/**
* Converts the PathFragment of the Skylark file to a Label using the BUILD file closest to the
* Skylark file in its directory hierarchy - finds the package to which the Skylark file belongs.
* Throws an exception if no such BUILD file exists.
*/
private Label pathFragmentToLabel(RepositoryName repo, PathFragment file, Environment env)
throws SkylarkImportLookupFunctionException {
ContainingPackageLookupValue containingPackageLookupValue = null;
try {
PackageIdentifier newPkgId = PackageIdentifier.create(repo, file.getParentDirectory());
containingPackageLookupValue =
(ContainingPackageLookupValue)
env.getValueOrThrow(
ContainingPackageLookupValue.key(newPkgId),
BuildFileNotFoundException.class,
InconsistentFilesystemException.class);
} catch (BuildFileNotFoundException e) {
// Thrown when there are IO errors looking for BUILD files.
throw new SkylarkImportLookupFunctionException(e, Transience.PERSISTENT);
} catch (InconsistentFilesystemException e) {
throw new SkylarkImportLookupFunctionException(e, Transience.PERSISTENT);
}
if (containingPackageLookupValue == null) {
return null;
}
if (!containingPackageLookupValue.hasContainingPackage()) {
throw new SkylarkImportLookupFunctionException(
SkylarkImportFailedException.noBuildFile(file));
}
PathFragment pkgName =
containingPackageLookupValue.getContainingPackageName().getPackageFragment();
PathFragment fileInPkg = file.relativeTo(pkgName);
try {
// This code relies on PackageIdentifier.RepositoryName.toString()
return Label.parseAbsolute(repo + "//" + pkgName.getPathString() + ":" + fileInPkg);
} catch (LabelSyntaxException e) {
throw new IllegalStateException(e);
}
}
/** Creates the Extension to be imported. */
private Extension createExtension(
BuildFileAST ast, PathFragment file, Map<PathFragment, Extension> importMap, Environment env)
throws InterruptedException, SkylarkImportLookupFunctionException {
StoredEventHandler eventHandler = new StoredEventHandler();
// TODO(bazel-team): this method overestimates the changes which can affect the
// Skylark RuleClass. For example changes to comments or unused functions can modify the hash.
// A more accurate - however much more complicated - way would be to calculate a hash based on
// the transitive closure of the accessible AST nodes.
try (Mutability mutability = Mutability.create("importing %s", file)) {
com.google.devtools.build.lib.syntax.Environment extensionEnv =
ruleClassProvider
.createSkylarkRuleClassEnvironment(
mutability, eventHandler, ast.getContentHashCode(), importMap)
.setupOverride("native", packageFactory.getNativeModule());
ast.exec(extensionEnv, eventHandler);
SkylarkRuleClassFunctions.exportRuleFunctions(extensionEnv, file);
Event.replayEventsOn(env.getListener(), eventHandler.getEvents());
if (eventHandler.hasErrors()) {
throw new SkylarkImportLookupFunctionException(SkylarkImportFailedException.errors(file));
}
return new Extension(extensionEnv);
}
}
SkyValue computeInternal(
SkyKey skyKey, Environment env, @Nullable Set<SkyKey> visitedKeysForCycle)
throws SkyFunctionException, InterruptedException {
PackageIdentifier arg = (PackageIdentifier) skyKey.argument();
PathFragment file = arg.getPackageFragment();
ASTFileLookupValue astLookupValue = null;
try {
SkyKey astLookupKey = ASTFileLookupValue.key(arg);
astLookupValue =
(ASTFileLookupValue)
env.getValueOrThrow(
astLookupKey,
ErrorReadingSkylarkExtensionException.class,
InconsistentFilesystemException.class);
} catch (ErrorReadingSkylarkExtensionException e) {
throw new SkylarkImportLookupFunctionException(
SkylarkImportFailedException.errorReadingFile(file, e.getMessage()));
} catch (InconsistentFilesystemException e) {
throw new SkylarkImportLookupFunctionException(e, Transience.PERSISTENT);
}
if (astLookupValue == null) {
return null;
}
if (astLookupValue.getAST() == null) {
// Skylark import files have to exist.
throw new SkylarkImportLookupFunctionException(SkylarkImportFailedException.noFile(file));
}
BuildFileAST ast = astLookupValue.getAST();
if (ast.containsErrors()) {
throw new SkylarkImportLookupFunctionException(
SkylarkImportFailedException.skylarkErrors(file));
}
Label label = pathFragmentToLabel(arg.getRepository(), file, env);
if (label == null) {
Preconditions.checkState(env.valuesMissing(), "null label with no missing %s", file);
return null;
}
Map<Location, PathFragment> astImports = ast.getImports();
Map<PathFragment, Extension> importMap = Maps.newHashMapWithExpectedSize(astImports.size());
ImmutableList.Builder<SkylarkFileDependency> fileDependencies = ImmutableList.builder();
Map<SkyKey, PathFragment> skylarkImports = Maps.newHashMapWithExpectedSize(astImports.size());
for (Map.Entry<Location, PathFragment> entry : ast.getImports().entrySet()) {
try {
skylarkImports.put(
PackageFunction.getImportKey(entry, ruleClassProvider.getPreludePath(), file, arg),
entry.getValue());
} catch (ASTLookupInputException e) {
throw new SkylarkImportLookupFunctionException(e, Transience.PERSISTENT);
}
}
Map<SkyKey, SkyValue> skylarkImportMap;
boolean valuesMissing = false;
if (visitedKeysForCycle == null) {
// Not inlining.
