blob: 9c906f2095be0c80a2bf0a6eed8634f23d9b216d [file] [log] [blame]
// Copyright 2016 Google Inc.
//
// 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.
// +build ignore
// Regen.go regenerates the genproto repository.
//
// Regen.go recursively walks through each directory named by given arguments,
// looking for all .proto files. (Symlinks are not followed.)
// If the pkg_prefix flag is not an empty string,
// any proto file without `go_package` option
// or whose option does not begin with the prefix is ignored.
// Protoc is executed on remaining files,
// one invocation per set of files declaring the same Go package.
package main
import (
"flag"
"fmt"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"regexp"
"strconv"
"strings"
)
var goPkgOptRe = regexp.MustCompile(`(?m)^option go_package = (.*);`)
func usage() {
fmt.Fprintln(os.Stderr, `usage: go run regen.go -go_out=path/to/output [-pkg_prefix=pkg/prefix] roots...
Most users will not need to run this file directly.
To regenerate this repository, run regen.sh instead.`)
flag.PrintDefaults()
}
func main() {
goOutDir := flag.String("go_out", "", "go_out argument to pass to protoc-gen-go")
pkgPrefix := flag.String("pkg_prefix", "", "only include proto files with go_package starting with this prefix")
flag.Usage = usage
flag.Parse()
if *goOutDir == "" {
log.Fatal("need go_out flag")
}
pkgFiles := make(map[string][]string)
walkFn := func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if !info.Mode().IsRegular() || !strings.HasSuffix(path, ".proto") {
return nil
}
pkg, err := goPkg(path)
if err != nil {
return err
}
pkgFiles[pkg] = append(pkgFiles[pkg], path)
return nil
}
for _, root := range flag.Args() {
if err := filepath.Walk(root, walkFn); err != nil {
log.Fatal(err)
}
}
for pkg, fnames := range pkgFiles {
if !strings.HasPrefix(pkg, *pkgPrefix) {
continue
}
if out, err := protoc(*goOutDir, flag.Args(), fnames); err != nil {
log.Fatalf("error executing protoc: %s\n%s", err, out)
}
}
}
// goPkg reports the import path declared in the given file's
// `go_package` option. If the option is missing, goPkg returns empty string.
func goPkg(fname string) (string, error) {
content, err := ioutil.ReadFile(fname)
if err != nil {
return "", err
}
var pkgName string
if match := goPkgOptRe.FindSubmatch(content); len(match) > 0 {
pn, err := strconv.Unquote(string(match[1]))
if err != nil {
return "", err
}
pkgName = pn
}
if p := strings.IndexRune(pkgName, ';'); p > 0 {
pkgName = pkgName[:p]
}
return pkgName, nil
}
// protoc executes the "protoc" command on files named in fnames,
// passing go_out and include flags specified in goOut and includes respectively.
// protoc returns combined output from stdout and stderr.
func protoc(goOut string, includes, fnames []string) ([]byte, error) {
args := []string{"--go_out=plugins=grpc:" + goOut}
for _, inc := range includes {
args = append(args, "-I", inc)
}
args = append(args, fnames...)
return exec.Command("protoc", args...).CombinedOutput()
}