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

// 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 static com.google.common.base.Preconditions.checkNotNull;
import static com.google.devtools.build.lib.analysis.config.BuildConfiguration.StrictDepsMode.OFF;
import static com.google.devtools.build.lib.rules.java.JavaHelper.getHostJavabaseInputs;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.ExecutionRequirements;
import com.google.devtools.build.lib.analysis.AnalysisEnvironment;
import com.google.devtools.build.lib.analysis.FileProvider;
import com.google.devtools.build.lib.analysis.FilesToRunProvider;
import com.google.devtools.build.lib.analysis.RuleContext;
import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
import com.google.devtools.build.lib.analysis.actions.CustomCommandLine;
import com.google.devtools.build.lib.analysis.actions.SpawnAction;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration.StrictDepsMode;
import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget.Mode;
import com.google.devtools.build.lib.analysis.test.InstrumentedFilesCollector;
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.AttributeMap;
import com.google.devtools.build.lib.rules.java.JavaConfiguration.JavaClasspathMode;
import com.google.devtools.build.lib.syntax.Type;
import com.google.devtools.build.lib.util.FileType;
import com.google.devtools.build.lib.vfs.FileSystemUtils;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.annotation.Nullable;

/**
 * A helper class for compiling Java targets. It contains method to create the
 * various intermediate Artifacts for using ijars and source ijars.
 * <p>
 * Also supports the creation of resource and source only Jars.
 */
public final class JavaCompilationHelper {

  private final RuleContext ruleContext;
  private final JavaToolchainProvider javaToolchain;
  private final NestedSet<Artifact> hostJavabase;
  private final Iterable<Artifact> jacocoInstrumentation;
  private JavaTargetAttributes.Builder attributes;
  private JavaTargetAttributes builtAttributes;
  private final ImmutableList<String> customJavacOpts;
  private final ImmutableList<String> customJavacJvmOpts;
  private final List<Artifact> translations = new ArrayList<>();
  private boolean translationsFrozen;
  private final JavaSemantics semantics;
  private final ImmutableList<Artifact> additionalJavaBaseInputs;
  private final StrictDepsMode strictJavaDeps;

  private static final String DEFAULT_ATTRIBUTES_SUFFIX = "";
  private static final PathFragment JAVAC = PathFragment.create("_javac");

  private JavaCompilationHelper(RuleContext ruleContext, JavaSemantics semantics,
      ImmutableList<String> javacOpts, JavaTargetAttributes.Builder attributes,
      JavaToolchainProvider javaToolchainProvider,
      NestedSet<Artifact> hostJavabase,
      Iterable<Artifact> jacocoInstrumentation,
      ImmutableList<Artifact> additionalJavaBaseInputs,
      boolean disableStrictDeps) {
    this.ruleContext = ruleContext;
    this.javaToolchain = javaToolchainProvider;
    this.hostJavabase = hostJavabase;
    this.jacocoInstrumentation = jacocoInstrumentation;
    this.attributes = attributes;
    this.customJavacOpts = javacOpts;
    this.customJavacJvmOpts = javaToolchain.getJvmOptions();
    this.semantics = semantics;
    this.additionalJavaBaseInputs = additionalJavaBaseInputs;
    this.strictJavaDeps = disableStrictDeps
        ? StrictDepsMode.OFF
        : getJavaConfiguration().getFilteredStrictJavaDeps();
  }

  public JavaCompilationHelper(RuleContext ruleContext, JavaSemantics semantics,
      ImmutableList<String> javacOpts, JavaTargetAttributes.Builder attributes,
      JavaToolchainProvider javaToolchainProvider,
      NestedSet<Artifact> hostJavabase,
      Iterable<Artifact> jacocoInstrumentation) {
    this(ruleContext, semantics, javacOpts, attributes, javaToolchainProvider, hostJavabase,
        jacocoInstrumentation, ImmutableList.<Artifact>of(), false);
  }

  public JavaCompilationHelper(RuleContext ruleContext, JavaSemantics semantics,
      ImmutableList<String> javacOpts, JavaTargetAttributes.Builder attributes) {
    this(
        ruleContext,
        semantics,
        javacOpts,
        attributes,
        getJavaToolchainProvider(ruleContext),
        getHostJavabaseInputs(ruleContext),
        getInstrumentationJars(ruleContext));
  }

  public JavaCompilationHelper(RuleContext ruleContext, JavaSemantics semantics,
      ImmutableList<String> javacOpts, JavaTargetAttributes.Builder attributes,
      ImmutableList<Artifact> additionalJavaBaseInputs, boolean disableStrictDeps) {
    this(
        ruleContext,
        semantics,
        javacOpts,
        attributes,
        getJavaToolchainProvider(ruleContext),
        getHostJavabaseInputs(ruleContext),
        getInstrumentationJars(ruleContext),
        additionalJavaBaseInputs,
        disableStrictDeps);
  }

