1 files changed, 370 insertions, 0 deletions
diff --git a/third_party/nix/src/libutil/config.cc b/third_party/nix/src/libutil/config.cc
new file mode 100644
index 000000000000..7c6e7af48752
--- /dev/null
+++ b/third_party/nix/src/libutil/config.cc
@@ -0,0 +1,370 @@
+#include "libutil/config.hh"
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include <absl/strings/numbers.h>
+#include <absl/strings/str_split.h>
+#include <absl/strings/string_view.h>
+#include <glog/logging.h>
+
+#include "libutil/args.hh"
+#include "libutil/json.hh"
+
+namespace nix {
+
+bool Config::set(const std::string& name, const std::string& value) {
+  auto i = _settings.find(name);
+  if (i == _settings.end()) {
+    return false;
+  }
+  i->second.setting->set(value);
+  i->second.setting->overriden = true;
+  return true;
+}
+
+void Config::addSetting(AbstractSetting* setting) {
+  _settings.emplace(setting->name, Config::SettingData(false, setting));
+  for (auto& alias : setting->aliases) {
+    _settings.emplace(alias, Config::SettingData(true, setting));
+  }
+
+  bool set = false;
+
+  auto i = unknownSettings.find(setting->name);
+  if (i != unknownSettings.end()) {
+    setting->set(i->second);
+    setting->overriden = true;
+    unknownSettings.erase(i);
+    set = true;
+  }
+
+  for (auto& alias : setting->aliases) {
+    auto i = unknownSettings.find(alias);
+    if (i != unknownSettings.end()) {
+      if (set) {
+        LOG(WARNING) << "setting '" << alias
+                     << "' is set, but it's an alias of '" << setting->name
+                     << "', which is also set";
+      }
+
+      else {
+        setting->set(i->second);
+        setting->overriden = true;
+        unknownSettings.erase(i);
+        set = true;
+      }
+    }
+  }
+}
+
+void AbstractConfig::warnUnknownSettings() {
+  for (auto& s : unknownSettings) {
+    LOG(WARNING) << "unknown setting: " << s.first;
+  }
+}
+
+void AbstractConfig::reapplyUnknownSettings() {
+  auto unknownSettings2 = std::move(unknownSettings);
+  for (auto& s : unknownSettings2) {
+    set(s.first, s.second);
+  }
+}
+
+void Config::getSettings(std::map<std::string, SettingInfo>& res,
+                         bool overridenOnly) {
+  for (auto& opt : _settings) {
+    if (!opt.second.isAlias &&
+        (!overridenOnly || opt.second.setting->overriden)) {
+      res.emplace(opt.first, SettingInfo{opt.second.setting->to_string(),
+                                         opt.second.setting->description});
+    }
+  }
+}
+
+void AbstractConfig::applyConfigFile(const Path& path) {
+  try {
+    std::string contents = readFile(path);
+
+    unsigned int pos = 0;
+
+    while (pos < contents.size()) {
+      std::string line;
+      while (pos < contents.size() && contents[pos] != '\n') {
+        line += contents[pos++];
+      }
+      pos++;
+
+      std::string::size_type hash = line.find('#');
+      if (hash != std::string::npos) {
+        line = std::string(line, 0, hash);
+      }
+
+      // TODO(tazjin): absl::string_view after path functions are fixed.
+      std::vector<std::string> tokens = absl::StrSplit(
+          line, absl::ByAnyChar(" \t\n\r"), absl::SkipWhitespace());
+      if (tokens.empty()) {
+        continue;
+      }
+
+      if (tokens.size() < 2) {
+        throw UsageError("illegal configuration line '%1%' in '%2%'", line,
+                         path);
+      }
+
+      auto include = false;
+      auto ignoreMissing = false;
+      if (tokens[0] == "include") {
+        include = true;
+      } else if (tokens[0] == "!include") {
+        include = true;
+        ignoreMissing = true;
+      }
+
+      if (include) {
+        if (tokens.size() != 2) {
+          throw UsageError("illegal configuration line '%1%' in '%2%'", line,
+                           path);
+        }
+        auto p = absPath(tokens[1], dirOf(path));
+        if (pathExists(p)) {
+          applyConfigFile(p);
+        } else if (!ignoreMissing) {
+          throw Error("file '%1%' included from '%2%' not found", p, path);
+        }
+        continue;
+      }
+
+      if (tokens[1] != "=") {
+        throw UsageError("illegal configuration line '%1%' in '%2%'", line,
+                         path);
+      }
+
+      std::string name = tokens[0];
+
+      auto i = tokens.begin();
+      advance(i, 2);
+
+      set(name,
+          concatStringsSep(" ", Strings(i, tokens.end())));  // FIXME: slow
+    };
+  } catch (SysError&) {
+  }
+}
+
+void Config::resetOverriden() {
+  for (auto& s : _settings) {
+    s.second.setting->overriden = false;
+  }
+}
+
+void Config::toJSON(JSONObject& out) {
+  for (auto& s : _settings) {
+    if (!s.second.isAlias) {
+      JSONObject out2(out.object(s.first));
+      out2.attr("description", s.second.setting->description);
+      JSONPlaceholder out3(out2.placeholder("value"));
+      s.second.setting->toJSON(out3);
+    }
+  }
+}
+
+void Config::convertToArgs(Args& args, const std::string& category) {
+  for (auto& s : _settings) {
+    if (!s.second.isAlias) {
+      s.second.setting->convertToArg(args, category);
+    }
+  }
