Apply PRODUCT_ENFORCE_RRO_TARGETS to dependencies.

With this change, users don't need to figure out which libraries
actually hold the resources to be overlaid when targetting apps with a
core lib dependency (e.g. Settings, SystemUI).

Fixes: 169898727
Test: app_test.go
Change-Id: I3c3b9dc0a377b1828db1199858a73d080a173205
diff --git a/java/aar.go b/java/aar.go
index 9cab0bd..c31fc95 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -34,10 +34,16 @@
 	ExportedStaticPackages() android.Paths
 	ExportedManifests() android.Paths
 	ExportedAssets() android.OptionalPath
+	SetRROEnforcedForDependent(enforce bool)
+	IsRROEnforced(ctx android.BaseModuleContext) bool
 }
 
 func init() {
 	RegisterAARBuildComponents(android.InitRegistrationContext)
+
+	android.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.TopDown("propagate_rro_enforcement", propagateRROEnforcementMutator).Parallel()
+	})
 }
 
 func RegisterAARBuildComponents(ctx android.RegistrationContext) {
@@ -82,6 +88,9 @@
 
 	// do not include AndroidManifest from dependent libraries
 	Dont_merge_manifests *bool
+
+	// true if RRO is enforced for any of the dependent modules
+	RROEnforcedForDependent bool `blueprint:"mutated"`
 }
 
 type aapt struct {
@@ -117,6 +126,18 @@
 	path   android.Path
 }
 
+// Propagate RRO enforcement flag to static lib dependencies transitively.
+func propagateRROEnforcementMutator(ctx android.TopDownMutatorContext) {
+	m := ctx.Module()
+	if d, ok := m.(AndroidLibraryDependency); ok && d.IsRROEnforced(ctx) {
+		ctx.VisitDirectDepsWithTag(staticLibTag, func(d android.Module) {
+			if a, ok := d.(AndroidLibraryDependency); ok {
+				a.SetRROEnforcedForDependent(true)
+			}
+		})
+	}
+}
+
 func (a *aapt) ExportPackage() android.Path {
 	return a.exportPackage
 }
@@ -133,6 +154,17 @@
 	return a.assetPackage
 }
 
+func (a *aapt) SetRROEnforcedForDependent(enforce bool) {
+	a.aaptProperties.RROEnforcedForDependent = enforce
+}
+
+func (a *aapt) IsRROEnforced(ctx android.BaseModuleContext) bool {
+	// True if RRO is enforced for this module or...
+	return ctx.Config().EnforceRROForModule(ctx.ModuleName()) ||
+		// if RRO is enforced for any of its dependents, and this module is not exempted.
+		(a.aaptProperties.RROEnforcedForDependent && !ctx.Config().EnforceRROExemptedForModule(ctx.ModuleName()))
+}
+
 func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkContext sdkContext,
 	manifestPath android.Path) (compileFlags, linkFlags []string, linkDeps android.Paths,
 	resDirs, overlayDirs []globbedResourceDir, rroDirs []rroDir, resZips android.Paths) {
@@ -156,7 +188,7 @@
 			dir:   dir,
 			files: androidResourceGlob(ctx, dir),
 		})
-		resOverlayDirs, resRRODirs := overlayResourceGlob(ctx, dir)
+		resOverlayDirs, resRRODirs := overlayResourceGlob(ctx, a, dir)
 		overlayDirs = append(overlayDirs, resOverlayDirs...)
 		rroDirs = append(rroDirs, resRRODirs...)
 	}
@@ -412,14 +444,16 @@
 					assets = append(assets, aarDep.ExportedAssets().Path())
 				}
 
-			outer:
-				for _, d := range aarDep.ExportedRRODirs() {
-					for _, e := range staticRRODirs {
-						if d.path == e.path {
-							continue outer
+				if !ctx.Config().EnforceRROExemptedForModule(ctx.ModuleName()) {
+				outer:
+					for _, d := range aarDep.ExportedRRODirs() {
+						for _, e := range staticRRODirs {
+							if d.path == e.path {
+								continue outer
+							}
 						}
+						staticRRODirs = append(staticRRODirs, d)
 					}
-					staticRRODirs = append(staticRRODirs, d)
 				}
 			}
 		}
@@ -621,6 +655,17 @@
 	return android.OptionalPath{}
 }
 
+// RRO enforcement is not available on aar_import since its RRO dirs are not
+// exported.
+func (a *AARImport) SetRROEnforcedForDependent(enforce bool) {
+}
+
+// RRO enforcement is not available on aar_import since its RRO dirs are not
+// exported.
+func (a *AARImport) IsRROEnforced(ctx android.BaseModuleContext) bool {
+	return false
+}
+
 func (a *AARImport) Prebuilt() *android.Prebuilt {
 	return &a.prebuilt
 }
diff --git a/java/android_resources.go b/java/android_resources.go
index c2bc746..97f7679 100644
--- a/java/android_resources.go
+++ b/java/android_resources.go
@@ -66,13 +66,13 @@
 	files android.Paths
 }
 
-func overlayResourceGlob(ctx android.ModuleContext, dir android.Path) (res []globbedResourceDir,
+func overlayResourceGlob(ctx android.ModuleContext, a *aapt, dir android.Path) (res []globbedResourceDir,
 	rroDirs []rroDir) {
 
 	overlayData := ctx.Config().Get(overlayDataKey).([]overlayGlobResult)
 
