| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.devtools.build.lib.skyframe; |
| |
| import com.google.common.collect.ImmutableMap; |
| import com.google.devtools.build.lib.actions.FileValue; |
| import com.google.devtools.build.lib.actions.InconsistentFilesystemException; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.events.Event; |
| import com.google.devtools.build.lib.packages.BuildFileNotFoundException; |
| import com.google.devtools.build.lib.packages.RuleClassProvider; |
| import com.google.devtools.build.lib.syntax.Module; |
| import com.google.devtools.build.lib.syntax.ParserInput; |
| import com.google.devtools.build.lib.syntax.StarlarkFile; |
| import com.google.devtools.build.lib.syntax.StarlarkSemantics; |
| import com.google.devtools.build.lib.syntax.ValidationEnvironment; |
| import com.google.devtools.build.lib.vfs.FileSystemUtils; |
| import com.google.devtools.build.lib.vfs.Path; |
| import com.google.devtools.build.lib.vfs.Root; |
| import com.google.devtools.build.lib.vfs.RootedPath; |
| import com.google.devtools.build.skyframe.SkyFunction; |
| import com.google.devtools.build.skyframe.SkyFunctionException; |
| import com.google.devtools.build.skyframe.SkyFunctionException.Transience; |
| import com.google.devtools.build.skyframe.SkyKey; |
| import com.google.devtools.build.skyframe.SkyValue; |
| import java.io.IOException; |
| import javax.annotation.Nullable; |
| |
| /** |
| * A SkyFunction for {@link ASTFileLookupValue}s. |
| * |
| * <p>Given a {@link Label} referencing a Skylark file, loads it as a syntax tree ({@link |
| * StarlarkFile}). The Label must be absolute, and must not reference the special {@code external} |
| * package. If the file (or the package containing it) doesn't exist, the function doesn't fail, but |
| * instead returns a specific {@code NO_FILE} {@link ASTFileLookupValue}. |
| */ |
| public class ASTFileLookupFunction implements SkyFunction { |
| |
| private final RuleClassProvider ruleClassProvider; |
| |
| public ASTFileLookupFunction(RuleClassProvider ruleClassProvider) { |
| this.ruleClassProvider = ruleClassProvider; |
| } |
| |
| @Override |
| public SkyValue compute(SkyKey skyKey, Environment env) throws SkyFunctionException, |
| InterruptedException { |
| Label fileLabel = (Label) skyKey.argument(); |
| |
| // Determine whether the package designated by fileLabel exists. |
| // TODO(bazel-team): After --incompatible_disallow_load_labels_to_cross_package_boundaries is |
| // removed and the new behavior is unconditional, we can instead safely assume the package |
| // exists and pass in the Root in the SkyKey and therefore this dep can be removed. |
| SkyKey pkgSkyKey = PackageLookupValue.key(fileLabel.getPackageIdentifier()); |
| PackageLookupValue pkgLookupValue = null; |
| try { |
| pkgLookupValue = (PackageLookupValue) env.getValueOrThrow( |
| pkgSkyKey, BuildFileNotFoundException.class, InconsistentFilesystemException.class); |
| } catch (BuildFileNotFoundException e) { |
| throw new ASTLookupFunctionException( |
| new ErrorReadingSkylarkExtensionException(e), Transience.PERSISTENT); |
| } catch (InconsistentFilesystemException e) { |
| throw new ASTLookupFunctionException(e, Transience.PERSISTENT); |
| } |
| if (pkgLookupValue == null) { |
| return null; |
| } |
| if (!pkgLookupValue.packageExists()) { |
| return ASTFileLookupValue.forBadPackage(fileLabel, pkgLookupValue.getErrorMsg()); |
| } |
| |
| // Determine whether the file designated by fileLabel exists. |
| Root packageRoot = pkgLookupValue.getRoot(); |
| RootedPath rootedPath = RootedPath.toRootedPath(packageRoot, fileLabel.toPathFragment()); |
| SkyKey fileSkyKey = FileValue.key(rootedPath); |
| FileValue fileValue = null; |
| try { |
| fileValue = (FileValue) env.getValueOrThrow(fileSkyKey, IOException.class); |
| } catch (InconsistentFilesystemException e) { |
| throw new ASTLookupFunctionException(e, Transience.PERSISTENT); |
| } catch (IOException e) { |
| throw new ASTLookupFunctionException( |
| new ErrorReadingSkylarkExtensionException(e), Transience.PERSISTENT); |
| } |
| if (fileValue == null) { |
| return null; |
| } |
| if (!fileValue.exists()) { |
| return ASTFileLookupValue.forMissingFile(fileLabel); |
| } |
| if (!fileValue.isFile()) { |
| return ASTFileLookupValue.forBadFile(fileLabel); |
| } |
| StarlarkSemantics starlarkSemantics = PrecomputedValue.STARLARK_SEMANTICS.get(env); |
| if (starlarkSemantics == null) { |
| return null; |
| } |
| |
| // Both the package and the file exist; load and parse the file. |
| Path path = rootedPath.asPath(); |
| StarlarkFile file = null; |
| try { |
| byte[] bytes = FileSystemUtils.readWithKnownFileSize(path, fileValue.getSize()); |
| ParserInput input = ParserInput.create(bytes, path.toString()); |
| file = StarlarkFile.parseWithDigest(input, path.getDigest()); |
| } catch (IOException e) { |
| throw new ASTLookupFunctionException(new ErrorReadingSkylarkExtensionException(e), |
| Transience.TRANSIENT); |
| } |
| |
| // validate (and soon, compile) |
| ImmutableMap<String, Object> predeclared = ruleClassProvider.getEnvironment(); |
| ValidationEnvironment.validateFile( |
| file, Module.createForBuiltins(predeclared), starlarkSemantics, /*isBuildFile=*/ false); |
| Event.replayEventsOn(env.getListener(), file.errors()); // TODO(adonovan): fail if !ok()? |
| |
| return ASTFileLookupValue.withFile(file); |
| } |
| |
| @Nullable |
| @Override |
| public String extractTag(SkyKey skyKey) { |
| return null; |
| } |
| |
| private static final class ASTLookupFunctionException extends SkyFunctionException { |
| private ASTLookupFunctionException(ErrorReadingSkylarkExtensionException e, |
| Transience transience) { |
| super(e, transience); |
| } |
| |
| private ASTLookupFunctionException(InconsistentFilesystemException e, Transience transience) { |
| super(e, transience); |
| } |
| } |
| } |