Java tutorial
// 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.rules.java; import com.google.common.collect.ImmutableListMultimap; import com.google.common.collect.Iterables; import com.google.devtools.build.lib.actions.Artifact; import com.google.devtools.build.lib.analysis.ConfiguredTarget; import com.google.devtools.build.lib.analysis.FileProvider; import com.google.devtools.build.lib.analysis.FilesToRunProvider; import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode; import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder; import com.google.devtools.build.lib.analysis.RuleContext; import com.google.devtools.build.lib.analysis.Runfiles; import com.google.devtools.build.lib.analysis.RunfilesProvider; import com.google.devtools.build.lib.analysis.TransitiveInfoCollection; import com.google.devtools.build.lib.collect.nestedset.NestedSet; import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder; import com.google.devtools.build.lib.collect.nestedset.Order; import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory; import com.google.devtools.build.lib.rules.java.JavaToolchainData.SupportsWorkers; import com.google.devtools.build.lib.syntax.Type; import java.util.List; import java.util.Map; /** * Implementation for the {@code java_toolchain} rule. */ public final class JavaToolchain implements RuleConfiguredTargetFactory { @Override public ConfiguredTarget create(RuleContext ruleContext) throws RuleErrorException { final String source = ruleContext.attributes().get("source_version", Type.STRING); final String target = ruleContext.attributes().get("target_version", Type.STRING); final NestedSet<Artifact> bootclasspath = getArtifactList("bootclasspath", ruleContext); final NestedSet<Artifact> extclasspath = getArtifactList("extclasspath", ruleContext); final String encoding = ruleContext.attributes().get("encoding", Type.STRING); final List<String> xlint = ruleContext.attributes().get("xlint", Type.STRING_LIST); final List<String> misc = ruleContext.getTokenizedStringListAttr("misc"); final List<String> jvmOpts = ruleContext.attributes().get("jvm_opts", Type.STRING_LIST); final boolean javacSupportsWorkers = ruleContext.attributes().get("javac_supports_workers", Type.BOOLEAN); Artifact javac = getArtifact("javac", ruleContext); Artifact javabuilder = getArtifact("javabuilder", ruleContext); Artifact headerCompiler = getArtifact("header_compiler", ruleContext); boolean forciblyDisableHeaderCompilation = ruleContext.attributes() .get("forcibly_disable_header_compilation", Type.BOOLEAN); Artifact singleJar = getArtifact("singlejar", ruleContext); Artifact genClass = getArtifact("genclass", ruleContext); FilesToRunProvider ijar = ruleContext.getExecutablePrerequisite("ijar", Mode.HOST); ImmutableListMultimap<String, String> compatibleJavacOptions = getCompatibleJavacOptions(ruleContext); final JavaToolchainData toolchainData = new JavaToolchainData(source, target, Artifact.toExecPaths(bootclasspath), Artifact.toExecPaths(extclasspath), encoding, xlint, misc, jvmOpts, javacSupportsWorkers ? SupportsWorkers.YES : SupportsWorkers.NO); final JavaConfiguration configuration = ruleContext.getFragment(JavaConfiguration.class); JavaToolchainProvider provider = JavaToolchainProvider.create(ruleContext.getLabel(), toolchainData, bootclasspath, extclasspath, configuration.getDefaultJavacFlags(), javac, javabuilder, headerCompiler, forciblyDisableHeaderCompilation, singleJar, genClass, ijar, compatibleJavacOptions); RuleConfiguredTargetBuilder builder = new RuleConfiguredTargetBuilder(ruleContext) .addSkylarkTransitiveInfo(JavaToolchainSkylarkApiProvider.NAME, new JavaToolchainSkylarkApiProvider()) .add(JavaToolchainProvider.class, provider) .setFilesToBuild(new NestedSetBuilder<Artifact>(Order.STABLE_ORDER).build()) .add(RunfilesProvider.class, RunfilesProvider.simple(Runfiles.EMPTY)); return builder.build(); } private static ImmutableListMultimap<String, String> getCompatibleJavacOptions(RuleContext ruleContext) { ImmutableListMultimap.Builder<String, String> result = ImmutableListMultimap.builder(); for (Map.Entry<String, List<String>> entry : ruleContext.attributes() .get("compatible_javacopts", Type.STRING_LIST_DICT).entrySet()) { result.putAll(entry.getKey(), JavaHelper.tokenizeJavaOptions(entry.getValue())); } return result.build(); } private static Artifact getArtifact(String attributeName, RuleContext ruleContext) { TransitiveInfoCollection prerequisite = ruleContext.getPrerequisite(attributeName, Mode.HOST); if (prerequisite == null) { return null; } Iterable<Artifact> artifacts = prerequisite.getProvider(FileProvider.class).getFilesToBuild(); if (Iterables.size(artifacts) != 1) { ruleContext.attributeError(attributeName, prerequisite.getLabel() + " expected a single artifact"); return null; } return Iterables.getOnlyElement(artifacts); } private static NestedSet<Artifact> getArtifactList(String attributeName, RuleContext ruleContext) { TransitiveInfoCollection prerequisite = ruleContext.getPrerequisite(attributeName, Mode.HOST); if (prerequisite == null) { return null; } return prerequisite.getProvider(FileProvider.class).getFilesToBuild(); } }