Merge changes from topic "header_libs_requirement"

* changes:
  Add libstagefright_mp3dec_headers to allowed apex deps
  Require libraries in header_libs to be cc_library_header

apex/allowed_deps.txt

@@ -407,6 +407,7 @@ libstagefright_m4vh263dec(minSdkVersion:29)
 libstagefright_m4vh263enc(minSdkVersion:29)
 libstagefright_metadatautils(minSdkVersion:29)
 libstagefright_mp3dec(minSdkVersion:29)
+libstagefright_mp3dec_headers(minSdkVersion:29)
 libstagefright_mpeg2extractor(minSdkVersion:29)
 libstagefright_mpeg2support_nocrypto(minSdkVersion:29)
 libstats_jni(minSdkVersion:(no version))

cc/cc.go

@@ -2411,7 +2411,14 @@ func (c *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 
 			switch {
 			case libDepTag.header():
-				// nothing
+				if !ctx.OtherModuleHasProvider(dep, HeaderLibraryInfoProvider) {
+					if !ctx.Config().AllowMissingDependencies() {
+						ctx.ModuleErrorf("module %q is not a header library", depName)
+					} else {
+						ctx.AddMissingDependencies([]string{depName})
+					}
+					return
+				}
 			case libDepTag.shared():
 				if !ctx.OtherModuleHasProvider(dep, SharedLibraryInfoProvider) {
 					if !ctx.Config().AllowMissingDependencies() {

cc/library.go

@@ -897,16 +897,22 @@ func (library *libraryDecorator) linkStatic(ctx ModuleContext,
 
 	ctx.CheckbuildFile(outputFile)
 
-	ctx.SetProvider(StaticLibraryInfoProvider, StaticLibraryInfo{
+	if library.static() {
-		StaticLibrary: outputFile,
+		ctx.SetProvider(StaticLibraryInfoProvider, StaticLibraryInfo{
-		ReuseObjects:  library.reuseObjects,
+			StaticLibrary: outputFile,
-		Objects:       library.objects,
+			ReuseObjects:  library.reuseObjects,
+			Objects:       library.objects,
 
-		TransitiveStaticLibrariesForOrdering: android.NewDepSetBuilder(android.TOPOLOGICAL).
+			TransitiveStaticLibrariesForOrdering: android.NewDepSetBuilder(android.TOPOLOGICAL).
-			Direct(outputFile).
+				Direct(outputFile).
-			Transitive(deps.TranstiveStaticLibrariesForOrdering).
+				Transitive(deps.TranstiveStaticLibrariesForOrdering).
-			Build(),
+				Build(),
-	})
+		})
+	}
+
+	if library.header() {
+		ctx.SetProvider(HeaderLibraryInfoProvider, HeaderLibraryInfo{})
+	}
 
 	return outputFile
 }

cc/linkable.go

@@ -130,6 +130,13 @@ type StaticLibraryInfo struct {
 
 var StaticLibraryInfoProvider = blueprint.NewProvider(StaticLibraryInfo{})
 
+// HeaderLibraryInfo is a marker provider that identifies a module as a header library.
+type HeaderLibraryInfo struct {
+}
+
+// HeaderLibraryInfoProvider is a marker provider that identifies a module as a header library.
+var HeaderLibraryInfoProvider = blueprint.NewProvider(HeaderLibraryInfo{})
+
 // FlagExporterInfo is a provider to propagate transitive library information
 // pertaining to exported include paths and flags.
 type FlagExporterInfo struct {

cc/prebuilt.go

@@ -190,6 +190,12 @@ func (p *prebuiltLibraryLinker) link(ctx ModuleContext,
 		}
 	}
 
+	if p.header() {
+		ctx.SetProvider(HeaderLibraryInfoProvider, HeaderLibraryInfo{})
+
+		return nil
+	}
+
 	return nil
 }