lix/src/nix/installables.cc
Eelco Dolstra 61fdb16aac
Improve error message when a directory is not a flake
So you now get

  $ nix build
  error: path '.' is not a flake (because it does not reference a Git repository)

rather than

  $ nix build
  error: unsupported argument '.'
2019-09-02 17:35:35 +02:00

565 lines
16 KiB
C++

#include "command.hh"
#include "attr-path.hh"
#include "common-eval-args.hh"
#include "derivations.hh"
#include "eval-inline.hh"
#include "eval.hh"
#include "get-drvs.hh"
#include "store-api.hh"
#include "shared.hh"
#include "flake/flake.hh"
#include "flake/eval-cache.hh"
#include <regex>
#include <queue>
namespace nix {
MixFlakeOptions::MixFlakeOptions()
{
mkFlag()
.longName("recreate-lock-file")
.description("recreate lock file from scratch")
.set(&recreateLockFile, true);
mkFlag()
.longName("no-save-lock-file")
.description("do not save the newly generated lock file")
.set(&saveLockFile, false);
mkFlag()
.longName("no-registries")
.description("don't use flake registries")
.set(&useRegistries, false);
}
flake::HandleLockFile MixFlakeOptions::getLockFileMode()
{
using namespace flake;
return
useRegistries
? recreateLockFile
? (saveLockFile ? RecreateLockFile : UseNewLockFile)
: (saveLockFile ? UpdateLockFile : UseUpdatedLockFile)
: AllPure;
}
SourceExprCommand::SourceExprCommand()
{
mkFlag()
.shortName('f')
.longName("file")
.label("file")
.description("evaluate a set of attributes from FILE (deprecated)")
.dest(&file);
}
ref<EvalState> EvalCommand::getEvalState()
{
if (!evalState)
evalState = std::make_shared<EvalState>(searchPath, getStore());
return ref<EvalState>(evalState);
}
Buildable Installable::toBuildable()
{
auto buildables = toBuildables();
if (buildables.size() != 1)
throw Error("installable '%s' evaluates to %d derivations, where only one is expected", what(), buildables.size());
return std::move(buildables[0]);
}
App::App(EvalState & state, Value & vApp)
{
state.forceAttrs(vApp);
auto aType = vApp.attrs->need(state.sType);
if (state.forceStringNoCtx(*aType.value, *aType.pos) != "app")
throw Error("value does not have type 'app', at %s", *aType.pos);
auto aProgram = vApp.attrs->need(state.symbols.create("program"));
program = state.forceString(*aProgram.value, context, *aProgram.pos);
// FIXME: check that 'program' is in the closure of 'context'.
if (!state.store->isInStore(program))
throw Error("app program '%s' is not in the Nix store", program);
}
App Installable::toApp(EvalState & state)
{
return App(state, *toValue(state));
}
struct InstallableStorePath : Installable
{
Path storePath;
InstallableStorePath(const Path & storePath) : storePath(storePath) { }
std::string what() override { return storePath; }
Buildables toBuildables() override
{
return {{isDerivation(storePath) ? storePath : "", {{"out", storePath}}}};
}
std::optional<Path> getStorePath() override
{
return storePath;
}
};
struct InstallableValue : Installable
{
SourceExprCommand & cmd;
InstallableValue(SourceExprCommand & cmd) : cmd(cmd) { }
virtual std::vector<flake::EvalCache::Derivation> toDerivations()
{
auto state = cmd.getEvalState();
auto v = toValue(*state);
Bindings & autoArgs = *cmd.getAutoArgs(*state);
DrvInfos drvInfos;
getDerivations(*state, *v, "", autoArgs, drvInfos, false);
std::vector<flake::EvalCache::Derivation> res;
for (auto & drvInfo : drvInfos) {
res.push_back({
drvInfo.queryDrvPath(),
drvInfo.queryOutPath(),
drvInfo.queryOutputName()
});
}
return res;
}
Buildables toBuildables() override
{
Buildables res;
PathSet drvPaths;
for (auto & drv : toDerivations()) {
Buildable b{drv.drvPath};
drvPaths.insert(b.drvPath);
auto outputName = drv.outputName;
if (outputName == "")
throw Error("derivation '%s' lacks an 'outputName' attribute", b.drvPath);
b.outputs.emplace(outputName, drv.outPath);
res.push_back(std::move(b));
}
// Hack to recognize .all: if all drvs have the same drvPath,
// merge the buildables.