  @VisibleForTesting
  JavaCompilationHelper(RuleContext ruleContext, JavaSemantics semantics,
      JavaTargetAttributes.Builder attributes) {
    this(ruleContext, semantics, getDefaultJavacOptsFromRule(ruleContext), attributes);
  }

  public JavaTargetAttributes getAttributes() {
    if (builtAttributes == null) {
      builtAttributes = attributes.build();
    }
    return builtAttributes;
  }

  public RuleContext getRuleContext() {
    return ruleContext;
  }

  private AnalysisEnvironment getAnalysisEnvironment() {
    return ruleContext.getAnalysisEnvironment();
  }

  private BuildConfiguration getConfiguration() {
    return ruleContext.getConfiguration();
  }

  private JavaConfiguration getJavaConfiguration() {
    return ruleContext.getFragment(JavaConfiguration.class);
  }

  /**
   * Creates the Action that compiles Java source files.
   *
   * @param outputJar the class jar Artifact to create with the Action
   * @param manifestProtoOutput the output artifact for the manifest proto emitted from JavaBuilder
   * @param gensrcOutputJar the generated sources jar Artifact to create with the Action
   *        (null if no sources will be generated).
   * @param outputDepsProto the compiler-generated jdeps file to create with the Action
   *        (null if not requested)
   * @param instrumentationMetadataJar metadata file (null if no instrumentation is needed or if
   * --experimental_java_coverage is true).
   */
  public void createCompileAction(
      Artifact outputJar,
      Artifact manifestProtoOutput,
      @Nullable Artifact gensrcOutputJar,
      @Nullable Artifact outputDepsProto,
      @Nullable Artifact instrumentationMetadataJar) {

    JavaTargetAttributes attributes = getAttributes();

    Artifact classJar;
    if (attributes.getResources().isEmpty()
        && attributes.getResourceJars().isEmpty()
        && attributes.getClassPathResources().isEmpty()
        && getTranslations().isEmpty()) {
      // if there are sources and no resource, the only output is from the javac action
      classJar = outputJar;
    } else {
      // otherwise create a separate jar for the compilation and add resources with singlejar
      classJar =
          ruleContext.getDerivedArtifact(
              FileSystemUtils.appendWithoutExtension(outputJar.getRootRelativePath(), "-class"),
              outputJar.getRoot());
      createResourceJarAction(outputJar, ImmutableList.of(classJar));
    }

    JavaCompileAction.Builder builder = createJavaCompileActionBuilder(semantics);
    builder.setArtifactForExperimentalCoverage(maybeCreateExperimentalCoverageArtifact(outputJar));
    builder.setClasspathEntries(attributes.getCompileTimeClassPath());
    builder.setBootclasspathEntries(getBootclasspathOrDefault());
    builder.setSourcePathEntries(attributes.getSourcePath());
    builder.setExtdirInputs(getExtdirInputs());
    builder.setLangtoolsJar(javaToolchain.getJavac());
    builder.setToolsJars(javaToolchain.getTools());
    builder.setJavaBuilder(javaToolchain.getJavaBuilder());
    builder.setOutputJar(classJar);
    builder.setManifestProtoOutput(manifestProtoOutput);
    builder.setGensrcOutputJar(gensrcOutputJar);
    builder.setOutputDepsProto(outputDepsProto);
    builder.setAdditionalOutputs(attributes.getAdditionalOutputs());
    builder.setMetadata(instrumentationMetadataJar);
    builder.setInstrumentationJars(jacocoInstrumentation);
    builder.setSourceFiles(attributes.getSourceFiles());
    builder.addSourceJars(attributes.getSourceJars());
    builder.setJavacOpts(customJavacOpts);
    builder.setJavacJvmOpts(customJavacJvmOpts);
    builder.setJavacExecutionInfo(getExecutionInfo());
    builder.setCompressJar(true);
    builder.setSourceGenDirectory(sourceGenDir(classJar));
    builder.setTempDirectory(tempDir(classJar));
    builder.setClassDirectory(classDir(classJar));
    builder.setProcessorPaths(attributes.getProcessorPath());
    builder.addProcessorNames(attributes.getProcessorNames());
    builder.setStrictJavaDeps(attributes.getStrictJavaDeps());
    builder.setDirectJars(attributes.getDirectJars());
    builder.setCompileTimeDependencyArtifacts(attributes.getCompileTimeDependencyArtifacts());
    builder.setRuleKind(attributes.getRuleKind());
    builder.setTargetLabel(
        attributes.getTargetLabel() == null
            ? ruleContext.getLabel() : attributes.getTargetLabel());
    AttributeMap attributeMap = ruleContext.attributes();
    if (attributeMap.has("testonly", Type.BOOLEAN)) {
      builder.setTestOnly(attributeMap.get("testonly", Type.BOOLEAN));
    }
    getAnalysisEnvironment().registerAction(builder.build());
  }

