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restic/build.go
Zlatko Čalušić 7e66b73ce0 Stop trying to detect Go version
It fails on pre-release versions, anyway.  It's enough to mention the oldest
supported version in README.md.  Anything older than two latest Go releases
is bad idea, anyway, 'cause it's unsupported by Go development team.

Closes #680
2016-12-01 20:06:23 +01:00

400 lines
9 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
)
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)
})
}
// 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":
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("", "restic-build-")
if err != nil {
die("TempDir(): %v\n", err)
}
verbosePrintf("create GOPATH at %v\n", gopath)
if err = updateGopath(gopath, filepath.Join(root, "src", "restic"), "restic"); err != nil {
die("copying files from %v/src/restic to %v/src/restic failed: %v\n", root, gopath, err)
}
if err = updateGopath(gopath, filepath.Join(root, "src", "cmds"), "cmds"); err != nil {
die("copying files from %v/src/cmds to %v/src/restic/cmds failed: %v\n", root, gopath, err)
}
vendor := filepath.Join(root, "vendor", "src")
if err = updateGopath(gopath, vendor, ""); err != nil {
die("copying files from %v to %v/src failed: %v\n", vendor, 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 := "restic"
if targetGOOS == "windows" {
outputFilename = "restic.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, "cmds/restic",
}
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(filepath.Join(gopath, "src"), gopath, "restic/...")
if err != nil {
die("running tests failed: %v\n", err)
}
}
}