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restic/build.go
Alexander Neumann 1815536534 Update build.go
2016-12-03 11:14:30 +01:00

422 lines
9.5 KiB
Go

// +build ignore
package main
import (
"fmt"
"io"
"io/ioutil"
"os"
"os/exec"
"path"
"path/filepath"
"runtime"
"strings"
"time"
)
var (
verbose bool
keepGopath bool
runTests bool
)
var config = struct {
Name string
Namespace string
Main string
Tests []string
}{
Name: "restic", // name of the program executable and directory
Namespace: "", // subdir of GOPATH, e.g. "github.com/foo/bar"
Main: "cmds/restic", // package name for the main package
Tests: []string{"restic/...", "cmds/..."}, // tests to run
}
const timeFormat = "2006-01-02 15:04:05"
// specialDir returns true if the file begins with a special character ('.' or '_').
func specialDir(name string) bool {
if name == "." {
return false
}
base := filepath.Base(name)
if base == "vendor" || base[0] == '_' || base[0] == '.' {
return true
}
return false
}
// excludePath returns true if the file should not be copied to the new GOPATH.
func excludePath(name string) bool {
ext := path.Ext(name)
if ext == ".go" || ext == ".s" {
return false
}
parentDir := filepath.Base(filepath.Dir(name))
if parentDir == "testdata" {
return false
}
return true
}
// updateGopath builds a valid GOPATH at dst, with all Go files in src/ copied
// to dst/prefix/, so calling
//
// updateGopath("/tmp/gopath", "/home/u/restic", "github.com/restic/restic")
//
// with "/home/u/restic" containing the file "foo.go" yields the following tree
// at "/tmp/gopath":
//
// /tmp/gopath
// └── src
// └── github.com
// └── restic
// └── restic
// └── foo.go
func updateGopath(dst, src, prefix string) error {
return filepath.Walk(src, func(name string, fi os.FileInfo, err error) error {
if specialDir(name) {
if fi.IsDir() {
return filepath.SkipDir
}
return nil
}
if fi.IsDir() {
return nil
}
if excludePath(name) {
return nil
}
intermediatePath, err := filepath.Rel(src, name)
if err != nil {
return err
}
fileSrc := filepath.Join(src, intermediatePath)
fileDst := filepath.Join(dst, "src", prefix, intermediatePath)
return copyFile(fileDst, fileSrc)
})
}
func directoryExists(dirname string) bool {
stat, err := os.Stat(dirname)
if err != nil && os.IsNotExist(err) {
return false
}
return stat.IsDir()
}
// copyFile creates dst from src, preserving file attributes and timestamps.
func copyFile(dst, src string) error {
fi, err := os.Stat(src)
if err != nil {
return err
}
fsrc, err := os.Open(src)
if err != nil {
return err
}
if err = os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
fmt.Printf("MkdirAll(%v)\n", filepath.Dir(dst))
return err
}
fdst, err := os.Create(dst)
if err != nil {
return err
}
if _, err = io.Copy(fdst, fsrc); err != nil {
return err
}
if err == nil {
err = fsrc.Close()
}
if err == nil {
err = fdst.Close()
}
if err == nil {
err = os.Chmod(dst, fi.Mode())
}
if err == nil {
err = os.Chtimes(dst, fi.ModTime(), fi.ModTime())
}
return nil
}
// die prints the message with fmt.Fprintf() to stderr and exits with an error
// code.
func die(message string, args ...interface{}) {
fmt.Fprintf(os.Stderr, message, args...)
os.Exit(1)
}
func showUsage(output io.Writer) {
fmt.Fprintf(output, "USAGE: go run build.go OPTIONS\n")
fmt.Fprintf(output, "\n")
fmt.Fprintf(output, "OPTIONS:\n")
fmt.Fprintf(output, " -v --verbose output more messages\n")
fmt.Fprintf(output, " -t --tags specify additional build tags\n")
fmt.Fprintf(output, " -k --keep-gopath do not remove the GOPATH after build\n")
fmt.Fprintf(output, " -T --test run tests\n")
fmt.Fprintf(output, " --goos value set GOOS for cross-compilation\n")
fmt.Fprintf(output, " --goarch value set GOARCH for cross-compilation\n")
}
func verbosePrintf(message string, args ...interface{}) {
if !verbose {
return
}
fmt.Printf("build: "+message, args...)
}
// cleanEnv returns a clean environment with GOPATH and GOBIN removed (if
// present).
func cleanEnv() (env []string) {
for _, v := range os.Environ() {
if strings.HasPrefix(v, "GOPATH=") || strings.HasPrefix(v, "GOBIN=") {
continue
}
env = append(env, v)
}
return env
}
// build runs "go build args..." with GOPATH set to gopath.
func build(cwd, goos, goarch, gopath string, args ...string) error {
args = append([]string{"build"}, args...)
cmd := exec.Command("go", args...)
cmd.Env = append(cleanEnv(), "GOPATH="+gopath, "GOARCH="+goarch, "GOOS="+goos)
cmd.Dir = cwd
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
verbosePrintf("go %s\n", args)
return cmd.Run()
}
// test runs "go test args..." with GOPATH set to gopath.
