Add Global ThinLTO option (2nd try) am: 8ea56f9da9 am: 370a0be4b8 am: 2d2452c88e am: 2168e3ba48 (ead0d42f) · Commits · e / os / android_build_soong

cc/lto.go

+53 −36

Original line number	Diff line number	Diff line
		@@ -51,6 +51,7 @@ type LTOProperties struct {
		// since it is an object dependency of an LTO module.
		FullDep bool `blueprint:"mutated"`
		ThinDep bool `blueprint:"mutated"`
		NoLtoDep bool `blueprint:"mutated"`

		// Use clang lld instead of gnu ld.
		Use_clang_lld *bool
		@@ -70,15 +71,6 @@ func (lto *lto) props() []interface{} {
		func (lto *lto) begin(ctx BaseModuleContext) {
		if ctx.Config().IsEnvTrue("DISABLE_LTO") {
		lto.Properties.Lto.Never = proptools.BoolPtr(true)
		} else if ctx.Config().IsEnvTrue("GLOBAL_THINLTO") {
		staticLib := ctx.static() && !ctx.staticBinary()
		hostBin := ctx.Host()
		vndk := ctx.isVndk() // b/169217596
		if !staticLib && !hostBin && !vndk {
		if !lto.Never() && !lto.FullLTO() {
		lto.Properties.Lto.Thin = proptools.BoolPtr(true)
		}
		}
		}
		}

		@@ -96,22 +88,27 @@ func (lto *lto) flags(ctx BaseModuleContext, flags Flags) Flags {
		return flags
		}

		if lto.LTO() {
		var ltoFlag string
		if lto.LTO(ctx) {
		var ltoCFlag string
		var ltoLdFlag string
		if lto.ThinLTO() {
		ltoFlag = "-flto=thin -fsplit-lto-unit"
		ltoCFlag = "-flto=thin -fsplit-lto-unit"
		} else if lto.FullLTO() {
		ltoCFlag = "-flto"
		} else {
		ltoFlag = "-flto"
		ltoCFlag = "-flto=thin -fsplit-lto-unit"
		ltoLdFlag = "-Wl,--lto-O0"
		}

		flags.Local.CFlags = append(flags.Local.CFlags, ltoFlag)
		flags.Local.LdFlags = append(flags.Local.LdFlags, ltoFlag)
		flags.Local.CFlags = append(flags.Local.CFlags, ltoCFlag)
		flags.Local.LdFlags = append(flags.Local.LdFlags, ltoCFlag)
		flags.Local.LdFlags = append(flags.Local.LdFlags, ltoLdFlag)

		if Bool(lto.Properties.Whole_program_vtables) {
		flags.Local.CFlags = append(flags.Local.CFlags, "-fwhole-program-vtables")
		}

		if lto.ThinLTO() && ctx.Config().IsEnvTrue("USE_THINLTO_CACHE") && lto.useClangLld(ctx) {
		if (lto.DefaultThinLTO(ctx) \|\| lto.ThinLTO()) && ctx.Config().IsEnvTrue("USE_THINLTO_CACHE") && lto.useClangLld(ctx) {
		// Set appropriate ThinLTO cache policy
		cacheDirFormat := "-Wl,--thinlto-cache-dir="
		cacheDir := android.PathForOutput(ctx, "thinlto-cache").String()
		@@ -134,33 +131,40 @@ func (lto *lto) flags(ctx BaseModuleContext, flags Flags) Flags {
		return flags
		}

		// Can be called with a null receiver
		func (lto *lto) LTO() bool {
		if lto == nil \|\| lto.Never() {
		return false
		func (lto *lto) LTO(ctx BaseModuleContext) bool {
		return lto.ThinLTO() \|\| lto.FullLTO() \|\| lto.DefaultThinLTO(ctx)
		}

		return lto.FullLTO() \|\| lto.ThinLTO()
		func (lto *lto) DefaultThinLTO(ctx BaseModuleContext) bool {
		host := ctx.Host()
		vndk := ctx.isVndk() // b/169217596
		return GlobalThinLTO(ctx) && !lto.Never() && !host && !vndk
		}

		func (lto *lto) FullLTO() bool {
		return Bool(lto.Properties.Lto.Full)
		return lto != nil && Bool(lto.Properties.Lto.Full)
		}

		func (lto *lto) ThinLTO() bool {
		return Bool(lto.Properties.Lto.Thin)
		return lto != nil && Bool(lto.Properties.Lto.Thin)
		}

