| // Copyright 2018 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.rules; |
| |
| import static com.google.devtools.build.lib.packages.Attribute.attr; |
| import static com.google.devtools.build.lib.packages.BuildType.LABEL; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.devtools.build.lib.actions.MutableActionGraph.ActionConflictException; |
| import com.google.devtools.build.lib.analysis.AliasProvider; |
| import com.google.devtools.build.lib.analysis.BaseRuleClasses; |
| import com.google.devtools.build.lib.analysis.ConfiguredTarget; |
| import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder; |
| import com.google.devtools.build.lib.analysis.RuleConfiguredTargetFactory; |
| import com.google.devtools.build.lib.analysis.RuleContext; |
| import com.google.devtools.build.lib.analysis.RuleDefinition; |
| import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment; |
| import com.google.devtools.build.lib.analysis.Runfiles; |
| import com.google.devtools.build.lib.analysis.RunfilesProvider; |
| import com.google.devtools.build.lib.analysis.VisibilityProvider; |
| import com.google.devtools.build.lib.analysis.VisibilityProviderImpl; |
| import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget.Mode; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.packages.Attribute; |
| import com.google.devtools.build.lib.packages.Attribute.LabelLateBoundDefault; |
| import com.google.devtools.build.lib.packages.RuleClass; |
| import java.util.function.Function; |
| |
| /** Implements template for creating custom alias rules. */ |
| public final class LateBoundAlias implements RuleConfiguredTargetFactory { |
| |
| private static final String ATTRIBUTE_NAME = ":alias"; |
| |
| @Override |
| public ConfiguredTarget create(RuleContext ruleContext) |
| throws ActionConflictException { |
| ConfiguredTarget actual = |
| (ConfiguredTarget) ruleContext.getPrerequisite(ATTRIBUTE_NAME, Mode.TARGET); |
| if (actual == null) { |
| return createEmptyConfiguredTarget(ruleContext); |
| } |
| |
| return new AliasConfiguredTarget( |
| ruleContext, |
| actual, |
| ImmutableMap.of( |
| AliasProvider.class, |
| AliasProvider.fromAliasRule(ruleContext.getLabel(), actual), |
| VisibilityProvider.class, |
| new VisibilityProviderImpl(ruleContext.getVisibility()))); |
| } |
| |
| private ConfiguredTarget createEmptyConfiguredTarget(RuleContext ruleContext) |
| throws ActionConflictException { |
| return new RuleConfiguredTargetBuilder(ruleContext) |
| .addProvider(RunfilesProvider.class, RunfilesProvider.simple(Runfiles.EMPTY)) |
| .build(); |
| } |
| |
| /** Rule definition for custom alias rules */ |
| public abstract static class CommonAliasRule<FragmentT> implements RuleDefinition { |
| |
| private static final String ATTRIBUTE_NAME = ":alias"; |
| |
| private final String ruleName; |
| private final Function<RuleDefinitionEnvironment, LabelLateBoundDefault<FragmentT>> |
| labelResolver; |
| private final Class<FragmentT> fragmentClass; |
| |
| public CommonAliasRule( |
| String ruleName, |
| Function<RuleDefinitionEnvironment, LabelLateBoundDefault<FragmentT>> labelResolver, |
| Class<FragmentT> fragmentClass) { |
| this.ruleName = Preconditions.checkNotNull(ruleName); |
| this.labelResolver = Preconditions.checkNotNull(labelResolver); |
| this.fragmentClass = Preconditions.checkNotNull(fragmentClass); |
| } |
| |
| protected Attribute.Builder<Label> makeAttribute(RuleDefinitionEnvironment environment) { |
| return attr(ATTRIBUTE_NAME, LABEL).value(labelResolver.apply(environment)); |
| } |
| |
| @Override |
| public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment environment) { |
| Attribute attribute = makeAttribute(environment).build(); |
| Preconditions.checkArgument(attribute.getName().equals(ATTRIBUTE_NAME)); |
| Preconditions.checkArgument(attribute.getType().equals(LABEL)); |
| |
| return builder |
| .requiresConfigurationFragments(fragmentClass) |
| .removeAttribute("licenses") |
| .removeAttribute("distribs") |
| .addAttribute(attribute) |
| .build(); |
| } |
| |
| @Override |
| public Metadata getMetadata() { |
| return Metadata.builder() |
| .name(ruleName) |
| .ancestors(BaseRuleClasses.BaseRule.class) |
| .factoryClass(LateBoundAlias.class) |
| .build(); |
| } |
| } |
| } |