+}
+
+AbstractSetting::AbstractSetting(std::string name, std::string description,
+                                 std::set<std::string> aliases)
+    : name(std::move(name)),
+      description(std::move(description)),
+      aliases(std::move(aliases)) {}
+
+void AbstractSetting::toJSON(JSONPlaceholder& out) { out.write(to_string()); }
+
+void AbstractSetting::convertToArg(Args& args, const std::string& category) {}
+
+template <typename T>
+void BaseSetting<T>::toJSON(JSONPlaceholder& out) {
+  out.write(value);
+}
+
+template <typename T>
+void BaseSetting<T>::convertToArg(Args& args, const std::string& category) {
+  args.mkFlag()
+      .longName(name)
+      .description(description)
+      .arity(1)
+      .handler([=](std::vector<std::string> ss) {
+        overriden = true;
+        set(ss[0]);
+      })
+      .category(category);
+}
+
+template <>
+void BaseSetting<std::string>::set(const std::string& str) {
+  value = str;
+}
+
+template <>
+std::string BaseSetting<std::string>::to_string() {
+  return value;
+}
+
+template <typename T>
+void BaseSetting<T>::set(const std::string& str) {
+  static_assert(std::is_integral<T>::value, "Integer required.");
+  if (!absl::SimpleAtoi(str, &value)) {
+    throw UsageError("setting '%s' has invalid value '%s'", name, str);
+  }
+}
+
+template <typename T>
+std::string BaseSetting<T>::to_string() {
+  static_assert(std::is_integral<T>::value, "Integer required.");
+  return std::to_string(value);
+}
+
+template <>
+void BaseSetting<bool>::set(const std::string& str) {
+  if (str == "true" || str == "yes" || str == "1") {
+    value = true;
+  } else if (str == "false" || str == "no" || str == "0") {
+    value = false;
+  } else {
+    throw UsageError("Boolean setting '%s' has invalid value '%s'", name, str);
+  }
+}
+
+template <>
+std::string BaseSetting<bool>::to_string() {
+  return value ? "true" : "false";
+}
+
+template <>
+void BaseSetting<bool>::convertToArg(Args& args, const std::string& category) {
+  args.mkFlag()
+      .longName(name)
+      .description(description)
+      .handler([=](const std::vector<std::string>& ss) { override(true); })
+      .category(category);
+  args.mkFlag()
+      .longName("no-" + name)
+      .description(description)
+      .handler([=](const std::vector<std::string>& ss) { override(false); })
+      .category(category);
+}
+
+template <>
+void BaseSetting<Strings>::set(const std::string& str) {
+  value = absl::StrSplit(str, absl::ByAnyChar(" \t\n\r"), absl::SkipEmpty());
+}
+
+template <>
+std::string BaseSetting<Strings>::to_string() {
+  return concatStringsSep(" ", value);
+}
+
+template <>
+void BaseSetting<Strings>::toJSON(JSONPlaceholder& out) {
+  JSONList list(out.list());
+  for (auto& s : value) {
+    list.elem(s);
+  }
+}
+
+template <>
+void BaseSetting<StringSet>::set(const std::string& str) {
+  value = absl::StrSplit(str, absl::ByAnyChar(" \t\n\r"), absl::SkipEmpty());
+}
+
+template <>
+std::string BaseSetting<StringSet>::to_string() {
+  return concatStringsSep(" ", value);
+}
+
+template <>
+void BaseSetting<StringSet>::toJSON(JSONPlaceholder& out) {
+  JSONList list(out.list());
+  for (auto& s : value) {
+    list.elem(s);
+  }
+}
+
+template class BaseSetting<int>;
+template class BaseSetting<unsigned int>;
+template class BaseSetting<long>;
+template class BaseSetting<unsigned long>;
+template class BaseSetting<long long>;
+template class BaseSetting<unsigned long long>;
+template class BaseSetting<bool>;
+template class BaseSetting<std::string>;
+template class BaseSetting<Strings>;
+template class BaseSetting<StringSet>;
+
+void PathSetting::set(const std::string& str) {
+  if (str.empty()) {
+    if (allowEmpty) {
+      value = "";
+    } else {
+      throw UsageError("setting '%s' cannot be empty", name);
+    }
+  } else {
+    value = canonPath(str);
+  }
+}
+
+bool GlobalConfig::set(const std::string& name, const std::string& value) {
+  for (auto& config : *configRegistrations) {
+    if (config->set(name, value)) {
+      return true;
+    }
+  }
+
+  unknownSettings.emplace(name, value);
+
+  return false;
+}
+
+void GlobalConfig::getSettings(std::map<std::string, SettingInfo>& res,
+                               bool overridenOnly) {
+  for (auto& config : *configRegistrations) {
+    config->getSettings(res, overridenOnly);
+  }
+}
+
+void GlobalConfig::resetOverriden() {
+  for (auto& config : *configRegistrations) {
+    config->resetOverriden();
+  }
+}
+
+void GlobalConfig::toJSON(JSONObject& out) {
+  for (auto& config : *configRegistrations) {
+    config->toJSON(out);
+  }
+}
+
+void GlobalConfig::convertToArgs(Args& args, const std::string& category) {
+  for (auto& config : *configRegistrations) {
+    config->convertToArgs(args, category);
+  }
+}
+
+GlobalConfig globalConfig;
+
+GlobalConfig::ConfigRegistrations* GlobalConfig::configRegistrations;
+
+GlobalConfig::Register::Register(Config* config) {
+  if (configRegistrations == nullptr) {
+    configRegistrations = new ConfigRegistrations;
+  }
+  configRegistrations->emplace_back(config);
+}
+
+}  // namespace nix