  private ImmutableMap<String, String> getExecutionInfo() {
    if (javaToolchain.getJavacSupportsWorkers()) {
      return ExecutionRequirements.WORKER_MODE_ENABLED;
    }
    return ImmutableMap.of();
  }

  /** Returns the bootclasspath explicit set in attributes if present, or else the default. */
  public ImmutableList<Artifact> getBootclasspathOrDefault() {
    JavaTargetAttributes attributes = getAttributes();
    if (!attributes.getBootClassPath().isEmpty()) {
      return attributes.getBootClassPath();
    } else {
      return getBootClasspath();
    }
  }

  /**
   * Creates an {@link Artifact} needed by {@code JacocoCoverageRunner} when
   * {@code --experimental_java_coverage} is true.
   *
   * <p> The {@link Artifact} is created in the same directory as the given {@code compileJar} and
   * has the suffix {@code -paths-for-coverage.txt}.
   *
   * <p> Returns {@code null} if {@code compileJar} should not be instrumented.
   */
  private Artifact maybeCreateExperimentalCoverageArtifact(Artifact compileJar) {
    if (!shouldInstrumentJar() || !getConfiguration().isExperimentalJavaCoverage()) {
      return null;
    }
    PathFragment packageRelativePath =
        compileJar.getRootRelativePath().relativeTo(ruleContext.getPackageDirectory());
    PathFragment path =
        FileSystemUtils.replaceExtension(packageRelativePath, "-paths-for-coverage.txt");
    return ruleContext.getPackageRelativeArtifact(path, compileJar.getRoot());
  }

  /**
   * Returns the instrumentation metadata files to be generated for a given output jar.
   *
   * <p>Only called if the output jar actually needs to be instrumented.
   */
  @Nullable
  private static Artifact createInstrumentationMetadataArtifact(
      RuleContext ruleContext, Artifact outputJar) {
    PathFragment packageRelativePath = outputJar.getRootRelativePath().relativeTo(
        ruleContext.getPackageDirectory());
    return ruleContext.getPackageRelativeArtifact(
        FileSystemUtils.replaceExtension(packageRelativePath, ".em"), outputJar.getRoot());
  }

  /**
   * Creates the Action that compiles Java source files and optionally instruments them for
   * coverage.
   *
   * @param outputJar the class jar Artifact to create with the Action
   * @param manifestProtoOutput the output artifact for the manifest proto emitted from JavaBuilder
   * @param gensrcJar the generated sources jar Artifact to create with the Action
   * @param outputDepsProto the compiler-generated jdeps file to create with the Action
   * @param javaArtifactsBuilder the build to store the instrumentation metadata in
   */
  public void createCompileActionWithInstrumentation(
      Artifact outputJar,
      Artifact manifestProtoOutput,
      @Nullable Artifact gensrcJar,
      @Nullable Artifact outputDepsProto,
      JavaCompilationArtifacts.Builder javaArtifactsBuilder) {
    createCompileAction(
        outputJar,
        manifestProtoOutput,
        gensrcJar,
        outputDepsProto,
        createInstrumentationMetadata(outputJar, javaArtifactsBuilder));
  }

  /**
   * Creates the instrumentation metadata artifact if needed.
   *
   * @return the instrumentation metadata artifact or null if instrumentation is
   *         disabled
   */
  @Nullable
  public Artifact createInstrumentationMetadata(Artifact outputJar,
      JavaCompilationArtifacts.Builder javaArtifactsBuilder) {
    // In the experimental java coverage we don't create the .em jar for instrumentation.
    if (getConfiguration().isExperimentalJavaCoverage()) {
      return null;
    }
    // If we need to instrument the jar, add additional output (the coverage metadata file) to the
    // JavaCompileAction.
    Artifact instrumentationMetadata = null;
    if (shouldInstrumentJar()) {
      instrumentationMetadata = createInstrumentationMetadataArtifact(
          getRuleContext(), outputJar);

