-                  sizeof(char32_t) * (len - startingPos + 1));
-          len -= startingPos - pos;
-          refreshLine(pi);
-        }
-        killRing.lastAction = KillRing::actionKill;
-        break;
-
-      case ctrlChar('J'):  // ctrl-J/linefeed/newline, accept line
-      case ctrlChar('M'):  // ctrl-M/return/enter
-        killRing.lastAction = KillRing::actionOther;
-        // we need one last refresh with the cursor at the end of the line
-        // so we don't display the next prompt over the previous input line
-        pos = len;  // pass len as pos for EOL
-        refreshLine(pi);
-        historyPreviousIndex = historyRecallMostRecent ? historyIndex : -2;
-        --historyLen;
-        free(history[historyLen]);
-        return len;
-
-      case ctrlChar('K'):  // ctrl-K, kill from cursor to end of line
-        killRing.kill(&buf32[pos], len - pos, true);
-        buf32[pos] = '\0';
-        len = pos;
-        refreshLine(pi);
-        killRing.lastAction = KillRing::actionKill;
-        historyRecallMostRecent = false;
-        break;
-
-      case ctrlChar('L'):  // ctrl-L, clear screen and redisplay line
-        clearScreen(pi);
-        break;
-
-      case META + 'l':  // meta-L, lowercase word
-      case META + 'L':
-        killRing.lastAction = KillRing::actionOther;
-        if (pos < len) {
-          historyRecallMostRecent = false;
-          while (pos < len && !isCharacterAlphanumeric(buf32[pos])) {
-            ++pos;
-          }
-          while (pos < len && isCharacterAlphanumeric(buf32[pos])) {
-            if (buf32[pos] >= 'A' && buf32[pos] <= 'Z') {
-              buf32[pos] += 'a' - 'A';
-            }
-            ++pos;
-          }
-          refreshLine(pi);
-        }
-        break;
-
-      case ctrlChar('N'):  // ctrl-N, recall next line in history
-      case ctrlChar('P'):  // ctrl-P, recall previous line in history
-      case DOWN_ARROW_KEY:
-      case UP_ARROW_KEY:
-        killRing.lastAction = KillRing::actionOther;
-        // if not already recalling, add the current line to the history list so
-        // we don't
-        // have to special case it
-        if (historyIndex == historyLen - 1) {
-          free(history[historyLen - 1]);
-          size_t tempBufferSize = sizeof(char32_t) * len + 1;
-          unique_ptr<char[]> tempBuffer(new char[tempBufferSize]);
-          copyString32to8(tempBuffer.get(), tempBufferSize, buf32);
-          history[historyLen - 1] = strdup8(tempBuffer.get());
-        }
-        if (historyLen > 1) {
-          if (c == UP_ARROW_KEY) {
-            c = ctrlChar('P');
-          }
-          if (historyPreviousIndex != -2 && c != ctrlChar('P')) {
-            historyIndex =
-                1 + historyPreviousIndex;  // emulate Windows down-arrow
-          } else {
-            historyIndex += (c == ctrlChar('P')) ? -1 : 1;
-          }
-          historyPreviousIndex = -2;
-          if (historyIndex < 0) {
-            historyIndex = 0;
-            break;
-          } else if (historyIndex >= historyLen) {
-            historyIndex = historyLen - 1;
-            break;
-          }
-          historyRecallMostRecent = true;
-          size_t ucharCount = 0;
-          copyString8to32(buf32, buflen, ucharCount, history[historyIndex]);
-          len = pos = static_cast<int>(ucharCount);
-          refreshLine(pi);
-        }
-        break;
-
-      case ctrlChar('R'):  // ctrl-R, reverse history search
-      case ctrlChar('S'):  // ctrl-S, forward history search
-        terminatingKeystroke = incrementalHistorySearch(pi, c);
-        break;
-
-      case ctrlChar('T'):  // ctrl-T, transpose characters
-        killRing.lastAction = KillRing::actionOther;
-        if (pos > 0 && len > 1) {
-          historyRecallMostRecent = false;
-          size_t leftCharPos = (pos == len) ? pos - 2 : pos - 1;
-          char32_t aux = buf32[leftCharPos];
-          buf32[leftCharPos] = buf32[leftCharPos + 1];
-          buf32[leftCharPos + 1] = aux;
-          if (pos != len) ++pos;
-          refreshLine(pi);
-        }
-        break;
-
-      case ctrlChar(
-          'U'):  // ctrl-U, kill all characters to the left of the cursor
-        if (pos > 0) {
-          historyRecallMostRecent = false;
-          killRing.kill(&buf32[0], pos, false);
-          len -= pos;
-          memmove(buf32, buf32 + pos, sizeof(char32_t) * (len + 1));
-          pos = 0;
-          refreshLine(pi);
-        }
-        killRing.lastAction = KillRing::actionKill;
-        break;
-
-      case META + 'u':  // meta-U, uppercase word
-      case META + 'U':
-        killRing.lastAction = KillRing::actionOther;
-        if (pos < len) {
-          historyRecallMostRecent = false;
-          while (pos < len && !isCharacterAlphanumeric(buf32[pos])) {
-            ++pos;
-          }
-          while (pos < len && isCharacterAlphanumeric(buf32[pos])) {
-            if (buf32[pos] >= 'a' && buf32[pos] <= 'z') {
-              buf32[pos] += 'A' - 'a';
-            }
-            ++pos;
-          }
-          refreshLine(pi);
-        }
-        break;
-
-      // ctrl-W, kill to whitespace (not word) to left of cursor
-      case ctrlChar('W'):
-        if (pos > 0) {
-          historyRecallMostRecent = false;
-          int startingPos = pos;
-          while (pos > 0 && buf32[pos - 1] == ' ') {
-            --pos;
-          }
-          while (pos > 0 && buf32[pos - 1] != ' ') {
-            --pos;
-          }
-          killRing.kill(&buf32[pos], startingPos - pos, false);
-          memmove(buf32 + pos, buf32 + startingPos,
-                  sizeof(char32_t) * (len - startingPos + 1));
-          len -= startingPos - pos;
-          refreshLine(pi);
-        }
-        killRing.lastAction = KillRing::actionKill;
-        break;
-
-      case ctrlChar('Y'):  // ctrl-Y, yank killed text
-        historyRecallMostRecent = false;
-        {
-          Utf32String* restoredText = killRing.yank();
-          if (restoredText) {
-            bool truncated = false;
-            size_t ucharCount = restoredText->length();
-            if (ucharCount > static_cast<size_t>(buflen - len)) {
-              ucharCount = buflen - len;
-              truncated = true;
-            }
-            memmove(buf32 + pos + ucharCount, buf32 + pos,
-                    sizeof(char32_t) * (len - pos + 1));
-            memmove(buf32 + pos, restoredText->get(),
-                    sizeof(char32_t) * ucharCount);
-            pos += static_cast<int>(ucharCount);
-            len += static_cast<int>(ucharCount);
-            refreshLine(pi);
-            killRing.lastAction = KillRing::actionYank;
-            killRing.lastYankSize = ucharCount;
-            if (truncated) {
-              beep();
-            }
-          } else {
-            beep();
-          }
-        }
-        break;
-
-      case META + 'y':  // meta-Y, "yank-pop", rotate popped text
-      case META + 'Y':
-        if (killRing.lastAction == KillRing::actionYank) {
-          historyRecallMostRecent = false;
-          Utf32String* restoredText = killRing.yankPop();
-          if (restoredText) {
-            bool truncated = false;
-            size_t ucharCount = restoredText->length();
-            if (ucharCount >
-                static_cast<size_t>(killRing.lastYankSize + buflen - len)) {
-              ucharCount = killRing.lastYankSize + buflen - len;
-              truncated = true;
-            }
-            if (ucharCount > killRing.lastYankSize) {
-              memmove(buf32 + pos + ucharCount - killRing.lastYankSize,
-                      buf32 + pos, sizeof(char32_t) * (len - pos + 1));
-              memmove(buf32 + pos - killRing.lastYankSize, restoredText->get(),
-                      sizeof(char32_t) * ucharCount);
-            } else {
-              memmove(buf32 + pos - killRing.lastYankSize, restoredText->get(),
-                      sizeof(char32_t) * ucharCount);
-              memmove(buf32 + pos + ucharCount - killRing.lastYankSize,
-                      buf32 + pos, sizeof(char32_t) * (len - pos + 1));
-            }
-            pos += static_cast<int>(ucharCount - killRing.lastYankSize);
-            len += static_cast<int>(ucharCount - killRing.lastYankSize);
-            killRing.lastYankSize = ucharCount;
-            refreshLine(pi);
-            if (truncated) {
-              beep();
-            }
-            break;
-          }
-        }
-        beep();
-        break;
-
-#ifndef _WIN32
-      case ctrlChar('Z'):  // ctrl-Z, job control
-        disableRawMode();  // Returning to Linux (whatever) shell, leave raw
-                           // mode
-        raise(SIGSTOP);    // Break out in mid-line
-        enableRawMode();   // Back from Linux shell, re-enter raw mode
-        if (!pi.write()) break;  // Redraw prompt
-        refreshLine(pi);         // Refresh the line
-        break;
-#endif
-
-      // DEL, delete the character under the cursor
-      case 127:
-      case DELETE_KEY:
-        killRing.lastAction = KillRing::actionOther;
-        if (len > 0 && pos < len) {
-          historyRecallMostRecent = false;
-          memmove(buf32 + pos, buf32 + pos + 1, sizeof(char32_t) * (len - pos));
-          --len;
-          refreshLine(pi);
-        }
-        break;
-
-      case META + '<':     // meta-<, beginning of history
-      case PAGE_UP_KEY:    // Page Up, beginning of history
-      case META + '>':     // meta->, end of history
-      case PAGE_DOWN_KEY:  // Page Down, end of history
-        killRing.lastAction = KillRing::actionOther;
-        // if not already recalling, add the current line to the history list so
-        // we don't
-        // have to special case it
-        if (historyIndex == historyLen - 1) {
-          free(history[historyLen - 1]);
-          size_t tempBufferSize = sizeof(char32_t) * len + 1;
-          unique_ptr<char[]> tempBuffer(new char[tempBufferSize]);
-          copyString32to8(tempBuffer.get(), tempBufferSize, buf32);
-          history[historyLen - 1] = strdup8(tempBuffer.get());
-        }
-        if (historyLen > 1) {
-          historyIndex =
-              (c == META + '<' || c == PAGE_UP_KEY) ? 0 : historyLen - 1;
-          historyPreviousIndex = -2;
-          historyRecallMostRecent = true;
-          size_t ucharCount = 0;
-          copyString8to32(buf32, buflen, ucharCount, history[historyIndex]);
-          len = pos = static_cast<int>(ucharCount);
-          refreshLine(pi);
-        }
-        break;
-
-      // not one of our special characters, maybe insert it in the buffer
-      default:
-        killRing.lastAction = KillRing::actionOther;
-        historyRecallMostRecent = false;
-        if (c & (META | CTRL)) {  // beep on unknown Ctrl and/or Meta keys
-          beep();
-          break;
-        }
-        if (len < buflen) {
-          if (isControlChar(c)) {  // don't insert control characters
-            beep();
-            break;
-          }
-          if (len == pos) {  // at end of buffer
-            buf32[pos] = c;
-            ++pos;
-            ++len;
-            buf32[len] = '\0';
-            int inputLen = calculateColumnPosition(buf32, len);
-            if (pi.promptIndentation + inputLen < pi.promptScreenColumns) {
-              if (inputLen > pi.promptPreviousInputLen)
-                pi.promptPreviousInputLen = inputLen;
-              /* Avoid a full update of the line in the
-               * trivial case. */
-              if (write32(1, reinterpret_cast<char32_t*>(&c), 1) == -1)
-                return -1;
-            } else {
-              refreshLine(pi);
-            }
-          } else {  // not at end of buffer, have to move characters to our
-                    // right
-            memmove(buf32 + pos + 1, buf32 + pos,
-                    sizeof(char32_t) * (len - pos));
-            buf32[pos] = c;
-            ++len;
-            ++pos;
-            buf32[len] = '\0';
-            refreshLine(pi);
-          }
-        } else {
-          beep();  // buffer is full, beep on new characters
-        }
-        break;
-    }
-  }
-  return len;
-}
-
-static string preloadedBufferContents;  // used with linenoisePreloadBuffer
-static string preloadErrorMessage;
-
-/**
- * linenoisePreloadBuffer provides text to be inserted into the command buffer
- *
- * the provided text will be processed to be usable and will be used to preload
- * the input buffer on the next call to linenoise()
- *
- * @param preloadText text to begin with on the next call to linenoise()
- */
-void linenoisePreloadBuffer(const char* preloadText) {
-  if (!preloadText) {
-    return;
-  }
-  int bufferSize = static_cast<int>(strlen(preloadText) + 1);
-  unique_ptr<char[]> tempBuffer(new char[bufferSize]);
-  strncpy(&tempBuffer[0], preloadText, bufferSize);
-
-  // remove characters that won't display correctly
-  char* pIn = &tempBuffer[0];
-  char* pOut = pIn;
-  bool controlsStripped = false;
-  bool whitespaceSeen = false;
-  while (*pIn) {
-    unsigned char c =
-        *pIn++;       // we need unsigned so chars 0x80 and above are allowed
-    if ('\r' == c) {  // silently skip CR
-      continue;
-    }
-    if ('\n' == c || '\t' == c) {  // note newline or tab
