lix/src/libstore/parsed-derivations.cc
2019-09-03 16:03:49 +02:00

117 lines
3.3 KiB
C++

#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::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::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();
}
bool ParsedDerivation::substitutesAllowed() const
{
return getBoolAttr("allowSubstitutes", true);
}
}