      if (instrumentationMetadata != null) {
        javaArtifactsBuilder.addInstrumentationMetadata(instrumentationMetadata);
      }
    }
    return instrumentationMetadata;
  }

  private boolean shouldInstrumentJar() {
    // TODO(bazel-team): What about source jars?
    return getConfiguration().isCodeCoverageEnabled() && attributes.hasSourceFiles()
        && InstrumentedFilesCollector.shouldIncludeLocalSources(getRuleContext());
  }

  private boolean shouldUseHeaderCompilation() {
    if (!getJavaConfiguration().useHeaderCompilation()) {
      return false;
    }
    if (!attributes.hasSourceFiles() && !attributes.hasSourceJars()) {
      return false;
    }
    if (javaToolchain.getForciblyDisableHeaderCompilation()) {
      return false;
    }
    if (javaToolchain.getHeaderCompiler() == null) {
      getRuleContext()
          .ruleError(
              String.format(
                  "header compilation was requested but it is not supported by the current Java"
                      + " toolchain '%s'; see the java_toolchain.header_compiler attribute",
                  javaToolchain.getToolchainLabel()));
      return false;
    }
    return true;
  }

  /**
   * Creates the Action that compiles ijars from source.
   *
   * @param runtimeJar the jar output of this java compilation, used to create output-relative
   *     paths for new artifacts.
   */
  private Artifact createHeaderCompilationAction(
      Artifact runtimeJar, JavaCompilationArtifacts.Builder artifactBuilder) {

    Artifact headerJar =
        getAnalysisEnvironment()
            .getDerivedArtifact(
                FileSystemUtils.replaceExtension(runtimeJar.getRootRelativePath(), "-hjar.jar"),
                runtimeJar.getRoot());
    Artifact headerDeps =
        getAnalysisEnvironment()
            .getDerivedArtifact(
                FileSystemUtils.replaceExtension(runtimeJar.getRootRelativePath(), "-hjar.jdeps"),
                runtimeJar.getRoot());

    JavaTargetAttributes attributes = getAttributes();
    JavaHeaderCompileAction.Builder builder =
        new JavaHeaderCompileAction.Builder(getRuleContext());
    builder.setSourceFiles(attributes.getSourceFiles());
    builder.addSourceJars(attributes.getSourceJars());
    builder.setClasspathEntries(attributes.getCompileTimeClassPath());
    builder.setBootclasspathEntries(
        ImmutableList.copyOf(Iterables.concat(getBootclasspathOrDefault(), getExtdirInputs())));

    // only run API-generating annotation processors during header compilation
    builder.setProcessorPaths(attributes.getApiGeneratingProcessorPath());
    builder.addProcessorNames(attributes.getApiGeneratingProcessorNames());
    builder.setJavacOpts(getJavacOpts());
    builder.setTempDirectory(tempDir(headerJar));
    builder.setOutputJar(headerJar);
    builder.setOutputDepsProto(headerDeps);
    builder.setStrictJavaDeps(attributes.getStrictJavaDeps());
    builder.setCompileTimeDependencyArtifacts(attributes.getCompileTimeDependencyArtifacts());
    builder.setDirectJars(attributes.getDirectJars());
    builder.setRuleKind(attributes.getRuleKind());
    builder.setTargetLabel(attributes.getTargetLabel());
    builder.setJavaBaseInputs(
        NestedSetBuilder
            .fromNestedSet(hostJavabase)
            .addAll(additionalJavaBaseInputs)
            .build());
    builder.setJavacJar(javaToolchain.getJavac());
    builder.setToolsJars(javaToolchain.getTools());
    builder.build(javaToolchain);

    artifactBuilder.setCompileTimeDependencies(headerDeps);
    return headerJar;
  }

  /**
   * Returns the artifact for a jar file containing class files that were generated by
   * annotation processors.
   */
  public Artifact createGenJar(Artifact outputJar) {
    return getRuleContext().getDerivedArtifact(
        FileSystemUtils.appendWithoutExtension(outputJar.getRootRelativePath(), "-gen"),
        outputJar.getRoot());
  }

  /**
   * Returns the artifact for a jar file containing source files that were generated by
   * annotation processors.
   */
  public Artifact createGensrcJar(Artifact outputJar) {
    return getRuleContext().getDerivedArtifact(
        FileSystemUtils.appendWithoutExtension(outputJar.getRootRelativePath(), "-gensrc"),
        outputJar.getRoot());
  }