-      whitespaceSeen = true;
-      continue;
-    }
-    if (isControlChar(
-            c)) {  // remove other control characters, flag for message
-      controlsStripped = true;
-      *pOut++ = ' ';
-      continue;
-    }
-    if (whitespaceSeen) {  // convert whitespace to a single space
-      *pOut++ = ' ';
-      whitespaceSeen = false;
-    }
-    *pOut++ = c;
-  }
-  *pOut = 0;
-  int processedLength = static_cast<int>(pOut - tempBuffer.get());
-  bool lineTruncated = false;
-  if (processedLength > (LINENOISE_MAX_LINE - 1)) {
-    lineTruncated = true;
-    tempBuffer[LINENOISE_MAX_LINE - 1] = 0;
-  }
-  preloadedBufferContents = tempBuffer.get();
-  if (controlsStripped) {
-    preloadErrorMessage +=
-        " [Edited line: control characters were converted to spaces]\n";
-  }
-  if (lineTruncated) {
-    preloadErrorMessage += " [Edited line: the line length was reduced from ";
-    char buf[128];
-    snprintf(buf, sizeof(buf), "%d to %d]\n", processedLength,
-             (LINENOISE_MAX_LINE - 1));
-    preloadErrorMessage += buf;
-  }
-}
-
-/**
- * linenoise is a readline replacement.
- *
- * call it with a prompt to display and it will return a line of input from the
- * user
- *
- * @param prompt text of prompt to display to the user
- * @return       the returned string belongs to the caller on return and must be
- * freed to prevent
- *               memory leaks
- */
-char* linenoise(const char* prompt) {
-#ifndef _WIN32
-  gotResize = false;
-#endif
-  if (isatty(STDIN_FILENO)) {  // input is from a terminal
-    char32_t buf32[LINENOISE_MAX_LINE];
-    char charWidths[LINENOISE_MAX_LINE];
-    if (!preloadErrorMessage.empty()) {
-      printf("%s", preloadErrorMessage.c_str());
-      fflush(stdout);
-      preloadErrorMessage.clear();
-    }
-    PromptInfo pi(prompt, getScreenColumns());
-    if (isUnsupportedTerm()) {
-      if (!pi.write()) return 0;
-      fflush(stdout);
-      if (preloadedBufferContents.empty()) {
-        unique_ptr<char[]> buf8(new char[LINENOISE_MAX_LINE]);
-        if (fgets(buf8.get(), LINENOISE_MAX_LINE, stdin) == NULL) {
-          return NULL;
-        }
-        size_t len = strlen(buf8.get());
-        while (len && (buf8[len - 1] == '\n' || buf8[len - 1] == '\r')) {
-          --len;
-          buf8[len] = '\0';
-        }
-        return strdup(buf8.get());  // caller must free buffer
-      } else {
-        char* buf8 = strdup(preloadedBufferContents.c_str());
-        preloadedBufferContents.clear();
-        return buf8;  // caller must free buffer
-      }
-    } else {
-      if (enableRawMode() == -1) {
-        return NULL;
-      }
-      InputBuffer ib(buf32, charWidths, LINENOISE_MAX_LINE);
-      if (!preloadedBufferContents.empty()) {
-        ib.preloadBuffer(preloadedBufferContents.c_str());
-        preloadedBufferContents.clear();
-      }
-      int count = ib.getInputLine(pi);
-      disableRawMode();
-      printf("\n");
-      if (count == -1) {
-        return NULL;
-      }
-      size_t bufferSize = sizeof(char32_t) * ib.length() + 1;
-      unique_ptr<char[]> buf8(new char[bufferSize]);
-      copyString32to8(buf8.get(), bufferSize, buf32);
-      return strdup(buf8.get());  // caller must free buffer
-    }
-  } else {  // input not from a terminal, we should work with piped input, i.e.
-            // redirected stdin
-    unique_ptr<char[]> buf8(new char[LINENOISE_MAX_LINE]);
-    if (fgets(buf8.get(), LINENOISE_MAX_LINE, stdin) == NULL) {
-      return NULL;
-    }
-
-    // if fgets() gave us the newline, remove it
-    int count = static_cast<int>(strlen(buf8.get()));
-    if (count > 0 && buf8[count - 1] == '\n') {
-      --count;
-      buf8[count] = '\0';
-    }
-    return strdup(buf8.get());  // caller must free buffer
-  }
-}
-
-/* Register a callback function to be called for tab-completion. */
-void linenoiseSetCompletionCallback(linenoiseCompletionCallback* fn) {
-  completionCallback = fn;
-}
-
-void linenoiseAddCompletion(linenoiseCompletions* lc, const char* str) {
-  lc->completionStrings.push_back(Utf32String(str));
-}
-
-int linenoiseHistoryAdd(const char* line) {
-  if (historyMaxLen == 0) {
-    return 0;
-  }
-  if (history == NULL) {
-    history =
-        reinterpret_cast<char8_t**>(malloc(sizeof(char8_t*) * historyMaxLen));
-    if (history == NULL) {
-      return 0;
-    }
-    memset(history, 0, (sizeof(char*) * historyMaxLen));
-  }
-  char8_t* linecopy = strdup8(line);
-  if (!linecopy) {
-    return 0;
-  }
-
-  // convert newlines in multi-line code to spaces before storing
-  char8_t* p = linecopy;
-  while (*p) {
-    if (*p == '\n') {
-      *p = ' ';
-    }
-    ++p;
-  }
-
-  // prevent duplicate history entries
-  if (historyLen > 0 && history[historyLen - 1] != nullptr &&
-      strcmp(reinterpret_cast<char const*>(history[historyLen - 1]),
-             reinterpret_cast<char const*>(linecopy)) == 0) {
-    free(linecopy);
-    return 0;
-  }
-
-  if (historyLen == historyMaxLen) {
-    free(history[0]);
-    memmove(history, history + 1, sizeof(char*) * (historyMaxLen - 1));
-    --historyLen;
-    if (--historyPreviousIndex < -1) {
-      historyPreviousIndex = -2;
-    }
-  }
-
-  history[historyLen] = linecopy;
-  ++historyLen;
-  return 1;
-}
-
-int linenoiseHistorySetMaxLen(int len) {
-  if (len < 1) {
-    return 0;
-  }
-  if (history) {
-    int tocopy = historyLen;
-    char8_t** newHistory =
-        reinterpret_cast<char8_t**>(malloc(sizeof(char8_t*) * len));
-    if (newHistory == NULL) {
-      return 0;
-    }
-    if (len < tocopy) {
-      tocopy = len;
-    }
-    memcpy(newHistory, history + historyMaxLen - tocopy,
-           sizeof(char8_t*) * tocopy);
-    free(history);
-    history = newHistory;
-  }
-  historyMaxLen = len;
-  if (historyLen > historyMaxLen) {
-    historyLen = historyMaxLen;
-  }
-  return 1;
-}
-
-/* Fetch a line of the history by (zero-based) index.  If the requested
- * line does not exist, NULL is returned.  The return value is a heap-allocated
- * copy of the line, and the caller is responsible for de-allocating it. */
-char* linenoiseHistoryLine(int index) {
-  if (index < 0 || index >= historyLen) return NULL;
-
-  return strdup(reinterpret_cast<char const*>(history[index]));
-}
-
-/* Save the history in the specified file. On success 0 is returned
- * otherwise -1 is returned. */
-int linenoiseHistorySave(const char* filename) {
-#if _WIN32
-  FILE* fp = fopen(filename, "wt");
-#else
-  int fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
-
-  if (fd < 0) {
-    return -1;
-  }
-
-  FILE* fp = fdopen(fd, "wt");
-#endif
-
-  if (fp == NULL) {
-    return -1;
-  }
-
-  for (int j = 0; j < historyLen; ++j) {
-    if (history[j][0] != '\0') {
-      fprintf(fp, "%s\n", history[j]);
-    }
-  }
-
-  fclose(fp);
-
-  return 0;
-}
-
-/* Load the history from the specified file. If the file does not exist
- * zero is returned and no operation is performed.
- *
- * If the file exists and the operation succeeded 0 is returned, otherwise
- * on error -1 is returned. */
-int linenoiseHistoryLoad(const char* filename) {
-  FILE* fp = fopen(filename, "rt");
-  if (fp == NULL) {
-    return -1;
-  }
-
-  char buf[LINENOISE_MAX_LINE];
-  while (fgets(buf, LINENOISE_MAX_LINE, fp) != NULL) {
-    char* p = strchr(buf, '\r');
-    if (!p) {
-      p = strchr(buf, '\n');
-    }
-    if (p) {
-      *p = '\0';
-    }
-    if (p != buf) {
-      linenoiseHistoryAdd(buf);
-    }
-  }
-  fclose(fp);
-  return 0;
-}
-
-/* Set if to use or not the multi line mode. */
-/* note that this is a stub only, as linenoise-ng always multi-line */
-void linenoiseSetMultiLine(int) {}
-
-/* This special mode is used by linenoise in order to print scan codes
- * on screen for debugging / development purposes. It is implemented
- * by the linenoise_example program using the --keycodes option. */
-void linenoisePrintKeyCodes(void) {
-  char quit[4];
-
-  printf(
-      "Linenoise key codes debugging mode.\n"
-      "Press keys to see scan codes. Type 'quit' at any time to exit.\n");
-  if (enableRawMode() == -1) return;
-  memset(quit, ' ', 4);
-  while (1) {
-    char c;
-    int nread;
-
-#if _WIN32
-    nread = _read(STDIN_FILENO, &c, 1);
-#else
-    nread = read(STDIN_FILENO, &c, 1);
-#endif
-    if (nread <= 0) continue;
-    memmove(quit, quit + 1, sizeof(quit) - 1); /* shift string to left. */
-    quit[sizeof(quit) - 1] = c; /* Insert current char on the right. */
-    if (memcmp(quit, "quit", sizeof(quit)) == 0) break;
-
-    printf("'%c' %02x (%d) (type quit to exit)\n", isprint(c) ? c : '?', (int)c,
-           (int)c);
-    printf("\r"); /* Go left edge manually, we are in raw mode. */
-    fflush(stdout);
-  }
-  disableRawMode();
-}
-
-#ifndef _WIN32
-static void WindowSizeChanged(int) {
-  // do nothing here but setting this flag
-  gotResize = true;
-}
-#endif
-
-int linenoiseInstallWindowChangeHandler(void) {
-#ifndef _WIN32
-  struct sigaction sa;
-  sigemptyset(&sa.sa_mask);
-  sa.sa_flags = 0;
-  sa.sa_handler = &WindowSizeChanged;
-
-  if (sigaction(SIGWINCH, &sa, nullptr) == -1) {
-    return errno;
-  }
-#endif
-  return 0;
-}
-
-int linenoiseKeyType(void) {
-  return keyType;
-}
diff --git a/src/linenoise/linenoise.h b/src/linenoise/linenoise.h
deleted file mode 100644
index 3a8eb9f7ee63..000000000000
--- a/src/linenoise/linenoise.h
+++ /dev/null
@@ -1,73 +0,0 @@
-/* linenoise.h -- guerrilla line editing library against the idea that a
- * line editing lib needs to be 20,000 lines of C code.
- *
- * See linenoise.c for more information.
- *
- * Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
- * Copyright (c) 2010, Pieter Noordhuis <pcnoordhuis at gmail dot com>
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *   * Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *   * Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- *   * Neither the name of Redis nor the names of its contributors may be used
- *     to endorse or promote products derived from this software without
- *     specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef __LINENOISE_H
-#define __LINENOISE_H
-
-#define LINENOISE_VERSION "1.0.0"
-#define LINENOISE_VERSION_MAJOR 1
-#define LINENOISE_VERSION_MINOR 1
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef struct linenoiseCompletions linenoiseCompletions;
-
-typedef void(linenoiseCompletionCallback)(const char*, linenoiseCompletions*);
-void linenoiseSetCompletionCallback(linenoiseCompletionCallback* fn);
-void linenoiseAddCompletion(linenoiseCompletions* lc, const char* str);
-
-char* linenoise(const char* prompt);
-void linenoisePreloadBuffer(const char* preloadText);
-int linenoiseHistoryAdd(const char* line);
-int linenoiseHistorySetMaxLen(int len);
-char* linenoiseHistoryLine(int index);
-int linenoiseHistorySave(const char* filename);
-int linenoiseHistoryLoad(const char* filename);
-void linenoiseHistoryFree(void);
-void linenoiseClearScreen(void);
-void linenoiseSetMultiLine(int ml);
-void linenoisePrintKeyCodes(void);
-/* the following are extensions to the original linenoise API */
-int linenoiseInstallWindowChangeHandler(void);
-/* returns type of key pressed: 1 = CTRL-C, 2 = CTRL-D, 0 = other */ 
-int linenoiseKeyType(void);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* __LINENOISE_H */
diff --git a/src/linenoise/wcwidth.cpp b/src/linenoise/wcwidth.cpp
deleted file mode 100644
index deec0ba6b57f..000000000000
--- a/src/linenoise/wcwidth.cpp
+++ /dev/null
@@ -1,315 +0,0 @@
-/*
- * This is an implementation of wcwidth() and wcswidth() (defined in
- * IEEE Std 1002.1-2001) for Unicode.
- *
- * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
- * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
- *
- * In fixed-width output devices, Latin characters all occupy a single
- * "cell" position of equal width, whereas ideographic CJK characters
- * occupy two such cells. Interoperability between terminal-line
- * applications and (teletype-style) character terminals using the
- * UTF-8 encoding requires agreement on which character should advance
- * the cursor by how many cell positions. No established formal
- * standards exist at present on which Unicode character shall occupy
- * how many cell positions on character terminals. These routines are
- * a first attempt of defining such behavior based on simple rules
- * applied to data provided by the Unicode Consortium.
- *
- * For some graphical characters, the Unicode standard explicitly
- * defines a character-cell width via the definition of the East Asian
- * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
- * In all these cases, there is no ambiguity about which width a
- * terminal shall use. For characters in the East Asian Ambiguous (A)
- * class, the width choice depends purely on a preference of backward
- * compatibility with either historic CJK or Western practice.
- * Choosing single-width for these characters is easy to justify as
- * the appropriate long-term solution, as the CJK practice of
- * displaying these characters as double-width comes from historic
- * implementation simplicity (8-bit encoded characters were displayed
- * single-width and 16-bit ones double-width, even for Greek,
