Make experimental-features a proper type

Rather than having them plain strings scattered through the whole
codebase, create an enum containing all the known experimental features.

This means that
- Nix can now `warn` when an unkwown experimental feature is passed
  (making it much nicer to spot typos and spot deprecated features)
- It’s now easy to remove a feature altogether (once the feature isn’t
  experimental anymore or is dropped) by just removing the field for the
  enum and letting the compiler point us to all the now invalid usages
  of it.
This commit is contained in:
regnat 2021-10-25 15:53:01 +02:00
parent 4a2b7cc68c
commit af99941279
28 changed files with 188 additions and 61 deletions

View file

@ -18,6 +18,7 @@
#include "derivations.hh"
#include "local-store.hh"
#include "legacy.hh"
#include "experimental-features.hh"
using namespace nix;
using std::cin;
@ -295,7 +296,7 @@ connected:
std::set<Realisation> missingRealisations;
StorePathSet missingPaths;
if (settings.isExperimentalFeatureEnabled("ca-derivations") && !derivationHasKnownOutputPaths(drv.type())) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations) && !derivationHasKnownOutputPaths(drv.type())) {
for (auto & outputName : wantedOutputs) {
auto thisOutputHash = outputHashes.at(outputName);
auto thisOutputId = DrvOutput{ thisOutputHash, outputName };
@ -327,7 +328,7 @@ connected:
for (auto & realisation : missingRealisations) {
// Should hold, because if the feature isn't enabled the set
// of missing realisations should be empty
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
store->registerDrvOutput(realisation);
}

View file

@ -714,7 +714,7 @@ BuiltPaths getBuiltPaths(ref<Store> evalStore, ref<Store> store, const DerivedPa
"the derivation '%s' doesn't have an output named '%s'",
store->printStorePath(bfd.drvPath), output);
if (settings.isExperimentalFeatureEnabled(
"ca-derivations")) {
Xp::CaDerivations)) {
auto outputId =
DrvOutput{outputHashes.at(output), output};
auto realisation =

View file

@ -466,7 +466,7 @@ EvalState::~EvalState()
void EvalState::requireExperimentalFeatureOnEvaluation(
const std::string & feature,
const ExperimentalFeature & feature,
const std::string_view fName,
const Pos & pos)
{

View file

@ -5,6 +5,7 @@
#include "nixexpr.hh"
#include "symbol-table.hh"
#include "config.hh"
#include "experimental-features.hh"
#include <map>
#include <optional>
@ -141,7 +142,7 @@ public:
~EvalState();
void requireExperimentalFeatureOnEvaluation(
const std::string & feature,
const ExperimentalFeature &,
const std::string_view fName,
const Pos & pos
);

View file

@ -297,7 +297,7 @@ LockedFlake lockFlake(
const FlakeRef & topRef,
const LockFlags & lockFlags)
{
settings.requireExperimentalFeature("flakes");
settings.requireExperimentalFeature(Xp::Flakes);
FlakeCache flakeCache;
@ -687,7 +687,7 @@ void callFlake(EvalState & state,
static void prim_getFlake(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.requireExperimentalFeatureOnEvaluation("flakes", "builtins.getFlake", pos);
state.requireExperimentalFeatureOnEvaluation(Xp::Flakes, "builtins.getFlake", pos);
auto flakeRefS = state.forceStringNoCtx(*args[0], pos);
auto flakeRef = parseFlakeRef(flakeRefS, {}, true);

View file

@ -418,7 +418,7 @@ expr_simple
new ExprString(data->symbols.create(path)));
}
| URI {
static bool noURLLiterals = settings.isExperimentalFeatureEnabled("no-url-literals");
static bool noURLLiterals = settings.isExperimentalFeatureEnabled(Xp::NoUrlLiterals);
if (noURLLiterals)
throw ParseError({
.msg = hintfmt("URL literals are disabled"),

View file

@ -985,7 +985,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
}
if (i->name == state.sContentAddressed) {
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
contentAddressed = state.forceBool(*i->value, pos);
}