  /**
   * Returns whether this target uses annotation processing.
   */
  public boolean usesAnnotationProcessing() {
    JavaTargetAttributes attributes = getAttributes();
    return getJavacOpts().contains("-processor") || !attributes.getProcessorNames().isEmpty();
  }

  /**
   * Returns the artifact for the manifest proto emitted from JavaBuilder. For example, for a
   * class jar foo.jar, returns "foo.jar_manifest_proto".
   *
   * @param outputJar The artifact for the class jar emitted form JavaBuilder
   * @return The output artifact for the manifest proto emitted from JavaBuilder
   */
  public Artifact createManifestProtoOutput(Artifact outputJar) {
    return getRuleContext().getDerivedArtifact(
        FileSystemUtils.appendExtension(outputJar.getRootRelativePath(), "_manifest_proto"),
        outputJar.getRoot());
  }

  /**
   * Creates the action for creating the gen jar.
   *
   * @param classJar The artifact for the class jar emitted from JavaBuilder
   * @param manifestProto The artifact for the manifest proto emitted from JavaBuilder
   * @param genClassJar The artifact for the gen jar to output
   */
  public void createGenJarAction(Artifact classJar, Artifact manifestProto,
      Artifact genClassJar) {
    getRuleContext()
        .registerAction(
            new SpawnAction.Builder()
                .addInput(manifestProto)
                .addInput(classJar)
                .addOutput(genClassJar)
                .addTransitiveInputs(getHostJavabaseInputs(getRuleContext()))
                .setJarExecutable(
                    JavaCommon.getHostJavaExecutable(ruleContext),
                    getGenClassJar(ruleContext),
                    javaToolchain.getJvmOptions())
                .addCommandLine(
                    CustomCommandLine.builder()
                        .addExecPath("--manifest_proto", manifestProto)
                        .addExecPath("--class_jar", classJar)
                        .addExecPath("--output_jar", genClassJar)
                        .add("--temp_dir")
                        .addPath(tempDir(genClassJar))
                        .build())
                .setProgressMessage("Building genclass jar %s", genClassJar.prettyPrint())
                .setMnemonic("JavaSourceJar")
                .build(getRuleContext()));
  }

  /** Returns the GenClass deploy jar Artifact. */
  private Artifact getGenClassJar(RuleContext ruleContext) {
    Artifact genClass = javaToolchain.getGenClass();
    if (genClass != null) {
      return genClass;
    }
    return ruleContext.getPrerequisiteArtifact("$genclass", Mode.HOST);
  }

  /**
   * Creates the jdeps file artifact if needed. Returns null if the target can't emit dependency
   * information (i.e there is no compilation step, the target acts as an alias).
   *
   * @param outputJar output jar artifact used to derive the name
   * @return the jdeps file artifact or null if the target can't generate such a file
   */
  public Artifact createOutputDepsProtoArtifact(Artifact outputJar,
      JavaCompilationArtifacts.Builder builder) {
    if (!generatesOutputDeps()) {
      return null;
    }

    Artifact outputDepsProtoArtifact =
        getRuleContext()
            .getDerivedArtifact(
                FileSystemUtils.replaceExtension(outputJar.getRootRelativePath(), ".jdeps"),
                outputJar.getRoot());

    builder.setCompileTimeDependencies(outputDepsProtoArtifact);
    return outputDepsProtoArtifact;
  }

  /**
   * Returns whether this target emits dependency information. Compilation must occur, so certain
   * targets acting as aliases have to be filtered out.
   */
  private boolean generatesOutputDeps() {
    return getJavaConfiguration().getGenerateJavaDeps() && attributes.hasSources();
  }

  /**
   * Creates and registers an Action that packages all of the resources into a Jar. This includes
   * the declared resources, the classpath resources and the translated messages.
   */
  public void createResourceJarAction(Artifact resourceJar) {
    createResourceJarAction(resourceJar, ImmutableList.<Artifact>of());
  }

  private void createResourceJarAction(Artifact resourceJar, ImmutableList<Artifact> extraJars) {
    checkNotNull(resourceJar, "resource jar output must not be null");
    JavaTargetAttributes attributes = getAttributes();
    new ResourceJarActionBuilder()
        .setJavabase(
            NestedSetBuilder.fromNestedSet(hostJavabase).addAll(additionalJavaBaseInputs).build())
        .setJavaToolchain(javaToolchain)
        .setOutputJar(resourceJar)
        .setResources(attributes.getResources())
        .setClasspathResources(attributes.getClassPathResources())
        .setTranslations(getTranslations())
        .setResourceJars(
            NestedSetBuilder.fromNestedSet(attributes.getResourceJars()).addAll(extraJars).build())
        .build(semantics, ruleContext);
  }

  private JavaCompileAction.Builder createJavaCompileActionBuilder(
      JavaSemantics semantics) {
    JavaCompileAction.Builder builder = new JavaCompileAction.Builder(ruleContext, semantics);
    builder.setJavaExecutable(JavaCommon.getHostJavaExecutable(ruleContext));
    builder.setJavaBaseInputs(
        NestedSetBuilder
            .fromNestedSet(hostJavabase)
            .addAll(additionalJavaBaseInputs)
            .build());
    builder.setTargetLabel(ruleContext.getLabel());
    return builder;
  }