- * Cyrillic, etc.) and not any typographic considerations.
- *
- * Much less clear is the choice of width for the Not East Asian
- * (Neutral) class. Existing practice does not dictate a width for any
- * of these characters. It would nevertheless make sense
- * typographically to allocate two character cells to characters such
- * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
- * represented adequately with a single-width glyph. The following
- * routines at present merely assign a single-cell width to all
- * neutral characters, in the interest of simplicity. This is not
- * entirely satisfactory and should be reconsidered before
- * establishing a formal standard in this area. At the moment, the
- * decision which Not East Asian (Neutral) characters should be
- * represented by double-width glyphs cannot yet be answered by
- * applying a simple rule from the Unicode database content. Setting
- * up a proper standard for the behavior of UTF-8 character terminals
- * will require a careful analysis not only of each Unicode character,
- * but also of each presentation form, something the author of these
- * routines has avoided to do so far.
- *
- * http://www.unicode.org/unicode/reports/tr11/
- *
- * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
- *
- * Permission to use, copy, modify, and distribute this software
- * for any purpose and without fee is hereby granted. The author
- * disclaims all warranties with regard to this software.
- *
- * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
- */
-
-#include <wchar.h>
-#include <string>
-#include <memory>
-
-namespace linenoise_ng {
-
-struct interval {
-  char32_t first;
-  char32_t last;
-};
-
-/* auxiliary function for binary search in interval table */
-static int bisearch(char32_t ucs, const struct interval *table, int max) {
-  int min = 0;
-  int mid;
-
-  if (ucs < table[0].first || ucs > table[max].last)
-    return 0;
-  while (max >= min) {
-    mid = (min + max) / 2;
-    if (ucs > table[mid].last)
-      min = mid + 1;
-    else if (ucs < table[mid].first)
-      max = mid - 1;
-    else
-      return 1;
-  }
-
-  return 0;
-}
-
-
-/* The following two functions define the column width of an ISO 10646
- * character as follows:
- *
- *    - The null character (U+0000) has a column width of 0.
- *
- *    - Other C0/C1 control characters and DEL will lead to a return
- *      value of -1.
- *
- *    - Non-spacing and enclosing combining characters (general
- *      category code Mn or Me in the Unicode database) have a
- *      column width of 0.
- *
- *    - SOFT HYPHEN (U+00AD) has a column width of 1.
- *
- *    - Other format characters (general category code Cf in the Unicode
- *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
- *
- *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
- *      have a column width of 0.
- *
- *    - Spacing characters in the East Asian Wide (W) or East Asian
- *      Full-width (F) category as defined in Unicode Technical
- *      Report #11 have a column width of 2.
- *
- *    - All remaining characters (including all printable
- *      ISO 8859-1 and WGL4 characters, Unicode control characters,
- *      etc.) have a column width of 1.
- *
- * This implementation assumes that wchar_t characters are encoded
- * in ISO 10646.
- */
-
-int mk_wcwidth(char32_t ucs)
-{
-  /* sorted list of non-overlapping intervals of non-spacing characters */
-  /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
-  static const struct interval combining[] = {
-    { 0x0300, 0x036F }, { 0x0483, 0x0486 }, { 0x0488, 0x0489 },
-    { 0x0591, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
-    { 0x05C4, 0x05C5 }, { 0x05C7, 0x05C7 }, { 0x0600, 0x0603 },
-    { 0x0610, 0x0615 }, { 0x064B, 0x065E }, { 0x0670, 0x0670 },
-    { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED },
-    { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A },
-    { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 }, { 0x0901, 0x0902 },
-    { 0x093C, 0x093C }, { 0x0941, 0x0948 }, { 0x094D, 0x094D },
-    { 0x0951, 0x0954 }, { 0x0962, 0x0963 }, { 0x0981, 0x0981 },
-    { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD },
-    { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C },
-    { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D },
-    { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC },
-    { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD },
-    { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 }, { 0x0B3C, 0x0B3C },
-    { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 }, { 0x0B4D, 0x0B4D },
-    { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 },
-    { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 },
-    { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 }, { 0x0CBC, 0x0CBC },
-    { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD },
-    { 0x0CE2, 0x0CE3 }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
-    { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
-    { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
-    { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
-    { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
-    { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
-    { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
-    { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
-    { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
-    { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x135F, 0x135F },
-    { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, { 0x1752, 0x1753 },
-    { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD },
-    { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD },
-    { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 },
-    { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, { 0x1939, 0x193B },
-    { 0x1A17, 0x1A18 }, { 0x1B00, 0x1B03 }, { 0x1B34, 0x1B34 },
-    { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C }, { 0x1B42, 0x1B42 },
-    { 0x1B6B, 0x1B73 }, { 0x1DC0, 0x1DCA }, { 0x1DFE, 0x1DFF },
-    { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x2063 },
-    { 0x206A, 0x206F }, { 0x20D0, 0x20EF }, { 0x302A, 0x302F },
-    { 0x3099, 0x309A }, { 0xA806, 0xA806 }, { 0xA80B, 0xA80B },
-    { 0xA825, 0xA826 }, { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F },
-    { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB },
-    { 0x10A01, 0x10A03 }, { 0x10A05, 0x10A06 }, { 0x10A0C, 0x10A0F },
-    { 0x10A38, 0x10A3A }, { 0x10A3F, 0x10A3F }, { 0x1D167, 0x1D169 },
-    { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
-    { 0x1D242, 0x1D244 }, { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F },
-    { 0xE0100, 0xE01EF }
-  };
-
-  /* test for 8-bit control characters */
-  if (ucs == 0)
-    return 0;
-  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
-    return -1;
-
-  /* binary search in table of non-spacing characters */
-  if (bisearch(ucs, combining,
-               sizeof(combining) / sizeof(struct interval) - 1))
-    return 0;
-
-  /* if we arrive here, ucs is not a combining or C0/C1 control character */
-
-  return 1 + 
-    (ucs >= 0x1100 &&
-     (ucs <= 0x115f ||                    /* Hangul Jamo init. consonants */
-      ucs == 0x2329 || ucs == 0x232a ||
-      (ucs >= 0x2e80 && ucs <= 0xa4cf &&
-       ucs != 0x303f) ||                  /* CJK ... Yi */
-      (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
-      (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
-      (ucs >= 0xfe10 && ucs <= 0xfe19) || /* Vertical forms */
-      (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
-      (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
-      (ucs >= 0xffe0 && ucs <= 0xffe6) ||
-      (ucs >= 0x20000 && ucs <= 0x2fffd) ||
-      (ucs >= 0x30000 && ucs <= 0x3fffd)));
-}
-
-
-int mk_wcswidth(const char32_t* pwcs, size_t n)
-{
-  int w, width = 0;
-
-  for (;*pwcs && n-- > 0; pwcs++)
-    if ((w = mk_wcwidth(*pwcs)) < 0)
-      return -1;
-    else
-      width += w;
-
-  return width;
-}
-
-
-/*
- * The following functions are the same as mk_wcwidth() and
- * mk_wcswidth(), except that spacing characters in the East Asian
- * Ambiguous (A) category as defined in Unicode Technical Report #11
- * have a column width of 2. This variant might be useful for users of
- * CJK legacy encodings who want to migrate to UCS without changing
- * the traditional terminal character-width behaviour. It is not
- * otherwise recommended for general use.
- */
-int mk_wcwidth_cjk(wchar_t ucs)
-{
-  /* sorted list of non-overlapping intervals of East Asian Ambiguous
-   * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
-  static const struct interval ambiguous[] = {
-    { 0x00A1, 0x00A1 }, { 0x00A4, 0x00A4 }, { 0x00A7, 0x00A8 },
-    { 0x00AA, 0x00AA }, { 0x00AE, 0x00AE }, { 0x00B0, 0x00B4 },
-    { 0x00B6, 0x00BA }, { 0x00BC, 0x00BF }, { 0x00C6, 0x00C6 },
-    { 0x00D0, 0x00D0 }, { 0x00D7, 0x00D8 }, { 0x00DE, 0x00E1 },
-    { 0x00E6, 0x00E6 }, { 0x00E8, 0x00EA }, { 0x00EC, 0x00ED },
-    { 0x00F0, 0x00F0 }, { 0x00F2, 0x00F3 }, { 0x00F7, 0x00FA },
-    { 0x00FC, 0x00FC }, { 0x00FE, 0x00FE }, { 0x0101, 0x0101 },
-    { 0x0111, 0x0111 }, { 0x0113, 0x0113 }, { 0x011B, 0x011B },
-    { 0x0126, 0x0127 }, { 0x012B, 0x012B }, { 0x0131, 0x0133 },
-    { 0x0138, 0x0138 }, { 0x013F, 0x0142 }, { 0x0144, 0x0144 },
-    { 0x0148, 0x014B }, { 0x014D, 0x014D }, { 0x0152, 0x0153 },
-    { 0x0166, 0x0167 }, { 0x016B, 0x016B }, { 0x01CE, 0x01CE },
-    { 0x01D0, 0x01D0 }, { 0x01D2, 0x01D2 }, { 0x01D4, 0x01D4 },
-    { 0x01D6, 0x01D6 }, { 0x01D8, 0x01D8 }, { 0x01DA, 0x01DA },
-    { 0x01DC, 0x01DC }, { 0x0251, 0x0251 }, { 0x0261, 0x0261 },
-    { 0x02C4, 0x02C4 }, { 0x02C7, 0x02C7 }, { 0x02C9, 0x02CB },
-    { 0x02CD, 0x02CD }, { 0x02D0, 0x02D0 }, { 0x02D8, 0x02DB },
-    { 0x02DD, 0x02DD }, { 0x02DF, 0x02DF }, { 0x0391, 0x03A1 },
-    { 0x03A3, 0x03A9 }, { 0x03B1, 0x03C1 }, { 0x03C3, 0x03C9 },
-    { 0x0401, 0x0401 }, { 0x0410, 0x044F }, { 0x0451, 0x0451 },
-    { 0x2010, 0x2010 }, { 0x2013, 0x2016 }, { 0x2018, 0x2019 },
-    { 0x201C, 0x201D }, { 0x2020, 0x2022 }, { 0x2024, 0x2027 },
-    { 0x2030, 0x2030 }, { 0x2032, 0x2033 }, { 0x2035, 0x2035 },
-    { 0x203B, 0x203B }, { 0x203E, 0x203E }, { 0x2074, 0x2074 },
-    { 0x207F, 0x207F }, { 0x2081, 0x2084 }, { 0x20AC, 0x20AC },
-    { 0x2103, 0x2103 }, { 0x2105, 0x2105 }, { 0x2109, 0x2109 },
-    { 0x2113, 0x2113 }, { 0x2116, 0x2116 }, { 0x2121, 0x2122 },
-    { 0x2126, 0x2126 }, { 0x212B, 0x212B }, { 0x2153, 0x2154 },
-    { 0x215B, 0x215E }, { 0x2160, 0x216B }, { 0x2170, 0x2179 },
-    { 0x2190, 0x2199 }, { 0x21B8, 0x21B9 }, { 0x21D2, 0x21D2 },
-    { 0x21D4, 0x21D4 }, { 0x21E7, 0x21E7 }, { 0x2200, 0x2200 },
-    { 0x2202, 0x2203 }, { 0x2207, 0x2208 }, { 0x220B, 0x220B },
-    { 0x220F, 0x220F }, { 0x2211, 0x2211 }, { 0x2215, 0x2215 },
-    { 0x221A, 0x221A }, { 0x221D, 0x2220 }, { 0x2223, 0x2223 },
-    { 0x2225, 0x2225 }, { 0x2227, 0x222C }, { 0x222E, 0x222E },
-    { 0x2234, 0x2237 }, { 0x223C, 0x223D }, { 0x2248, 0x2248 },
-    { 0x224C, 0x224C }, { 0x2252, 0x2252 }, { 0x2260, 0x2261 },
-    { 0x2264, 0x2267 }, { 0x226A, 0x226B }, { 0x226E, 0x226F },
-    { 0x2282, 0x2283 }, { 0x2286, 0x2287 }, { 0x2295, 0x2295 },
-    { 0x2299, 0x2299 }, { 0x22A5, 0x22A5 }, { 0x22BF, 0x22BF },
-    { 0x2312, 0x2312 }, { 0x2460, 0x24E9 }, { 0x24EB, 0x254B },
-    { 0x2550, 0x2573 }, { 0x2580, 0x258F }, { 0x2592, 0x2595 },
-    { 0x25A0, 0x25A1 }, { 0x25A3, 0x25A9 }, { 0x25B2, 0x25B3 },
-    { 0x25B6, 0x25B7 }, { 0x25BC, 0x25BD }, { 0x25C0, 0x25C1 },
-    { 0x25C6, 0x25C8 }, { 0x25CB, 0x25CB }, { 0x25CE, 0x25D1 },
-    { 0x25E2, 0x25E5 }, { 0x25EF, 0x25EF }, { 0x2605, 0x2606 },
-    { 0x2609, 0x2609 }, { 0x260E, 0x260F }, { 0x2614, 0x2615 },
-    { 0x261C, 0x261C }, { 0x261E, 0x261E }, { 0x2640, 0x2640 },
-    { 0x2642, 0x2642 }, { 0x2660, 0x2661 }, { 0x2663, 0x2665 },
-    { 0x2667, 0x266A }, { 0x266C, 0x266D }, { 0x266F, 0x266F },
-    { 0x273D, 0x273D }, { 0x2776, 0x277F }, { 0xE000, 0xF8FF },
-    { 0xFFFD, 0xFFFD }, { 0xF0000, 0xFFFFD }, { 0x100000, 0x10FFFD }
-  };
-
-  /* binary search in table of non-spacing characters */
-  if (bisearch(ucs, ambiguous,
-               sizeof(ambiguous) / sizeof(struct interval) - 1))
-    return 2;
-
-  return mk_wcwidth(ucs);
-}
-
-
-int mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
-{
-  int w, width = 0;
-
-  for (;*pwcs && n-- > 0; pwcs++)
-    if ((w = mk_wcwidth_cjk(*pwcs)) < 0)
-      return -1;
-    else
-      width += w;
-
-  return width;
-}
-
-}
diff --git a/src/nix-build/local.mk b/src/nix-build/local.mk
deleted file mode 100644
index a2d1c91dfd9d..000000000000
--- a/src/nix-build/local.mk
+++ /dev/null
@@ -1,9 +0,0 @@
-programs += nix-build
-
-nix-build_DIR := $(d)
-
-nix-build_SOURCES := $(d)/nix-build.cc
-
-nix-build_LIBS = libmain libexpr libstore libutil libformat
-
-$(eval $(call install-symlink, nix-build, $(bindir)/nix-shell))
diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc
index 21d99878a518..11ea3b1f7ae1 100755
--- a/src/nix-build/nix-build.cc
+++ b/src/nix-build/nix-build.cc
@@ -16,6 +16,7 @@
 #include "get-drvs.hh"
 #include "common-eval-args.hh"
 #include "attr-path.hh"
+#include "legacy.hh"
 
