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#include "deprecated-features.hh"
// Required for instances of to_json and from_json for DeprecatedFeature
#include "deprecated-features-json.hh"
#include "strings.hh"
#include "nlohmann/json.hpp"
namespace nix {
struct DeprecatedFeatureDetails
{
DeprecatedFeature tag;
std::string_view name;
std::string_view description;
};
/**
* If two different PRs both add a deprecated feature, and we just
* used a number for this, we *woudln't* get merge conflict and the
* counter will be incremented once instead of twice, causing a build
* failure.
*
* By instead defining this instead as 1 + the bottom deprecated
* feature, we either have no issue at all if few features are not added
* at the end of the list, or a proper merge conflict if they are.
*/
constexpr size_t numDepFeatures = 1 + static_cast<size_t>(Dep::UrlLiterals);
constexpr std::array<DeprecatedFeatureDetails, numDepFeatures> depFeatureDetails = {{
{
.tag = Dep::UrlLiterals,
.name = "url-literals",
.description = R"(
Allow unquoted URLs as part of the Nix language syntax.
)",
},
}};
static_assert(
[]() constexpr {
for (auto [index, feature] : enumerate(depFeatureDetails))
if (index != (size_t)feature.tag)
return false;
return true;
}(),
"array order does not match enum tag order");
const std::optional<DeprecatedFeature> parseDeprecatedFeature(const std::string_view & name)
{
using ReverseDepMap = std::map<std::string_view, DeprecatedFeature>;
static std::unique_ptr<ReverseDepMap> reverseDepMap = []() {
auto reverseDepMap = std::make_unique<ReverseDepMap>();
for (auto & depFeature : depFeatureDetails)
(*reverseDepMap)[depFeature.name] = depFeature.tag;
return reverseDepMap;
}();
if (auto feature = get(*reverseDepMap, name))
return *feature;
else
return std::nullopt;
}
std::string_view showDeprecatedFeature(const DeprecatedFeature tag)
{
assert((size_t)tag < depFeatureDetails.size());
return depFeatureDetails[(size_t)tag].name;
}
nlohmann::json documentDeprecatedFeatures()
{
StringMap res;
for (auto & depFeature : depFeatureDetails)
res[std::string { depFeature.name }] =
trim(stripIndentation(depFeature.description));
return (nlohmann::json) res;
}
std::set<DeprecatedFeature> parseDeprecatedFeatures(const std::set<std::string> & rawFeatures)
{
std::set<DeprecatedFeature> res;
for (auto & rawFeature : rawFeatures)
if (auto feature = parseDeprecatedFeature(rawFeature))
res.insert(*feature);
return res;
}
MissingDeprecatedFeature::MissingDeprecatedFeature(DeprecatedFeature feature)
: Error("Lix feature '%1%' is deprecated and should not be used anymore; use '--extra-deprecated-features %1%' to disable this error", showDeprecatedFeature(feature))
, missingFeature(feature)
{}
std::ostream & operator <<(std::ostream & str, const DeprecatedFeature & feature)
{
return str << showDeprecatedFeature(feature);
}
void to_json(nlohmann::json & j, const DeprecatedFeature & feature)
{
j = showDeprecatedFeature(feature);
}
void from_json(const nlohmann::json & j, DeprecatedFeature & feature)
{
const std::string input = j;
const auto parsed = parseDeprecatedFeature(input);
if (parsed.has_value())
feature = *parsed;
else
throw Error("Unknown deprecated feature '%s' in JSON input", input);
}
}
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