platform_build_soong/bp2build/bp2build.go

66 lines
2.5 KiB
Go

// 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 bp2build
import (
"android/soong/android"
"fmt"
"os"
"strings"
)
// Codegen is the backend of bp2build. The code generator is responsible for
// writing .bzl files that are equivalent to Android.bp files that are capable
// of being built with Bazel.
func Codegen(ctx *CodegenContext) CodegenMetrics {
outputDir := android.PathForOutput(ctx, "bp2build")
android.RemoveAllOutputDir(outputDir)
buildToTargets, metrics := GenerateBazelTargets(ctx)
filesToWrite := CreateBazelFiles(nil, buildToTargets, ctx.mode)
generatedBuildFiles := []string{}
for _, f := range filesToWrite {
p := getOrCreateOutputDir(outputDir, ctx, f.Dir).Join(ctx, f.Basename)
if err := writeFile(ctx, p, f.Contents); err != nil {
fmt.Errorf("Failed to write %q (dir %q) due to %q", f.Basename, f.Dir, err)
}
// if these generated files are modified, regenerate on next run.
generatedBuildFiles = append(generatedBuildFiles, p.String())
}
// The MANIFEST file contains the full list of files generated by bp2build, excluding itself.
// Its purpose is for downstream tools to understand the set of files converted by bp2build.
manifestFile := outputDir.Join(ctx, "MANIFEST")
writeFile(ctx, manifestFile, strings.Join(generatedBuildFiles, "\n"))
generatedBuildFiles = append(generatedBuildFiles, manifestFile.String())
return metrics
}
// Get the output directory and create it if it doesn't exist.
func getOrCreateOutputDir(outputDir android.OutputPath, ctx android.PathContext, dir string) android.OutputPath {
dirPath := outputDir.Join(ctx, dir)
android.CreateOutputDirIfNonexistent(dirPath, os.ModePerm)
return dirPath
}
func writeFile(ctx android.PathContext, pathToFile android.OutputPath, content string) error {
// These files are made editable to allow users to modify and iterate on them
// in the source tree.
return android.WriteFileToOutputDir(pathToFile, []byte(content), 0644)
}