 using namespace nix;
 using namespace std::string_literals;
@@ -66,11 +67,8 @@ std::vector<string> shellwords(const string & s)
     return res;
 }
 
-void mainWrapped(int argc, char * * argv)
+static void _main(int argc, char * * argv)
 {
-    initNix();
-    initGC();
-
     auto dryRun = false;
     auto runEnv = std::regex_search(argv[0], std::regex("nix-shell$"));
     auto pure = false;
@@ -85,7 +83,6 @@ void mainWrapped(int argc, char * * argv)
     BuildMode buildMode = bmNormal;
     bool readStdin = false;
 
-    auto shell = getEnv("SHELL", "/bin/sh");
     std::string envCommand; // interactive shell
     Strings envExclude;
 
@@ -99,6 +96,9 @@ void mainWrapped(int argc, char * * argv)
 
     std::string outLink = "./result";
 
+    // List of environment variables kept for --pure
+    std::set<string> keepVars{"HOME", "USER", "LOGNAME", "DISPLAY", "PATH", "TERM", "IN_NIX_SHELL", "TZ", "PAGER", "NIX_BUILD_SHELL", "SHLVL"};
+
     Strings args;
     for (int i = 1; i < argc; ++i)
         args.push_back(argv[i]);
@@ -218,6 +218,9 @@ void mainWrapped(int argc, char * * argv)
             }
         }
 
+        else if (*arg == "--keep")
+            keepVars.insert(getArg(*arg, arg, end));
+
         else if (*arg == "-")
             readStdin = true;
 
@@ -239,10 +242,10 @@ void mainWrapped(int argc, char * * argv)
 
     auto store = openStore();
 
-    EvalState state(myArgs.searchPath, store);
-    state.repair = repair;
+    auto state = std::make_unique<EvalState>(myArgs.searchPath, store);
+    state->repair = repair;
 
-    Bindings & autoArgs = *myArgs.getAutoArgs(state);
+    Bindings & autoArgs = *myArgs.getAutoArgs(*state);
 
     if (packages) {
         std::ostringstream joined;
@@ -268,7 +271,7 @@ void mainWrapped(int argc, char * * argv)
     std::vector<Expr *> exprs;
 
     if (readStdin)
-        exprs = {state.parseStdin()};
+        exprs = {state->parseStdin()};
     else
         for (auto i : left) {
             auto absolute = i;
@@ -276,13 +279,13 @@ void mainWrapped(int argc, char * * argv)
                 absolute = canonPath(absPath(i), true);
             } catch (Error e) {};
             if (fromArgs)
-                exprs.push_back(state.parseExprFromString(i, absPath(".")));
+                exprs.push_back(state->parseExprFromString(i, absPath(".")));
             else if (store->isStorePath(absolute) && std::regex_match(absolute, std::regex(".*\\.drv(!.*)?")))
-                drvs.push_back(DrvInfo(state, store, absolute));
+                drvs.push_back(DrvInfo(*state, store, absolute));
             else
                 /* If we're in a #! script, interpret filenames
                    relative to the script. */
-                exprs.push_back(state.parseExprFromFile(resolveExprPath(state.checkSourcePath(lookupFileArg(state,
+                exprs.push_back(state->parseExprFromFile(resolveExprPath(state->checkSourcePath(lookupFileArg(*state,
                     inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i)))));
         }
 
@@ -291,15 +294,17 @@ void mainWrapped(int argc, char * * argv)
 
     for (auto e : exprs) {
         Value vRoot;
-        state.eval(e, vRoot);
+        state->eval(e, vRoot);
 
         for (auto & i : attrPaths) {
-            Value & v(*findAlongAttrPath(state, i, autoArgs, vRoot));
-            state.forceValue(v);
-            getDerivations(state, v, "", autoArgs, drvs, false);
+            Value & v(*findAlongAttrPath(*state, i, autoArgs, vRoot));
+            state->forceValue(v);
+            getDerivations(*state, v, "", autoArgs, drvs, false);
         }
     }
 
+    state->printStats();
+
     auto buildPaths = [&](const PathSet & paths) {
         /* Note: we do this even when !printMissing to efficiently
            fetch binary cache data. */
@@ -332,12 +337,12 @@ void mainWrapped(int argc, char * * argv)
         if (shell == "") {
 
             try {
-                auto expr = state.parseExprFromString("(import <nixpkgs> {}).bashInteractive", absPath("."));
+                auto expr = state->parseExprFromString("(import <nixpkgs> {}).bashInteractive", absPath("."));
 
                 Value v;
-                state.eval(expr, v);
+                state->eval(expr, v);
 
-                auto drv = getDerivation(state, v, false);
+                auto drv = getDerivation(*state, v, false);
                 if (!drv)
                     throw Error("the 'bashInteractive' attribute in <nixpkgs> did not evaluate to a derivation");
 
@@ -368,7 +373,6 @@ void mainWrapped(int argc, char * * argv)
         auto tmp = getEnv("TMPDIR", getEnv("XDG_RUNTIME_DIR", "/tmp"));
 
         if (pure) {
-            std::set<string> keepVars{"HOME", "USER", "LOGNAME", "DISPLAY", "PATH", "TERM", "IN_NIX_SHELL", "TZ", "PAGER", "NIX_BUILD_SHELL", "SHLVL"};
             decltype(env) newEnv;
             for (auto & i : env)
                 if (keepVars.count(i.first))
@@ -397,8 +401,6 @@ void mainWrapped(int argc, char * * argv)
             } else
                 env[var.first] = var.second;
 
-        restoreAffinity();
-
         /* Run a shell using the derivation's environment.  For
            convenience, source $stdenv/setup to setup additional
            environment variables and shell functions.  Also don't
@@ -411,17 +413,20 @@ void mainWrapped(int argc, char * * argv)
                 "dontAddDisableDepTrack=1; "
                 "[ -e $stdenv/setup ] && source $stdenv/setup; "
                 "%3%"
+                "PATH=\"%4%:$PATH\"; "
+                "SHELL=%5%; "
                 "set +e; "
                 R"s([ -n "$PS1" ] && PS1='\n\[\033[1;32m\][nix-shell:\w]\$\[\033[0m\] '; )s"
                 "if [ \"$(type -t runHook)\" = function ]; then runHook shellHook; fi; "
                 "unset NIX_ENFORCE_PURITY; "
-                "unset NIX_INDENT_MAKE; "
                 "shopt -u nullglob; "
-                "unset TZ; %4%"
-                "%5%",
+                "unset TZ; %6%"
+                "%7%",
                 (Path) tmpDir,
                 (pure ? "" : "p=$PATH; "),
                 (pure ? "" : "PATH=$PATH:$p; unset p; "),
+                dirOf(shell),
+                shell,
                 (getenv("TZ") ? (string("export TZ='") + getenv("TZ") + "'; ") : ""),
                 envCommand));
 
@@ -439,7 +444,9 @@ void mainWrapped(int argc, char * * argv)
 
         auto argPtrs = stringsToCharPtrs(args);
 
+        restoreAffinity();
         restoreSignals();
+        restoreMountNamespace();
 
         execvp(shell.c_str(), argPtrs.data());
 
@@ -495,9 +502,5 @@ void mainWrapped(int argc, char * * argv)
     }
 }
 
-int main(int argc, char * * argv)
-{
-    return handleExceptions(argv[0], [&]() {
-        return mainWrapped(argc, argv);
-    });
-}
+static RegisterLegacyCommand s1("nix-build", _main);
+static RegisterLegacyCommand s2("nix-shell", _main);
diff --git a/src/nix-channel/local.mk b/src/nix-channel/local.mk
deleted file mode 100644
index c14e8c359ca0..000000000000
--- a/src/nix-channel/local.mk
+++ /dev/null
@@ -1,7 +0,0 @@
-programs += nix-channel
-
-nix-channel_DIR := $(d)
-
-nix-channel_LIBS = libmain libformat libstore libutil
-
-nix-channel_SOURCES := $(d)/nix-channel.cc
diff --git a/src/nix-channel/nix-channel.cc b/src/nix-channel/nix-channel.cc
index 55ebda438965..8b66cc7e314e 100755
--- a/src/nix-channel/nix-channel.cc
+++ b/src/nix-channel/nix-channel.cc
@@ -1,9 +1,11 @@
 #include "shared.hh"
 #include "globals.hh"
 #include "download.hh"
+#include "store-api.hh"
+#include "legacy.hh"
+
 #include <fcntl.h>
 #include <regex>
-#include "store-api.hh"
 #include <pwd.h>
 
 using namespace nix;
@@ -157,11 +159,9 @@ static void update(const StringSet & channelNames)
     replaceSymlink(profile, channelLink);
 }
 
-int main(int argc, char ** argv)
+static int _main(int argc, char ** argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-
+    {
         // Figure out the name of the `.nix-channels' file to use
         auto home = getHome();
         channelsList = home + "/.nix-channels";
@@ -169,7 +169,7 @@ int main(int argc, char ** argv)
 
         // Figure out the name of the channels profile.
         ;
-        auto pw = getpwuid(getuid());
+        auto pw = getpwuid(geteuid());
         std::string name = pw ? pw->pw_name : getEnv("USER", "");
         if (name.empty())
             throw Error("cannot figure out user name");
@@ -255,5 +255,9 @@ int main(int argc, char ** argv)
                 runProgram(settings.nixBinDir + "/nix-env", false, envArgs);
                 break;
         }
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-channel", _main);
diff --git a/src/nix-collect-garbage/local.mk b/src/nix-collect-garbage/local.mk
deleted file mode 100644
index 02d14cf62199..000000000000
--- a/src/nix-collect-garbage/local.mk
+++ /dev/null
@@ -1,7 +0,0 @@
-programs += nix-collect-garbage
-
-nix-collect-garbage_DIR := $(d)
-
-nix-collect-garbage_SOURCES := $(d)/nix-collect-garbage.cc
-
-nix-collect-garbage_LIBS = libmain libstore libutil libformat
diff --git a/src/nix-collect-garbage/nix-collect-garbage.cc b/src/nix-collect-garbage/nix-collect-garbage.cc
index 37fe22f48134..d4060ac937fc 100644
--- a/src/nix-collect-garbage/nix-collect-garbage.cc
+++ b/src/nix-collect-garbage/nix-collect-garbage.cc
@@ -2,6 +2,7 @@
 #include "profiles.hh"
 #include "shared.hh"
 #include "globals.hh"
+#include "legacy.hh"
 
 #include <iostream>
 #include <cerrno>
@@ -48,12 +49,10 @@ void removeOldGenerations(std::string dir)
     }
 }
 
-int main(int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    bool removeOld = false;
-
-    return handleExceptions(argv[0], [&]() {
-        initNix();
+    {
+        bool removeOld = false;
 
         GCOptions options;
 
@@ -90,5 +89,9 @@ int main(int argc, char * * argv)
             PrintFreed freed(true, results);
             store->collectGarbage(options, results);
         }
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-collect-garbage", _main);
diff --git a/src/nix-copy-closure/local.mk b/src/nix-copy-closure/local.mk
deleted file mode 100644
index 5018ab975b44..000000000000
--- a/src/nix-copy-closure/local.mk
+++ /dev/null
@@ -1,7 +0,0 @@
-programs += nix-copy-closure
-
-nix-copy-closure_DIR := $(d)
-
-nix-copy-closure_LIBS = libmain libformat libstore libutil
-
-nix-copy-closure_SOURCES := $(d)/nix-copy-closure.cc
diff --git a/src/nix-copy-closure/nix-copy-closure.cc b/src/nix-copy-closure/nix-copy-closure.cc
index dfb1b8fc5dc4..fdcde8b076b5 100755
--- a/src/nix-copy-closure/nix-copy-closure.cc
+++ b/src/nix-copy-closure/nix-copy-closure.cc
@@ -1,13 +1,12 @@
 #include "shared.hh"
 #include "store-api.hh"
+#include "legacy.hh"
 
 using namespace nix;
 
