blob: f31dd4fbd04e8e28bf5085f3ebc8841f944c551d [file] [log] [blame]
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate go build -o gotext.latest
//go:generate ./gotext.latest help gendocumentation
//go:generate rm gotext.latest
package main
import (
"bufio"
"bytes"
"flag"
"fmt"
"go/build"
"go/format"
"io"
"io/ioutil"
"log"
"os"
"strings"
"sync"
"text/template"
"unicode"
"unicode/utf8"
"golang.org/x/text/message/pipeline"
"golang.org/x/text/language"
"golang.org/x/tools/go/buildutil"
)
func init() {
flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
}
var (
srcLang = flag.String("srclang", "en-US", "the source-code language")
dir = flag.String("dir", "locales", "default subdirectory to store translation files")
)
func config() (*pipeline.Config, error) {
tag, err := language.Parse(*srcLang)
if err != nil {
return nil, wrap(err, "invalid srclang")
}
return &pipeline.Config{
SourceLanguage: tag,
Supported: getLangs(),
TranslationsPattern: `messages\.(.*)\.json`,
GenFile: *out,
}, nil
}
// NOTE: the Command struct is copied from the go tool in core.
// A Command is an implementation of a go command
// like go build or go fix.
type Command struct {
// Run runs the command.
// The args are the arguments after the command name.
Run func(cmd *Command, c *pipeline.Config, args []string) error
// UsageLine is the one-line usage message.
// The first word in the line is taken to be the command name.
UsageLine string
// Short is the short description shown in the 'go help' output.
Short string
// Long is the long message shown in the 'go help <this-command>' output.
Long string
// Flag is a set of flags specific to this command.
Flag flag.FlagSet
}
// Name returns the command's name: the first word in the usage line.
func (c *Command) Name() string {
name := c.UsageLine
i := strings.Index(name, " ")
if i >= 0 {
name = name[:i]
}
return name
}
func (c *Command) Usage() {
fmt.Fprintf(os.Stderr, "usage: %s\n\n", c.UsageLine)
fmt.Fprintf(os.Stderr, "%s\n", strings.TrimSpace(c.Long))
os.Exit(2)
}
// Runnable reports whether the command can be run; otherwise
// it is a documentation pseudo-command such as importpath.
func (c *Command) Runnable() bool {
return c.Run != nil
}
// Commands lists the available commands and help topics.
// The order here is the order in which they are printed by 'go help'.
var commands = []*Command{
cmdUpdate,
cmdExtract,
cmdRewrite,
cmdGenerate,
// TODO:
// - update: full-cycle update of extraction, sending, and integration
// - report: report of freshness of translations
}
var exitStatus = 0
var exitMu sync.Mutex
func setExitStatus(n int) {
exitMu.Lock()
if exitStatus < n {
exitStatus = n
}
exitMu.Unlock()
}
var origEnv []string
func main() {
flag.Usage = usage
flag.Parse()
log.SetFlags(0)
args := flag.Args()
if len(args) < 1 {
usage()
}
if args[0] == "help" {
help(args[1:])
return
}
for _, cmd := range commands {
if cmd.Name() == args[0] && cmd.Runnable() {
cmd.Flag.Usage = func() { cmd.Usage() }
cmd.Flag.Parse(args[1:])
args = cmd.Flag.Args()
config, err := config()
if err != nil {
fatalf("gotext: %+v", err)
}
if err := cmd.Run(cmd, config, args); err != nil {
fatalf("gotext: %+v", err)
}
exit()
return
}
}
fmt.Fprintf(os.Stderr, "gotext: unknown subcommand %q\nRun 'go help' for usage.\n", args[0])
setExitStatus(2)
exit()
}
var usageTemplate = `gotext is a tool for managing text in Go source code.
Usage:
gotext command [arguments]
The commands are:
{{range .}}{{if .Runnable}}
{{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}
Use "gotext help [command]" for more information about a command.
Additional help topics:
{{range .}}{{if not .Runnable}}
{{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}
Use "gotext help [topic]" for more information about that topic.
`
var helpTemplate = `{{if .Runnable}}usage: gotext {{.UsageLine}}
{{end}}{{.Long | trim}}
`
var documentationTemplate = `{{range .}}{{if .Short}}{{.Short | capitalize}}
{{end}}{{if .Runnable}}Usage:
gotext {{.UsageLine}}
{{end}}{{.Long | trim}}
{{end}}`
// commentWriter writes a Go comment to the underlying io.Writer,
// using line comment form (//).
type commentWriter struct {
W io.Writer
wroteSlashes bool // Wrote "//" at the beginning of the current line.