View file

@ -176,7 +176,7 @@ static void fetchTree(
static void prim_fetchTree(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
settings.requireExperimentalFeature("flakes");
settings.requireExperimentalFeature(Xp::Flakes);
fetchTree(state, pos, args, v, std::nullopt, FetchTreeParams { .allowNameArgument = false });
}

View file

@ -204,7 +204,7 @@ void DerivationGoal::haveDerivation()
trace("have derivation");
if (drv->type() == DerivationType::CAFloating)
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
retrySubstitution = false;
@ -453,7 +453,7 @@ void DerivationGoal::inputsRealised()
if (useDerivation) {
auto & fullDrv = *dynamic_cast<Derivation *>(drv.get());
if (settings.isExperimentalFeatureEnabled("ca-derivations") &&
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations) &&
((!fullDrv.inputDrvs.empty() && derivationIsCA(fullDrv.type()))
|| fullDrv.type() == DerivationType::DeferredInputAddressed)) {
/* We are be able to resolve this derivation based on the
@ -1273,7 +1273,7 @@ void DerivationGoal::checkPathValidity()
: PathStatus::Corrupt,
};
}
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
auto drvOutput = DrvOutput{initialOutputs.at(i.first).outputHash, i.first};
if (auto real = worker.store.queryRealisation(drvOutput)) {
info.known = {

View file

@ -74,7 +74,7 @@ BuildResult Store::buildDerivation(const StorePath & drvPath, const BasicDerivat
outputId,
Realisation{ outputId, *staticOutput.second}
);
if (settings.isExperimentalFeatureEnabled("ca-derivations") && !derivationHasKnownOutputPaths(drv.type())) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations) && !derivationHasKnownOutputPaths(drv.type())) {
auto realisation = this->queryRealisation(outputId);
if (realisation)
result.builtOutputs.insert_or_assign(

View file

@ -1259,7 +1259,7 @@ struct RestrictedStore : public virtual RestrictedStoreConfig, public virtual Lo
for (auto & [outputName, outputPath] : outputs)
if (wantOutput(outputName, bfd.outputs)) {
newPaths.insert(outputPath);
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
auto thisRealisation = next->queryRealisation(
DrvOutput{drvHashes.at(outputName), outputName}
);
@ -1320,7 +1320,7 @@ struct RestrictedStore : public virtual RestrictedStoreConfig, public virtual Lo
void LocalDerivationGoal::startDaemon()
{
settings.requireExperimentalFeature("recursive-nix");
settings.requireExperimentalFeature(Xp::RecursiveNix);
Store::Params params;
params["path-info-cache-size"] = "0";
@ -2561,7 +2561,7 @@ void LocalDerivationGoal::registerOutputs()
that for floating CA derivations, which otherwise couldn't be cached,
but it's fine to do in all cases. */
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
for (auto& [outputName, newInfo] : infos) {
auto thisRealisation = Realisation{
.id = DrvOutput{initialOutputs.at(outputName).outputHash,

View file

@ -230,7 +230,7 @@ struct ClientSettings
else if (name == settings.experimentalFeatures.name) {
// We dont want to forward the experimental features to
// the daemon, as that could cause some pretty weird stuff
if (tokenizeString<Strings>(value) != settings.experimentalFeatures.get())
if (parseFeatures(tokenizeString<StringSet>(value)) != settings.experimentalFeatures.get())
debug("Ignoring the client-specified experimental features");
}
else if (trusted

View file

@ -187,7 +187,7 @@ static DerivationOutput parseDerivationOutput(const Store & store,
},
};
} else {
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
assert(pathS == "");
return DerivationOutput {
.output = DerivationOutputCAFloating {

View file

@ -100,7 +100,7 @@ RealisedPath::Set BuiltPath::toRealisedPaths(Store & store) const
staticOutputHashes(store, store.readDerivation(p.drvPath));
for (auto& [outputName, outputPath] : p.outputs) {
if (settings.isExperimentalFeatureEnabled(
"ca-derivations")) {
Xp::CaDerivations)) {
auto thisRealisation = store.queryRealisation(
DrvOutput{drvHashes.at(outputName), outputName});
assert(thisRealisation); // Weve built it, so we must h