-int main(int argc, char ** argv)
+static int _main(int argc, char ** argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-
+    {
         auto gzip = false;
         auto toMode = true;
         auto includeOutputs = false;
@@ -61,5 +60,9 @@ int main(int argc, char ** argv)
         from->computeFSClosure(storePaths2, closure, false, includeOutputs);
 
         copyPaths(from, to, closure, NoRepair, NoCheckSigs, useSubstitutes);
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-copy-closure", _main);
diff --git a/src/nix-daemon/local.mk b/src/nix-daemon/local.mk
deleted file mode 100644
index 5a4474465b3c..000000000000
--- a/src/nix-daemon/local.mk
+++ /dev/null
@@ -1,13 +0,0 @@
-programs += nix-daemon
-
-nix-daemon_DIR := $(d)
-
-nix-daemon_SOURCES := $(d)/nix-daemon.cc
-
-nix-daemon_LIBS = libmain libstore libutil libformat
-
-nix-daemon_LDFLAGS = -pthread
-
-ifeq ($(OS), SunOS)
-        nix-daemon_LDFLAGS += -lsocket
-endif
diff --git a/src/nix-daemon/nix-daemon.cc b/src/nix-daemon/nix-daemon.cc
index 423e6bb67893..8368c3266142 100644
--- a/src/nix-daemon/nix-daemon.cc
+++ b/src/nix-daemon/nix-daemon.cc
@@ -9,6 +9,7 @@
 #include "monitor-fd.hh"
 #include "derivations.hh"
 #include "finally.hh"
+#include "legacy.hh"
 
 #include <algorithm>
 
@@ -233,7 +234,7 @@ struct RetrieveRegularNARSink : ParseSink
 };
 
 
-static void performOp(TunnelLogger * logger, ref<LocalStore> store,
+static void performOp(TunnelLogger * logger, ref<Store> store,
     bool trusted, unsigned int clientVersion,
     Source & from, Sink & to, unsigned int op)
 {
@@ -362,7 +363,11 @@ static void performOp(TunnelLogger * logger, ref<LocalStore> store,
 
         logger->startWork();
         if (!savedRegular.regular) throw Error("regular file expected");
-        Path path = store->addToStoreFromDump(recursive ? *savedNAR.data : savedRegular.s, baseName, recursive, hashAlgo);
+
+        auto store2 = store.dynamic_pointer_cast<LocalStore>();
+        if (!store2) throw Error("operation is only supported by LocalStore");
+
+        Path path = store2->addToStoreFromDump(recursive ? *savedNAR.data : savedRegular.s, baseName, recursive, hashAlgo);
         logger->stopWork();
 
         to << path;
@@ -553,7 +558,8 @@ static void performOp(TunnelLogger * logger, ref<LocalStore> store,
                     ;
                 else if (trusted
                     || name == settings.buildTimeout.name
-                    || name == "connect-timeout")
+                    || name == "connect-timeout"
+                    || (name == "builders" && value == ""))
                     settings.set(name, value);
                 else if (setSubstituters(settings.substituters))
                     ;
@@ -703,7 +709,8 @@ static void performOp(TunnelLogger * logger, ref<LocalStore> store,
 
         logger->startWork();
 
-        store.cast<Store>()->addToStore(info, *source, (RepairFlag) repair,
+        // FIXME: race if addToStore doesn't read source?
+        store->addToStore(info, *source, (RepairFlag) repair,
             dontCheckSigs ? NoCheckSigs : CheckSigs, nullptr);
 
         logger->stopWork();
@@ -776,7 +783,7 @@ static void processConnection(bool trusted)
         Store::Params params; // FIXME: get params from somewhere
         // Disable caching since the client already does that.
         params["path-info-cache-size"] = "0";
-        auto store = make_ref<LocalStore>(params);
+        auto store = openStore(settings.storeUri, params);
 
         tunnelLogger->stopWork();
         to.flush();
@@ -1052,11 +1059,9 @@ static void daemonLoop(char * * argv)
 }
 
 
-int main(int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-
+    {
         auto stdio = false;
 
         parseCmdLine(argc, argv, [&](Strings::iterator & arg, const Strings::iterator & end) {
@@ -1116,7 +1121,7 @@ int main(int argc, char * * argv)
                         if (res == -1)
                             throw SysError("splicing data from stdin to daemon socket");
                         else if (res == 0)
-                            return;
+                            return 0;
                     }
                 }
             } else {
@@ -1125,5 +1130,9 @@ int main(int argc, char * * argv)
         } else {
             daemonLoop(argv);
         }
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-daemon", _main);
diff --git a/src/nix-env/local.mk b/src/nix-env/local.mk
deleted file mode 100644
index e80719cd76f7..000000000000
--- a/src/nix-env/local.mk
+++ /dev/null
@@ -1,7 +0,0 @@
-programs += nix-env
-
-nix-env_DIR := $(d)
-
-nix-env_SOURCES := $(wildcard $(d)/*.cc)
-
-nix-env_LIBS = libexpr libmain libstore libutil libformat
diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index a43b103f6ec6..56ed75daee44 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -13,6 +13,7 @@
 #include "json.hh"
 #include "value-to-json.hh"
 #include "xml-writer.hh"
+#include "legacy.hh"
 
 #include <cerrno>
 #include <ctime>
@@ -150,10 +151,8 @@ static void loadSourceExpr(EvalState & state, const Path & path, Value & v)
     if (stat(path.c_str(), &st) == -1)
         throw SysError(format("getting information about '%1%'") % path);
 
-    if (isNixExpr(path, st)) {
+    if (isNixExpr(path, st))
         state.evalFile(path, v);
-        return;
-    }
 
     /* The path is a directory.  Put the Nix expressions in the
        directory in a set, with the file name of each expression as
@@ -161,13 +160,15 @@ static void loadSourceExpr(EvalState & state, const Path & path, Value & v)
        set flat, not nested, to make it easier for a user to have a
        ~/.nix-defexpr directory that includes some system-wide
        directory). */
-    if (S_ISDIR(st.st_mode)) {
+    else if (S_ISDIR(st.st_mode)) {
         state.mkAttrs(v, 1024);
         state.mkList(*state.allocAttr(v, state.symbols.create("_combineChannels")), 0);
         StringSet attrs;
         getAllExprs(state, path, attrs, v);
         v.attrs->sort();
     }
+
+    else throw Error("path '%s' is not a directory or a Nix expression", path);
 }
 
 
@@ -1311,12 +1312,9 @@ static void opVersion(Globals & globals, Strings opFlags, Strings opArgs)
 }
 
 
-int main(int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-        initGC();
-
+    {
         Strings opFlags, opArgs;
         Operation op = 0;
         RepairFlag repair = NoRepair;
@@ -1428,5 +1426,9 @@ int main(int argc, char * * argv)
         op(globals, opFlags, opArgs);
 
         globals.state->printStats();
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-env", _main);
diff --git a/src/nix-instantiate/local.mk b/src/nix-instantiate/local.mk
deleted file mode 100644
index 7d1bc5ec9dfb..000000000000
--- a/src/nix-instantiate/local.mk
+++ /dev/null
@@ -1,7 +0,0 @@
-programs += nix-instantiate
-
-nix-instantiate_DIR := $(d)
-
-nix-instantiate_SOURCES := $(d)/nix-instantiate.cc
-
-nix-instantiate_LIBS = libexpr libmain libstore libutil libformat
diff --git a/src/nix-instantiate/nix-instantiate.cc b/src/nix-instantiate/nix-instantiate.cc
index 5049460c7544..a736caa8f056 100644
--- a/src/nix-instantiate/nix-instantiate.cc
+++ b/src/nix-instantiate/nix-instantiate.cc
@@ -9,6 +9,7 @@
 #include "util.hh"
 #include "store-api.hh"
 #include "common-eval-args.hh"
+#include "legacy.hh"
 
 #include <map>
 #include <iostream>
@@ -83,12 +84,9 @@ void processExpr(EvalState & state, const Strings & attrPaths,
 }
 
 
-int main(int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-        initGC();
-
+    {
         Strings files;
         bool readStdin = false;
         bool fromArgs = false;
@@ -158,37 +156,41 @@ int main(int argc, char * * argv)
 
         auto store = openStore();
 
-        EvalState state(myArgs.searchPath, store);
-        state.repair = repair;
+        auto state = std::make_unique<EvalState>(myArgs.searchPath, store);
+        state->repair = repair;
 
-        Bindings & autoArgs = *myArgs.getAutoArgs(state);
+        Bindings & autoArgs = *myArgs.getAutoArgs(*state);
 
         if (attrPaths.empty()) attrPaths = {""};
 
         if (findFile) {
             for (auto & i : files) {
-                Path p = state.findFile(i);
+                Path p = state->findFile(i);
                 if (p == "") throw Error(format("unable to find '%1%'") % i);
                 std::cout << p << std::endl;
             }
-            return;
+            return 0;
         }
 
         if (readStdin) {
-            Expr * e = state.parseStdin();
-            processExpr(state, attrPaths, parseOnly, strict, autoArgs,
+            Expr * e = state->parseStdin();
+            processExpr(*state, attrPaths, parseOnly, strict, autoArgs,
                 evalOnly, outputKind, xmlOutputSourceLocation, e);
         } else if (files.empty() && !fromArgs)
             files.push_back("./default.nix");
 
         for (auto & i : files) {
             Expr * e = fromArgs
-                ? state.parseExprFromString(i, absPath("."))
-                : state.parseExprFromFile(resolveExprPath(state.checkSourcePath(lookupFileArg(state, i))));
-            processExpr(state, attrPaths, parseOnly, strict, autoArgs,
+                ? state->parseExprFromString(i, absPath("."))
+                : state->parseExprFromFile(resolveExprPath(state->checkSourcePath(lookupFileArg(*state, i))));
+            processExpr(*state, attrPaths, parseOnly, strict, autoArgs,
                 evalOnly, outputKind, xmlOutputSourceLocation, e);
         }
 
-        state.printStats();
-    });
+        state->printStats();
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-instantiate", _main);
diff --git a/src/nix-prefetch-url/local.mk b/src/nix-prefetch-url/local.mk
deleted file mode 100644
index 3e7735406af0..000000000000
--- a/src/nix-prefetch-url/local.mk
+++ /dev/null
@@ -1,7 +0,0 @@
-programs += nix-prefetch-url
-
-nix-prefetch-url_DIR := $(d)
-
-nix-prefetch-url_SOURCES := $(d)/nix-prefetch-url.cc
-
-nix-prefetch-url_LIBS = libmain libexpr libstore libutil libformat
diff --git a/src/nix-prefetch-url/nix-prefetch-url.cc b/src/nix-prefetch-url/nix-prefetch-url.cc
index fa7ee254500c..f54706a8a011 100644
--- a/src/nix-prefetch-url/nix-prefetch-url.cc
+++ b/src/nix-prefetch-url/nix-prefetch-url.cc
@@ -6,9 +6,16 @@
 #include "eval-inline.hh"
 #include "common-eval-args.hh"
 #include "attr-path.hh"
+#include "legacy.hh"
+#include "finally.hh"
+#include "progress-bar.hh"
 
 #include <iostream>
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
 using namespace nix;
 
 
@@ -40,12 +47,9 @@ string resolveMirrorUri(EvalState & state, string uri)
 }
 
 
-int main(int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-        initGC();
-
+    {
         HashType ht = htSHA256;
         std::vector<string> args;
         bool printPath = getEnv("PRINT_PATH") != "";
@@ -94,10 +98,15 @@ int main(int argc, char * * argv)
         if (args.size() > 2)
             throw UsageError("too many arguments");
 
+        Finally f([]() { stopProgressBar(); });
+
+        if (isatty(STDERR_FILENO))
+          startProgressBar();
+
         auto store = openStore();
-        EvalState state(myArgs.searchPath, store);
+        auto state = std::make_unique<EvalState>(myArgs.searchPath, store);
 
-        Bindings & autoArgs = *myArgs.getAutoArgs(state);
+        Bindings & autoArgs = *myArgs.getAutoArgs(*state);
 
         /* If -A is given, get the URI from the specified Nix
            expression. */
@@ -107,33 +116,33 @@ int main(int argc, char * * argv)
                 throw UsageError("you must specify a URI");
             uri = args[0];
         } else {
-            Path path = resolveExprPath(lookupFileArg(state, args.empty() ? "." : args[0]));
+            Path path = resolveExprPath(lookupFileArg(*state, args.empty() ? "." : args[0]));
             Value vRoot;
-            state.evalFile(path, vRoot);
-            Value & v(*findAlongAttrPath(state, attrPath, autoArgs, vRoot));
-            state.forceAttrs(v);
+            state->evalFile(path, vRoot);
+            Value & v(*findAlongAttrPath(*state, attrPath, autoArgs, vRoot));
+            state->forceAttrs(v);
 
             /* Extract the URI. */
-            auto attr = v.attrs->find(state.symbols.create("urls"));
+            auto attr = v.attrs->find(state->symbols.create("urls"));
             if (attr == v.attrs->end())
                 throw Error("attribute set does not contain a 'urls' attribute");
-            state.forceList(*attr->value);
+            state->forceList(*attr->value);
             if (attr->value->listSize() < 1)
                 throw Error("'urls' list is empty");
-            uri = state.forceString(*attr->value->listElems()[0]);
+            uri = state->forceString(*attr->value->listElems()[0]);
 
             /* Extract the hash mode. */
-            attr = v.attrs->find(state.symbols.create("outputHashMode"));
+            attr = v.attrs->find(state->symbols.create("outputHashMode"));
             if (attr == v.attrs->end())
                 printInfo("warning: this does not look like a fetchurl call");
             else
-                unpack = state.forceString(*attr->value) == "recursive";
+                unpack = state->forceString(*attr->value) == "recursive";
 
             /* Extract the name. */
             if (name.empty()) {
-                attr = v.attrs->find(state.symbols.create("name"));
+                attr = v.attrs->find(state->symbols.create("name"));
                 if (attr != v.attrs->end())
-                    name = state.forceString(*attr->value);
+                    name = state->forceString(*attr->value);
             }
         }
 
@@ -158,16 +167,22 @@ int main(int argc, char * * argv)
 
         if (storePath.empty()) {
 
-            auto actualUri = resolveMirrorUri(state, uri);
-
-            /* Download the file. */
-            DownloadRequest req(actualUri);
-            req.decompress = false;
-            auto result = getDownloader()->download(req);
+            auto actualUri = resolveMirrorUri(*state, uri);
 
