Merge changes Idd50ed38,Icbc86b21

* changes:
  Add cc_prebuilt_library_headers
  Separate cc_library_headers to its own file and add tests

Android.bp

@@ -207,6 +207,7 @@ bootstrap_go_package {
         "cc/binary_sdk_member.go",
         "cc/fuzz.go",
         "cc/library.go",
+        "cc/library_headers.go",
         "cc/library_sdk_member.go",
         "cc/object.go",
         "cc/test.go",
@@ -232,6 +233,7 @@ bootstrap_go_package {
         "cc/compiler_test.go",
         "cc/gen_test.go",
         "cc/genrule_test.go",
+        "cc/library_headers_test.go",
         "cc/library_test.go",
         "cc/object_test.go",
         "cc/prebuilt_test.go",

cc/library.go

@@ -183,7 +183,6 @@ func RegisterLibraryBuildComponents(ctx android.RegistrationContext) {
 	ctx.RegisterModuleType("cc_library", LibraryFactory)
 	ctx.RegisterModuleType("cc_library_host_static", LibraryHostStaticFactory)
 	ctx.RegisterModuleType("cc_library_host_shared", LibraryHostSharedFactory)
-	ctx.RegisterModuleType("cc_library_headers", LibraryHeaderFactory)
 }
 
 // cc_library creates both static and/or shared libraries for a device and/or
@@ -233,16 +232,6 @@ func LibraryHostSharedFactory() android.Module {
 	return module.Init()
 }
 
-// cc_library_headers contains a set of c/c++ headers which are imported by
-// other soong cc modules using the header_libs property. For best practices,
-// use export_include_dirs property or LOCAL_EXPORT_C_INCLUDE_DIRS for
-// Make.
-func LibraryHeaderFactory() android.Module {
-	module, library := NewLibrary(android.HostAndDeviceSupported)
-	library.HeaderOnly()
-	return module.Init()
-}
-
 type flagExporter struct {
 	Properties FlagExporterProperties
 
@@ -1314,22 +1303,28 @@ func LinkageMutator(mctx android.BottomUpMutatorContext) {
 	if cc_prebuilt {
 		library := mctx.Module().(*Module).linker.(prebuiltLibraryInterface)
 
-		// Always create both the static and shared variants for prebuilt libraries, and then disable the one
+		// Differentiate between header only and building an actual static/shared library
-		// that is not being used.  This allows them to share the name of a cc_library module, which requires that
+		if library.buildStatic() || library.buildShared() {
-		// all the variants of the cc_library also exist on the prebuilt.
+			// Always create both the static and shared variants for prebuilt libraries, and then disable the one
-		modules := mctx.CreateLocalVariations("static", "shared")
+			// that is not being used.  This allows them to share the name of a cc_library module, which requires that
-		static := modules[0].(*Module)
+			// all the variants of the cc_library also exist on the prebuilt.
-		shared := modules[1].(*Module)
+			modules := mctx.CreateLocalVariations("static", "shared")
+			static := modules[0].(*Module)
+			shared := modules[1].(*Module)
 
-		static.linker.(prebuiltLibraryInterface).setStatic()
+			static.linker.(prebuiltLibraryInterface).setStatic()
-		shared.linker.(prebuiltLibraryInterface).setShared()
+			shared.linker.(prebuiltLibraryInterface).setShared()
 
-		if !library.buildStatic() {
+			if !library.buildStatic() {
-			static.linker.(prebuiltLibraryInterface).disablePrebuilt()
+				static.linker.(prebuiltLibraryInterface).disablePrebuilt()
-		}
+			}
-		if !library.buildShared() {
+			if !library.buildShared() {
-			shared.linker.(prebuiltLibraryInterface).disablePrebuilt()
+				shared.linker.(prebuiltLibraryInterface).disablePrebuilt()
+			}
+		} else {
+			// Header only
 		}
+
 	} else if library, ok := mctx.Module().(LinkableInterface); ok && library.CcLibraryInterface() {
 
 		// Non-cc.Modules may need an empty variant for their mutators.

