path: root/src/main/java/com/google/devtools/build/lib/rules/java/JavaBinary.java

// Copyright 2014 Google Inc. 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 static com.google.devtools.build.lib.rules.java.DeployArchiveBuilder.Compression.COMPRESSED;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
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.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.RunfilesSupport;
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.packages.Type;
import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
import com.google.devtools.build.lib.rules.cpp.CppHelper;
import com.google.devtools.build.lib.rules.cpp.LinkerInput;
import com.google.devtools.build.lib.rules.java.JavaCompilationArgs.ClasspathType;
import com.google.devtools.build.lib.vfs.PathFragment;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * An implementation of java_binary.
 */
public class JavaBinary implements RuleConfiguredTargetFactory {
  private static final PathFragment CPP_RUNTIMES = new PathFragment("_cpp_runtimes");

  private final JavaSemantics semantics;

  protected JavaBinary(JavaSemantics semantics) {
    this.semantics = semantics;
  }

  @Override
  public ConfiguredTarget create(RuleContext ruleContext) {
    final JavaCommon common = new JavaCommon(ruleContext, semantics);
    DeployArchiveBuilder deployArchiveBuilder =  new DeployArchiveBuilder(semantics, ruleContext);
    Runfiles.Builder runfilesBuilder = new Runfiles.Builder();
    List<String> jvmFlags = new ArrayList<>();

    common.initializeJavacOpts();
    JavaTargetAttributes.Builder attributesBuilder = common.initCommon();
    attributesBuilder.addClassPathResources(
        ruleContext.getPrerequisiteArtifacts("classpath_resources", Mode.TARGET).list());

    List<String> userJvmFlags = common.getJvmFlags();

    ruleContext.checkSrcsSamePackage(true);
    boolean createExecutable = ruleContext.attributes().get("create_executable", Type.BOOLEAN);
    List<TransitiveInfoCollection> deps =
        Lists.newArrayList(common.targetsTreatedAsDeps(ClasspathType.COMPILE_ONLY));
    semantics.checkRule(ruleContext, common);
    String mainClass = semantics.getMainClass(ruleContext, common);
    String originalMainClass = mainClass;
    if (ruleContext.hasErrors()) {
      return null;
    }

    // Collect the transitive dependencies.
    JavaCompilationHelper helper = new JavaCompilationHelper(
        ruleContext, semantics, common.getJavacOpts(), attributesBuilder);
    helper.addLibrariesToAttributes(deps);
    helper.addProvidersToAttributes(common.compilationArgsFromSources(), /* isNeverLink */ false);
    attributesBuilder.addNativeLibraries(
        collectNativeLibraries(common.targetsTreatedAsDeps(ClasspathType.BOTH)));

    // deploy_env is valid for java_binary, but not for java_test.
    if (ruleContext.getRule().isAttrDefined("deploy_env", Type.LABEL_LIST)) {
      for (JavaRuntimeClasspathProvider envTarget : ruleContext.getPrerequisites(
               "deploy_env", Mode.TARGET, JavaRuntimeClasspathProvider.class)) {
        attributesBuilder.addExcludedArtifacts(envTarget.getRuntimeClasspath());
      }
    }

    Artifact srcJar =
        ruleContext.getImplicitOutputArtifact(JavaSemantics.JAVA_BINARY_SOURCE_JAR);

    Artifact classJar =
        ruleContext.getImplicitOutputArtifact(JavaSemantics.JAVA_BINARY_CLASS_JAR);

    ImmutableList<Artifact> srcJars = ImmutableList.of(srcJar);

    Artifact launcher = semantics.getLauncher(ruleContext, common, deployArchiveBuilder,
        runfilesBuilder, jvmFlags, attributesBuilder);
    JavaCompilationArtifacts.Builder javaArtifactsBuilder = new JavaCompilationArtifacts.Builder();
    Artifact instrumentationMetadata =
        helper.createInstrumentationMetadata(classJar, javaArtifactsBuilder);

