Merge changes from topic "kotlin_kythe" into main

* changes:
  Add kotlin kzips to build_kzip.bash
  Create .kzip files for kotlin translation units
diff --git a/build_kzip.bash b/build_kzip.bash
index 4c42048..850aeda 100755
--- a/build_kzip.bash
+++ b/build_kzip.bash
@@ -40,6 +40,7 @@
   merge_zips
   xref_cxx
   xref_java
+  xref_kotlin
   # TODO: b/286390153 - reenable rust
   # xref_rust
 )
diff --git a/java/base.go b/java/base.go
index ef299b2..ff7e068 100644
--- a/java/base.go
+++ b/java/base.go
@@ -535,7 +535,8 @@
 	linter
 
 	// list of the xref extraction files
-	kytheFiles android.Paths
+	kytheFiles       android.Paths
+	kytheKotlinFiles android.Paths
 
 	hideApexVariantFromMake bool
 
@@ -1370,7 +1371,7 @@
 
 		kotlinJar := android.PathForModuleOut(ctx, "kotlin", jarName)
 		kotlinHeaderJar := android.PathForModuleOut(ctx, "kotlin_headers", jarName)
-		kotlinCompile(ctx, kotlinJar, kotlinHeaderJar, uniqueSrcFiles, kotlinCommonSrcFiles, srcJars, flags)
+		j.kotlinCompile(ctx, kotlinJar, kotlinHeaderJar, uniqueSrcFiles, kotlinCommonSrcFiles, srcJars, flags)
 		if ctx.Failed() {
 			return
 		}
diff --git a/java/config/config.go b/java/config/config.go
index c28e070..4c1c723 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -145,6 +145,7 @@
 	pctx.SourcePathVariable("JmodCmd", "${JavaToolchain}/jmod")
 	pctx.SourcePathVariable("JrtFsJar", "${JavaHome}/lib/jrt-fs.jar")
 	pctx.SourcePathVariable("JavaKytheExtractorJar", "prebuilts/build-tools/common/framework/javac_extractor.jar")
+	pctx.SourcePathVariable("KotlinKytheExtractor", "prebuilts/build-tools/${hostPrebuiltTag}/bin/kotlinc_extractor")
 	pctx.SourcePathVariable("Ziptime", "prebuilts/build-tools/${hostPrebuiltTag}/bin/ziptime")
 
 	pctx.SourcePathVariable("ResourceProcessorBusyBox", "prebuilts/bazel/common/android_tools/android_tools/all_android_tools_deploy.jar")
diff --git a/java/java.go b/java/java.go
index 95f4fd8..cdd48d7 100644
--- a/java/java.go
+++ b/java/java.go
@@ -356,12 +356,17 @@
 // TODO(jungjw): Move this to kythe.go once it's created.
 type xref interface {
 	XrefJavaFiles() android.Paths
+	XrefKotlinFiles() android.Paths
 }
 
 func (j *Module) XrefJavaFiles() android.Paths {
 	return j.kytheFiles
 }
 
+func (j *Module) XrefKotlinFiles() android.Paths {
+	return j.kytheKotlinFiles
+}
+
 func (d dependencyTag) PropagateAconfigValidation() bool {
 	return d.static
 }
@@ -3304,15 +3309,20 @@
 
 func (ks *kytheExtractJavaSingleton) GenerateBuildActions(ctx android.SingletonContext) {
 	var xrefTargets android.Paths
+	var xrefKotlinTargets android.Paths
 	ctx.VisitAllModules(func(module android.Module) {
 		if javaModule, ok := module.(xref); ok {
 			xrefTargets = append(xrefTargets, javaModule.XrefJavaFiles()...)
+			xrefKotlinTargets = append(xrefKotlinTargets, javaModule.XrefKotlinFiles()...)
 		}
 	})
 	// TODO(asmundak): perhaps emit a rule to output a warning if there were no xrefTargets
 	if len(xrefTargets) > 0 {
 		ctx.Phony("xref_java", xrefTargets...)
 	}
+	if len(xrefKotlinTargets) > 0 {
+		ctx.Phony("xref_kotlin", xrefKotlinTargets...)
+	}
 }
 
 var Bool = proptools.Bool
diff --git a/java/kotlin.go b/java/kotlin.go
index c28bc3f..79781a0 100644
--- a/java/kotlin.go
+++ b/java/kotlin.go
@@ -64,6 +64,29 @@
 	"kotlincFlags", "classpath", "srcJars", "commonSrcFilesArg", "srcJarDir", "classesDir",
 	"headerClassesDir", "headerJar", "kotlinJvmTarget", "kotlinBuildFile", "emptyDir", "name")
 
