Merge "Capture list of unused methods when shrinking in R8"

android/override_module.go

@@ -313,3 +313,15 @@ func replaceDepsOnOverridingModuleMutator(ctx BottomUpMutatorContext) {
 		}
 	}
 }
+
+// ModuleNameWithPossibleOverride returns the name of the OverrideModule that overrides the current
+// variant of this OverridableModule, or ctx.ModuleName() if this module is not an OverridableModule
+// or if this variant is not overridden.
+func ModuleNameWithPossibleOverride(ctx ModuleContext) string {
+	if overridable, ok := ctx.Module().(OverridableModule); ok {
+		if o := overridable.GetOverriddenBy(); o != "" {
+			return o
+		}
+	}
+	return ctx.ModuleName()
+}

java/androidmk.go

@@ -127,9 +127,8 @@ func (library *Library) AndroidMkEntries() []android.AndroidMkEntries {
 						entries.AddStrings("LOCAL_ADDITIONAL_CHECKED_MODULE", library.additionalCheckedModules.Strings()...)
 					}
 
-					if library.dexer.proguardDictionary.Valid() {
+					entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_DICT", library.dexer.proguardDictionary)
-						entries.SetPath("LOCAL_SOONG_PROGUARD_DICT", library.dexer.proguardDictionary.Path())
+					entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_USAGE_ZIP", library.dexer.proguardUsageZip)
-					}
 					entries.SetString("LOCAL_MODULE_STEM", library.Stem())
 
 					entries.SetOptionalPaths("LOCAL_SOONG_LINT_REPORTS", library.linter.reports)
@@ -332,9 +331,8 @@ func (app *AndroidApp) AndroidMkEntries() []android.AndroidMkEntries {
 				if app.jacocoReportClassesFile != nil {
 					entries.SetPath("LOCAL_SOONG_JACOCO_REPORT_CLASSES_JAR", app.jacocoReportClassesFile)
 				}
-				if app.dexer.proguardDictionary.Valid() {
+				entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_DICT", app.dexer.proguardDictionary)
-					entries.SetPath("LOCAL_SOONG_PROGUARD_DICT", app.dexer.proguardDictionary.Path())
+				entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_USAGE_ZIP", app.dexer.proguardUsageZip)
-				}
 
 				if app.Name() == "framework-res" {
 					entries.SetString("LOCAL_MODULE_PATH", "$(TARGET_OUT_JAVA_LIBRARIES)")

java/dex.go

@@ -72,6 +72,7 @@ type dexer struct {
 	// list of extra proguard flag files
 	extraProguardFlagFiles android.Paths
 	proguardDictionary     android.OptionalPath
+	proguardUsageZip       android.OptionalPath
 }
 
 func (d *dexer) effectiveOptimizeEnabled() bool {
@@ -109,13 +110,17 @@ var d8, d8RE = remoteexec.MultiCommandStaticRules(pctx, "d8",
 var r8, r8RE = remoteexec.MultiCommandStaticRules(pctx, "r8",
 	blueprint.RuleParams{
 		Command: `rm -rf "$outDir" && mkdir -p "$outDir" && ` +
-			`rm -f "$outDict" && ` +
+			`rm -f "$outDict" && rm -rf "${outUsageDir}" && ` +
+			`mkdir -p $$(dirname ${outUsage}) && ` +
 			`$r8Template${config.R8Cmd} ${config.DexFlags} -injars $in --output $outDir ` +
 			`--force-proguard-compatibility ` +
 			`--no-data-resources ` +
-			`-printmapping $outDict ` +
+			`-printmapping ${outDict} ` +
+			`-printusage ${outUsage} ` +
 			`$r8Flags && ` +
-			`touch "$outDict" && ` +
+			`touch "${outDict}" "${outUsage}" && ` +
+			`${config.SoongZipCmd} -o ${outUsageZip} -C ${outUsageDir} -f ${outUsage} && ` +
+			`rm -rf ${outUsageDir} && ` +
 			`$zipTemplate${config.SoongZipCmd} $zipFlags -o $outDir/classes.dex.jar -C $outDir -f "$outDir/classes*.dex" && ` +
 			`${config.MergeZipsCmd} -D -stripFile "**/*.class" $out $outDir/classes.dex.jar $in`,
 		CommandDeps: []string{
@@ -138,7 +143,15 @@ var r8, r8RE = remoteexec.MultiCommandStaticRules(pctx, "r8",
 			ExecStrategy: "${config.RER8ExecStrategy}",
 			Platform:     map[string]string{remoteexec.PoolKey: "${config.REJavaPool}"},
 		},
-	}, []string{"outDir", "outDict", "r8Flags", "zipFlags"}, []string{"implicits"})
+		"$zipUsageTemplate": &remoteexec.REParams{
+			Labels:       map[string]string{"type": "tool", "name": "soong_zip"},
+			Inputs:       []string{"${config.SoongZipCmd}", "${outUsage}"},
+			OutputFiles:  []string{"${outUsageZip}"},
+			ExecStrategy: "${config.RER8ExecStrategy}",
+			Platform:     map[string]string{remoteexec.PoolKey: "${config.REJavaPool}"},
+		},
+	}, []string{"outDir", "outDict", "outUsage", "outUsageZip", "outUsageDir",
+		"r8Flags", "zipFlags"}, []string{"implicits"})
 
 func (d *dexer) dexCommonFlags(ctx android.ModuleContext, minSdkVersion sdkSpec) []string {
 	flags := d.dexProperties.Dxflags
@@ -259,12 +272,20 @@ func (d *dexer) compileDex(ctx android.ModuleContext, flags javaBuilderFlags, mi
 	if useR8 {
 		proguardDictionary := android.PathForModuleOut(ctx, "proguard_dictionary")
 		d.proguardDictionary = android.OptionalPathForPath(proguardDictionary)
+		proguardUsageDir := android.PathForModuleOut(ctx, "proguard_usage")
+		proguardUsage := proguardUsageDir.Join(ctx, ctx.Namespace().Path,
+			android.ModuleNameWithPossibleOverride(ctx), "unused.txt")
+		proguardUsageZip := android.PathForModuleOut(ctx, "proguard_usage.zip")
+		d.proguardUsageZip = android.OptionalPathForPath(proguardUsageZip)
 		r8Flags, r8Deps := d.r8Flags(ctx, flags)
 		rule := r8
 		args := map[string]string{
 			"r8Flags":     strings.Join(append(commonFlags, r8Flags...), " "),
 			"zipFlags":    zipFlags,
 			"outDict":     proguardDictionary.String(),
+			"outUsageDir": proguardUsageDir.String(),
+			"outUsage":    proguardUsage.String(),
+			"outUsageZip": proguardUsageZip.String(),
 			"outDir":      outDir.String(),
 		}
 		if ctx.Config().IsEnvTrue("RBE_R8") {
@@ -275,7 +296,7 @@ func (d *dexer) compileDex(ctx android.ModuleContext, flags javaBuilderFlags, mi
 			Rule:            rule,
 			Description:     "r8",
 			Output:          javalibJar,
-			ImplicitOutput: proguardDictionary,
+			ImplicitOutputs: android.WritablePaths{proguardDictionary, proguardUsageZip},
 			Input:           classesJar,
 			Implicits:       r8Deps,
 			Args:            args,