    NestedSetBuilder<Artifact> filesBuilder = NestedSetBuilder.stableOrder();
    Artifact executable = null;
    if (createExecutable) {
      executable = ruleContext.createOutputArtifact(); // the artifact for the rule itself
      filesBuilder.add(classJar).add(executable);

      if (ruleContext.getConfiguration().isCodeCoverageEnabled()) {
        mainClass = semantics.addCoverageSupport(helper, attributesBuilder,
            executable, instrumentationMetadata, javaArtifactsBuilder, mainClass);
      }
    } else {
      filesBuilder.add(classJar);
    }

    JavaTargetAttributes attributes = helper.getAttributes();
    List<Artifact> nativeLibraries = attributes.getNativeLibraries();
    if (!nativeLibraries.isEmpty()) {
      jvmFlags.add("-Djava.library.path="
          + JavaCommon.javaLibraryPath(nativeLibraries, ruleContext.getRule().getWorkspaceName()));
    }

    JavaConfiguration javaConfig = ruleContext.getFragment(JavaConfiguration.class);
    if (attributes.hasMessages()) {
      helper.addTranslations(semantics.translate(ruleContext, javaConfig,
          attributes.getMessages()));
    }

    if (attributes.hasSourceFiles() || attributes.hasSourceJars()
        || attributes.hasResources() || attributes.hasClassPathResources()) {
      // We only want to add a jar to the classpath of a dependent rule if it has content.
      javaArtifactsBuilder.addRuntimeJar(classJar);
    }

    // Any JAR files should be added to the collection of runtime jars.
    javaArtifactsBuilder.addRuntimeJars(attributes.getJarFiles());

    Artifact outputDepsProto = helper.createOutputDepsProtoArtifact(classJar, javaArtifactsBuilder);

    common.setJavaCompilationArtifacts(javaArtifactsBuilder.build());

    // The gensrc jar is created only if the target uses annotation processing. Otherwise,
    // it is null, and the source jar action will not depend on the compile action.
    Artifact gensrcJar = helper.createGensrcJar(classJar);
    Artifact manifestProtoOutput = helper.createManifestProtoOutput(classJar);

    helper.createCompileAction(
        classJar, manifestProtoOutput, gensrcJar, outputDepsProto, instrumentationMetadata);
    helper.createSourceJarAction(srcJar, gensrcJar);

    Artifact genClassJar = ruleContext.getImplicitOutputArtifact(JavaSemantics.JAVA_BINARY_GEN_JAR);
    helper.createGenJarAction(classJar, manifestProtoOutput, genClassJar);

    common.setClassPathFragment(new ClasspathConfiguredFragment(
        common.getJavaCompilationArtifacts(), attributes, false));

    // Collect the action inputs for the runfiles collector here because we need to access the
    // analysis environment, and that may no longer be safe when the runfiles collector runs.
    Iterable<Artifact> dynamicRuntimeActionInputs =
        CppHelper.getToolchain(ruleContext).getDynamicRuntimeLinkInputs();


    Iterables.addAll(jvmFlags, semantics.getJvmFlags(ruleContext, common, launcher, userJvmFlags));
    if (ruleContext.hasErrors()) {
      return null;
    }

    if (createExecutable) {
      // Create a shell stub for a Java application
      semantics.createStubAction(ruleContext, common, jvmFlags, executable, mainClass,
          common.getJavaBinSubstitution(launcher));
    }

    NestedSet<Artifact> transitiveSourceJars = collectTransitiveSourceJars(common, srcJar);

    // TODO(bazel-team): if (getOptions().sourceJars) then make this a dummy prerequisite for the
    // DeployArchiveAction ? Needs a few changes there as we can't pass inputs
    helper.createSourceJarAction(semantics, ImmutableList.<Artifact>of(),
        transitiveSourceJars.toCollection(),
        ruleContext.getImplicitOutputArtifact(JavaSemantics.JAVA_BINARY_DEPLOY_SOURCE_JAR));

    RuleConfiguredTargetBuilder builder =
        new RuleConfiguredTargetBuilder(ruleContext);

    semantics.addProviders(ruleContext, common, jvmFlags, classJar, srcJar, genClassJar, gensrcJar,
        ImmutableMap.<Artifact, Artifact>of(), helper, filesBuilder, builder);

