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.objc; import static com.google.devtools.build.lib.rules.objc.J2ObjcSource.SourceType; import com.google.common.collect.ImmutableList; import com.google.devtools.build.lib.actions.Artifact; import com.google.devtools.build.lib.analysis.Aspect; import com.google.devtools.build.lib.analysis.ConfiguredAspectFactory; import com.google.devtools.build.lib.analysis.ConfiguredTarget; import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode; import com.google.devtools.build.lib.analysis.RuleContext; import com.google.devtools.build.lib.cmdline.Label; import com.google.devtools.build.lib.cmdline.LabelSyntaxException; import com.google.devtools.build.lib.collect.nestedset.NestedSet; import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder; import com.google.devtools.build.lib.packages.AspectDefinition; import com.google.devtools.build.lib.packages.AspectParameters; import com.google.devtools.build.lib.rules.proto.ProtoCommon; import com.google.devtools.build.lib.rules.proto.ProtoSourcesProvider; import com.google.devtools.build.lib.vfs.PathFragment; /** * J2ObjC aspect for the proto_library rule. * * <p>J2ObjC proto is different from other proto languages in that it needs to implement both the * Java API and the Objective-C API. The Java API implementation is needed for compatibility with * ObjC code translated by J2ObjC from Java. The Objective-C API is also required for compatibility * with hand-written ObjC code. As an example, for an accessor of a int field called int_value in * message Foo, both the Java API version (getIntValue) and the ObjC version (intValue) are needed. * * <p>On the whole, the dependency chain looks like: objc_binary -> objc_library -> j2objc_library * -> java_library -> proto_library. The jars containing compiled Java protos provided by * proto_library are needed in the classpath for J2ObjC transpilation in java_library, but they * themselves are not transpiled or exported to objc_* rules. Instead, the J2ObjC protos generated * by this class and provided by proto_library will be exported all the way to objc_binary for ObjC * compilation and linking into the final application bundle. */ public abstract class AbstractJ2ObjcProtoAspect implements ConfiguredAspectFactory { public static final String NAME = "J2ObjcProtoAspect"; public AspectDefinition getDefinition() { AspectDefinition.Builder builder = new AspectDefinition.Builder("J2ObjcProtoAspect") .requireProvider(ProtoSourcesProvider.class).attributeAspect("deps", getClass()) .attributeAspect("exports", getClass()).attributeAspect("runtime_deps", getClass()); return addAdditionalAttributes(builder).build(); } protected abstract AspectDefinition.Builder addAdditionalAttributes(AspectDefinition.Builder builder); protected static Label parseLabel(String from) { try { return Label.parseAbsolute(from); } catch (LabelSyntaxException e) { throw new IllegalArgumentException(from); } } protected abstract boolean checkShouldCreateAspect(RuleContext ruleContext); @Override public Aspect create(ConfiguredTarget base, RuleContext ruleContext, AspectParameters parameters) { if (!checkShouldCreateAspect(ruleContext)) { return new Aspect.Builder(NAME).build(); } ProtoSourcesProvider protoSourcesProvider = base.getProvider(ProtoSourcesProvider.class); ImmutableList<Artifact> protoSources = protoSourcesProvider.getProtoSources(); NestedSet<Artifact> transitiveImports = protoSourcesProvider.getTransitiveImports(); J2ObjcSrcsProvider.Builder srcsBuilder = new J2ObjcSrcsProvider.Builder(); Iterable<Artifact> headerMappingFiles; Iterable<Artifact> classMappingFiles; if (protoSources.isEmpty()) { headerMappingFiles = ImmutableList.of(); classMappingFiles = ImmutableList.of(); } else { J2ObjcSource j2ObjcSource = j2ObjcSource(ruleContext, protoSources); headerMappingFiles = headerMappingFiles(ruleContext, protoSources); classMappingFiles = classMappingFiles(ruleContext, protoSources); srcsBuilder.addSource(j2ObjcSource); createActions(base, ruleContext, protoSources, transitiveImports, headerMappingFiles, classMappingFiles, j2ObjcSource); } J2ObjcSrcsProvider j2objcSrcsProvider = srcsBuilder.addTransitiveJ2ObjcSrcs(ruleContext, "deps").build(); NestedSet<Artifact> j2ObjcTransitiveHeaderMappingFiles = j2ObjcTransitiveHeaderMappingFiles(ruleContext, headerMappingFiles); NestedSet<Artifact> j2ObjcTransitiveClassMappingFiles = j2ObjcTransitiveClassMappingFiles(ruleContext, classMappingFiles); return new Aspect.Builder(NAME).addProvider(J2ObjcSrcsProvider.class, j2objcSrcsProvider) .addProvider(J2ObjcMappingFileProvider.class, new J2ObjcMappingFileProvider(j2ObjcTransitiveHeaderMappingFiles, j2ObjcTransitiveClassMappingFiles, NestedSetBuilder.<Artifact>stableOrder().build())) .build(); } protected abstract void createActions(ConfiguredTarget base, RuleContext ruleContext, Iterable<Artifact> protoSources, NestedSet<Artifact> transitiveProtoSources, Iterable<Artifact> headerMappingFiles, Iterable<Artifact> classMappingFiles, J2ObjcSource j2ObjcSource); protected abstract boolean checkShouldCreateSources(RuleContext ruleContext); private J2ObjcSource j2ObjcSource(RuleContext ruleContext, ImmutableList<Artifact> protoSources) { Iterable<Artifact> generatedSourceFiles = checkShouldCreateSources(ruleContext) ? ProtoCommon.getGeneratedOutputs(ruleContext, protoSources, ".j2objc.pb.m") : ImmutableList.<Artifact>of(); PathFragment objcFileRootExecPath = ruleContext.getConfiguration().getGenfilesDirectory().getExecPath(); Iterable<PathFragment> headerSearchPaths = J2ObjcLibrary.j2objcSourceHeaderSearchPaths(ruleContext, objcFileRootExecPath, protoSources); return new J2ObjcSource(ruleContext.getTarget().getLabel(), generatedSourceFiles, ProtoCommon.getGeneratedOutputs(ruleContext, protoSources, ".j2objc.pb.h"), objcFileRootExecPath, SourceType.PROTO, headerSearchPaths); } private static Iterable<Artifact> headerMappingFiles(RuleContext ruleContext, ImmutableList<Artifact> protoSources) { return ProtoCommon.getGeneratedOutputs(ruleContext, protoSources, ".j2objc.mapping"); } private static Iterable<Artifact> classMappingFiles(RuleContext ruleContext, ImmutableList<Artifact> protoSources) { return ProtoCommon.getGeneratedOutputs(ruleContext, protoSources, ".clsmap.properties"); } private static NestedSet<Artifact> j2ObjcTransitiveHeaderMappingFiles(RuleContext ruleContext, Iterable<Artifact> headerMappingFiles) { NestedSetBuilder<Artifact> mappingFileBuilder = NestedSetBuilder.stableOrder(); mappingFileBuilder.addAll(headerMappingFiles); for (J2ObjcMappingFileProvider provider : ruleContext.getPrerequisites("deps", Mode.TARGET, J2ObjcMappingFileProvider.class)) { mappingFileBuilder.addTransitive(provider.getHeaderMappingFiles()); } return mappingFileBuilder.build(); } private static NestedSet<Artifact> j2ObjcTransitiveClassMappingFiles(RuleContext ruleContext, Iterable<Artifact> classMappingFiles) { NestedSetBuilder<Artifact> mappingFileBuilder = NestedSetBuilder.stableOrder(); mappingFileBuilder.addAll(classMappingFiles); for (J2ObjcMappingFileProvider provider : ruleContext.getPrerequisites("deps", Mode.TARGET, J2ObjcMappingFileProvider.class)) { mappingFileBuilder.addTransitive(provider.getClassMappingFiles()); } return mappingFileBuilder.build(); } }