  /**
   * Produces a derived directory where source files generated by annotation processors should be
   * stored.
   */
  private PathFragment sourceGenDir(Artifact outputJar) {
    return workDir(outputJar, "_sourcegenfiles");
  }

  private PathFragment tempDir(Artifact outputJar) {
    return workDir(outputJar, "_temp");
  }

  private PathFragment classDir(Artifact outputJar) {
    return workDir(outputJar, "_classes");
  }

  /**
   * For an output jar and a suffix, produces a derived directory under
   * {@code bin} directory with a given suffix.
   *
   * <p>Note that this won't work if a rule produces two jars with the same basename.
   */
  private PathFragment workDir(Artifact outputJar, String suffix) {
    String basename = FileSystemUtils.removeExtension(outputJar.getExecPath().getBaseName());
    return getConfiguration().getBinDirectory(ruleContext.getRule().getRepository()).getExecPath()
        .getRelative(ruleContext.getUniqueDirectory(JAVAC))
        .getRelative(basename + suffix);
  }

  /**
   * Creates an Action that packages the Java source files into a Jar.  If {@code gensrcJar} is
   * non-null, includes the contents of the {@code gensrcJar} with the output source jar.
   *
   * @param outputJar the Artifact to create with the Action
   * @param gensrcJar the generated sources jar Artifact that should be included with the
   *        sources in the output Artifact.  May be null.
   * @param javaToolchainProvider is used by SingleJarActionBuilder to retrieve jvm options
   * @param hostJavabaseInputs Artifacts required to invoke java executable in the SingleJar action
   * @param hostJavaExecutable the jar executable of the SingleJar action
   */
  public void createSourceJarAction(
      Artifact outputJar,
      @Nullable Artifact gensrcJar,
      JavaToolchainProvider javaToolchainProvider,
      NestedSet<Artifact> hostJavabaseInputs,
      PathFragment hostJavaExecutable) {
    JavaTargetAttributes attributes = getAttributes();
    NestedSetBuilder<Artifact> resourceJars = NestedSetBuilder.stableOrder();
    resourceJars.addAll(attributes.getSourceJars());
    if (gensrcJar != null) {
      resourceJars.add(gensrcJar);
    }
    SingleJarActionBuilder.createSourceJarAction(
        ruleContext, semantics, attributes.getSourceFiles(),
        resourceJars.build(), outputJar, javaToolchainProvider,
        hostJavabaseInputs, hostJavaExecutable);
  }

  public void createSourceJarAction(Artifact outputJar, @Nullable Artifact gensrcJar) {
    JavaTargetAttributes attributes = getAttributes();
    NestedSetBuilder<Artifact> resourceJars = NestedSetBuilder.stableOrder();
    resourceJars.addAll(attributes.getSourceJars());
    if (gensrcJar != null) {
      resourceJars.add(gensrcJar);
    }
    SingleJarActionBuilder.createSourceJarAction(
        ruleContext, semantics, attributes.getSourceFiles(), resourceJars.build(), outputJar);
  }

  /**
   * Creates the actions that produce the interface jar. Adds the jar artifacts to the given
   * JavaCompilationArtifacts builder.
   *
   * @return the header jar (if requested), or ijar (if requested), or else the class jar
   */
  public Artifact createCompileTimeJarAction(
      Artifact runtimeJar, JavaCompilationArtifacts.Builder builder) {
    Artifact jar;
    boolean isFullJar = false;
    if (shouldUseHeaderCompilation()) {
      jar = createHeaderCompilationAction(runtimeJar, builder);
    } else if (getJavaConfiguration().getUseIjars()) {
      jar = createIjarAction(ruleContext, javaToolchain, runtimeJar, false);
    } else {
      jar = runtimeJar;
      isFullJar = true;
    }
    if (isFullJar) {
      builder.addCompileTimeJarAsFullJar(jar);
    } else {
      builder.addInterfaceJarWithFullJar(jar, runtimeJar);
    }
    return jar;
  }

  private void addArgsAndJarsToAttributes(
      JavaCompilationArgs args, NestedSet<Artifact> directJars) {
    // Can only be non-null when isStrict() returns true.
    if (directJars != null) {
      attributes.addDirectJars(directJars);
    }

    attributes.merge(args);
  }

  private void addLibrariesToAttributesInternal(Iterable<? extends TransitiveInfoCollection> deps) {
    JavaCompilationArgs args = JavaCompilationArgs.builder()
        .addTransitiveTargets(deps).build();

