platform_build_soong/cc/proto.go

// Copyright 2016 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 (
	"github.com/google/blueprint"
	"github.com/google/blueprint/proptools"

	"android/soong/android"
)

func init() {
	pctx.HostBinToolVariable("protocCmd", "aprotoc")
}

var (
	proto = pctx.AndroidStaticRule("protoc",
		blueprint.RuleParams{
			Command:     "$protocCmd --cpp_out=$protoOutParams:$outDir $protoFlags $in",
			CommandDeps: []string{"$protocCmd"},
		}, "protoFlags", "protoOutParams", "outDir")
)

// genProto creates a rule to convert a .proto file to generated .pb.cc and .pb.h files and returns
// the paths to the generated files.
func genProto(ctx android.ModuleContext, protoFile android.Path,
	protoFlags string, protoOutParams string) (ccFile, headerFile android.WritablePath) {

	ccFile = android.GenPathWithExt(ctx, "proto", protoFile, "pb.cc")
	headerFile = android.GenPathWithExt(ctx, "proto", protoFile, "pb.h")

	ctx.Build(pctx, android.BuildParams{
		Rule:        proto,
		Description: "protoc " + protoFile.Rel(),
		Outputs:     android.WritablePaths{ccFile, headerFile},
		Input:       protoFile,
		Args: map[string]string{
			"outDir":         android.ProtoDir(ctx).String(),
			"protoFlags":     protoFlags,
			"protoOutParams": protoOutParams,
		},
	})

	return ccFile, headerFile
}

func protoDeps(ctx BaseModuleContext, deps Deps, p *android.ProtoProperties, static bool) Deps {
	var lib string

	switch String(p.Proto.Type) {
	case "full":
		if ctx.useSdk() {
			lib = "libprotobuf-cpp-full-ndk"
			static = true
		} else {
			lib = "libprotobuf-cpp-full"
		}
	case "lite", "":
		if ctx.useSdk() {
			lib = "libprotobuf-cpp-lite-ndk"
			static = true
		} else {
			lib = "libprotobuf-cpp-lite"
		}
	default:
		ctx.PropertyErrorf("proto.type", "unknown proto type %q",
			String(p.Proto.Type))
	}

	if static {
		deps.StaticLibs = append(deps.StaticLibs, lib)
		deps.ReexportStaticLibHeaders = append(deps.ReexportStaticLibHeaders, lib)
	} else {
		deps.SharedLibs = append(deps.SharedLibs, lib)
		deps.ReexportSharedLibHeaders = append(deps.ReexportSharedLibHeaders, lib)
	}

	return deps
}

func protoFlags(ctx ModuleContext, flags Flags, p *android.ProtoProperties) Flags {
	flags.CFlags = append(flags.CFlags, "-DGOOGLE_PROTOBUF_NO_RTTI")
	flags.GlobalFlags = append(flags.GlobalFlags,
		"-I"+android.ProtoSubDir(ctx).String(),
		"-I"+android.ProtoDir(ctx).String(),
	)

	flags.protoFlags = android.ProtoFlags(ctx, p)

	if proptools.String(p.Proto.Type) == "lite" {
		flags.protoOutParams = []string{"lite"}
	}

	return flags
}