Add 'third_party/nix/' from commit 'be66c7a6b24e3c3c6157fd37b86c7203d14acf10' r/724

git-subtree-dir: third_party/nix
git-subtree-mainline: cf8cd640c1adf74a3706efbcb0ea4625da106fb2
git-subtree-split: be66c7a6b24e3c3c6157fd37b86c7203d14acf10

1 files changed, 338 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..9023cb1bb6de
--- /dev/null
+++ b/third_party/nix/src/libutil/config.cc
@@ -0,0 +1,338 @@
+#include "config.hh"
+#include "args.hh"
+#include "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)
+                warn("setting '%s' is set, but it's an alias of '%s' which is also set",
+                    alias, setting->name);
+            else {
+                setting->set(i->second);
+                setting->overriden = true;
+                unknownSettings.erase(i);
+                set = true;
+            }
+        }
+    }
+}
+
+void AbstractConfig::warnUnknownSettings()
+{
+    for (auto & s : unknownSettings)
+        warn("unknown setting '%s'", 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 {
+        string contents = readFile(path);
+
+        unsigned int pos = 0;
+
+        while (pos < contents.size()) {
+            string line;
+            while (pos < contents.size() && contents[pos] != '\n')
+                line += contents[pos++];
+            pos++;
+
+            string::size_type hash = line.find('#');
+            if (hash != string::npos)
+                line = string(line, 0, hash);
+
+            vector<string> tokens = tokenizeString<vector<string> >(line);
+            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);
+
+            string name = tokens[0];
+
+            vector<string>::iterator 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(
+    const std::string & name,
+    const std::string & description,
+    const std::set<std::string> & aliases)
+    : name(name), description(description), aliases(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 (!string2Int(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([=](std::vector<std::string> ss) { override(true); })
+        .category(category);
+    args.mkFlag()
+        .longName("no-" + name)
+        .description(description)
+        .handler([=](std::vector<std::string> ss) { override(false); })
+        .category(category);
+}
+
+template<> void BaseSetting<Strings>::set(const std::string & str)
+{
+    value = tokenizeString<Strings>(str);
+}
+
+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 = tokenizeString<StringSet>(str);
+}
+
+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 == "") {
+        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)
+        configRegistrations = new ConfigRegistrations;
+    configRegistrations->emplace_back(config);
+}
+
+}