if (drvPaths.size() == 1) {
Buildable b{*drvPaths.begin()};
for (auto & b2 : res)
b.outputs.insert(b2.outputs.begin(), b2.outputs.end());
return {b};
} else
return res;
}
};
struct InstallableExpr : InstallableValue
{
std::string text;
InstallableExpr(SourceExprCommand & cmd, const std::string & text)
: InstallableValue(cmd), text(text) { }
std::string what() override { return text; }
Value * toValue(EvalState & state) override
{
auto v = state.allocValue();
state.eval(state.parseExprFromString(text, absPath(".")), *v);
return v;
}
};
struct InstallableAttrPath : InstallableValue
{
Value * v;
std::string attrPath;
InstallableAttrPath(SourceExprCommand & cmd, Value * v, const std::string & attrPath)
: InstallableValue(cmd), v(v), attrPath(attrPath)
{ }
std::string what() override { return attrPath; }
Value * toValue(EvalState & state) override
{
auto vRes = findAlongAttrPath(state, attrPath, *cmd.getAutoArgs(state), *v);
state.forceValue(*vRes);
return vRes;
}
};
void makeFlakeClosureGCRoot(Store & store,
const FlakeRef & origFlakeRef,
const flake::ResolvedFlake & resFlake)
{
if (std::get_if<FlakeRef::IsPath>(&origFlakeRef.data)) return;
/* Get the store paths of all non-local flakes. */
PathSet closure;
assert(store.isValidPath(resFlake.flake.sourceInfo.storePath));
closure.insert(resFlake.flake.sourceInfo.storePath);
std::queue<std::reference_wrapper<const flake::LockedInputs>> queue;
queue.push(resFlake.lockFile);
while (!queue.empty()) {
const flake::LockedInputs & flake = queue.front();
queue.pop();
/* Note: due to lazy fetching, these paths might not exist
yet. */
for (auto & dep : flake.inputs) {
auto path = dep.second.computeStorePath(store);
if (store.isValidPath(path))
closure.insert(path);
queue.push(dep.second);
}
}
if (closure.empty()) return;
/* Write the closure to a file in the store. */
auto closurePath = store.addTextToStore("flake-closure", concatStringsSep(" ", closure), closure);
Path cacheDir = getCacheDir() + "/nix/flake-closures";
createDirs(cacheDir);
auto s = origFlakeRef.to_string();
assert(s[0] != '.');
s = replaceStrings(s, "%", "%25");
s = replaceStrings(s, "/", "%2f");
s = replaceStrings(s, ":", "%3a");
Path symlink = cacheDir + "/" + s;
debug("writing GC root '%s' for flake closure of '%s'", symlink, origFlakeRef);
replaceSymlink(closurePath, symlink);
store.addIndirectRoot(symlink);
}
struct InstallableFlake : InstallableValue
{
FlakeRef flakeRef;
Strings attrPaths;
Strings prefixes;
InstallableFlake(SourceExprCommand & cmd, FlakeRef && flakeRef, Strings attrPaths)
: InstallableValue(cmd), flakeRef(flakeRef), attrPaths(std::move(attrPaths))
{ }
InstallableFlake(SourceExprCommand & cmd, FlakeRef && flakeRef,
std::string attrPath, Strings && prefixes)
: InstallableValue(cmd), flakeRef(flakeRef), attrPaths{attrPath},
prefixes(prefixes)
{ }
std::string what() override { return flakeRef.to_string() + ":" + *attrPaths.begin(); }
std::vector<std::string> getActualAttrPaths()
{
std::vector<std::string> res;
for (auto & prefix : prefixes)
res.push_back(prefix + *attrPaths.begin());
for (auto & s : attrPaths)
res.push_back(s);
return res;
}
Value * getFlakeOutputs(EvalState & state, const flake::ResolvedFlake & resFlake)
{
auto vFlake = state.allocValue();
callFlake(state, resFlake, *vFlake);