skylarkImportMap = env.getValues(skylarkImports.keySet());
valuesMissing = env.valuesMissing();
} else {
// inlining calls to SkylarkImportLookupFunction.
if (!visitedKeysForCycle.add(skyKey)) {
ImmutableList<SkyKey> cycle =
CycleUtils.splitIntoPathAndChain(Predicates.equalTo(skyKey), visitedKeysForCycle)
.second;
if (env.getValue(SkylarkImportUniqueCycleValue.key(cycle)) == null) {
return null;
}
throw new SkylarkImportLookupFunctionException(
new SkylarkImportFailedException("Skylark import cycle"));
}
skylarkImportMap = Maps.newHashMapWithExpectedSize(astImports.size());
for (SkyKey skylarkImport : skylarkImports.keySet()) {
SkyValue skyValue = this.computeWithInlineCalls(skylarkImport, env, visitedKeysForCycle);
if (skyValue == null) {
Preconditions.checkState(
env.valuesMissing(), "no skylark import value for %s", skylarkImport);
// Don't give up on computing. This is against the Skyframe contract, but we don't want to
// pay the price of serializing all these calls, since they are fundamentally independent.
valuesMissing = true;
} else {
skylarkImportMap.put(skylarkImport, skyValue);
}
}
// All imports traversed, this key can no longer be part of a cycle.
visitedKeysForCycle.remove(skyKey);
}
if (valuesMissing) {
// This means some imports are unavailable.
return null;
}
for (Map.Entry<SkyKey, SkyValue> entry : skylarkImportMap.entrySet()) {
SkylarkImportLookupValue importLookupValue = (SkylarkImportLookupValue) entry.getValue();
importMap.put(
skylarkImports.get(entry.getKey()), importLookupValue.getEnvironmentExtension());
fileDependencies.add(importLookupValue.getDependency());
}
// Skylark UserDefinedFunction-s in that file will share this function definition Environment,
// which will be frozen by the time it is returned by createExtension.
Extension extension = createExtension(ast, file, importMap, env);
return new SkylarkImportLookupValue(
extension, new SkylarkFileDependency(label, fileDependencies.build()));
}
@Override
public SkyValue compute(SkyKey skyKey, Environment env)
throws SkyFunctionException, InterruptedException {
PackageIdentifier arg = (PackageIdentifier) skyKey.argument();
PathFragment file = arg.getPackageFragment();
ASTFileLookupValue astLookupValue = null;
try {
SkyKey astLookupKey = ASTFileLookupValue.key(arg);
astLookupValue =
(ASTFileLookupValue)
env.getValueOrThrow(
astLookupKey,
ErrorReadingSkylarkExtensionException.class,
InconsistentFilesystemException.class);
} catch (ErrorReadingSkylarkExtensionException e) {
throw new SkylarkImportLookupFunctionException(
SkylarkImportFailedException.errorReadingFile(file, e.getMessage()));
} catch (InconsistentFilesystemException e) {
throw new SkylarkImportLookupFunctionException(e, Transience.PERSISTENT);
}
if (astLookupValue == null) {
return null;
}
if (astLookupValue.getAST() == null) {
// Skylark import files have to exist.
throw new SkylarkImportLookupFunctionException(SkylarkImportFailedException.noFile(file));
}
BuildFileAST ast = astLookupValue.getAST();
if (ast.containsErrors()) {
throw new SkylarkImportLookupFunctionException(
SkylarkImportFailedException.skylarkErrors(file));
}
Map<Location, PathFragment> astImports = ast.getImports();
Map<PathFragment, Extension> importMap = Maps.newHashMapWithExpectedSize(astImports.size());
ImmutableList.Builder<SkylarkFileDependency> fileDependencies = ImmutableList.builder();
Map<SkyKey, PathFragment> skylarkImports = Maps.newHashMapWithExpectedSize(astImports.size());
for (Map.Entry<Location, PathFragment> entry : ast.getImports().entrySet()) {
try {
skylarkImports.put(
PackageFunction.getImportKey(entry, ruleClassProvider.getPreludePath(), file, arg),
entry.getValue());
} catch (ASTLookupInputException e) {
throw new SkylarkImportLookupFunctionException(e, Transience.PERSISTENT);
}
}
Map<SkyKey, SkyValue> skylarkImportMap = env.getValues(skylarkImports.keySet());
if (env.valuesMissing()) {
// This means some imports are unavailable.
return null;
}
for (Map.Entry<SkyKey, SkyValue> entry : skylarkImportMap.entrySet()) {
SkylarkImportLookupValue importLookupValue = (SkylarkImportLookupValue) entry.getValue();
importMap.put(
skylarkImports.get(entry.getKey()), importLookupValue.getEnvironmentExtension());
fileDependencies.add(importLookupValue.getDependency());
}
Label label = pathFragmentToLabel(arg.getRepository(), file, env);
if (label == null) {
Preconditions.checkState(env.valuesMissing(), "label null but no missing for %s", file);
return null;
}
// Skylark UserDefinedFunction-s in that file will share this function definition Environment,
// which will be frozen by the time it is returned by createExtension.
Extension extension = createExtension(ast, file, importMap, env);
return new SkylarkImportLookupValue(
extension, new SkylarkFileDependency(label, fileDependencies.build()));
}