View file

@ -160,21 +160,16 @@ StringSet Settings::getDefaultExtraPlatforms()
return extraPlatforms;
}
bool Settings::isExperimentalFeatureEnabled(const std::string & name)
bool Settings::isExperimentalFeatureEnabled(const ExperimentalFeature & feature)
{
auto & f = experimentalFeatures.get();
return std::find(f.begin(), f.end(), name) != f.end();
return std::find(f.begin(), f.end(), feature) != f.end();
}
MissingExperimentalFeature::MissingExperimentalFeature(std::string feature)
: Error("experimental Nix feature '%1%' is disabled; use '--extra-experimental-features %1%' to override", feature)
, missingFeature(feature)
{}
void Settings::requireExperimentalFeature(const std::string & name)
void Settings::requireExperimentalFeature(const ExperimentalFeature & feature)
{
if (!isExperimentalFeatureEnabled(name))
throw MissingExperimentalFeature(name);
if (!isExperimentalFeatureEnabled(feature))
throw MissingExperimentalFeature(feature);
}
bool Settings::isWSL1()

View file

@ -3,6 +3,7 @@
#include "types.hh"
#include "config.hh"
#include "util.hh"
#include "experimental-features.hh"
#include <map>
#include <limits>
@ -45,15 +46,6 @@ struct PluginFilesSetting : public BaseSetting<Paths>
void set(const std::string & str, bool append = false) override;
};
class MissingExperimentalFeature: public Error
{
public:
std::string missingFeature;
MissingExperimentalFeature(std::string feature);
virtual const char* sname() const override { return "MissingExperimentalFeature"; }
};
class Settings : public Config {
unsigned int getDefaultCores();
@ -925,12 +917,12 @@ public:
value.
)"};
Setting<Strings> experimentalFeatures{this, {}, "experimental-features",
Setting<std::set<ExperimentalFeature>> experimentalFeatures{this, {}, "experimental-features",
"Experimental Nix features to enable."};
bool isExperimentalFeatureEnabled(const std::string & name);
bool isExperimentalFeatureEnabled(const ExperimentalFeature &);
void requireExperimentalFeature(const std::string & name);
void requireExperimentalFeature(const ExperimentalFeature &);
Setting<bool> allowDirty{this, true, "allow-dirty",
"Whether to allow dirty Git/Mercurial trees."};

View file

@ -309,7 +309,7 @@ LocalStore::LocalStore(const Params & params)
else openDB(*state, false);
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
migrateCASchema(state->db, dbDir + "/ca-schema", globalLock);
}
@ -339,7 +339,7 @@ LocalStore::LocalStore(const Params & params)
state->stmts->QueryPathFromHashPart.create(state->db,
"select path from ValidPaths where path >= ? limit 1;");
state->stmts->QueryValidPaths.create(state->db, "select path from ValidPaths");
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
state->stmts->RegisterRealisedOutput.create(state->db,
R"(
insert into Realisations (drvPath, outputName, outputPath, signatures)
@ -708,7 +708,7 @@ void LocalStore::checkDerivationOutputs(const StorePath & drvPath, const Derivat
void LocalStore::registerDrvOutput(const Realisation & info, CheckSigsFlag checkSigs)
{
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
if (checkSigs == NoCheckSigs || !realisationIsUntrusted(info))
registerDrvOutput(info);
else
@ -717,7 +717,7 @@ void LocalStore::registerDrvOutput(const Realisation & info, CheckSigsFlag check
void LocalStore::registerDrvOutput(const Realisation & info)
{
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
retrySQLite<void>([&]() {
auto state(_state.lock());
if (auto oldR = queryRealisation_(*state, info.id)) {
@ -1003,7 +1003,7 @@ LocalStore::queryPartialDerivationOutputMap(const StorePath & path_)
return outputs;
});
if (!settings.isExperimentalFeatureEnabled("ca-derivations"))
if (!settings.isExperimentalFeatureEnabled(Xp::CaDerivations))
return outputs;
auto drv = readInvalidDerivation(path);