             AutoDelete tmpDir(createTempDir(), true);
             Path tmpFile = (Path) tmpDir + "/tmp";
-            writeFile(tmpFile, *result.data);
+
+            /* Download the file. */
+            {
+                AutoCloseFD fd = open(tmpFile.c_str(), O_WRONLY | O_CREAT | O_EXCL, 0600);
+                if (!fd) throw SysError("creating temporary file '%s'", tmpFile);
+
+                FdSink sink(fd.get());
+
+                DownloadRequest req(actualUri);
+                req.decompress = false;
+                getDownloader()->download(std::move(req), sink);
+            }
 
             /* Optionally unpack the file. */
             if (unpack) {
@@ -191,7 +206,7 @@ int main(int argc, char * * argv)
 
             /* FIXME: inefficient; addToStore() will also hash
                this. */
-            hash = unpack ? hashPath(ht, tmpFile).first : hashString(ht, *result.data);
+            hash = unpack ? hashPath(ht, tmpFile).first : hashFile(ht, tmpFile);
 
             if (expectedHash != Hash(ht) && expectedHash != hash)
                 throw Error(format("hash mismatch for '%1%'") % uri);
@@ -205,11 +220,17 @@ int main(int argc, char * * argv)
             assert(storePath == store->makeFixedOutputPath(unpack, hash, name));
         }
 
+        stopProgressBar();
+
         if (!printPath)
             printInfo(format("path is '%1%'") % storePath);
 
         std::cout << printHash16or32(hash) << std::endl;
         if (printPath)
             std::cout << storePath << std::endl;
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-prefetch-url", _main);
diff --git a/src/nix-store/graphml.cc b/src/nix-store/graphml.cc
new file mode 100644
index 000000000000..670fbe227a4c
--- /dev/null
+++ b/src/nix-store/graphml.cc
@@ -0,0 +1,90 @@
+#include "graphml.hh"
+#include "util.hh"
+#include "store-api.hh"
+#include "derivations.hh"
+
+#include <iostream>
+
+
+using std::cout;
+
+namespace nix {
+
+
+static inline const string & xmlQuote(const string & s)
+{
+    // Luckily, store paths shouldn't contain any character that needs to be
+    // quoted.
+    return s;
+}
+
+
+static string symbolicName(const string & path)
+{
+    string p = baseNameOf(path);
+    return string(p, p.find('-') + 1);
+}
+
+
+static string makeEdge(const string & src, const string & dst)
+{
+    return fmt("  <edge source=\"%1%\" target=\"%2%\"/>\n",
+        xmlQuote(src), xmlQuote(dst));
+}
+
+
+static string makeNode(const ValidPathInfo & info)
+{
+    return fmt(
+        "  <node id=\"%1%\">\n"
+        "    <data key=\"narSize\">%2%</data>\n"
+        "    <data key=\"name\">%3%</data>\n"
+        "    <data key=\"type\">%4%</data>\n"
+        "  </node>\n",
+        info.path,
+        info.narSize,
+        symbolicName(info.path),
+        (isDerivation(info.path) ? "derivation" : "output-path"));
+}
+
+
+void printGraphML(ref<Store> store, const PathSet & roots)
+{
+    PathSet workList(roots);
+    PathSet doneSet;
+    std::pair<PathSet::iterator,bool> ret;
+
+    cout << "<?xml version='1.0' encoding='utf-8'?>\n"
+         << "<graphml xmlns='http://graphml.graphdrawing.org/xmlns'\n"
+         << "    xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'\n"
+         << "    xsi:schemaLocation='http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd'>\n"
+         << "<key id='narSize' for='node' attr.name='narSize' attr.type='int'/>"
+         << "<key id='name' for='node' attr.name='name' attr.type='string'/>"
+         << "<key id='type' for='node' attr.name='type' attr.type='string'/>"
+         << "<graph id='G' edgedefault='directed'>\n";
+
+    while (!workList.empty()) {
+        Path path = *(workList.begin());
+        workList.erase(path);
+
+        ret = doneSet.insert(path);
+        if (ret.second == false) continue;
+
+        ValidPathInfo info = *(store->queryPathInfo(path));
+        cout << makeNode(info);
+
+        for (auto & p : store->queryPathInfo(path)->references) {
+            if (p != path) {
+                workList.insert(p);
+                cout << makeEdge(path, p);
+            }
+        }
+
+    }
+
+    cout << "</graph>\n";
+    cout << "</graphml>\n";
+}
+
+
+}
diff --git a/src/nix-store/xmlgraph.hh b/src/nix-store/graphml.hh
index a6e7d4e2805a..b78df1e49a67 100644
--- a/src/nix-store/xmlgraph.hh
+++ b/src/nix-store/graphml.hh
@@ -6,6 +6,6 @@ namespace nix {
 
 class Store;
 
-void printXmlGraph(ref<Store> store, const PathSet & roots);
+void printGraphML(ref<Store> store, const PathSet & roots);
 
 }
diff --git a/src/nix-store/local.mk b/src/nix-store/local.mk
deleted file mode 100644
index ade0b233adf3..000000000000
--- a/src/nix-store/local.mk
+++ /dev/null
@@ -1,9 +0,0 @@
-programs += nix-store
-
-nix-store_DIR := $(d)
-
-nix-store_SOURCES := $(wildcard $(d)/*.cc)
-
-nix-store_LIBS = libmain libstore libutil libformat
-
-nix-store_LDFLAGS = -lbz2 -pthread $(SODIUM_LIBS)
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index e1e27ceef94d..a9ad14762e62 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -8,7 +8,8 @@
 #include "shared.hh"
 #include "util.hh"
 #include "worker-protocol.hh"
-#include "xmlgraph.hh"
+#include "graphml.hh"
+#include "legacy.hh"
 
 #include <iostream>
 #include <algorithm>
@@ -273,7 +274,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
     enum QueryType
         { qDefault, qOutputs, qRequisites, qReferences, qReferrers
         , qReferrersClosure, qDeriver, qBinding, qHash, qSize
-        , qTree, qGraph, qXml, qResolve, qRoots };
+        , qTree, qGraph, qGraphML, qResolve, qRoots };
     QueryType query = qDefault;
     bool useOutput = false;
     bool includeOutputs = false;
@@ -299,7 +300,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
         else if (i == "--size") query = qSize;
         else if (i == "--tree") query = qTree;
         else if (i == "--graph") query = qGraph;
-        else if (i == "--xml") query = qXml;
+        else if (i == "--graphml") query = qGraphML;
         else if (i == "--resolve") query = qResolve;
         else if (i == "--roots") query = qRoots;
         else if (i == "--use-output" || i == "-u") useOutput = true;
@@ -403,13 +404,13 @@ static void opQuery(Strings opFlags, Strings opArgs)
             break;
         }
 
-        case qXml: {
+        case qGraphML: {
             PathSet roots;
             for (auto & i : opArgs) {
                 PathSet paths = maybeUseOutputs(store->followLinksToStorePath(i), useOutput, forceRealise);
                 roots.insert(paths.begin(), paths.end());
             }
-            printXmlGraph(ref<Store>(store), roots);
+            printGraphML(ref<Store>(store), roots);
             break;
         }
 
@@ -860,7 +861,7 @@ static void opServe(Strings opFlags, Strings opArgs)
             }
 
             case cmdDumpStorePath:
-                dumpPath(readStorePath(*store, in), out);
+                store->narFromPath(readStorePath(*store, in), out);
                 break;
 
             case cmdImportPaths: {
@@ -924,6 +925,28 @@ static void opServe(Strings opFlags, Strings opArgs)
                 break;
             }
 
+            case cmdAddToStoreNar: {
+                if (!writeAllowed) throw Error("importing paths is not allowed");
+
+                ValidPathInfo info;
+                info.path = readStorePath(*store, in);
+                in >> info.deriver;
+                if (!info.deriver.empty())
+                    store->assertStorePath(info.deriver);
+                info.narHash = Hash(readString(in), htSHA256);
+                info.references = readStorePaths<PathSet>(*store, in);
+                in >> info.registrationTime >> info.narSize >> info.ultimate;
+                info.sigs = readStrings<StringSet>(in);
+                in >> info.ca;
+
+                // FIXME: race if addToStore doesn't read source?
+                store->addToStore(info, in, NoRepair, NoCheckSigs);
+
+                out << 1; // indicate success
+
+                break;
+            }
+
             default:
                 throw Error(format("unknown serve command %1%") % cmd);
         }
@@ -971,11 +994,9 @@ static void opVersion(Strings opFlags, Strings opArgs)
 /* Scan the arguments; find the operation, set global flags, put all
    other flags in a list, and put all other arguments in another
    list. */
-int main(int argc, char * * argv)
+static int _main(int argc, char * * argv)
 {
-    return handleExceptions(argv[0], [&]() {
-        initNix();
-
+    {
         Strings opFlags, opArgs;
         Operation op = 0;
 
@@ -1062,5 +1083,9 @@ int main(int argc, char * * argv)
             store = openStore();
 
         op(opFlags, opArgs);
-    });
+
+        return 0;
+    }
 }
+
+static RegisterLegacyCommand s1("nix-store", _main);
diff --git a/src/nix-store/xmlgraph.cc b/src/nix-store/xmlgraph.cc
deleted file mode 100644
index 0f7be7f7a02d..000000000000
--- a/src/nix-store/xmlgraph.cc
+++ /dev/null
@@ -1,66 +0,0 @@
-#include "xmlgraph.hh"
-#include "util.hh"
-#include "store-api.hh"
-
-#include <iostream>
-
-
-using std::cout;
-
-namespace nix {
-
-
-static inline const string & xmlQuote(const string & s)
-{
-    // Luckily, store paths shouldn't contain any character that needs to be
-    // quoted.
-    return s;
-}
-
-
-static string makeEdge(const string & src, const string & dst)
-{
-    format f = format("  <edge src=\"%1%\" dst=\"%2%\"/>\n")
-      % xmlQuote(src) % xmlQuote(dst);
-    return f.str();
-}
-
-
-static string makeNode(const string & id)
-{
-    format f = format("  <node name=\"%1%\"/>\n") % xmlQuote(id);
-    return f.str();
-}
-
-
-void printXmlGraph(ref<Store> store, const PathSet & roots)
-{
-    PathSet workList(roots);
-    PathSet doneSet;
-
-    cout << "<?xml version='1.0' encoding='utf-8'?>\n"
-         << "<nix>\n";
-
-    while (!workList.empty()) {
-        Path path = *(workList.begin());
-        workList.erase(path);
-
-        if (doneSet.find(path) != doneSet.end()) continue;
-        doneSet.insert(path);
-
-        cout << makeNode(path);
-
-        for (auto & p : store->queryPathInfo(path)->references) {
-            if (p != path) {
-                workList.insert(p);
-                cout << makeEdge(p, path);
-            }
-        }
-
-    }
-
-    cout << "</nix>\n";
-}
-
-
-}
diff --git a/src/nix/copy.cc b/src/nix/copy.cc
index e4e6c3e303ed..96bd453d87b4 100644
--- a/src/nix/copy.cc
+++ b/src/nix/copy.cc
@@ -69,8 +69,12 @@ struct CmdCopy : StorePathsCommand
             },
 #ifdef ENABLE_S3
             Example{
-                "To populate the current folder build output to a S3 binary cache:",
-                "nix copy --to s3://my-bucket?region=eu-west-1"
+                "To copy Hello to an S3 binary cache:",
+                "nix copy --to s3://my-bucket?region=eu-west-1 nixpkgs.hello"
+            },
+            Example{
+                "To copy Hello to an S3-compatible binary cache:",
+                "nix copy --to s3://my-bucket?region=eu-west-1&endpoint=example.com nixpkgs.hello"
             },
 #endif
         };
diff --git a/src/nix/doctor.cc b/src/nix/doctor.cc
new file mode 100644
index 000000000000..7b5444619470
--- /dev/null
+++ b/src/nix/doctor.cc
@@ -0,0 +1,124 @@
+#include "command.hh"
+#include "serve-protocol.hh"
+#include "shared.hh"
+#include "store-api.hh"
+#include "worker-protocol.hh"
+
+using namespace nix;
+
+std::string formatProtocol(unsigned int proto)
+{
+    if (proto) {
+        auto major = GET_PROTOCOL_MAJOR(proto) >> 8;
+        auto minor = GET_PROTOCOL_MINOR(proto);
+        return (format("%1%.%2%") % major % minor).str();
+    }
+    return "unknown";
+}
+
+struct CmdDoctor : StoreCommand
+{
+    bool success = true;
+
+    std::string name() override
+    {
+        return "doctor";
+    }
+
+    std::string description() override
+    {
+        return "check your system for potential problems";
+    }
+
+    void run(ref<Store> store) override
+    {
+        std::cout << "Store uri: " << store->getUri() << std::endl;
+        std::cout << std::endl;
+
+        auto type = getStoreType();
+
+        if (type < tOther) {
+            success &= checkNixInPath();
+            success &= checkProfileRoots(store);
+        }
+        success &= checkStoreProtocol(store->getProtocol());
+
+        if (!success)
+            throw Exit(2);
+    }
+
+    bool checkNixInPath()
+    {
+        PathSet dirs;
+
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
+            if (pathExists(dir + "/nix-env"))
+                dirs.insert(dirOf(canonPath(dir + "/nix-env", true)));
+
+        if (dirs.size() != 1) {
+            std::cout << "Warning: multiple versions of nix found in PATH." << std::endl;
+            std::cout << std::endl;
+            for (auto & dir : dirs)
+                std::cout << "  " << dir << std::endl;
+            std::cout << std::endl;
+            return false;
+        }
+
+        return true;
+    }
+
+    bool checkProfileRoots(ref<Store> store)
+    {
+        PathSet dirs;
+
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":")) {
+            Path profileDir = dirOf(dir);
+            try {
+                Path userEnv = canonPath(profileDir, true);
+
+                if (store->isStorePath(userEnv) && hasSuffix(userEnv, "user-environment")) {
+                    while (profileDir.find("/profiles/") == std::string::npos && isLink(profileDir))
+                        profileDir = absPath(readLink(profileDir), dirOf(profileDir));
+
+                    if (profileDir.find("/profiles/") == std::string::npos)
+                        dirs.insert(dir);
+                }
+            } catch (SysError &) {}
+        }
+
+        if (!dirs.empty()) {
+            std::cout << "Warning: found profiles outside of " << settings.nixStateDir << "/profiles." << std::endl;
+            std::cout << "The generation this profile points to might not have a gcroot and could be" << std::endl;
+            std::cout << "garbage collected, resulting in broken symlinks." << std::endl;
+            std::cout << std::endl;
+            for (auto & dir : dirs)
+                std::cout << "  " << dir << std::endl;
+            std::cout << std::endl;
+            return false;
+        }
+
+        return true;
+    }
+
+    bool checkStoreProtocol(unsigned int storeProto)
+    {
+        unsigned int clientProto = GET_PROTOCOL_MAJOR(SERVE_PROTOCOL_VERSION) == GET_PROTOCOL_MAJOR(storeProto)
+            ? SERVE_PROTOCOL_VERSION
+            : PROTOCOL_VERSION;
+
+        if (clientProto != storeProto) {
+            std::cout << "Warning: protocol version of this client does not match the store." << std::endl;
+            std::cout << "While this is not necessarily a problem it's recommended to keep the client in" << std::endl;
+            std::cout << "sync with the daemon." << std::endl;
+            std::cout << std::endl;
+            std::cout << "Client protocol: " << formatProtocol(clientProto) << std::endl;
+            std::cout << "Store protocol: " << formatProtocol(storeProto) << std::endl;
+            std::cout << std::endl;
+            return false;
+        }
+
+        return true;
+    }
+};
+
+static RegisterCommand r1(make_ref<CmdDoctor>());
diff --git a/src/nix/edit.cc b/src/nix/edit.cc
index c9671f76d0fa..d8d5895bd867 100644
--- a/src/nix/edit.cc
+++ b/src/nix/edit.cc
@@ -3,6 +3,7 @@
 #include "eval.hh"
 #include "attr-path.hh"
 #include "progress-bar.hh"
+#include "affinity.hh"
 