+var kotlinKytheExtract = pctx.AndroidStaticRule("kotlinKythe",
+	// TODO (b/265428637): To prevent kotlinc version skew between android builds and internal kotlin indexers (g3), consider embedding the kotlinc used by android into the kzip file.
+	// This has an impact on .kzip sizes, so defer that for now.
+	blueprint.RuleParams{
+		Command: `rm -rf "$srcJarDir" && mkdir -p "$srcJarDir" && ` +
+			`${config.ZipSyncCmd} -d $srcJarDir -l $srcJarDir/list -f "*.java" -f "*.kt" $srcJars && ` +
+			`${config.KotlinKytheExtractor} -corpus ${kytheCorpus} --srcs @$out.rsp --srcs @"$srcJarDir/list" $commonSrcFilesList --cp @$classpath -o $out --kotlin_out $outJar ` +
+			// wrap the additional kotlin args.
+			// Skip Xbuild file, pass the cp explicitly.
+			// Skip header jars, those should not have an effect on kythe results.
+			` --args '${config.KotlincGlobalFlags} ` +
+			` ${config.KotlincSuppressJDK9Warnings} ${config.JavacHeapFlags} ` +
+			` $kotlincFlags -jvm-target $kotlinJvmTarget'`,
+		CommandDeps: []string{
+			"${config.KotlinKytheExtractor}",
+			"${config.ZipSyncCmd}",
+		},
+		Rspfile:        "$out.rsp",
+		RspfileContent: "$in",
+	},
+	"classpath", "kotlincFlags", "commonSrcFilesList", "kotlinJvmTarget", "outJar", "srcJars", "srcJarDir",
+)
+
 func kotlinCommonSrcsList(ctx android.ModuleContext, commonSrcFiles android.Paths) android.OptionalPath {
 	if len(commonSrcFiles) > 0 {
 		// The list of common_srcs may be too long to put on the command line, but
@@ -81,7 +104,7 @@
 }
 
 // kotlinCompile takes .java and .kt sources and srcJars, and compiles the .kt sources into a classes jar in outputFile.
-func kotlinCompile(ctx android.ModuleContext, outputFile, headerOutputFile android.WritablePath,
+func (j *Module) kotlinCompile(ctx android.ModuleContext, outputFile, headerOutputFile android.WritablePath,
 	srcFiles, commonSrcFiles, srcJars android.Paths,
 	flags javaBuilderFlags) {
 
@@ -127,6 +150,31 @@
 			"name":              kotlinName,
 		},
 	})
+
+	// Emit kythe xref rule
+	if (ctx.Config().EmitXrefRules()) && ctx.Module() == ctx.PrimaryModule() {
+		extractionFile := outputFile.ReplaceExtension(ctx, "kzip")
+		args := map[string]string{
+			"classpath":       classpathRspFile.String(),
+			"kotlincFlags":    flags.kotlincFlags,
+			"kotlinJvmTarget": flags.javaVersion.StringForKotlinc(),
+			"outJar":          outputFile.String(),
+			"srcJars":         strings.Join(srcJars.Strings(), " "),
+			"srcJarDir":       android.PathForModuleOut(ctx, "kotlinc", "srcJars.xref").String(),
+		}
+		if commonSrcsList.Valid() {
+			args["commonSrcFilesList"] = "--srcs @" + commonSrcsList.String()
+		}
+		ctx.Build(pctx, android.BuildParams{
+			Rule:        kotlinKytheExtract,
+			Description: "kotlinKythe",
+			Output:      extractionFile,
+			Inputs:      srcFiles,
+			Implicits:   deps,
+			Args:        args,
+		})
+		j.kytheKotlinFiles = append(j.kytheKotlinFiles, extractionFile)
+	}
 }
 
 var kaptStubs = pctx.AndroidRemoteStaticRule("kaptStubs", android.RemoteRuleSupports{Goma: true},