Add Global ThinLTO option (2nd try)
Instead of making everything into ThinLTO variant by default (it works
but many Soong tests don't like this, and got bit rot due to lack of
active builder for this configuration), let the default option be
ThinLTO and no LTO be a special variant.
Test: m GLOBAL_THINLTO=true
Test: m
Bug: 195134194
Change-Id: I2fd98061ba55eba1fdfdd056fb2f8c2051fd2553
diff --git a/cc/lto.go b/cc/lto.go
index d9a0118..6d55579 100644
--- a/cc/lto.go
+++ b/cc/lto.go
@@ -49,8 +49,9 @@
// Dep properties indicate that this module needs to be built with LTO
// since it is an object dependency of an LTO module.
- FullDep bool `blueprint:"mutated"`
- ThinDep bool `blueprint:"mutated"`
+ 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) 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 @@
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 @@
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 @@
}
}
- 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 @@
// 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 @@
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 @@
// 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
}
}
}