makeFlakeClosureGCRoot(*state.store, flakeRef, resFlake);
auto vOutputs = (*vFlake->attrs->get(state.symbols.create("outputs")))->value;
state.forceValue(*vOutputs);
return vOutputs;
}
std::vector<flake::EvalCache::Derivation> toDerivations() override
{
auto state = cmd.getEvalState();
auto resFlake = resolveFlake(*state, flakeRef, cmd.getLockFileMode());
Value * vOutputs = nullptr;
auto emptyArgs = state->allocBindings(0);
auto & evalCache = flake::EvalCache::singleton();
auto fingerprint = resFlake.getFingerprint();
for (auto & attrPath : getActualAttrPaths()) {
auto drv = evalCache.getDerivation(fingerprint, attrPath);
if (drv) {
if (state->store->isValidPath(drv->drvPath))
return {*drv};
}
if (!vOutputs)
vOutputs = getFlakeOutputs(*state, resFlake);
try {
auto * v = findAlongAttrPath(*state, attrPath, *emptyArgs, *vOutputs);
state->forceValue(*v);
auto drvInfo = getDerivation(*state, *v, false);
if (!drvInfo)
throw Error("flake output attribute '%s' is not a derivation", attrPath);
auto drv = flake::EvalCache::Derivation{
drvInfo->queryDrvPath(),
drvInfo->queryOutPath(),
drvInfo->queryOutputName()
};
evalCache.addDerivation(fingerprint, attrPath, drv);
return {drv};
} catch (AttrPathNotFound & e) {
}
}
throw Error("flake '%s' does not provide attribute %s",
flakeRef, concatStringsSep(", ", quoteStrings(attrPaths)));
}
Value * toValue(EvalState & state) override
{
auto resFlake = resolveFlake(state, flakeRef, cmd.getLockFileMode());
auto vOutputs = getFlakeOutputs(state, resFlake);
auto emptyArgs = state.allocBindings(0);
for (auto & attrPath : getActualAttrPaths()) {
try {
auto * v = findAlongAttrPath(state, attrPath, *emptyArgs, *vOutputs);
state.forceValue(*v);
return v;
} catch (AttrPathNotFound & e) {
}
}
throw Error("flake '%s' does not provide attribute %s",
flakeRef, concatStringsSep(", ", quoteStrings(attrPaths)));
}
};
// FIXME: extend
std::string attrRegex = R"([A-Za-z_][A-Za-z0-9-_+]*)";
static std::regex attrPathRegex(fmt(R"(%1%(\.%1%)*)", attrRegex));
std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
ref<Store> store, std::vector<std::string> ss)
{
std::vector<std::shared_ptr<Installable>> result;
if (file) {
// FIXME: backward compatibility hack
evalSettings.pureEval = false;
auto state = getEvalState();
auto vFile = state->allocValue();
state->evalFile(lookupFileArg(*state, *file), *vFile);
if (ss.empty())
ss = {""};
for (auto & s : ss)
result.push_back(std::make_shared<InstallableAttrPath>(*this, vFile, s));
} else {
auto follow = [&](const std::string & s) -> std::optional<Path> {
try {
return store->followLinksToStorePath(s);
} catch (NotInStore &) {
return {};
}
};
for (auto & s : ss) {
size_t colon;
std::optional<Path> storePath;
if (s.compare(0, 1, "(") == 0)
result.push_back(std::make_shared<InstallableExpr>(*this, s));
else if (hasPrefix(s, "nixpkgs.")) {
bool static warned;
warnOnce(warned, "the syntax 'nixpkgs.<attr>' is deprecated; use 'nixpkgs:<attr>' instead");
result.push_back(std::make_shared<InstallableFlake>(*this, FlakeRef("nixpkgs"),
Strings{"legacyPackages." + std::string(s, 8)}));
}
else {
std::exception_ptr flakeEx;
try {
auto flakeRef = FlakeRef(s, true);
result.push_back(std::make_shared<InstallableFlake>(
*this, std::move(flakeRef), getDefaultFlakeAttrPaths()));
