Refactor cc/sabi.go

* Rename `vndk_deps` mutator to `sabi_deps` to better reflect its
  purpose.
* Eliminate duplication of ABI dump generation logic. sabiDepsMutator
  should call libraryDecorator.shouldCreateSourceAbiDump() to determine
  if a module needs to be marked with CreateSAbiDumps.
* Non-VNDK libraries that are opt-in to ABI check would have their
  dependencies correctly marked with CreateSAbiDumps.
* Refactor some lines to idiomatic syntax.
* Add comment strings.

Bug: 145608479
Bug: 173492236
Test: TH presubmit
Change-Id: I99e97787bdf2a4f0c970809161b64aa668ff3d1a

cc/cc.go

@@ -79,7 +79,6 @@ func RegisterCCBuildComponents(ctx android.RegistrationContext) {
 		ctx.BottomUp("sanitize_runtime", sanitizerRuntimeMutator).Parallel()
 
 		ctx.BottomUp("coverage", coverageMutator).Parallel()
-		ctx.TopDown("vndk_deps", sabiDepsMutator)
 
 		ctx.TopDown("lto_deps", ltoDepsMutator)
 		ctx.BottomUp("lto", ltoMutator).Parallel()
@@ -88,6 +87,11 @@ func RegisterCCBuildComponents(ctx android.RegistrationContext) {
 		ctx.TopDown("double_loadable", checkDoubleLoadableLibraries).Parallel()
 	})
 
+	ctx.FinalDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		// sabi mutator needs to be run after apex mutator finishes.
+		ctx.TopDown("sabi_deps", sabiDepsMutator)
+	})
+
 	ctx.RegisterSingletonType("kythe_extract_all", kytheExtractAllFactory)
 }
 

cc/config/clang.go

@@ -249,6 +249,10 @@ func ClangFilterUnknownLldflags(lldflags []string) []string {
 	return result
 }
 
+func ClangLibToolingFilterUnknownCflags(libToolingFlags []string) []string {
+	return android.RemoveListFromList(libToolingFlags, ClangLibToolingUnknownCflags)
+}
+
 func inListSorted(s string, list []string) bool {
 	for _, l := range list {
 		if s == l {

cc/library.go

@@ -596,7 +596,7 @@ func (library *libraryDecorator) compilerFlags(ctx ModuleContext, flags Flags, d
 
 // Returns a string that represents the class of the ABI dump.
 // Returns an empty string if ABI check is disabled for this library.
-func (library *libraryDecorator) classifySourceAbiDump(ctx ModuleContext) string {
+func (library *libraryDecorator) classifySourceAbiDump(ctx BaseModuleContext) string {
 	enabled := library.Properties.Header_abi_checker.Enabled
 	if enabled != nil && !Bool(enabled) {
 		return ""
@@ -629,7 +629,7 @@ func (library *libraryDecorator) classifySourceAbiDump(ctx ModuleContext) string
 	return ""
 }
 
-func (library *libraryDecorator) shouldCreateSourceAbiDump(ctx ModuleContext) bool {
+func (library *libraryDecorator) shouldCreateSourceAbiDump(ctx BaseModuleContext) bool {
 	if !ctx.shouldCreateSourceAbiDump() {
 		return false
 	}

cc/sabi.go

@@ -15,7 +15,6 @@
 package cc
 
 import (
-	"strings"
 	"sync"
 
 	"android/soong/android"
@@ -24,11 +23,15 @@ import (
 
 var (
 	lsdumpPaths     []string
-	sabiLock    sync.Mutex
+	lsdumpPathsLock sync.Mutex
 )
 
 type SAbiProperties struct {
+	// True if need to generate ABI dump.
 	CreateSAbiDumps bool `blueprint:"mutated"`
+
+	// Include directories that may contain ABI information exported by a library.
+	// These directories are passed to the header-abi-dumper.
 	ReexportedIncludes []string `blueprint:"mutated"`
 }
 
@@ -46,56 +49,55 @@ func (sabimod *sabi) deps(ctx BaseModuleContext, deps Deps) Deps {
 	return deps
 }
 
