Separate cc_library_headers to its own file and add tests

Preparation for adding cc_library_headers to sdk.

Bug: 148933848
Test: m nothing
Change-Id: Icbc86b21f44dc79393b82be339cf3b133cbf9d8c

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
 

cc/library_headers.go

@@ -0,0 +1,35 @@
+// 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)
+}
+
+// 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/library_headers_test.go

@@ -0,0 +1,41 @@
+// 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)
+	}
+}

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)