Add experimental flag for collecting code coverage for generated files

Author: Rasrack

src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfigurationValue.java

@@ -565,6 +565,13 @@ public boolean shouldInstrumentTestTargets() {
     return options.instrumentTestTargets;
   }
 
+  /**
+   * Returns a boolean of whether to collect code coverage for generated files or not.
+   */
+  public boolean shouldCollectCodeCoverageForGeneratedFiles() {
+    return options.collectCodeCoverageForGeneratedFiles;
+  }
+
   /**
    * Returns a new, unordered mapping of names to values of "Make" variables defined by this
    * configuration.

src/main/java/com/google/devtools/build/lib/analysis/config/CoreOptions.java

@@ -440,6 +440,14 @@ public ExecConfigurationDistinguisherSchemeConverter() {
               + " not be specified directly - 'bazel coverage' command should be used instead.")
   public boolean collectCodeCoverage;
 
+  @Option(
+          name = "experimental_collect_code_coverage_for_generated_files",
+          defaultValue = "false",
+          documentationCategory = OptionDocumentationCategory.OUTPUT_PARAMETERS,
+          effectTags = {OptionEffectTag.AFFECTS_OUTPUTS},
+          help = "If specified, Bazel will also generate collect coverage information for generated files.")
+  public boolean collectCodeCoverageForGeneratedFiles;
+
   @Option(
       name = "build_runfile_manifests",
       defaultValue = "true",

src/main/java/com/google/devtools/build/lib/analysis/test/InstrumentedFilesCollector.java

@@ -208,7 +208,8 @@ public static InstrumentedFilesInfo collect(
       for (TransitiveInfoCollection dep :
           getPrerequisitesForAttributes(ruleContext, spec.sourceAttributes)) {
         for (Artifact artifact : dep.getProvider(FileProvider.class).getFilesToBuild().toList()) {
-          if (spec.instrumentedFileTypes.matches(artifact.getFilename())) {
+          if (shouldIncludeArtifact(ruleContext.getConfiguration(), artifact) &&
+              spec.instrumentedFileTypes.matches(artifact.getFilename())) {
             localSourcesBuilder.add(artifact);
           }
         }
@@ -256,6 +257,15 @@ public static boolean shouldIncludeLocalSources(
         && config.getInstrumentationFilter().isIncluded(label.toString()));
   }
 
+  /**
+   * Return whether the artifact should be collected based on the origin of the artifact
+   * and the --experimental_collect_code_coverage_for_generated_files config setting.
+   */
+  public static boolean shouldIncludeArtifact(
+          BuildConfigurationValue config, Artifact artifact) {
+    return artifact.isSourceArtifact() || config.shouldCollectCodeCoverageForGeneratedFiles();
+  }
+
   /**
    * The set of file types and attributes to visit to collect instrumented files for a certain rule
    * type. The class is intentionally immutable, so that a single instance is sufficient for all