    NestedSet<Artifact> filesToBuild = filesBuilder.build();

    collectDefaultRunfiles(runfilesBuilder, ruleContext, common, filesToBuild, launcher,
        dynamicRuntimeActionInputs);
    Runfiles defaultRunfiles = runfilesBuilder.build();

    RunfilesSupport runfilesSupport = createExecutable
        ? runfilesSupport = RunfilesSupport.withExecutable(
            ruleContext, defaultRunfiles, executable,
            semantics.getExtraArguments(ruleContext, common))
        : null;

    RunfilesProvider runfilesProvider = RunfilesProvider.withData(
        defaultRunfiles,
        new Runfiles.Builder().merge(runfilesSupport).build());

    ImmutableList<String> deployManifestLines =
        getDeployManifestLines(ruleContext, originalMainClass);

    Artifact deployJar =
        ruleContext.getImplicitOutputArtifact(JavaSemantics.JAVA_BINARY_DEPLOY_JAR);

    deployArchiveBuilder
        .setOutputJar(deployJar)
        .setJavaStartClass(mainClass)
        .setDeployManifestLines(deployManifestLines)
        .setAttributes(attributes)
        .addRuntimeJars(common.getJavaCompilationArtifacts().getRuntimeJars())
        .setIncludeBuildData(true)
        .setRunfilesMiddleman(
            runfilesSupport == null ? null : runfilesSupport.getRunfilesMiddleman())
        .setCompression(COMPRESSED)
        .setLauncher(launcher);

    deployArchiveBuilder.build();

    common.addTransitiveInfoProviders(builder, filesToBuild, classJar);

    return builder
        .setFilesToBuild(filesToBuild)
        .add(RunfilesProvider.class, runfilesProvider)
        .setRunfilesSupport(runfilesSupport, executable)
        .add(JavaRuntimeClasspathProvider.class,
            new JavaRuntimeClasspathProvider(common.getRuntimeClasspath()))
        .add(JavaSourceJarsProvider.class,
            new JavaSourceJarsProvider(transitiveSourceJars, srcJars))
        .addOutputGroup(JavaSemantics.SOURCE_JARS_OUTPUT_GROUP, transitiveSourceJars)
        .addOutputGroup(JavaSemantics.GENERATED_JARS_OUTPUT_GROUP, genClassJar)
        .build();
  }

  // Create the deploy jar and make it dependent on the runfiles middleman if an executable is
  // created. Do not add the deploy jar to files to build, so we will only build it when it gets
  // requested.
  private ImmutableList<String> getDeployManifestLines(RuleContext ruleContext,
      String originalMainClass) {
    ImmutableList.Builder<String> builder = ImmutableList.<String>builder()
          .addAll(ruleContext.attributes().get("deploy_manifest_lines", Type.STRING_LIST));
    if (ruleContext.getConfiguration().isCodeCoverageEnabled()) {
      builder.add("Coverage-Main-Class: " + originalMainClass);
    }
    return builder.build();
  }

  private void collectDefaultRunfiles(Runfiles.Builder builder, RuleContext ruleContext,
      JavaCommon common, NestedSet<Artifact> filesToBuild, Artifact launcher,
      Iterable<Artifact> dynamicRuntimeActionInputs) {
    // Convert to iterable: filesToBuild has a different order.
    builder.addArtifacts((Iterable<Artifact>) filesToBuild);
    builder.addArtifacts(common.getJavaCompilationArtifacts().getRuntimeJars());
    if (launcher != null) {
      final TransitiveInfoCollection defaultLauncher =
          JavaHelper.launcherForTarget(semantics, ruleContext);
      final Artifact defaultLauncherArtifact =
          JavaHelper.launcherArtifactForTarget(semantics, ruleContext);
      if (!defaultLauncherArtifact.equals(launcher)) {
        builder.addArtifact(launcher);