 #include <unistd.h>
 
@@ -72,6 +73,10 @@ struct CmdEdit : InstallableCommand
 
         stopProgressBar();
 
+        restoreAffinity();
+        restoreSignals();
+        restoreMountNamespace();
+
         execvp(args.front().c_str(), stringsToCharPtrs(args).data());
 
         throw SysError("cannot run editor '%s'", editor);
diff --git a/src/nix/installables.cc b/src/nix/installables.cc
index a3fdd8a2808d..0c1ad3ab3db0 100644
--- a/src/nix/installables.cc
+++ b/src/nix/installables.cc
@@ -86,22 +86,6 @@ Buildable Installable::toBuildable()
     return std::move(buildables[0]);
 }
 
-struct InstallableStoreDrv : Installable
-{
-    Path drvPath;
-
-    InstallableStoreDrv(const Path & drvPath) : drvPath(drvPath) { }
-
-    std::string what() override { return drvPath; }
-
-    Buildables toBuildables() override
-    {
-        Buildable b = {drvPath};
-        // FIXME: add outputs?
-        return {b};
-    }
-};
-
 struct InstallableStorePath : Installable
 {
     Path storePath;
@@ -112,7 +96,7 @@ struct InstallableStorePath : Installable
 
     Buildables toBuildables() override
     {
-        return {{"", {{"out", storePath}}}};
+        return {{isDerivation(storePath) ? storePath : "", {{"out", storePath}}}};
     }
 };
 
@@ -226,12 +210,8 @@ static std::vector<std::shared_ptr<Installable>> parseInstallables(
 
             auto path = store->toStorePath(store->followLinksToStore(s));
 
-            if (store->isStorePath(path)) {
-                if (isDerivation(path))
-                    result.push_back(std::make_shared<InstallableStoreDrv>(path));
-                else
-                    result.push_back(std::make_shared<InstallableStorePath>(path));
-            }
+            if (store->isStorePath(path))
+                result.push_back(std::make_shared<InstallableStorePath>(path));
         }
 
         else if (s == "" || std::regex_match(s, attrPathRegex))
diff --git a/src/nix/local.mk b/src/nix/local.mk
index f76da194467c..40a0e8d6bde1 100644
--- a/src/nix/local.mk
+++ b/src/nix/local.mk
@@ -2,10 +2,24 @@ programs += nix
 
 nix_DIR := $(d)
 
-nix_SOURCES := $(wildcard $(d)/*.cc) $(wildcard src/linenoise/*.cpp)
+nix_SOURCES := \
+  $(wildcard $(d)/*.cc) \
+  $(wildcard src/build-remote/*.cc) \
+  $(wildcard src/nix-build/*.cc) \
+  $(wildcard src/nix-channel/*.cc) \
+  $(wildcard src/nix-collect-garbage/*.cc) \
+  $(wildcard src/nix-copy-closure/*.cc) \
+  $(wildcard src/nix-daemon/*.cc) \
+  $(wildcard src/nix-env/*.cc) \
+  $(wildcard src/nix-instantiate/*.cc) \
+  $(wildcard src/nix-prefetch-url/*.cc) \
+  $(wildcard src/nix-store/*.cc) \
 
 nix_LIBS = libexpr libmain libstore libutil libformat
 
-nix_LDFLAGS = -pthread
+nix_LDFLAGS = -pthread $(SODIUM_LIBS) $(EDITLINE_LIBS)
 
-$(eval $(call install-symlink, nix, $(bindir)/nix-hash))
+$(foreach name, \
+  nix-build nix-channel nix-collect-garbage nix-copy-closure nix-daemon nix-env nix-hash nix-instantiate nix-prefetch-url nix-shell nix-store, \
+  $(eval $(call install-symlink, nix, $(bindir)/$(name))))
+$(eval $(call install-symlink, $(bindir)/nix, $(libexecdir)/nix/build-remote))
diff --git a/src/nix/ls.cc b/src/nix/ls.cc
index e99622faf472..d089be42fb20 100644
--- a/src/nix/ls.cc
+++ b/src/nix/ls.cc
@@ -148,7 +148,7 @@ struct CmdLsNar : Command, MixLs
 
     void run() override
     {
-        list(makeNarAccessor(make_ref<std::string>(readFile(narPath))));
+        list(makeNarAccessor(make_ref<std::string>(readFile(narPath, true))));
     }
 };
 
diff --git a/src/nix/main.cc b/src/nix/main.cc
index 9cd5d21c84b6..64c1dc35787c 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -24,7 +24,6 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
     {
         mkFlag()
             .longName("help")
-            .shortName('h')
             .description("show usage information")
             .handler([&]() { showHelpAndExit(); });
 
@@ -68,9 +67,6 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
 
 void mainWrapped(int argc, char * * argv)
 {
-    verbosity = lvlError;
-    settings.verboseBuild = false;
-
     /* The chroot helper needs to be run before any threads have been
        started. */
     if (argc > 0 && argv[0] == chrootHelperName) {
@@ -89,6 +85,9 @@ void mainWrapped(int argc, char * * argv)
         if (legacy) return legacy(argc, argv);
     }
 
+    verbosity = lvlError;
+    settings.verboseBuild = false;
+
     NixArgs args;
 
     args.parseCmdline(argvToStrings(argc, argv));
diff --git a/src/nix/path-info.cc b/src/nix/path-info.cc
index 47caa401d3c9..dea5f0557b81 100644
--- a/src/nix/path-info.cc
+++ b/src/nix/path-info.cc
@@ -4,8 +4,8 @@
 #include "json.hh"
 #include "common-args.hh"
 
-#include <iomanip>
 #include <algorithm>
+#include <array>
 
 using namespace nix;
 
@@ -13,12 +13,14 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
 {
     bool showSize = false;
     bool showClosureSize = false;
+    bool humanReadable = false;
     bool showSigs = false;
 
     CmdPathInfo()
     {
         mkFlag('s', "size", "print size of the NAR dump of each path", &showSize);
         mkFlag('S', "closure-size", "print sum size of the NAR dumps of the closure of each path", &showClosureSize);
+        mkFlag('h', "human-readable", "with -s and -S, print sizes like 1K 234M 5.67G etc.", &humanReadable);
         mkFlag(0, "sigs", "show signatures", &showSigs);
     }
 
@@ -40,6 +42,10 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
                 "nix path-info -rS /run/current-system | sort -nk2"
             },
             Example{
+                "To show a package's closure size and all its dependencies with human readable sizes:",
+                "nix path-info -rsSh nixpkgs.rust"
+            },
+            Example{
                 "To check the existence of a path in a binary cache:",
                 "nix path-info -r /nix/store/7qvk5c91...-geeqie-1.1 --store https://cache.nixos.org/"
             },
@@ -58,6 +64,25 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
         };
     }
 
+    void printSize(unsigned long long value)
+    {
+        if (!humanReadable) {
+            std::cout << fmt("\t%11d", value);
+            return;
+        }
+
+        static const std::array<char, 9> idents{{
+            ' ', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
+        }};
+        size_t power = 0;
+        double res = value;
+        while (res > 1024 && power < idents.size()) {
+            ++power;
+            res /= 1024;
+        }
+        std::cout << fmt("\t%6.1f%c", res, idents.at(power));
+    }
+
     void run(ref<Store> store, Paths storePaths) override
     {
         size_t pathLen = 0;
@@ -78,13 +103,16 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
                 auto info = store->queryPathInfo(storePath);
                 storePath = info->path; // FIXME: screws up padding
 
-                std::cout << storePath << std::string(std::max(0, (int) pathLen - (int) storePath.size()), ' ');
+                std::cout << storePath;
+
+                if (showSize || showClosureSize || showSigs)
+                    std::cout << std::string(std::max(0, (int) pathLen - (int) storePath.size()), ' ');
 
                 if (showSize)
-                    std::cout << '\t' << std::setw(11) << info->narSize;
+                    printSize(info->narSize);
 
                 if (showClosureSize)
-                    std::cout << '\t' << std::setw(11) << store->getClosureSize(storePath).first;
+                    printSize(store->getClosureSize(storePath).first);
 
                 if (showSigs) {
                     std::cout << '\t';
diff --git a/src/nix/repl.cc b/src/nix/repl.cc
index f84774a53367..d93fd770e807 100644
--- a/src/nix/repl.cc
+++ b/src/nix/repl.cc
@@ -1,8 +1,17 @@
 #include <iostream>
 #include <cstdlib>
+#include <cstring>
+#include <climits>
 
 #include <setjmp.h>
 
+#ifdef READLINE
+#include <readline/history.h>
+#include <readline/readline.h>
+#else
+#include <editline.h>
+#endif
+
 #include "shared.hh"
 #include "eval.hh"
 #include "eval-inline.hh"
@@ -15,8 +24,6 @@
 #include "command.hh"
 #include "finally.hh"
 
-#include "src/linenoise/linenoise.h"
-
 namespace nix {
 
 #define ESC_RED "\033[31m"
@@ -31,6 +38,7 @@ struct NixRepl
 {
     string curDir;
     EvalState state;
+    Bindings * autoArgs;
 
     Strings loadedFiles;
 
@@ -117,17 +125,71 @@ NixRepl::NixRepl(const Strings & searchPath, nix::ref<Store> store)
 
 NixRepl::~NixRepl()
 {
-    linenoiseHistorySave(historyFile.c_str());
+    write_history(historyFile.c_str());
 }
 
-
 static NixRepl * curRepl; // ugly
 
-static void completionCallback(const char * s, linenoiseCompletions *lc)
-{
-    /* Otherwise, return all symbols that start with the prefix. */
-    for (auto & c : curRepl->completePrefix(s))
-        linenoiseAddCompletion(lc, c.c_str());
+static char * completionCallback(char * s, int *match) {
+  auto possible = curRepl->completePrefix(s);
+  if (possible.size() == 1) {
+    *match = 1;
+    auto *res = strdup(possible.begin()->c_str() + strlen(s));
+    if (!res) throw Error("allocation failure");
+    return res;
+  } else if (possible.size() > 1) {
+    auto checkAllHaveSameAt = [&](size_t pos) {
+      auto &first = *possible.begin();
+      for (auto &p : possible) {
+        if (p.size() <= pos || p[pos] != first[pos])
+          return false;
+      }
+      return true;
+    };
+    size_t start = strlen(s);
+    size_t len = 0;
+    while (checkAllHaveSameAt(start + len)) ++len;
+    if (len > 0) {
+      *match = 1;
+      auto *res = strdup(std::string(*possible.begin(), start, len).c_str());
+      if (!res) throw Error("allocation failure");
+      return res;
+    }
+  }
+
+  *match = 0;
+  return nullptr;
+}
+
+static int listPossibleCallback(char *s, char ***avp) {
+  auto possible = curRepl->completePrefix(s);
+
+  if (possible.size() > (INT_MAX / sizeof(char*)))
+    throw Error("too many completions");
+
+  int ac = 0;
+  char **vp = nullptr;
+
+  auto check = [&](auto *p) {
+    if (!p) {
+      if (vp) {
+        while (--ac >= 0)
+          free(vp[ac]);
+        free(vp);
+      }
+      throw Error("allocation failure");
+    }
+    return p;
+  };
+
+  vp = check((char **)malloc(possible.size() * sizeof(char*)));
+
+  for (auto & p : possible)
+    vp[ac++] = check(strdup(p.c_str()));
+
+  *avp = vp;
+
+  return ac;
 }
 
