Embed NOTICE output as an APEX asset.

Instead of outputting an aggregated NOTICE file as an intermediate build
resource to allow Make to include it in the final system-wide NOTICE,
process and embed it as an asset in the final APEX. This allows us to
update the NOTICE contents automatically when an APEX is updated.

Fixes: 135218846
Test: Built mainline modules, apex_test.go
Change-Id: Ic851b330fe93be1f602907d44ecc7886c3b0171b

apex/apex.go

@@ -394,8 +394,6 @@ type apexBundle struct {
 	container_certificate_file android.Path
 	container_private_key_file android.Path
 
-	mergedNoticeFile android.WritablePath
-
 	// list of files to be included in this apex
 	filesInfo []apexFile
 
@@ -828,8 +826,6 @@ func (a *apexBundle) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.installDir = android.PathForModuleInstall(ctx, "apex")
 	a.filesInfo = filesInfo
 
-	a.buildNoticeFile(ctx)
-
 	if a.apexTypes.zip() {
 		a.buildUnflattenedApex(ctx, zipApex)
 	}
@@ -843,7 +839,7 @@ func (a *apexBundle) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	}
 }
 
-func (a *apexBundle) buildNoticeFile(ctx android.ModuleContext) {
+func (a *apexBundle) buildNoticeFile(ctx android.ModuleContext, apexFileName string) android.OptionalPath {
 	noticeFiles := []android.Path{}
 	for _, f := range a.filesInfo {
 		if f.module != nil {
@@ -858,10 +854,12 @@ func (a *apexBundle) buildNoticeFile(ctx android.ModuleContext) {
 		noticeFiles = append(noticeFiles, a.NoticeFile().Path())
 	}
 
-	if len(noticeFiles) > 0 {
+	if len(noticeFiles) == 0 {
-		a.mergedNoticeFile = android.PathForModuleOut(ctx, "NOTICE")
+		return android.OptionalPath{}
-		android.MergeNotices(ctx, a.mergedNoticeFile, noticeFiles)
 	}
+
+	return android.OptionalPathForPath(
+		android.BuildNoticeOutput(ctx, a.installDir, apexFileName, android.FirstUniquePaths(noticeFiles)))
 }
 
 func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext, apexType apexPackaging) {
@@ -986,6 +984,13 @@ func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext, apexType ap
 		}
 		optFlags = append(optFlags, "--target_sdk_version "+targetSdkVersion)
 
+		noticeFile := a.buildNoticeFile(ctx, ctx.ModuleName()+suffix)
+		if noticeFile.Valid() {
+			// If there's a NOTICE file, embed it as an asset file in the APEX.
+			implicitInputs = append(implicitInputs, noticeFile.Path())
+			optFlags = append(optFlags, "--assets_dir "+filepath.Dir(noticeFile.String()))
+		}
+
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        apexRule,
 			Implicits:   implicitInputs,
@@ -1232,9 +1237,6 @@ func (a *apexBundle) androidMkForType(apexType apexPackaging) android.AndroidMkD
 				fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", filepath.Join("$(OUT_DIR)", a.installDir.RelPathString()))
 				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+apexType.suffix())
 				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
-				if a.installable() && a.mergedNoticeFile != nil {
-					fmt.Fprintln(w, "LOCAL_NOTICE_FILE :=", a.mergedNoticeFile.String())
-				}
 				if len(moduleNames) > 0 {
 					fmt.Fprintln(w, "LOCAL_REQUIRED_MODULES +=", strings.Join(moduleNames, " "))
 				}

apex/apex_test.go

@@ -27,8 +27,11 @@ import (
 	"android/soong/java"
 )
 
+var buildDir string
+
 func testApex(t *testing.T, bp string) *android.TestContext {
-	config, buildDir := setup(t)
+	var config android.Config
+	config, buildDir = setup(t)
 	defer teardown(buildDir)
 
 	ctx := android.NewTestArchContext()
@@ -310,6 +313,8 @@ func TestBasicApex(t *testing.T) {
 
 	optFlags := apexRule.Args["opt_flags"]
 	ensureContains(t, optFlags, "--pubkey vendor/foo/devkeys/testkey.avbpubkey")
+	// Ensure that the NOTICE output is being packaged as an asset.
+	ensureContains(t, optFlags, "--assets_dir "+buildDir+"/.intermediates/myapex/android_common_myapex/NOTICE")
 
 	copyCmds := apexRule.Args["copy_commands"]
 
@@ -349,8 +354,8 @@ func TestBasicApex(t *testing.T) {
 
 	mergeNoticesRule := ctx.ModuleForTests("myapex", "android_common_myapex").Rule("mergeNoticesRule")
 	noticeInputs := mergeNoticesRule.Inputs.Strings()
-	if len(noticeInputs) != 4 {
+	if len(noticeInputs) != 2 {
-		t.Errorf("number of input notice files: expected = 4, actual = %q", len(noticeInputs))
+		t.Errorf("number of input notice files: expected = 2, actual = %q", len(noticeInputs))
 	}
 	ensureListContains(t, noticeInputs, "NOTICE")
 	ensureListContains(t, noticeInputs, "custom_notice")