 	// Runtime resource overlays (RRO) may be turned on by the product config for some modules
-	rroEnabled := ctx.Config().EnforceRROForModule(ctx.ModuleName())
+	rroEnabled := a.IsRROEnforced(ctx)
 
 	for _, data := range overlayData {
 		files := data.paths.PathsInDirectory(filepath.Join(data.dir, dir.String()))
diff --git a/java/app_test.go b/java/app_test.go
index 4347db8..b7be189 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -848,19 +848,17 @@
 				"lib": {
 					buildDir + "/.intermediates/lib2/android_common/package-res.apk",
 					"lib/res/res/values/strings.xml",
-					"device/vendor/blah/overlay/lib/res/values/strings.xml",
 				},
 			},
 
 			rroDirs: map[string][]string{
 				"foo": {
 					"device:device/vendor/blah/overlay/foo/res",
-					// Enforce RRO on "foo" could imply RRO on static dependencies, but for now it doesn't.
-					// "device/vendor/blah/overlay/lib/res",
 					"product:product/vendor/blah/overlay/foo/res",
+					"device:device/vendor/blah/overlay/lib/res",
 				},
 				"bar": nil,
-				"lib": nil,
+				"lib": {"device:device/vendor/blah/overlay/lib/res"},
 			},
 		},
 		{
@@ -3401,3 +3399,114 @@
 		checkAapt2LinkFlag(t, aapt2Flags, "rename-overlay-target-package", expected.targetPackageFlag)
 	}
 }
+
+func TestEnforceRRO_propagatesToDependencies(t *testing.T) {
+	testCases := []struct {
+		name                    string
+		enforceRROTargets       []string
+		enforceRROExemptTargets []string
+		rroDirs                 map[string][]string
+	}{
+		{
+			name:                    "no RRO",
+			enforceRROTargets:       nil,
+			enforceRROExemptTargets: nil,
+			rroDirs: map[string][]string{
+				"foo": nil,
+				"bar": nil,
+			},
+		},
+		{
+			name:                    "enforce RRO on all",
+			enforceRROTargets:       []string{"*"},
+			enforceRROExemptTargets: nil,
+			rroDirs: map[string][]string{
+				"foo": {"product/vendor/blah/overlay/lib2/res"},
+				"bar": {"product/vendor/blah/overlay/lib2/res"},
+			},
+		},
+		{
+			name:                    "enforce RRO on foo",
+			enforceRROTargets:       []string{"foo"},
+			enforceRROExemptTargets: nil,
+			rroDirs: map[string][]string{
+				"foo": {"product/vendor/blah/overlay/lib2/res"},
+				"bar": {"product/vendor/blah/overlay/lib2/res"},
+			},
+		},
+		{
+			name:                    "enforce RRO on foo, bar exempted",
+			enforceRROTargets:       []string{"foo"},
+			enforceRROExemptTargets: []string{"bar"},
+			rroDirs: map[string][]string{
+				"foo": {"product/vendor/blah/overlay/lib2/res"},
+				"bar": nil,
+			},
+		},
+	}
+
+	productResourceOverlays := []string{
+		"product/vendor/blah/overlay",
+	}
+
+	fs := map[string][]byte{
+		"lib2/res/values/strings.xml":                             nil,
+		"product/vendor/blah/overlay/lib2/res/values/strings.xml": nil,
+	}
+
+	bp := `
+			android_app {
+				name: "foo",
+				sdk_version: "current",
+				resource_dirs: [],
+				static_libs: ["lib"],
+			}
+
+			android_app {
+				name: "bar",
+				sdk_version: "current",
+				resource_dirs: [],
+				static_libs: ["lib"],
+			}
+
+			android_library {
+				name: "lib",
+				sdk_version: "current",
+				resource_dirs: [],
+				static_libs: ["lib2"],
+			}
+
+			android_library {
+				name: "lib2",
+				sdk_version: "current",
+				resource_dirs: ["lib2/res"],
+			}
+		`
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			config := testAppConfig(nil, bp, fs)
+			config.TestProductVariables.ProductResourceOverlays = productResourceOverlays
+			if testCase.enforceRROTargets != nil {
+				config.TestProductVariables.EnforceRROTargets = testCase.enforceRROTargets
+			}
+			if testCase.enforceRROExemptTargets != nil {
+				config.TestProductVariables.EnforceRROExemptedTargets = testCase.enforceRROExemptTargets
+			}
+
+			ctx := testContext()
+			run(t, ctx, config)
+
+			modules := []string{"foo", "bar"}
+			for _, moduleName := range modules {
+				module := ctx.ModuleForTests(moduleName, "android_common")
+				mkEntries := android.AndroidMkEntriesForTest(t, config, "", module.Module())[0]
+				actualRRODirs := mkEntries.EntryMap["LOCAL_SOONG_PRODUCT_RRO_DIRS"]
+				if !reflect.DeepEqual(actualRRODirs, testCase.rroDirs[moduleName]) {
+					t.Errorf("exected %s LOCAL_SOONG_PRODUCT_RRO_DIRS entry: %v\ngot:%q",
+						moduleName, testCase.rroDirs[moduleName], actualRRODirs)
+				}
+			}
+		})
+	}
+}
diff --git a/java/java_test.go b/java/java_test.go
index f16639a..bb200d3 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -102,6 +102,10 @@
 
 	dexpreopt.RegisterToolModulesForTest(ctx)
 
+	ctx.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.TopDown("propagate_rro_enforcement", propagateRROEnforcementMutator).Parallel()
+	})
+
 	return ctx
 }