Merge changes from topic "optimize_for_size" into main

* changes:
  Enable MLGO inliner optimization for optimize_for_size cases
  Add "Optimize_for_size" build property

cc/cc.go

@@ -286,6 +286,11 @@ type BaseProperties struct {
 	// Deprecated. true is the default, false is invalid.
 	Clang *bool `android:"arch_variant"`
 
+	// Aggresively trade performance for smaller binary size.
+	// This should only be used for on-device binaries that are rarely executed and not
+	// performance critical.
+	Optimize_for_size *bool `android:"arch_variant"`
+
 	// The API level that this module is built against. The APIs of this API level will be
 	// visible at build time, but use of any APIs newer than min_sdk_version will render the
 	// module unloadable on older devices.  In the future it will be possible to weakly-link new
@@ -546,6 +551,7 @@ type ModuleContextIntf interface {
 	isCfiAssemblySupportEnabled() bool
 	getSharedFlags() *SharedFlags
 	notInPlatform() bool
+	optimizeForSize() bool
 }
 
 type SharedFlags struct {
@@ -985,6 +991,7 @@ func (c *Module) AddJSONData(d *map[string]interface{}) {
 		"WinMsgSrcs":             hasWinMsg,
 		"YaccSrsc":               hasYacc,
 		"OnlyCSrcs":              !(hasAidl || hasLex || hasProto || hasRenderscript || hasSysprop || hasWinMsg || hasYacc),
+		"OptimizeForSize":        c.OptimizeForSize(),
 	}
 }
 
@@ -1070,6 +1077,10 @@ func (c *Module) StubDecorator() bool {
 	return false
 }
 
+func (c *Module) OptimizeForSize() bool {
+	return Bool(c.Properties.Optimize_for_size)
+}
+
 func (c *Module) SdkVersion() string {
 	return String(c.Properties.Sdk_version)
 }
@@ -1613,6 +1624,10 @@ func (ctx *moduleContextImpl) object() bool {
 	return ctx.mod.Object()
 }
 
+func (ctx *moduleContextImpl) optimizeForSize() bool {
+	return ctx.mod.OptimizeForSize()
+}
+
 func (ctx *moduleContextImpl) canUseSdk() bool {
 	return ctx.mod.canUseSdk()
 }

cc/compiler.go

@@ -693,6 +693,11 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps
 		flags.Local.CFlags = append(flags.Local.CFlags, "-fopenmp")
 	}
 
+	if ctx.optimizeForSize() {
+		flags.Local.CFlags = append(flags.Local.CFlags, "-Oz")
+		flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,-mllvm,-enable-ml-inliner=release")
+	}
+
 	// Exclude directories from manual binder interface allowed list.
 	//TODO(b/145621474): Move this check into IInterface.h when clang-tidy no longer uses absolute paths.
 	if android.HasAnyPrefix(ctx.ModuleDir(), allowedManualInterfacePaths) {

cc/lto.go

@@ -144,7 +144,7 @@ func (lto *lto) flags(ctx ModuleContext, flags Flags) Flags {
 
 		if !ctx.Config().IsEnvFalse("THINLTO_USE_MLGO") {
 			// Register allocation MLGO flags for ARM64.
-			if ctx.Arch().ArchType == android.Arm64 {
+			if ctx.Arch().ArchType == android.Arm64 && !ctx.optimizeForSize() {
 				ltoLdFlags = append(ltoLdFlags, "-Wl,-mllvm,-regalloc-enable-advisor=release")
 			}
 			// Flags for training MLGO model.