cc/library_headers.go

@@ -0,0 +1,43 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cc
+
+import "android/soong/android"
+
+func init() {
+	RegisterLibraryHeadersBuildComponents(android.InitRegistrationContext)
+}
+
+func RegisterLibraryHeadersBuildComponents(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("cc_library_headers", LibraryHeaderFactory)
+	ctx.RegisterModuleType("cc_prebuilt_library_headers", prebuiltLibraryHeaderFactory)
+}
+
+// cc_library_headers contains a set of c/c++ headers which are imported by
+// other soong cc modules using the header_libs property. For best practices,
+// use export_include_dirs property or LOCAL_EXPORT_C_INCLUDE_DIRS for
+// Make.
+func LibraryHeaderFactory() android.Module {
+	module, library := NewLibrary(android.HostAndDeviceSupported)
+	library.HeaderOnly()
+	return module.Init()
+}
+
+// cc_prebuilt_library_headers is a prebuilt version of cc_library_headers
+func prebuiltLibraryHeaderFactory() android.Module {
+	module, library := NewPrebuiltLibrary(android.HostAndDeviceSupported)
+	library.HeaderOnly()
+	return module.Init()
+}

cc/library_headers_test.go

@@ -0,0 +1,62 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cc
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestLibraryHeaders(t *testing.T) {
+	ctx := testCc(t, `
+	cc_library_headers {
+		name: "headers",
+		export_include_dirs: ["my_include"],
+	}
+	cc_library_static {
+		name: "lib",
+		srcs: ["foo.c"],
+		header_libs: ["headers"],
+	}
+	`)
+
+	// test if header search paths are correctly added
+	cc := ctx.ModuleForTests("lib", "android_arm64_armv8-a_static").Rule("cc")
+	cflags := cc.Args["cFlags"]
+	if !strings.Contains(cflags, " -Imy_include ") {
+		t.Errorf("cflags for libsystem must contain -Imy_include, but was %#v.", cflags)
+	}
+}
+
+func TestPrebuiltLibraryHeaders(t *testing.T) {
+	ctx := testCc(t, `
+	cc_prebuilt_library_headers {
+		name: "headers",
+		export_include_dirs: ["my_include"],
+	}
+	cc_library_static {
+		name: "lib",
+		srcs: ["foo.c"],
+		header_libs: ["headers"],
+	}
+	`)
+
+	// test if header search paths are correctly added
+	cc := ctx.ModuleForTests("lib", "android_arm64_armv8-a_static").Rule("cc")
+	cflags := cc.Args["cFlags"]
+	if !strings.Contains(cflags, " -Imy_include ") {
+		t.Errorf("cflags for libsystem must contain -Imy_include, but was %#v.", cflags)
+	}
+}

cc/prebuilt.go

@@ -87,15 +87,16 @@ func (p *prebuiltLibraryLinker) linkerProps() []interface{} {
 
 func (p *prebuiltLibraryLinker) link(ctx ModuleContext,
 	flags Flags, deps PathDeps, objs Objects) android.Path {
+
+	p.libraryDecorator.exportIncludes(ctx)
+	p.libraryDecorator.reexportDirs(deps.ReexportedDirs...)
+	p.libraryDecorator.reexportSystemDirs(deps.ReexportedSystemDirs...)
+	p.libraryDecorator.reexportFlags(deps.ReexportedFlags...)
+	p.libraryDecorator.reexportDeps(deps.ReexportedDeps...)
+	p.libraryDecorator.addExportedGeneratedHeaders(deps.ReexportedGeneratedHeaders...)
+
 	// TODO(ccross): verify shared library dependencies
 	if len(p.properties.Srcs) > 0 {
-		p.libraryDecorator.exportIncludes(ctx)
-		p.libraryDecorator.reexportDirs(deps.ReexportedDirs...)
-		p.libraryDecorator.reexportSystemDirs(deps.ReexportedSystemDirs...)
-		p.libraryDecorator.reexportFlags(deps.ReexportedFlags...)
-		p.libraryDecorator.reexportDeps(deps.ReexportedDeps...)
-		p.libraryDecorator.addExportedGeneratedHeaders(deps.ReexportedGeneratedHeaders...)
-
 		builderFlags := flagsToBuilderFlags(flags)
 
 		in := p.Prebuilt.SingleSourcePath(ctx)

cc/testing.go

@@ -25,6 +25,7 @@ func RegisterRequiredBuildComponentsForTest(ctx android.RegistrationContext) {
 	RegisterCCBuildComponents(ctx)
 	RegisterBinaryBuildComponents(ctx)
 	RegisterLibraryBuildComponents(ctx)
+	RegisterLibraryHeadersBuildComponents(ctx)
 
 	ctx.RegisterModuleType("toolchain_library", ToolchainLibraryFactory)
 	ctx.RegisterModuleType("llndk_library", LlndkLibraryFactory)