Add soong support for resource shrinking

This adds a new flag to the optimize section to allow invoking the resource shrinker

Bug: 246217952
Test: m
Change-Id: I2e7851af1189db2a6adf6f9f9f444a1d7f3a8d60

7 files changed, 64 insertions, 11 deletions

diff --git a/java/Android.bp b/java/Android.bp
index 9df4ab4de..8510e045c 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -64,6 +64,7 @@ bootstrap_go_package {
         "plugin.go",
         "prebuilt_apis.go",
         "proto.go",
+        "resourceshrinker.go",
         "robolectric.go",
         "rro.go",
         "sdk.go",
diff --git a/java/aapt2.go b/java/aapt2.go
index 5346ddf89..7845a0b23 100644
--- a/java/aapt2.go
+++ b/java/aapt2.go
@@ -256,17 +256,21 @@ func aapt2Link(ctx android.ModuleContext,
 
 var aapt2ConvertRule = pctx.AndroidStaticRule("aapt2Convert",
 	blueprint.RuleParams{
-		Command:     `${config.Aapt2Cmd} convert --output-format proto $in -o $out`,
+		Command:     `${config.Aapt2Cmd} convert --output-format $format $in -o $out`,
 		CommandDeps: []string{"${config.Aapt2Cmd}"},
-	})
+	}, "format",
+)
 
 // Converts xml files and resource tables (resources.arsc) in the given jar/apk file to a proto
 // format. The proto definition is available at frameworks/base/tools/aapt2/Resources.proto.
-func aapt2Convert(ctx android.ModuleContext, out android.WritablePath, in android.Path) {
+func aapt2Convert(ctx android.ModuleContext, out android.WritablePath, in android.Path, format string) {
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        aapt2ConvertRule,
 		Input:       in,
 		Output:      out,
-		Description: "convert to proto",
+		Description: "convert to " + format,
+		Args: map[string]string{
+			"format": format,
+		},
 	})
 }
diff --git a/java/app.go b/java/app.go
index bccd37fa0..9f6b7d847 100755
--- a/java/app.go
+++ b/java/app.go
@@ -667,10 +667,9 @@ func (a *AndroidApp) generateAndroidBuildActions(ctx android.ModuleContext) {
 	if lineage := String(a.overridableAppProperties.Lineage); lineage != "" {
 		lineageFile = android.PathForModuleSrc(ctx, lineage)
 	}
-
 	rotationMinSdkVersion := String(a.overridableAppProperties.RotationMinSdkVersion)
 
-	CreateAndSignAppPackage(ctx, packageFile, a.exportPackage, jniJarFile, dexJarFile, certificates, apkDeps, v4SignatureFile, lineageFile, rotationMinSdkVersion)
+	CreateAndSignAppPackage(ctx, packageFile, a.exportPackage, jniJarFile, dexJarFile, certificates, apkDeps, v4SignatureFile, lineageFile, rotationMinSdkVersion, Bool(a.dexProperties.Optimize.Shrink_resources))
 	a.outputFile = packageFile
 	if v4SigningRequested {
 		a.extraOutputFiles = append(a.extraOutputFiles, v4SignatureFile)
@@ -699,7 +698,7 @@ func (a *AndroidApp) generateAndroidBuildActions(ctx android.ModuleContext) {
 		if v4SigningRequested {
 			v4SignatureFile = android.PathForModuleOut(ctx, a.installApkName+"_"+split.suffix+".apk.idsig")
 		}
-		CreateAndSignAppPackage(ctx, packageFile, split.path, nil, nil, certificates, apkDeps, v4SignatureFile, lineageFile, rotationMinSdkVersion)
+		CreateAndSignAppPackage(ctx, packageFile, split.path, nil, nil, certificates, apkDeps, v4SignatureFile, lineageFile, rotationMinSdkVersion, false)
 		a.extraOutputFiles = append(a.extraOutputFiles, packageFile)
 		if v4SigningRequested {
 			a.extraOutputFiles = append(a.extraOutputFiles, v4SignatureFile)
diff --git a/java/app_builder.go b/java/app_builder.go
index 18a975181..d20a6bfe4 100644
--- a/java/app_builder.go
+++ b/java/app_builder.go
@@ -52,7 +52,7 @@ var combineApk = pctx.AndroidStaticRule("combineApk",
 	})
 
 func CreateAndSignAppPackage(ctx android.ModuleContext, outputFile android.WritablePath,
-	packageFile, jniJarFile, dexJarFile android.Path, certificates []Certificate, deps android.Paths, v4SignatureFile android.WritablePath, lineageFile android.Path, rotationMinSdkVersion string) {
+	packageFile, jniJarFile, dexJarFile android.Path, certificates []Certificate, deps android.Paths, v4SignatureFile android.WritablePath, lineageFile android.Path, rotationMinSdkVersion string, shrinkResources bool) {
 