 
@@ -142,12 +204,18 @@ void NixRepl::mainLoop(const std::vector<std::string> & files)
     reloadFiles();
     if (!loadedFiles.empty()) std::cout << std::endl;
 
+    // Allow nix-repl specific settings in .inputrc
+    rl_readline_name = "nix-repl";
     createDirs(dirOf(historyFile));
-    linenoiseHistorySetMaxLen(1000);
-    linenoiseHistoryLoad(historyFile.c_str());
-
+#ifndef READLINE
+    el_hist_size = 1000;
+#endif
+    read_history(historyFile.c_str());
     curRepl = this;
-    linenoiseSetCompletionCallback(completionCallback);
+#ifndef READLINE
+    rl_set_complete_func(completionCallback);
+    rl_set_list_possib_func(listPossibleCallback);
+#endif
 
     std::string input;
 
@@ -175,7 +243,6 @@ void NixRepl::mainLoop(const std::vector<std::string> & files)
 
         // We handled the current input fully, so we should clear it
         // and read brand new input.
-        linenoiseHistoryAdd(input.c_str());
         input.clear();
         std::cout << std::endl;
     }
@@ -184,19 +251,10 @@ void NixRepl::mainLoop(const std::vector<std::string> & files)
 
 bool NixRepl::getLine(string & input, const std::string &prompt)
 {
-    char * s = linenoise(prompt.c_str());
+    char * s = readline(prompt.c_str());
     Finally doFree([&]() { free(s); });
-    if (!s) {
-      switch (auto type = linenoiseKeyType()) {
-        case 1: // ctrl-C
-          input = "";
-          return true;
-        case 2: // ctrl-D
-          return false;
-        default:
-          throw Error(format("Unexpected linenoise keytype: %1%") % type);
-      }
-    }
+    if (!s)
+      return false;
     input += s;
     input += '\n';
     return true;
@@ -279,6 +337,8 @@ static int runProgram(const string & program, const Strings & args)
     if (pid == -1) throw SysError("forking");
     if (pid == 0) {
         restoreAffinity();
+        restoreSignals();
+        restoreMountNamespace();
         execvp(program.c_str(), stringsToCharPtrs(args2).data());
         _exit(1);
     }
@@ -385,7 +445,7 @@ bool NixRepl::processLine(string line)
             /* We could do the build in this process using buildPaths(),
                but doing it in a child makes it easier to recover from
                problems / SIGINT. */
-            if (runProgram(settings.nixBinDir + "/nix-store", Strings{"-r", drvPath}) == 0) {
+            if (runProgram(settings.nixBinDir + "/nix", Strings{"build", drvPath}) == 0) {
                 Derivation drv = readDerivation(drvPath);
                 std::cout << std::endl << "this derivation produced the following outputs:" << std::endl;
                 for (auto & i : drv.outputs)
@@ -441,8 +501,7 @@ void NixRepl::loadFile(const Path & path)
     loadedFiles.push_back(path);
     Value v, v2;
     state.evalFile(lookupFileArg(state, path), v);
-    Bindings & bindings(*state.allocBindings(0));
-    state.autoCallFunction(bindings, v, v2);
+    state.autoCallFunction(*autoArgs, v, v2);
     addAttrsToScope(v2);
 }
 
@@ -693,8 +752,9 @@ struct CmdRepl : StoreCommand, MixEvalArgs
 
     void run(ref<Store> store) override
     {
-        NixRepl repl(searchPath, openStore());
-        repl.mainLoop(files);
+        auto repl = std::make_unique<NixRepl>(searchPath, openStore());
+        repl->autoArgs = getAutoArgs(repl->state);
+        repl->mainLoop(files);
     }
 };
 
diff --git a/src/nix/run.cc b/src/nix/run.cc
index d04e106e037b..1297072989b9 100644
--- a/src/nix/run.cc
+++ b/src/nix/run.cc
@@ -7,11 +7,14 @@
 #include "finally.hh"
 #include "fs-accessor.hh"
 #include "progress-bar.hh"
+#include "affinity.hh"
 
 #if __linux__
 #include <sys/mount.h>
 #endif
 
+#include <queue>
+
 using namespace nix;
 
 std::string chrootHelperName = "__run_in_chroot";
@@ -121,10 +124,27 @@ struct CmdRun : InstallablesCommand
                 unsetenv(var.c_str());
         }
 
+        std::unordered_set<Path> done;
+        std::queue<Path> todo;
+        for (auto & path : outPaths) todo.push(path);
+
         auto unixPath = tokenizeString<Strings>(getEnv("PATH"), ":");
-        for (auto & path : outPaths)
-            if (accessor->stat(path + "/bin").type != FSAccessor::tMissing)
+
+        while (!todo.empty()) {
+            Path path = todo.front();
+            todo.pop();
+            if (!done.insert(path).second) continue;
+
+            if (true)
                 unixPath.push_front(path + "/bin");
+
+            auto propPath = path + "/nix-support/propagated-user-env-packages";
+            if (accessor->stat(propPath).type == FSAccessor::tRegular) {
+                for (auto & p : tokenizeString<Paths>(readFile(propPath)))
+                    todo.push(p);
+            }
+        }
+
         setenv("PATH", concatStringsSep(":", unixPath).c_str(), 1);
 
         std::string cmd = *command.begin();
@@ -133,7 +153,9 @@ struct CmdRun : InstallablesCommand
 
         stopProgressBar();
 
+        restoreAffinity();
         restoreSignals();
+        restoreMountNamespace();
 
         /* If this is a diverted store (i.e. its "logical" location
            (typically /nix/store) differs from its "physical" location
diff --git a/src/nix/search.cc b/src/nix/search.cc
index 539676698086..e086de2260a6 100644
--- a/src/nix/search.cc
+++ b/src/nix/search.cc
@@ -7,19 +7,25 @@
 #include "common-args.hh"
 #include "json.hh"
 #include "json-to-value.hh"
+#include "shared.hh"
 
 #include <regex>
 #include <fstream>
 
 using namespace nix;
 
-std::string hilite(const std::string & s, const std::smatch & m)
+std::string wrap(std::string prefix, std::string s)
+{
+    return prefix + s + ANSI_NORMAL;
+}
+
+std::string hilite(const std::string & s, const std::smatch & m, std::string postfix)
 {
     return
         m.empty()
         ? s
         : std::string(m.prefix())
-          + ANSI_RED + std::string(m.str()) + ANSI_NORMAL
+          + ANSI_RED + std::string(m.str()) + postfix
           + std::string(m.suffix());
 }
 
@@ -75,6 +81,10 @@ struct CmdSearch : SourceExprCommand, MixJSON
                 "To search for git and frontend or gui:",
                 "nix search git 'frontend|gui'"
             },
+            Example{
+                "To display the description of the found packages:",
+                "nix search git --verbose"
+            }
         };
     }
 
@@ -163,15 +173,13 @@ struct CmdSearch : SourceExprCommand, MixJSON
                             jsonElem.attr("description", description);
 
                         } else {
+                            auto name = hilite(parsed.name, nameMatch, "\e[0;2m")
+                                + std::string(parsed.fullName, parsed.name.length());
                             results[attrPath] = fmt(
-                                "Attribute name: %s\n"
-                                "Package name: %s\n"
-                                "Version: %s\n"
-                                "Description: %s\n",
-                                hilite(attrPath, attrPathMatch),
-                                hilite(name, nameMatch),
-                                parsed.version,
-                                hilite(description, descriptionMatch));
+                                "* %s (%s)\n  %s\n",
+                                wrap("\e[0;1m", hilite(attrPath, attrPathMatch, "\e[0;1m")),
+                                wrap("\e[0;2m", hilite(name, nameMatch, "\e[0;2m")),
+                                hilite(description, descriptionMatch, ANSI_NORMAL));
                         }
                     }
 
@@ -263,6 +271,10 @@ struct CmdSearch : SourceExprCommand, MixJSON
                 throw SysError("cannot rename '%s' to '%s'", tmpFile, jsonCacheFileName);
         }
 
+        if (results.size() == 0)
+            throw Error("no results for the given search term(s)!");
+
+        RunPager pager;
         for (auto el : results) std::cout << el.second << "\n";
 
     }
diff --git a/src/nix/upgrade-nix.cc b/src/nix/upgrade-nix.cc
index 21892c31a893..35c44a70cf52 100644
--- a/src/nix/upgrade-nix.cc
+++ b/src/nix/upgrade-nix.cc
@@ -1,14 +1,18 @@
 #include "command.hh"
+#include "common-args.hh"
 #include "store-api.hh"
 #include "download.hh"
 #include "eval.hh"
 #include "attr-path.hh"
+#include "names.hh"
+#include "progress-bar.hh"
 
 using namespace nix;
 
-struct CmdUpgradeNix : StoreCommand
+struct CmdUpgradeNix : MixDryRun, StoreCommand
 {
     Path profileDir;
+    std::string storePathsUrl = "https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix";
 
     CmdUpgradeNix()
     {
@@ -18,6 +22,12 @@ struct CmdUpgradeNix : StoreCommand
             .labels({"profile-dir"})
             .description("the Nix profile to upgrade")
             .dest(&profileDir);
+
+        mkFlag()
+            .longName("nix-store-paths-url")
+            .labels({"url"})
+            .description("URL of the file that contains the store paths of the latest Nix release")
+            .dest(&storePathsUrl);
     }
 
     std::string name() override
@@ -59,6 +69,14 @@ struct CmdUpgradeNix : StoreCommand
             storePath = getLatestNix(store);
         }
 
+        auto version = DrvName(storePathToName(storePath)).version;
+
+        if (dryRun) {
+            stopProgressBar();
+            printError("would upgrade to version %s", version);
+            return;
+        }
+
         {
             Activity act(*logger, lvlInfo, actUnknown, fmt("downloading '%s'...", storePath));
             store->ensurePath(storePath);
@@ -72,11 +90,15 @@ struct CmdUpgradeNix : StoreCommand
                 throw Error("could not verify that '%s' works", program);
         }
 
+        stopProgressBar();
+
         {
             Activity act(*logger, lvlInfo, actUnknown, fmt("installing '%s' into profile '%s'...", storePath, profileDir));
             runProgram(settings.nixBinDir + "/nix-env", false,
                 {"--profile", profileDir, "-i", storePath, "--no-sandbox"});
         }
+
+        printError(ANSI_GREEN "upgrade to version %s done" ANSI_NORMAL, version);
     }
 
     /* Return the profile in which Nix is installed. */
@@ -98,11 +120,18 @@ struct CmdUpgradeNix : StoreCommand
         if (hasPrefix(where, "/run/current-system"))
             throw Error("Nix on NixOS must be upgraded via 'nixos-rebuild'");
 
-        Path profileDir;
-        Path userEnv;
+        Path profileDir = dirOf(where);
+
+        // Resolve profile to /nix/var/nix/profiles/<name> link.
+        while (canonPath(profileDir).find("/profiles/") == std::string::npos && isLink(profileDir))
+            profileDir = readLink(profileDir);
+
+        printInfo("found profile '%s'", profileDir);
+
+        Path userEnv = canonPath(profileDir, true);
 
         if (baseNameOf(where) != "bin" ||
-            !hasSuffix(userEnv = canonPath(profileDir = dirOf(where), true), "user-environment"))
+            !hasSuffix(userEnv, "user-environment"))
             throw Error("directory '%s' does not appear to be part of a Nix profile", where);
 
         if (!store->isValidPath(userEnv))
@@ -115,16 +144,16 @@ struct CmdUpgradeNix : StoreCommand
     Path getLatestNix(ref<Store> store)
     {
         // FIXME: use nixos.org?
-        auto req = DownloadRequest("https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix");
+        auto req = DownloadRequest(storePathsUrl);
         auto res = getDownloader()->download(req);
 
-        EvalState state(Strings(), store);
-        auto v = state.allocValue();
-        state.eval(state.parseExprFromString(*res.data, "/no-such-path"), *v);
-        Bindings & bindings(*state.allocBindings(0));
-        auto v2 = findAlongAttrPath(state, settings.thisSystem, bindings, *v);
+        auto state = std::make_unique<EvalState>(Strings(), store);
+        auto v = state->allocValue();
+        state->eval(state->parseExprFromString(*res.data, "/no-such-path"), *v);
+        Bindings & bindings(*state->allocBindings(0));
+        auto v2 = findAlongAttrPath(*state, settings.thisSystem, bindings, *v);
 
-        return state.forceString(*v2);
+        return state->forceString(*v2);
     }
 };
 
diff --git a/src/nix/verify.cc b/src/nix/verify.cc
index 6540208a8a2c..7ef571561a0e 100644
--- a/src/nix/verify.cc
+++ b/src/nix/verify.cc
@@ -120,7 +120,7 @@ struct CmdVerify : StorePathsCommand
                             for (auto sig : sigs) {
                                 if (sigsSeen.count(sig)) continue;
                                 sigsSeen.insert(sig);
-                                if (info->checkSignature(publicKeys, sig))
+                                if (validSigs < ValidPathInfo::maxSigs && info->checkSignature(publicKeys, sig))
                                     validSigs++;
                             }
                         };
diff --git a/src/nix/why-depends.cc b/src/nix/why-depends.cc
index 17e0595ae887..325a2be0a793 100644
--- a/src/nix/why-depends.cc
+++ b/src/nix/why-depends.cc
@@ -2,6 +2,7 @@
 #include "store-api.hh"
 #include "progress-bar.hh"
 #include "fs-accessor.hh"
+#include "shared.hh"
 
 #include <queue>
 
@@ -237,6 +238,7 @@ struct CmdWhyDepends : SourceExprCommand
 
             visitPath(node.path);
 
+            RunPager pager;
             for (auto & ref : refs) {
                 auto hash = storePathToHash(ref.second->path);