View file

@ -355,7 +355,7 @@ ValidPathInfo Store::addToStoreSlow(std::string_view name, const Path & srcPath,
StringSet StoreConfig::getDefaultSystemFeatures()
{
auto res = settings.systemFeatures.get();
if (settings.isExperimentalFeatureEnabled("ca-derivations"))
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations))
res.insert("ca-derivations");
return res;
}
@ -860,7 +860,7 @@ std::map<StorePath, StorePath> copyPaths(
for (auto & path : paths) {
storePaths.insert(path.path());
if (auto realisation = std::get_if<Realisation>(&path.raw)) {
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
toplevelRealisations.insert(*realisation);
}
}
@ -892,7 +892,7 @@ std::map<StorePath, StorePath> copyPaths(
// Don't fail if the remote doesn't support CA derivations is it might
// not be within our control to change that, and we might still want
// to at least copy the output paths.
if (e.missingFeature == "ca-derivations")
if (e.missingFeature == Xp::CaDerivations)
ignoreException();
else
throw;

View file

@ -1,6 +1,7 @@
#include "config.hh"
#include "args.hh"
#include "abstract-setting-to-json.hh"
#include "experimental-features.hh"
#include <nlohmann/json.hpp>
@ -313,6 +314,31 @@ template<> std::string BaseSetting<StringSet>::to_string() const
return concatStringsSep(" ", value);
}
template<> void BaseSetting<std::set<ExperimentalFeature>>::set(const std::string & str, bool append)
{
if (!append) value.clear();
for (auto & s : tokenizeString<StringSet>(str)) {
auto thisXpFeature = parseExperimentalFeature(s);
if (thisXpFeature)
value.insert(thisXpFeature.value());
else
warn("Unknown experimental feature %s", s);
}
}
template<> bool BaseSetting<std::set<ExperimentalFeature>>::isAppendable()
{
return true;
}
template<> std::string BaseSetting<std::set<ExperimentalFeature>>::to_string() const
{
StringSet stringifiedXpFeatures;
for (auto & feature : value)
stringifiedXpFeatures.insert(std::string(showExperimentalFeature(feature)));
return concatStringsSep(" ", stringifiedXpFeatures);
}
template<> void BaseSetting<StringMap>::set(const std::string & str, bool append)
{
if (!append) value.clear();
@ -348,6 +374,7 @@ template class BaseSetting<std::string>;
template class BaseSetting<Strings>;
template class BaseSetting<StringSet>;
template class BaseSetting<StringMap>;
template class BaseSetting<std::set<ExperimentalFeature>>;
void PathSetting::set(const std::string & str, bool append)
{

View file

@ -0,0 +1,55 @@
#include "experimental-features.hh"
#include "nlohmann/json.hpp"
namespace nix {
std::map<ExperimentalFeature, std::string> stringifiedXpFeatures = {
{ Xp::CaDerivations, "ca-derivations" },
{ Xp::Flakes, "flakes" },
{ Xp::NixCommand, "nix-command" },
{ Xp::RecursiveNix, "recursive-nix" },
{ Xp::NoUrlLiterals, "no-url-literals" },
};
const std::optional<ExperimentalFeature> parseExperimentalFeature(const std::string_view & name)
{
using ReverseXpMap = std::map<std::string_view, ExperimentalFeature>;
static ReverseXpMap * reverseXpMap;
if (!reverseXpMap) {
reverseXpMap = new ReverseXpMap{};
for (auto & [feature, name] : stringifiedXpFeatures)
(*reverseXpMap)[name] = feature;
}
auto featureIter = reverseXpMap->find(name);
if (featureIter == reverseXpMap->end())
return std::nullopt;
return {featureIter->second};
}
std::string_view showExperimentalFeature(const ExperimentalFeature feature)
{
return stringifiedXpFeatures.at(feature);
}
std::set<ExperimentalFeature> parseFeatures(const std::set<std::string> & rawFeatures)
{
std::set<ExperimentalFeature> res;
for (auto & rawFeature : rawFeatures) {
if (auto feature = parseExperimentalFeature(rawFeature))
res.insert(*feature);
}
return res;
}
MissingExperimentalFeature::MissingExperimentalFeature(ExperimentalFeature feature)
: Error("experimental Nix feature '%1%' is disabled; use '--extra-experimental-features %1%' to override", showExperimentalFeature(feature))
, missingFeature(feature)
{}
std::ostream & operator <<(std::ostream & str, const ExperimentalFeature & feature)
{
return str << showExperimentalFeature(feature);
}
}

