| // Copyright 2015 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.ImmutableList; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.Iterables; |
| import com.google.devtools.build.lib.actions.ActionLookupValue; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.events.Event; |
| import com.google.devtools.build.lib.packages.AspectDescriptor; |
| import com.google.devtools.build.lib.packages.AspectParameters; |
| import com.google.devtools.build.lib.packages.SkylarkAspect; |
| import com.google.devtools.build.lib.skyframe.AspectFunction.AspectCreationException; |
| import com.google.devtools.build.lib.skyframe.AspectValue.SkylarkAspectLoadingKey; |
| import com.google.devtools.build.lib.skyframe.SkylarkImportLookupFunction.SkylarkImportFailedException; |
| import com.google.devtools.build.lib.syntax.SkylarkImport; |
| import com.google.devtools.build.skyframe.SkyFunction; |
| import com.google.devtools.build.skyframe.SkyFunctionException; |
| import com.google.devtools.build.skyframe.SkyKey; |
| import com.google.devtools.build.skyframe.SkyValue; |
| import javax.annotation.Nullable; |
| |
| /** |
| * SkyFunction to load aspects from Skylark extensions and calculate their values. |
| * |
| * Used for loading top-level aspects. At top level, in |
| * {@link com.google.devtools.build.lib.analysis.BuildView}, we cannot invoke two SkyFunctions |
| * one after another, so BuildView calls this function to do the work. |
| */ |
| public class ToplevelSkylarkAspectFunction implements SkyFunction { |
| |
| @Nullable |
| @Override |
| public SkyValue compute(SkyKey skyKey, Environment env) |
| throws LoadSkylarkAspectFunctionException, InterruptedException { |
| SkylarkAspectLoadingKey aspectLoadingKey = (SkylarkAspectLoadingKey) skyKey.argument(); |
| String skylarkValueName = aspectLoadingKey.getSkylarkValueName(); |
| SkylarkImport extensionFile = aspectLoadingKey.getSkylarkImport(); |
| |
| // Find label corresponding to skylark file, if one exists. |
| ImmutableMap<String, Label> labelLookupMap; |
| try { |
| labelLookupMap = |
| SkylarkImportLookupFunction.findLabelsForLoadStatements( |
| ImmutableList.of(extensionFile), |
| Label.parseAbsoluteUnchecked("//:empty"), |
| env |
| ); |
| } catch (SkylarkImportFailedException e) { |
| env.getListener().handle(Event.error(e.getMessage())); |
| throw new LoadSkylarkAspectFunctionException( |
| new AspectCreationException(e.getMessage())); |
| } |
| if (labelLookupMap == null) { |
| return null; |
| } |
| |
| SkylarkAspect skylarkAspect; |
| Label extensionFileLabel = Iterables.getOnlyElement(labelLookupMap.values()); |
| try { |
| skylarkAspect = AspectFunction.loadSkylarkAspect( |
| env, extensionFileLabel, skylarkValueName); |
| if (skylarkAspect == null) { |
| return null; |
| } |
| if (!skylarkAspect.getParamAttributes().isEmpty()) { |
| throw new AspectCreationException("Cannot instantiate parameterized aspect " |
| + skylarkAspect.getName() + " at the top level.", extensionFileLabel); |
| } |
| } catch (AspectCreationException e) { |
| throw new LoadSkylarkAspectFunctionException(e); |
| } |
| SkyKey aspectKey = |
| ActionLookupValue.key(AspectValue.createAspectKey( |
| aspectLoadingKey.getTargetLabel(), aspectLoadingKey.getTargetConfiguration(), |
| new AspectDescriptor(skylarkAspect.getAspectClass(), AspectParameters.EMPTY), |
| aspectLoadingKey.getAspectConfiguration() |
| )); |
| |
| return env.getValue(aspectKey); |
| } |
| |
| @Nullable |
| @Override |
| public String extractTag(SkyKey skyKey) { |
| return null; |
| } |
| |
| /** |
| * Exceptions thrown from ToplevelSkylarkAspectFunction. |
| */ |
| public class LoadSkylarkAspectFunctionException extends SkyFunctionException { |
| public LoadSkylarkAspectFunctionException(AspectCreationException cause) { |
| super(cause, Transience.PERSISTENT); |
| } |
| } |
| } |