func test(cwd, gopath string, args ...string) error {
args = append([]string{"test"}, args...)
cmd := exec.Command("go", args...)
cmd.Env = append(cleanEnv(), "GOPATH="+gopath)
cmd.Dir = cwd
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
verbosePrintf("go %s\n", args)
return cmd.Run()
}
// getVersion returns the version string from the file VERSION in the current
// directory.
func getVersionFromFile() string {
buf, err := ioutil.ReadFile("VERSION")
if err != nil {
verbosePrintf("error reading file VERSION: %v\n", err)
return ""
}
return strings.TrimSpace(string(buf))
}
// getVersion returns a version string which is a combination of the contents
// of the file VERSION in the current directory and the version from git (if
// available).
func getVersion() string {
versionFile := getVersionFromFile()
versionGit := getVersionFromGit()
verbosePrintf("version from file 'VERSION' is %q, version from git %q\n",
versionFile, versionGit)
switch {
case versionFile == "":
return versionGit
case versionGit == "":
return versionFile
}
return fmt.Sprintf("%s (%s)", versionFile, versionGit)
}
// getVersionFromGit returns a version string that identifies the currently
// checked out git commit.
func getVersionFromGit() string {
cmd := exec.Command("git", "describe",
"--long", "--tags", "--dirty", "--always")
out, err := cmd.Output()
if err != nil {
verbosePrintf("git describe returned error: %v\n", err)
return ""
}
version := strings.TrimSpace(string(out))
verbosePrintf("git version is %s\n", version)
return version
}
// Constants represents a set of constants that are set in the final binary to
// the given value via compiler flags.
type Constants map[string]string
// LDFlags returns the string that can be passed to go build's `-ldflags`.
func (cs Constants) LDFlags() string {
l := make([]string, 0, len(cs))
for k, v := range cs {
l = append(l, fmt.Sprintf(`-X "%s=%s"`, k, v))
}
return strings.Join(l, " ")
}
func main() {
buildTags := []string{}
skipNext := false
params := os.Args[1:]
targetGOOS := runtime.GOOS
targetGOARCH := runtime.GOARCH
for i, arg := range params {
if skipNext {
skipNext = false
continue
}
switch arg {
case "-v", "--verbose":
verbose = true
case "-k", "--keep-gopath":
keepGopath = true
case "-t", "-tags", "--tags":
if i+1 >= len(params) {
die("-t given but no tag specified")
}
skipNext = true
buildTags = strings.Split(params[i+1], " ")
case "-T", "--test":
runTests = true
case "--goos":
skipNext = true
targetGOOS = params[i+1]
case "--goarch":
skipNext = true
targetGOARCH = params[i+1]
case "-h":
showUsage(os.Stdout)
return
default:
fmt.Fprintf(os.Stderr, "Error: unknown option %q\n\n", arg)
showUsage(os.Stderr)
os.Exit(1)
}
}
if len(buildTags) == 0 {
verbosePrintf("adding build-tag release\n")
buildTags = []string{"release"}
}
for i := range buildTags {
buildTags[i] = strings.TrimSpace(buildTags[i])
}
verbosePrintf("build tags: %s\n", buildTags)
root, err := os.Getwd()
if err != nil {
die("Getwd(): %v\n", err)
}
gopath, err := ioutil.TempDir("", fmt.Sprintf("%v-build-", config.Name))
if err != nil {
die("TempDir(): %v\n", err)
}
verbosePrintf("create GOPATH at %v\n", gopath)
if err = updateGopath(gopath, filepath.Join(root, "src"), config.Namespace); err != nil {
die("copying files from %v/src to %v/src failed: %v\n", root, gopath, err)
}
vendor := filepath.Join(root, "vendor", "src")
if directoryExists(vendor) {
if err = updateGopath(gopath, vendor, ""); err != nil {
die("copying files from %v to %v failed: %v\n", root, gopath, err)
}
}
defer func() {
if !keepGopath {
verbosePrintf("remove %v\n", gopath)
if err = os.RemoveAll(gopath); err != nil {
die("remove GOPATH at %s failed: %v\n", err)
}
} else {
verbosePrintf("leaving temporary GOPATH at %v\n", gopath)
}
}()
outputFilename := config.Name
if targetGOOS == "windows" {
outputFilename += ".exe"
}
cwd, err := os.Getwd()
if err != nil {
die("Getwd() returned %v\n", err)
}
output := filepath.Join(cwd, outputFilename)
version := getVersion()
compileTime := time.Now().Format(timeFormat)
constants := Constants{`main.compiledAt`: compileTime}
if version != "" {
constants["main.version"] = version
}
ldflags := "-s -w " + constants.LDFlags()
verbosePrintf("ldflags: %s\n", ldflags)
args := []string{
"-tags", strings.Join(buildTags, " "),
"-ldflags", ldflags,
"-o", output, config.Main,
}
err = build(filepath.Join(gopath, "src"), targetGOOS, targetGOARCH, gopath, args...)
if err != nil {
die("build failed: %v\n", err)
}
if runTests {
verbosePrintf("running tests\n")
err = test(cwd, gopath, config.Tests...)
if err != nil {
die("running tests failed: %v\n", err)
}
}
}