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#include "parsed-derivations.hh"
#include "strings.hh"
#include <nlohmann/json.hpp>
#include <regex>
namespace nix {
ParsedDerivation::ParsedDerivation(const StorePath & 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 = std::make_unique<nlohmann::json>(nlohmann::json::parse(jsonAttr->second));
} catch (std::exception & e) {
throw Error("cannot process __json attribute of '%s': %s", drvPath.to_string(), e.what());
}
}
}
ParsedDerivation::~ParsedDerivation() { }
std::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.to_string());
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.to_string());
return i->get<bool>();
}
} else {
auto i = drv.env.find(name);
if (i == drv.env.end())
return def;
else
return i->second == "1";
}
}
std::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.to_string());
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.to_string());
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
{
// FIXME: cache this?
StringSet res;
for (auto & i : getStringsAttr("requiredSystemFeatures").value_or(Strings()))
res.insert(i);
if (!drv.type().hasKnownOutputPaths())
res.insert("ca-derivations");
return res;
}
bool ParsedDerivation::canBuildLocally(Store & localStore) const
{
if (drv.platform != settings.thisSystem.get()
&& !settings.extraPlatforms.get().count(drv.platform)
&& !drv.isBuiltin())
return false;
if (settings.maxBuildJobs.get() == 0
&& !drv.isBuiltin())
return false;
for (auto & feature : getRequiredSystemFeatures())
if (!localStore.systemFeatures.get().count(feature)) return false;
return true;
}
bool ParsedDerivation::willBuildLocally(Store & localStore) const
{
return getBoolAttr("preferLocalBuild") && canBuildLocally(localStore);
}
bool ParsedDerivation::substitutesAllowed() const
{
return settings.alwaysAllowSubstitutes ? true : getBoolAttr("allowSubstitutes", true);
}
bool ParsedDerivation::useUidRange() const
{
return getRequiredSystemFeatures().count("uid-range");
}
static std::regex shVarName("[A-Za-z_][A-Za-z0-9_]*");
std::optional<nlohmann::json> ParsedDerivation::prepareStructuredAttrs(Store & store, const StorePathSet & inputPaths)
{
auto structuredAttrs = getStructuredAttrs();
if (!structuredAttrs) return std::nullopt;
auto json = *structuredAttrs;
/* Add an "outputs" object containing the output paths. */
nlohmann::json outputs;
for (auto & i : drv.outputs)
outputs[i.first] = hashPlaceholder(i.first);
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) {
StorePathSet storePaths;
for (auto & p : *i)
storePaths.insert(store.toStorePath(p.get<std::string>()).first);
json[i.key()] = store.pathInfoToJSON(
store.exportReferences(storePaths, inputPaths), false, true);
}
}
return json;
}
/* 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.) */
std::string writeStructuredAttrsShell(const nlohmann::json & json)
{
auto handleSimpleType = [](const nlohmann::json & value) -> std::optional<std::string> {
if (value.is_string())
return shellEscape(value.get<std::string_view>());
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_boolean())
return value.get<bool>() ? std::string("1") : std::string("");
return {};
};
std::string jsonSh;
for (auto & [key, value] : json.items()) {
if (!std::regex_match(key, shVarName)) continue;
auto s = handleSimpleType(value);
if (s)
jsonSh += fmt("declare %s=%s\n", key, *s);
else if (value.is_array()) {
std::string s2;
bool good = true;
for (auto & value2 : value) {
auto s3 = handleSimpleType(value2);
if (!s3) { good = false; break; }
s2 += *s3; s2 += ' ';
}
if (good)
jsonSh += fmt("declare -a %s=(%s)\n", key, s2);
}
else if (value.is_object()) {
std::string s2;
bool good = true;
for (auto & [key2, value2] : value.items()) {
auto s3 = handleSimpleType(value2);
if (!s3) { good = false; break; }
s2 += fmt("[%s]=%s ", shellEscape(key2), *s3);
}
if (good)
jsonSh += fmt("declare -A %s=(%s)\n", key, s2);
}
}
return jsonSh;
}
}
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