From 2d5b1b24bf70a498e4c0b378704cfdb6471cc699 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 25 Oct 2017 13:01:50 +0200 Subject: Pass lists/attrsets to bash as (associative) arrays --- src/libexpr/primops.cc | 6 +-- src/libstore/build.cc | 96 ++++++++++++++++++++++++++++++++++++++++++++-- src/libutil/util.cc | 10 +++++ src/libutil/util.hh | 6 +-- src/nix-build/nix-build.cc | 4 -- src/nix-store/nix-store.cc | 11 +----- 6 files changed, 109 insertions(+), 24 deletions(-) (limited to 'src') diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index fcd3f8efee3f..afd344286607 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -713,7 +713,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * if (outputHashRecursive) outputHashAlgo = "r:" + outputHashAlgo; Path outPath = state.store->makeFixedOutputPath(outputHashRecursive, h, drvName); - drv.env["out"] = outPath; + if (!jsonObject) drv.env["out"] = outPath; drv.outputs["out"] = DerivationOutput(outPath, outputHashAlgo, *outputHash); } @@ -724,7 +724,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * an empty value. This ensures that changes in the set of output names do get reflected in the hash. */ for (auto & i : outputs) { - drv.env[i] = ""; + if (!jsonObject) drv.env[i] = ""; drv.outputs[i] = DerivationOutput("", "", ""); } @@ -735,7 +735,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * for (auto & i : drv.outputs) if (i.second.path == "") { Path outPath = state.store->makeOutputPath(i.first, h, drvName); - drv.env[i.first] = outPath; + if (!jsonObject) drv.env[i.first] = outPath; i.second.path = outPath; } } diff --git a/src/libstore/build.cc b/src/libstore/build.cc index 856d516d2bb3..a7d418404e87 100644 --- a/src/libstore/build.cc +++ b/src/libstore/build.cc @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -55,6 +56,8 @@ #include #endif +#include + namespace nix { @@ -2286,12 +2289,99 @@ void DerivationGoal::initEnv() } +static std::regex shVarName("[A-Za-z_][A-Za-z0-9_]*"); + + void DerivationGoal::writeStructuredAttrs() { - auto json = drv->env.find("__json"); - if (json == drv->env.end()) return; + auto jsonAttr = drv->env.find("__json"); + if (jsonAttr == drv->env.end()) return; + + try { + + auto jsonStr = rewriteStrings(jsonAttr->second, inputRewrites); + + auto json = nlohmann::json::parse(jsonStr); + + /* 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; + + writeFile(tmpDir + "/.attrs.json", json.dump()); + + /* 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 { + if (value.is_string()) + return shellEscape(value); + + if (value.is_number()) { + auto f = value.get(); + if (std::ceil(f) == f) + return std::to_string(value.get()); + } + + if (value.is_null()) + return "''"; + + if (value.is_boolean()) + return value.get() ? "1" : ""; + + return {}; + }; + + std::string jsonSh; - writeFile(tmpDir + "/.attrs.json", rewriteStrings(json->second, inputRewrites)); + for (auto i = json.begin(); i != json.end(); ++i) { + + if (!std::regex_match(i.key(), shVarName)) continue; + + auto & value = i.value(); + + auto s = handleSimpleType(value); + if (s) + jsonSh += fmt("declare %s=%s\n", i.key(), *s); + + else if (value.is_array()) { + std::string s2; + bool good = true; + + for (auto i = value.begin(); i != value.end(); ++i) { + auto s3 = handleSimpleType(i.value()); + if (!s3) { good = false; break; } + s2 += *s3; s2 += ' '; + } + + if (good) + jsonSh += fmt("declare -a %s=(%s)\n", i.key(), s2); + } + + else if (value.is_object()) { + std::string s2; + bool good = true; + + 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); + } + + if (good) + jsonSh += fmt("declare -A %s=(%s)\n", i.key(), s2); + } + } + + writeFile(tmpDir + "/.attrs.sh", jsonSh); + + } catch (std::exception & e) { + throw Error("cannot process __json attribute of '%s': %s", drvPath, e.what()); + } } diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 3c98a61f9e50..9346d5dc4cf8 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -1142,6 +1142,16 @@ std::string toLower(const std::string & s) } +std::string shellEscape(const std::string & s) +{ + std::string r = "'"; + for (auto & i : s) + if (i == '\'') r += "'\\''"; else r += i; + r += '\''; + return r; +} + + void ignoreException() { try { diff --git a/src/libutil/util.hh b/src/libutil/util.hh index 6a66576e96ce..fccf5d854800 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -352,10 +352,8 @@ bool hasSuffix(const string & s, const string & suffix); std::string toLower(const std::string & s); -/* Escape a string that contains octal-encoded escape codes such as - used in /etc/fstab and /proc/mounts (e.g. "foo\040bar" decodes to - "foo bar"). */ -string decodeOctalEscaped(const string & s); +/* Escape a string as a shell word. */ +std::string shellEscape(const std::string & s); /* Exception handling in destructors: print an error message, then diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc index 85137206fa73..8e56e5a46b19 100755 --- a/src/nix-build/nix-build.cc +++ b/src/nix-build/nix-build.cc @@ -196,10 +196,6 @@ void mainWrapped(int argc, char * * argv) interactive = false; auto execArgs = ""; - auto shellEscape = [](const string & s) { - return "'" + std::regex_replace(s, std::regex("'"), "'\\''") + "'"; - }; - // Überhack to support Perl. Perl examines the shebang and // executes it unless it contains the string "perl" or "indir", // or (undocumented) argv[0] does not contain "perl". Exploit diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc index 85bcbc22e9db..f6f276dd1798 100644 --- a/src/nix-store/nix-store.cc +++ b/src/nix-store/nix-store.cc @@ -440,15 +440,6 @@ static void opQuery(Strings opFlags, Strings opArgs) } -static string shellEscape(const string & s) -{ - string r; - for (auto & i : s) - if (i == '\'') r += "'\\''"; else r += i; - return r; -} - - static void opPrintEnv(Strings opFlags, Strings opArgs) { if (!opFlags.empty()) throw UsageError("unknown flag"); @@ -460,7 +451,7 @@ static void opPrintEnv(Strings opFlags, Strings opArgs) /* Print each environment variable in the derivation in a format that can be sourced by the shell. */ for (auto & i : drv.env) - cout << format("export %1%; %1%='%2%'\n") % i.first % shellEscape(i.second); + cout << format("export %1%; %1%=%2%\n") % i.first % shellEscape(i.second); /* Also output the arguments. This doesn't preserve whitespace in arguments. */ -- cgit 1.4.1