blob: 0423482a1a1325e90699b40404cd2b297fa926a0 [file] [log] [blame]
// Copyright 2018 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.
// The gotip command compiles and runs the go command from the development tree.
//
// To install, run:
//
// $ go get golang.org/dl/gotip
// $ gotip download
//
// And then use the gotip command as if it were your normal go command.
//
// To update, run "gotip download" again.
package main
import (
"errors"
"fmt"
"log"
"os"
"os/exec"
"os/user"
"path/filepath"
"runtime"
"strings"
)
func main() {
log.SetFlags(0)
root, err := goroot("gotip")
if err != nil {
log.Fatalf("gotip: %v", err)
}
if len(os.Args) == 2 && os.Args[1] == "download" {
if err := installTip(root); err != nil {
log.Fatalf("gotip: %v", err)
}
log.Printf("Success. You may now run 'gotip'!")
os.Exit(0)
}
gobin := filepath.Join(root, "bin", "go"+exe())
if _, err := os.Stat(gobin); err != nil {
log.Fatalf("gotip: not downloaded. Run 'gotip download' to install to %v", root)
}
cmd := exec.Command(gobin, os.Args[1:]...)
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if err := cmd.Run(); err != nil {
if _, ok := err.(*exec.ExitError); ok {
// TODO: return the same exit status maybe.
os.Exit(1)
}
log.Fatalf("gotip: failed to execute %v: %v", gobin, err)
}
os.Exit(0)
}
func installTip(root string) error {
git := func(args ...string) error {
cmd := exec.Command("git", args...)
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
cmd.Dir = root
return cmd.Run()
}
if _, err := os.Stat(filepath.Join(root, ".git")); err != nil {
if err := os.MkdirAll(root, 0755); err != nil {
return fmt.Errorf("failed to create repository: %v", err)
}
if err := git("clone", "--depth=1", "https://go.googlesource.com/go", root); err != nil {
return fmt.Errorf("failed to clone git repository: %v", err)
}
} else {
log.Printf("Updating the go development tree...")
if err := git("fetch", "origin"); err != nil {
return fmt.Errorf("failed to fetch git repository updates: %v", err)
}
}
// Use checkout and a detached HEAD, because it will refuse to overwrite
// local changes, and warn if commits are being left behind, but will not
// mind if master is force-pushed upstream.
if err := git("-c", "advice.detachedHead=false", "checkout", "origin/master"); err != nil {
return fmt.Errorf("failed to checkout git repository: %v", err)
}
// It shouldn't be the case, but in practice sometimes binary artifacts
// generated by earlier Go versions interfere with the build.
//
// Ask the user what to do about them if they are not gitignored. They might
// be artifacts that used to be ignored in previous versions, or precious
// uncommitted source files.
if err := git("clean", "-i", "-d"); err != nil {
return fmt.Errorf("failed to cleanup git repository: %v", err)
}
// Wipe away probably boring ignored files without bothering the user.
if err := git("clean", "-q", "-f", "-d", "-X"); err != nil {
return fmt.Errorf("failed to cleanup git repository: %v", err)
}
cmd := exec.Command(filepath.Join(root, "src", make()))
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
cmd.Dir = filepath.Join(root, "src")
if runtime.GOOS == "windows" {
// Workaround make.bat not autodetecting GOROOT_BOOTSTRAP. Issue 28641.
goroot, err := exec.Command("go", "env", "GOROOT").Output()
if err != nil {
return fmt.Errorf("failed to detect an existing go installation for bootstrap: %v", err)
}
cmd.Env = append(os.Environ(), "GOROOT_BOOTSTRAP="+strings.TrimSpace(string(goroot)))
}
if err := cmd.Run(); err != nil {
return fmt.Errorf("failed to build go: %v", err)
}
return nil
}
func make() string {
switch runtime.GOOS {
case "plan9":
return "make.rc"
case "windows":
return "make.bat"
default:
return "make.bash"
}
}
func exe() string {
if runtime.GOOS == "windows" {
return ".exe"
}
return ""
}
func goroot(version string) (string, error) {
home, err := homedir()
if err != nil {
return "", fmt.Errorf("failed to get home directory: %v", err)
}
return filepath.Join(home, "sdk", version), nil
}
func homedir() (string, error) {
// This could be replaced with os.UserHomeDir, but it was introduced too
// recently, and we want this to work with go as packaged by Linux
// distributions. Note that user.Current is not enough as it does not
// prioritize $HOME. See also Issue 26463.
switch runtime.GOOS {
case "plan9":
return "", fmt.Errorf("%q not yet supported", runtime.GOOS)
case "windows":
if dir := os.Getenv("USERPROFILE"); dir != "" {
return dir, nil
}
return "", errors.New("can't find user home directory; %USERPROFILE% is empty")
default:
if dir := os.Getenv("HOME"); dir != "" {
return dir, nil
}
if u, err := user.Current(); err == nil && u.HomeDir != "" {
return u.HomeDir, nil
}
return "", errors.New("can't find user home directory; $HOME is empty")
}
}