View file

@ -0,0 +1,56 @@
#pragma once
#include "comparator.hh"
#include "error.hh"
#include "nlohmann/json_fwd.hpp"
#include "types.hh"
namespace nix {
/**
* The list of available experimental features.
*
* If you update this, dont forget to also change the map defining their
* string representation in the corresponding `.cc` file.
**/
enum struct ExperimentalFeature
{
CaDerivations,
Flakes,
NixCommand,
RecursiveNix,
NoUrlLiterals
};
/**
* Just because writing `ExperimentalFeature::CaDerivations` is way too long
*/
using Xp = ExperimentalFeature;
const std::optional<ExperimentalFeature> parseExperimentalFeature(
const std::string_view & name);
std::string_view showExperimentalFeature(const ExperimentalFeature);
std::ostream & operator<<(
std::ostream & str,
const ExperimentalFeature & feature);
/**
* Parse a set of strings to the corresponding set of experimental features,
* ignoring (but warning for) any unkwown feature.
*/
std::set<ExperimentalFeature> parseFeatures(const std::set<std::string> &);
class MissingExperimentalFeature : public Error
{
public:
ExperimentalFeature missingFeature;
MissingExperimentalFeature(ExperimentalFeature);
virtual const char * sname() const override
{
return "MissingExperimentalFeature";
}
};
}

View file

@ -401,7 +401,7 @@ static void main_nix_build(int argc, char * * argv)
if (dryRun) return;
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
auto resolvedDrv = drv.tryResolve(*store);
assert(resolvedDrv && "Successfully resolved the derivation");
drv = *resolvedDrv;

View file

@ -195,7 +195,7 @@ static StorePath getDerivationEnvironment(ref<Store> store, ref<Store> evalStore
'buildDerivation', but that's privileged. */
drv.name += "-env";
drv.inputSrcs.insert(std::move(getEnvShPath));
if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) {
for (auto & output : drv.outputs) {
output.second = {
.output = DerivationOutputDeferred{},

View file

@ -1138,7 +1138,7 @@ struct CmdFlake : NixMultiCommand
{
if (!command)
throw UsageError("'nix flake' requires a sub-command.");
settings.requireExperimentalFeature("flakes");
settings.requireExperimentalFeature(Xp::Flakes);
command->second->prepare();
command->second->run();
}

View file

@ -337,7 +337,7 @@ void mainWrapped(int argc, char * * argv)
if (args.command->first != "repl"
&& args.command->first != "doctor"
&& args.command->first != "upgrade-nix")
settings.requireExperimentalFeature("nix-command");
settings.requireExperimentalFeature(Xp::NixCommand);
if (args.useNet && !haveInternet()) {
warn("you don't have Internet access; disabling some network-dependent features");

View file

@ -46,7 +46,7 @@ struct CmdRealisationInfo : BuiltPathsCommand, MixJSON
void run(ref<Store> store, BuiltPaths && paths) override
{
settings.requireExperimentalFeature("ca-derivations");
settings.requireExperimentalFeature(Xp::CaDerivations);
RealisedPath::Set realisations;
for (auto & builtPath : paths) {

View file

@ -219,7 +219,7 @@ struct CmdKey : NixMultiCommand
{
if (!command)
throw UsageError("'nix flake' requires a sub-command.");
settings.requireExperimentalFeature("flakes");
settings.requireExperimentalFeature(Xp::Flakes);
command->second->prepare();
command->second->run();
}

View file

@ -50,4 +50,4 @@ exp_cores=$(nix show-config | grep '^cores' | cut -d '=' -f 2 | xargs)
exp_features=$(nix show-config | grep '^experimental-features' | cut -d '=' -f 2 | xargs)
[[ $prev != $exp_cores ]]
[[ $exp_cores == "4242" ]]
[[ $exp_features == "nix-command flakes" ]]
[[ $exp_features == "flakes nix-command" ]]