    NestedSet<Artifact> directJars = isStrict()
        ? getNonRecursiveCompileTimeJarsFromCollection(deps)
        : null;
    addArgsAndJarsToAttributes(args, directJars);
  }

  private boolean isStrict() {
    return getStrictJavaDeps() != OFF;
  }

  private NestedSet<Artifact> getNonRecursiveCompileTimeJarsFromCollection(
      Iterable<? extends TransitiveInfoCollection> deps) {
    JavaCompilationArgs.Builder builder = JavaCompilationArgs.builder();
    builder.addTransitiveTargets(deps, /*recursive=*/false);
    return builder.build().getCompileTimeJars();
  }

  static void addDependencyArtifactsToAttributes(
      JavaTargetAttributes.Builder attributes,
      Iterable<? extends JavaCompilationArgsProvider> deps) {
    NestedSetBuilder<Artifact> result = NestedSetBuilder.stableOrder();
    for (JavaCompilationArgsProvider provider : deps) {
      result.addTransitive(provider.getCompileTimeJavaDependencyArtifacts());
    }
    attributes.addCompileTimeDependencyArtifacts(result.build());
  }

  /**
   * Adds the compile time and runtime Java libraries in the transitive closure
   * of the deps to the attributes.
   *
   * @param deps the dependencies to be included as roots of the transitive
   *        closure
   */
  public void addLibrariesToAttributes(Iterable<? extends TransitiveInfoCollection> deps) {
    // Enforcing strict Java dependencies: when the --strict_java_deps flag is
    // WARN or ERROR, or is DEFAULT and strict_java_deps attribute is unset,
    // we use a stricter javac compiler to perform direct deps checks.
    attributes.setStrictJavaDeps(getStrictJavaDeps());
    addLibrariesToAttributesInternal(deps);

    JavaClasspathMode classpathMode = getJavaConfiguration().getReduceJavaClasspath();
    if (isStrict() && classpathMode != JavaClasspathMode.OFF) {
      List<JavaCompilationArgsProvider> compilationArgsProviders = new ArrayList<>();
      for (TransitiveInfoCollection dep : deps) {
        JavaCompilationArgsProvider provider =
            JavaInfo.getProvider(JavaCompilationArgsProvider.class, dep);
        if (provider != null) {
          compilationArgsProviders.add(provider);
        }
      }
      addDependencyArtifactsToAttributes(attributes, compilationArgsProviders);
    }
  }

  /**
   * Determines whether to enable strict_java_deps.
   *
   * @return filtered command line flag value, defaulting to ERROR
   */
  public StrictDepsMode getStrictJavaDeps() {
    return strictJavaDeps;
  }

  /**
   * Gets the value of the "javacopts" attribute combining them with the
   * default options. If the current rule has no javacopts attribute, this
   * method only returns the default options.
   */
  @VisibleForTesting
  public ImmutableList<String> getJavacOpts() {
    return customJavacOpts;
  }

  /**
   * Obtains the standard list of javac opts needed to build {@code rule}.
   *
   * This method must only be called during initialization.
   *
   * @param ruleContext a rule context
   * @return a list of options to provide to javac
   */
  private static ImmutableList<String> getDefaultJavacOptsFromRule(RuleContext ruleContext) {
    return ImmutableList.copyOf(
        Iterables.concat(
            JavaToolchainProvider.from(ruleContext).getJavacOptions(),
            ruleContext.getExpander().withDataLocations().tokenized("javacopts")));
  }

  public void setTranslations(Collection<Artifact> translations) {
    Preconditions.checkArgument(!translationsFrozen);
    this.translations.addAll(translations);
  }

  private ImmutableList<Artifact> getTranslations() {
    translationsFrozen = true;
    return ImmutableList.copyOf(translations);
  }

  public static JavaToolchainProvider getJavaToolchainProvider(
      RuleContext ruleContext, String implicitAttributesSuffix) {
    return JavaToolchainProvider.from(ruleContext, ":java_toolchain" + implicitAttributesSuffix);
  }

  public static JavaToolchainProvider getJavaToolchainProvider(RuleContext ruleContext) {
    return getJavaToolchainProvider(ruleContext, DEFAULT_ATTRIBUTES_SUFFIX);
  }