 	unsignedApkName := strings.TrimSuffix(outputFile.Base(), ".apk") + "-unsigned.apk"
 	unsignedApk := android.PathForModuleOut(ctx, unsignedApkName)
@@ -65,7 +65,6 @@ func CreateAndSignAppPackage(ctx android.ModuleContext, outputFile android.Writa
 	if jniJarFile != nil {
 		inputs = append(inputs, jniJarFile)
 	}
-
 	ctx.Build(pctx, android.BuildParams{
 		Rule:      combineApk,
 		Inputs:    inputs,
@@ -73,6 +72,11 @@ func CreateAndSignAppPackage(ctx android.ModuleContext, outputFile android.Writa
 		Implicits: deps,
 	})
 
+	if shrinkResources {
+		shrunkenApk := android.PathForModuleOut(ctx, "resource-shrunken", unsignedApk.Base())
+		ShrinkResources(ctx, unsignedApk, shrunkenApk)
+		unsignedApk = shrunkenApk
+	}
 	SignAppPackage(ctx, outputFile, unsignedApk, certificates, v4SignatureFile, lineageFile, rotationMinSdkVersion)
 }
 
@@ -84,7 +88,6 @@ func SignAppPackage(ctx android.ModuleContext, signedApk android.WritablePath, u
 		certificateArgs = append(certificateArgs, c.Pem.String(), c.Key.String())
 		deps = append(deps, c.Pem, c.Key)
 	}
-
 	outputFiles := android.WritablePaths{signedApk}
 	var flags []string
 	if v4SignatureFile != nil {
@@ -182,7 +185,7 @@ func BuildBundleModule(ctx android.ModuleContext, outputFile android.WritablePat
 	packageFile, jniJarFile, dexJarFile android.Path) {
 
 	protoResJarFile := android.PathForModuleOut(ctx, "package-res.pb.apk")
-	aapt2Convert(ctx, protoResJarFile, packageFile)
+	aapt2Convert(ctx, protoResJarFile, packageFile, "proto")
 
 	var zips android.Paths
 
diff --git a/java/config/config.go b/java/config/config.go
index b026d73cf..5cc4e51b1 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -165,6 +165,7 @@ func init() {
 	pctx.HostBinToolVariable("ApiCheckCmd", "apicheck")
 	pctx.HostBinToolVariable("D8Cmd", "d8")
 	pctx.HostBinToolVariable("R8Cmd", "r8")
+	pctx.HostBinToolVariable("ResourceShrinkerCmd", "resourceshrinker")
 	pctx.HostBinToolVariable("HiddenAPICmd", "hiddenapi")
 	pctx.HostBinToolVariable("ExtractApksCmd", "extract_apks")
 	pctx.VariableFunc("TurbineJar", func(ctx android.PackageVarContext) string {
diff --git a/java/dex.go b/java/dex.go
index a44d7921f..f5969a5db 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -63,6 +63,8 @@ type DexProperties struct {
 		// classes referenced by the app manifest.  Defaults to false.
 		No_aapt_flags *bool
 
+		Shrink_resources *bool
+
 		// Flags to pass to proguard.
 		Proguard_flags []string
 
diff --git a/java/resourceshrinker.go b/java/resourceshrinker.go
new file mode 100644
index 000000000..6d5960157
--- /dev/null
+++ b/java/resourceshrinker.go
@@ -0,0 +1,43 @@
+// Copyright 2022 Google Inc. 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 java
+
+import (
+	"android/soong/android"
+
+	"github.com/google/blueprint"
+)
+
+var shrinkResources = pctx.AndroidStaticRule("shrinkResources",
+	blueprint.RuleParams{
+		Command:     `${config.ResourceShrinkerCmd} --output $out --input $in --raw_resources $raw_resources`,
+		CommandDeps: []string{"${config.ResourceShrinkerCmd}"},
+	}, "raw_resources")
+
+func ShrinkResources(ctx android.ModuleContext, apk android.Path, outputFile android.WritablePath) {
+	protoFile := android.PathForModuleOut(ctx, apk.Base()+".proto.apk")
+	aapt2Convert(ctx, protoFile, apk, "proto")
+	strictModeFile := android.PathForSource(ctx, "prebuilts/cmdline-tools/shrinker.xml")
+	protoOut := android.PathForModuleOut(ctx, apk.Base()+".proto.out.apk")
+	ctx.Build(pctx, android.BuildParams{
+		Rule:   shrinkResources,
+		Input:  protoFile,
+		Output: protoOut,
+		Args: map[string]string{
+			"raw_resources": strictModeFile.String(),
+		},
+	})
+	aapt2Convert(ctx, outputFile, protoOut, "binary")
+}