}
func (c *commentWriter) Write(p []byte) (int, error) {
var n int
for i, b := range p {
if !c.wroteSlashes {
s := "//"
if b != '\n' {
s = "// "
}
if _, err := io.WriteString(c.W, s); err != nil {
return n, err
}
c.wroteSlashes = true
}
n0, err := c.W.Write(p[i : i+1])
n += n0
if err != nil {
return n, err
}
if b == '\n' {
c.wroteSlashes = false
}
}
return len(p), nil
}
// An errWriter wraps a writer, recording whether a write error occurred.
type errWriter struct {
w io.Writer
err error
}
func (w *errWriter) Write(b []byte) (int, error) {
n, err := w.w.Write(b)
if err != nil {
w.err = err
}
return n, err
}
// tmpl executes the given template text on data, writing the result to w.
func tmpl(w io.Writer, text string, data interface{}) {
t := template.New("top")
t.Funcs(template.FuncMap{"trim": strings.TrimSpace, "capitalize": capitalize})
template.Must(t.Parse(text))
ew := &errWriter{w: w}
err := t.Execute(ew, data)
if ew.err != nil {
// I/O error writing. Ignore write on closed pipe.
if strings.Contains(ew.err.Error(), "pipe") {
os.Exit(1)
}
fatalf("writing output: %v", ew.err)
}
if err != nil {
panic(err)
}
}
func capitalize(s string) string {
if s == "" {
return s
}
r, n := utf8.DecodeRuneInString(s)
return string(unicode.ToTitle(r)) + s[n:]
}
func printUsage(w io.Writer) {
bw := bufio.NewWriter(w)
tmpl(bw, usageTemplate, commands)
bw.Flush()
}
func usage() {
printUsage(os.Stderr)
os.Exit(2)
}
// help implements the 'help' command.
func help(args []string) {
if len(args) == 0 {
printUsage(os.Stdout)
// not exit 2: succeeded at 'go help'.
return
}
if len(args) != 1 {
fmt.Fprintf(os.Stderr, "usage: go help command\n\nToo many arguments given.\n")
os.Exit(2) // failed at 'go help'
}
arg := args[0]
// 'go help documentation' generates doc.go.
if strings.HasSuffix(arg, "documentation") {
w := &bytes.Buffer{}
fmt.Fprintln(w, "// Code generated by go generate. DO NOT EDIT.")
fmt.Fprintln(w)
buf := new(bytes.Buffer)
printUsage(buf)
usage := &Command{Long: buf.String()}
tmpl(&commentWriter{W: w}, documentationTemplate, append([]*Command{usage}, commands...))
fmt.Fprintln(w, "package main")
if arg == "gendocumentation" {
b, err := format.Source(w.Bytes())
if err != nil {
logf("Could not format generated docs: %v\n", err)
}
if err := ioutil.WriteFile("doc.go", b, 0666); err != nil {
logf("Could not create file alldocs.go: %v\n", err)
}
} else {
fmt.Println(w.String())
}
return
}
for _, cmd := range commands {
if cmd.Name() == arg {
tmpl(os.Stdout, helpTemplate, cmd)
// not exit 2: succeeded at 'go help cmd'.
return
}
}
fmt.Fprintf(os.Stderr, "Unknown help topic %#q. Run 'gotext help'.\n", arg)
os.Exit(2) // failed at 'go help cmd'
}
func getLangs() (tags []language.Tag) {
for _, t := range strings.Split(*lang, ",") {
if t == "" {
continue
}
tag, err := language.Parse(t)
if err != nil {
fatalf("gotext: could not parse language %q: %v", t, err)
}
tags = append(tags, tag)
}
return tags
}
var atexitFuncs []func()
func atexit(f func()) {
atexitFuncs = append(atexitFuncs, f)
}
func exit() {
for _, f := range atexitFuncs {
f()
}
os.Exit(exitStatus)
}
func fatalf(format string, args ...interface{}) {
logf(format, args...)
exit()
}
func logf(format string, args ...interface{}) {
log.Printf(format, args...)
setExitStatus(1)
}
func exitIfErrors() {
if exitStatus != 0 {
exit()
}
}