  /**
   * Returns the instrumentation jar in the given semantics.
   */
  public static Iterable<Artifact> getInstrumentationJars(
      RuleContext ruleContext, String implicitAttributesSuffix) {
    TransitiveInfoCollection instrumentationTarget = ruleContext.getPrerequisite(
        "$jacoco_instrumentation" + implicitAttributesSuffix, Mode.HOST);
    if (instrumentationTarget == null) {
      return ImmutableList.<Artifact>of();
    }
    return FileType.filter(
        instrumentationTarget.getProvider(FileProvider.class).getFilesToBuild(),
        JavaSemantics.JAR);
  }

  public static Iterable<Artifact> getInstrumentationJars(RuleContext ruleContext) {
    return getInstrumentationJars(ruleContext, DEFAULT_ATTRIBUTES_SUFFIX);
  }

  /**
   * Returns the javac bootclasspath artifacts from the given toolchain (if it has any) or the rule.
   */
  public static ImmutableList<Artifact> getBootClasspath(JavaToolchainProvider javaToolchain) {
    return ImmutableList.copyOf(javaToolchain.getBootclasspath());
  }

  private ImmutableList<Artifact> getBootClasspath() {
    return ImmutableList.copyOf(javaToolchain.getBootclasspath());
  }

  /**
   * Returns the extdir artifacts.
   */
  private final ImmutableList<Artifact> getExtdirInputs() {
    return ImmutableList.copyOf(javaToolchain.getExtclasspath());
  }

  /**
   * Creates the Action that creates ijars from Jar files.
   *
   * @param inputJar the Jar to create the ijar for
   * @param addPrefix whether to prefix the path of the generated ijar with the package and
   *     name of the current rule
   * @return the Artifact to create with the Action
   */
  protected static Artifact createIjarAction(
      RuleContext ruleContext,
      JavaToolchainProvider javaToolchain,
      Artifact inputJar, boolean addPrefix) {
    Artifact interfaceJar = getIjarArtifact(ruleContext, inputJar, addPrefix);
    FilesToRunProvider ijarTarget = javaToolchain.getIjar();
    if (!ruleContext.hasErrors()) {
      ruleContext.registerAction(
          new SpawnAction.Builder()
              .addInput(inputJar)
              .addOutput(interfaceJar)
              .setExecutable(ijarTarget)
              // On Windows, ijar.exe needs msys-2.0.dll and zlib1.dll in PATH.
              // Use default shell environment so that those can be found.
              // TODO(dslomov): revisit this. If ijar is not msys-dependent, this is not needed.
              .useDefaultShellEnvironment()
              .setProgressMessage("Extracting interface %s", ruleContext.getLabel())
              .setMnemonic("JavaIjar")
              .addCommandLine(
                  CustomCommandLine.builder()
                      .addExecPath(inputJar)
                      .addExecPath(interfaceJar)
                      .build())
              .build(ruleContext));
    }
    return interfaceJar;
  }

  private static Artifact getIjarArtifact(
      RuleContext ruleContext, Artifact jar, boolean addPrefix) {
    if (addPrefix) {
      PathFragment ruleBase = ruleContext.getUniqueDirectory("_ijar");
      PathFragment artifactDirFragment = jar.getRootRelativePath().getParentDirectory();
      String ijarBasename = FileSystemUtils.removeExtension(jar.getFilename()) + "-ijar.jar";
      return ruleContext.getDerivedArtifact(
          ruleBase.getRelative(artifactDirFragment).getRelative(ijarBasename),
          ruleContext.getConfiguration().getGenfilesDirectory(
              ruleContext.getRule().getRepository()));
    } else {
      return derivedArtifact(ruleContext, jar, "", "-ijar.jar");
    }
  }

  /**
   * Creates a derived artifact from the given artifact by adding the given
   * prefix and removing the extension and replacing it by the given suffix.
   * The new artifact will have the same root as the given one.
   */
  static Artifact derivedArtifact(
      RuleContext ruleContext, Artifact artifact, String prefix, String suffix) {
    PathFragment path = artifact.getRootRelativePath();
    String basename = FileSystemUtils.removeExtension(path.getBaseName()) + suffix;
    path = path.replaceName(prefix + basename);
    return ruleContext.getDerivedArtifact(path, artifact.getRoot());
  }
}