        // N.B. The "default launcher" referred to here is the launcher target specified through
        // an attribute or flag. We wish to retain the runfiles of the default launcher, *except*
        // for the original cc_binary artifact, because we've swapped it out with our custom
        // launcher. Hence, instead of calling builder.addTarget(), or adding an odd method
        // to Runfiles.Builder, we "unravel" the call and manually add things to the builder.
        // Because the NestedSet representing each target's launcher runfiles is re-built here,
        // we may see increased memory consumption for representing the target's runfiles.
        Runfiles runfiles =
            defaultLauncher.getProvider(RunfilesProvider.class)
              .getDefaultRunfiles();
        NestedSetBuilder<Artifact> unconditionalArtifacts = NestedSetBuilder.compileOrder();
        for (Artifact a : runfiles.getUnconditionalArtifacts()) {
          if (!a.equals(defaultLauncherArtifact)) {
            unconditionalArtifacts.add(a);
          }
        }
        builder.addTransitiveArtifacts(unconditionalArtifacts.build());
        builder.addSymlinks(runfiles.getSymlinks());
        builder.addRootSymlinks(runfiles.getRootSymlinks());
        builder.addPruningManifests(runfiles.getPruningManifests());
      } else {
        builder.addTarget(defaultLauncher, RunfilesProvider.DEFAULT_RUNFILES);
      }
    }

    semantics.addRunfilesForBinary(ruleContext, launcher, builder);
    builder.addRunfiles(ruleContext, RunfilesProvider.DEFAULT_RUNFILES);
    builder.add(ruleContext, JavaRunfilesProvider.TO_RUNFILES);

    List<? extends TransitiveInfoCollection> runtimeDeps =
        ruleContext.getPrerequisites("runtime_deps", Mode.TARGET);
    builder.addTargets(runtimeDeps, JavaRunfilesProvider.TO_RUNFILES);
    builder.addTargets(runtimeDeps, RunfilesProvider.DEFAULT_RUNFILES);
    semantics.addDependenciesForRunfiles(ruleContext, builder);

    if (ruleContext.getConfiguration().isCodeCoverageEnabled()) {
      Artifact instrumentedJar = common.getJavaCompilationArtifacts().getInstrumentedJar();
      if (instrumentedJar != null) {
        builder.addArtifact(instrumentedJar);
      }
    }

    builder.addArtifacts((Iterable<Artifact>) common.getRuntimeClasspath());

    // Add the JDK files if it comes from the source repository (see java_stub_template.txt).
    TransitiveInfoCollection javabaseTarget = ruleContext.getPrerequisite(":jvm", Mode.HOST);
    if (javabaseTarget != null) {
      builder.addArtifacts(
          (Iterable<Artifact>) javabaseTarget.getProvider(FileProvider.class).getFilesToBuild());

      // Add symlinks to the C++ runtime libraries under a path that can be built
      // into the Java binary without having to embed the crosstool, gcc, and grte
      // version information contained within the libraries' package paths.
      for (Artifact lib : dynamicRuntimeActionInputs) {
        PathFragment path = CPP_RUNTIMES.getRelative(lib.getExecPath().getBaseName());
        builder.addSymlink(path, lib);
      }
    }
  }

  private NestedSet<Artifact> collectTransitiveSourceJars(JavaCommon common, Artifact srcJar) {
    NestedSetBuilder<Artifact> builder = NestedSetBuilder.stableOrder();

    builder.add(srcJar);
    for (JavaSourceJarsProvider dep : common.getDependencies(JavaSourceJarsProvider.class)) {
      builder.addTransitive(dep.getTransitiveSourceJars());
    }
    return builder.build();
  }

  /**
   * Collects the native libraries in the transitive closure of the deps.
   *
   * @param deps the dependencies to be included as roots of the transitive closure.
   * @return the native libraries found in the transitive closure of the deps.
   */
  public static Collection<Artifact> collectNativeLibraries(
      Iterable<? extends TransitiveInfoCollection> deps) {
    NestedSet<LinkerInput> linkerInputs = new NativeLibraryNestedSetBuilder()
        .addJavaTargets(deps)
        .build();
    ImmutableList.Builder<Artifact> result = ImmutableList.builder();
    for (LinkerInput linkerInput : linkerInputs) {
      result.add(linkerInput.getArtifact());
    }

    return result.build();
  }
}