		// Is lto.never explicitly set to true?
		func (lto *lto) Never() bool {
		return Bool(lto.Properties.Lto.Never)
		return lto != nil && Bool(lto.Properties.Lto.Never)
		}

		func GlobalThinLTO(ctx android.BaseModuleContext) bool {
		return ctx.Config().IsEnvTrue("GLOBAL_THINLTO")
		}

		// Propagate lto requirements down from binaries
		func ltoDepsMutator(mctx android.TopDownMutatorContext) {
		if m, ok := mctx.Module().(*Module); ok && m.lto.LTO() {
		globalThinLTO := GlobalThinLTO(mctx)

		if m, ok := mctx.Module().(*Module); ok {
		full := m.lto.FullLTO()
		thin := m.lto.ThinLTO()
		never := m.lto.Never()
		if full && thin {
		mctx.PropertyErrorf("LTO", "FullLTO and ThinLTO are mutually exclusive")
		}
		@@ -180,14 +184,16 @@ func ltoDepsMutator(mctx android.TopDownMutatorContext) {
		}
		}

		if dep, ok := dep.(*Module); ok && dep.lto != nil &&
		!dep.lto.Never() {
		if dep, ok := dep.(*Module); ok {
		if full && !dep.lto.FullLTO() {
		dep.lto.Properties.FullDep = true
		}
		if thin && !dep.lto.ThinLTO() {
		if !globalThinLTO && thin && !dep.lto.ThinLTO() {
		dep.lto.Properties.ThinDep = true
		}
		if globalThinLTO && never && !dep.lto.Never() {
		dep.lto.Properties.NoLtoDep = true
		}
		}

		// Recursively walk static dependencies
		@@ -198,6 +204,8 @@ func ltoDepsMutator(mctx android.TopDownMutatorContext) {

		// Create lto variants for modules that need them
		func ltoMutator(mctx android.BottomUpMutatorContext) {
		globalThinLTO := GlobalThinLTO(mctx)

		if m, ok := mctx.Module().(*Module); ok && m.lto != nil {
		// Create variations for LTO types required as static
		// dependencies
		@@ -205,18 +213,25 @@ func ltoMutator(mctx android.BottomUpMutatorContext) {
		if m.lto.Properties.FullDep && !m.lto.FullLTO() {
		variationNames = append(variationNames, "lto-full")
		}
		if m.lto.Properties.ThinDep && !m.lto.ThinLTO() {
		if !globalThinLTO && m.lto.Properties.ThinDep && !m.lto.ThinLTO() {
		variationNames = append(variationNames, "lto-thin")
		}
		if globalThinLTO && m.lto.Properties.NoLtoDep && !m.lto.Never() {
		variationNames = append(variationNames, "lto-none")
		}

		// Use correct dependencies if LTO property is explicitly set
		// (mutually exclusive)
		if m.lto.FullLTO() {
		mctx.SetDependencyVariation("lto-full")
		}
		if m.lto.ThinLTO() {
		if !globalThinLTO && m.lto.ThinLTO() {
		mctx.SetDependencyVariation("lto-thin")
		}
		// Never must be the last, it overrides Thin or Full.
		if globalThinLTO && m.lto.Never() {
		mctx.SetDependencyVariation("lto-none")
		}

		if len(variationNames) > 1 {
		modules := mctx.CreateVariations(variationNames...)
		@@ -232,16 +247,18 @@ func ltoMutator(mctx android.BottomUpMutatorContext) {
		// LTO properties for dependencies
		if name == "lto-full" {
		variation.lto.Properties.Lto.Full = proptools.BoolPtr(true)
		variation.lto.Properties.Lto.Thin = proptools.BoolPtr(false)
		}
		if name == "lto-thin" {
		variation.lto.Properties.Lto.Full = proptools.BoolPtr(false)
		variation.lto.Properties.Lto.Thin = proptools.BoolPtr(true)
		}
		if name == "lto-none" {
		variation.lto.Properties.Lto.Never = proptools.BoolPtr(true)
		}
		variation.Properties.PreventInstall = true
		variation.Properties.HideFromMake = true
		variation.lto.Properties.FullDep = false
		variation.lto.Properties.ThinDep = false
		variation.lto.Properties.NoLtoDep = false
		}
		}
		}