| // Copyright 2019 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.analysis.config; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static com.google.common.collect.ImmutableList.toImmutableList; |
| import static com.google.devtools.build.lib.packages.ExecGroup.DEFAULT_EXEC_GROUP_NAME; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.devtools.build.lib.analysis.PlatformOptions; |
| import com.google.devtools.build.lib.analysis.config.transitions.PatchTransition; |
| import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.events.EventHandler; |
| import com.google.devtools.build.lib.packages.AttributeTransitionData; |
| import com.google.devtools.build.lib.rules.config.FeatureFlagValue; |
| import com.google.devtools.build.lib.starlarkbuildapi.StarlarkConfigApi.ExecTransitionFactoryApi; |
| import java.util.Map; |
| import javax.annotation.Nullable; |
| |
| /** |
| * {@link TransitionFactory} implementation which creates a {@link PatchTransition} which will |
| * transition to a configuration suitable for building dependencies for the execution platform of |
| * the depending target. |
| */ |
| public class ExecutionTransitionFactory |
| implements TransitionFactory<AttributeTransitionData>, ExecTransitionFactoryApi { |
| |
| private final String execGroup; |
| |
| private ExecutionTransitionFactory(String execGroup) { |
| this.execGroup = execGroup; |
| } |
| |
| /** |
| * Returns a new {@link ExecutionTransitionFactory} for the default {@link |
| * com.google.devtools.build.lib.packages.ExecGroup}. |
| */ |
| public static ExecutionTransitionFactory create() { |
| return new ExecutionTransitionFactory(DEFAULT_EXEC_GROUP_NAME); |
| } |
| |
| @Override |
| public TransitionType transitionType() { |
| return TransitionType.ATTRIBUTE; |
| } |
| |
| /** |
| * Returns a new {@link ExecutionTransitionFactory} for the given {@link |
| * com.google.devtools.build.lib.packages.ExecGroup}. |
| */ |
| public static ExecutionTransitionFactory create(String execGroup) { |
| return new ExecutionTransitionFactory(execGroup); |
| } |
| |
| @Override |
| public PatchTransition create(AttributeTransitionData data) { |
| return new ExecutionTransition(data.executionPlatform()); |
| } |
| |
| public String getExecGroup() { |
| return execGroup; |
| } |
| |
| @Override |
| public boolean isTool() { |
| return true; |
| } |
| |
| private static final class ExecutionTransition implements PatchTransition { |
| @Nullable private final Label executionPlatform; |
| |
| ExecutionTransition(@Nullable Label executionPlatform) { |
| this.executionPlatform = executionPlatform; |
| } |
| |
| @Override |
| public String getName() { |
| return "exec"; |
| } |
| |
| // We added this cache after observing an O(100,000)-node build graph that applied multiple exec |
| // transitions on every node via an aspect. Before this cache, this produced O(500,000) |
| // BuildOptions instances that consumed over 3 gigabytes of memory. |
| private static final BuildOptionsCache<Label> cache = |
| new BuildOptionsCache<>(ExecutionTransition::transitionImpl); |
| |
| private static final ImmutableSet<Class<? extends FragmentOptions>> FRAGMENTS = |
| ImmutableSet.of(CoreOptions.class, PlatformOptions.class); |
| |
| @Override |
| public ImmutableSet<Class<? extends FragmentOptions>> requiresOptionFragments() { |
| return FRAGMENTS; |
| } |
| |
| @Override |
| public BuildOptions patch(BuildOptionsView options, EventHandler eventHandler) { |
| if (executionPlatform == null) { |
| // No execution platform is known, so don't change anything. |
| return options.underlying(); |
| } |
| return cache.applyTransition( |
| options, |
| // The execution platform impacts the output's --platform_suffix and --platforms flags. |
| executionPlatform); |
| } |
| |
| private static BuildOptions transitionImpl(BuildOptionsView options, Label executionPlatform) { |
| // Start by converting to host options. |
| BuildOptionsView execOptions = |
| new BuildOptionsView(options.underlying().createHostOptions(), FRAGMENTS); |
| |
| // Then unset isHost. |
| CoreOptions coreOptions = checkNotNull(execOptions.get(CoreOptions.class)); |
| coreOptions.isHost = false; |
| coreOptions.isExec = true; |
| coreOptions.platformSuffix = |
| String.format("exec-%X", executionPlatform.getCanonicalForm().hashCode()); |
| |
| // Then set the target to the saved execution platform if there is one. |
| PlatformOptions platformOptions = execOptions.get(PlatformOptions.class); |
| if (platformOptions != null) { |
| platformOptions.platforms = ImmutableList.of(executionPlatform); |
| } |
| |
| BuildOptions result = execOptions.underlying(); |
| // Remove any FeatureFlags that were set. |
| ImmutableList<Label> featureFlags = |
| execOptions.underlying().getStarlarkOptions().entrySet().stream() |
| .filter(entry -> entry.getValue() instanceof FeatureFlagValue) |
| .map(Map.Entry::getKey) |
| .collect(toImmutableList()); |
| if (!featureFlags.isEmpty()) { |
| BuildOptions.Builder resultBuilder = result.toBuilder(); |
| featureFlags.forEach(resultBuilder::removeStarlarkOption); |
| result = resultBuilder.build(); |
| } |
| |
| return result; |
| } |
| } |
| } |