continue;
} catch (MissingFlake &) {
/* 's' could be parsed as a flakeref, but it
references a local path that is not a flake. So
take note of that. */
flakeEx = std::current_exception();
} catch (BadFlakeRef &) {
}
if ((colon = s.rfind(':')) != std::string::npos) {
auto flakeRef = std::string(s, 0, colon);
auto attrPath = std::string(s, colon + 1);
result.push_back(std::make_shared<InstallableFlake>(
*this,
FlakeRef(flakeRef, true),
attrPath,
getDefaultFlakeAttrPathPrefixes()));
}
else if (s.find('/') != std::string::npos && (storePath = follow(s)))
result.push_back(std::make_shared<InstallableStorePath>(*storePath));
else {
if (flakeEx)
std::rethrow_exception(flakeEx);
else
throw Error("unsupported argument '%s'", s);
}
}
}
}
return result;
}
std::shared_ptr<Installable> SourceExprCommand::parseInstallable(
ref<Store> store, const std::string & installable)
{
auto installables = parseInstallables(store, {installable});
assert(installables.size() == 1);
return installables.front();
}
Buildables build(ref<Store> store, RealiseMode mode,
std::vector<std::shared_ptr<Installable>> installables)
{
if (mode != Build)
settings.readOnlyMode = true;
Buildables buildables;
PathSet pathsToBuild;
for (auto & i : installables) {
for (auto & b : i->toBuildables()) {
if (b.drvPath != "") {
StringSet outputNames;
for (auto & output : b.outputs)
outputNames.insert(output.first);
pathsToBuild.insert(
b.drvPath + "!" + concatStringsSep(",", outputNames));
} else
for (auto & output : b.outputs)
pathsToBuild.insert(output.second);
buildables.push_back(std::move(b));
}
}
if (mode == DryRun)
printMissing(store, pathsToBuild, lvlError);
else if (mode == Build)
store->buildPaths(pathsToBuild);
return buildables;
}
PathSet toStorePaths(ref<Store> store, RealiseMode mode,
std::vector<std::shared_ptr<Installable>> installables)
{
PathSet outPaths;
for (auto & b : build(store, mode, installables))
for (auto & output : b.outputs)
outPaths.insert(output.second);
return outPaths;
}
Path toStorePath(ref<Store> store, RealiseMode mode,
std::shared_ptr<Installable> installable)
{
auto paths = toStorePaths(store, mode, {installable});
if (paths.size() != 1)
throw Error("argument '%s' should evaluate to one store path", installable->what());
return *paths.begin();
}
PathSet toDerivations(ref<Store> store,
std::vector<std::shared_ptr<Installable>> installables, bool useDeriver)
{
PathSet drvPaths;
for (auto & i : installables)
for (auto & b : i->toBuildables()) {
if (b.drvPath.empty()) {
if (!useDeriver)
throw Error("argument '%s' did not evaluate to a derivation", i->what());
for (auto & output : b.outputs) {
auto derivers = store->queryValidDerivers(output.second);
if (derivers.empty())
throw Error("'%s' does not have a known deriver", i->what());
// FIXME: use all derivers?
drvPaths.insert(*derivers.begin());
}
} else
drvPaths.insert(b.drvPath);
}
return drvPaths;
}
void InstallablesCommand::prepare()
{
if (_installables.empty() && !file && useDefaultInstallables())
// FIXME: commands like "nix install" should not have a
// default, probably.
_installables.push_back(".");
installables = parseInstallables(getStore(), _installables);
}
void InstallableCommand::prepare()
{
installable = parseInstallable(getStore(), _installable);
}
}