-func inListWithPrefixSearch(flag string, filter []string) bool {
-	// Assuming the filter is small enough.
-	// If the suffix of a filter element is *, try matching prefixes as well.
-	for _, f := range filter {
-		if (f == flag) || (strings.HasSuffix(f, "*") && strings.HasPrefix(flag, strings.TrimSuffix(f, "*"))) {
-			return true
-		}
-	}
-	return false
-}
-
-func filterOutWithPrefix(list []string, filter []string) (remainder []string) {
-	// Go through the filter, matching and optionally doing a prefix search for list elements.
-	for _, l := range list {
-		if !inListWithPrefixSearch(l, filter) {
-			remainder = append(remainder, l)
-		}
-	}
-	return
-}
-
 func (sabimod *sabi) flags(ctx ModuleContext, flags Flags) Flags {
-	// Assuming that the cflags which clang LibTooling tools cannot
+	// Filter out flags which libTooling don't understand.
-	// understand have not been converted to ninja variables yet.
+	// This is here for legacy reasons and future-proof, in case the version of libTooling and clang
-	flags.Local.ToolingCFlags = filterOutWithPrefix(flags.Local.CFlags, config.ClangLibToolingUnknownCflags)
+	// diverge.
-	flags.Global.ToolingCFlags = filterOutWithPrefix(flags.Global.CFlags, config.ClangLibToolingUnknownCflags)
+	flags.Local.ToolingCFlags = config.ClangLibToolingFilterUnknownCflags(flags.Local.CFlags)
-	flags.Local.ToolingCppFlags = filterOutWithPrefix(flags.Local.CppFlags, config.ClangLibToolingUnknownCflags)
+	flags.Global.ToolingCFlags = config.ClangLibToolingFilterUnknownCflags(flags.Global.CFlags)
-	flags.Global.ToolingCppFlags = filterOutWithPrefix(flags.Global.CppFlags, config.ClangLibToolingUnknownCflags)
+	flags.Local.ToolingCppFlags = config.ClangLibToolingFilterUnknownCflags(flags.Local.CppFlags)
-
+	flags.Global.ToolingCppFlags = config.ClangLibToolingFilterUnknownCflags(flags.Global.CppFlags)
 	return flags
 }
 
+func shouldSkipSabiDepsMutator(mctx android.TopDownMutatorContext, m *Module) bool {
+	if m.sabi != nil && m.sabi.Properties.CreateSAbiDumps {
+		return false
+	}
+	if library, ok := m.linker.(*libraryDecorator); ok {
+		ctx := &baseModuleContext{
+			BaseModuleContext: mctx,
+			moduleContextImpl: moduleContextImpl{
+				mod: m,
+			},
+		}
+		ctx.ctx = ctx
+		return !library.shouldCreateSourceAbiDump(ctx)
+	}
+	return true
+}
+
+// Mark the direct and transitive dependencies of libraries that need ABI check, so that ABI dumps
+// of their dependencies would be generated.
 func sabiDepsMutator(mctx android.TopDownMutatorContext) {
-	if c, ok := mctx.Module().(*Module); ok &&
+	if c, ok := mctx.Module().(*Module); ok {
-		((c.IsVndk() && c.UseVndk()) || c.isLlndk(mctx.Config()) ||
+		if shouldSkipSabiDepsMutator(mctx, c) {
-			(c.sabi != nil && c.sabi.Properties.CreateSAbiDumps)) {
-		mctx.VisitDirectDeps(func(m android.Module) {
-			if tag, ok := mctx.OtherModuleDependencyTag(m).(libraryDependencyTag); ok && tag.static() {
-				cc, _ := m.(*Module)
-				if cc == nil {
 			return
 		}
+		mctx.VisitDirectDeps(func(m android.Module) {
+			if tag, ok := mctx.OtherModuleDependencyTag(m).(libraryDependencyTag); ok && tag.static() {
+				if cc, ok := m.(*Module); ok {
 					cc.sabi.Properties.CreateSAbiDumps = true
 				}
+			}
 		})
 	}
 }
 
+// Add an entry to the global list of lsdump. The list is exported to a Make variable by
+// `cc.makeVarsProvider`.
 func addLsdumpPath(lsdumpPath string) {
-	sabiLock.Lock()
+	lsdumpPathsLock.Lock()
+	defer lsdumpPathsLock.Unlock()
 	lsdumpPaths = append(lsdumpPaths, lsdumpPath)
-	sabiLock.Unlock()
 }