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cmd/go: move all Shell methods to shell.go

Browse Source 
This is a pure code movement change.

Now that we've introduced a Shell type that lives in shell.go, move
all of its methods (which used to be on Builder) to shell.go as well.

Change-Id: Ie1802353c8a64590219b08893e8c74649228e5e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/536536
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
This commit is contained in:
Austin Clements 2023-10-19 13:43:51 -04:00 committed by Gopher Robot
parent 5bddb52a0b
commit ff6dd7125e
2 changed files with 590 additions and 574 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

574
src/cmd/go/internal/work/exec.go
View File

@ -1862,179 +1862,6 @@ func (b *Builder) cleanup(a *Action) {
}
}
// RemoveAll is like 'rm -rf'. It attempts to remove all paths even if there's
// an error, and returns the first error.
func (sh *Shell) RemoveAll(paths ...string) error {
if cfg.BuildN || cfg.BuildX {
// Don't say we are removing the directory if we never created it.
show := func() bool {
for _, path := range paths {
if _, ok := sh.mkdirCache.Get(path); ok {
return true
}
if _, err := os.Stat(path); !os.IsNotExist(err) {
return true
}
}
return false
}
if show() {
sh.ShowCmd("", "rm -rf %s", strings.Join(paths, " "))
}
}
if cfg.BuildN {
return nil
}
var err error
for _, path := range paths {
if err2 := os.RemoveAll(path); err2 != nil && err == nil {
err = err2
}
}
return err
}
// moveOrCopyFile is like 'mv src dst' or 'cp src dst'.
func (sh *Shell) moveOrCopyFile(dst, src string, perm fs.FileMode, force bool) error {
if cfg.BuildN {
sh.ShowCmd("", "mv %s %s", src, dst)
return nil
}
// If we can update the mode and rename to the dst, do it.
// Otherwise fall back to standard copy.
// If the source is in the build cache, we need to copy it.
if strings.HasPrefix(src, cache.DefaultDir()) {
return sh.CopyFile(dst, src, perm, force)
}
// On Windows, always copy the file, so that we respect the NTFS
// permissions of the parent folder. https://golang.org/issue/22343.
// What matters here is not cfg.Goos (the system we are building
// for) but runtime.GOOS (the system we are building on).
if runtime.GOOS == "windows" {
return sh.CopyFile(dst, src, perm, force)
}
// If the destination directory has the group sticky bit set,
// we have to copy the file to retain the correct permissions.
// https://golang.org/issue/18878
if fi, err := os.Stat(filepath.Dir(dst)); err == nil {
if fi.IsDir() && (fi.Mode()&fs.ModeSetgid) != 0 {
return sh.CopyFile(dst, src, perm, force)
}
}
// The perm argument is meant to be adjusted according to umask,
// but we don't know what the umask is.
// Create a dummy file to find out.
// This avoids build tags and works even on systems like Plan 9
// where the file mask computation incorporates other information.
mode := perm
f, err := os.OpenFile(filepath.Clean(dst)+"-go-tmp-umask", os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
if err == nil {
fi, err := f.Stat()
if err == nil {
mode = fi.Mode() & 0777
}
name := f.Name()
f.Close()
os.Remove(name)
}
if err := os.Chmod(src, mode); err == nil {
if err := os.Rename(src, dst); err == nil {
if cfg.BuildX {
sh.ShowCmd("", "mv %s %s", src, dst)
}
return nil
}
}
return sh.CopyFile(dst, src, perm, force)
}
// copyFile is like 'cp src dst'.
func (sh *Shell) CopyFile(dst, src string, perm fs.FileMode, force bool) error {
if cfg.BuildN || cfg.BuildX {
sh.ShowCmd("", "cp %s %s", src, dst)
if cfg.BuildN {
return nil
}
}
sf, err := os.Open(src)
if err != nil {
return err
}
defer sf.Close()
// Be careful about removing/overwriting dst.
// Do not remove/overwrite if dst exists and is a directory
// or a non-empty non-object file.
if fi, err := os.Stat(dst); err == nil {
if fi.IsDir() {
return fmt.Errorf("build output %q already exists and is a directory", dst)
}
if !force && fi.Mode().IsRegular() && fi.Size() != 0 && !isObject(dst) {
return fmt.Errorf("build output %q already exists and is not an object file", dst)
}
}
// On Windows, remove lingering ~ file from last attempt.
if runtime.GOOS == "windows" {
if _, err := os.Stat(dst + "~"); err == nil {
os.Remove(dst + "~")
}
}
mayberemovefile(dst)
df, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
if err != nil && runtime.GOOS == "windows" {
// Windows does not allow deletion of a binary file
// while it is executing. Try to move it out of the way.
// If the move fails, which is likely, we'll try again the
// next time we do an install of this binary.
if err := os.Rename(dst, dst+"~"); err == nil {
os.Remove(dst + "~")
}
df, err = os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
}
if err != nil {
return fmt.Errorf("copying %s: %w", src, err) // err should already refer to dst
}
_, err = io.Copy(df, sf)
df.Close()
if err != nil {
mayberemovefile(dst)
return fmt.Errorf("copying %s to %s: %v", src, dst, err)
}
return nil
}
// writeFile writes the text to file.
func (sh *Shell) writeFile(file string, text []byte) error {
if cfg.BuildN || cfg.BuildX {
switch {
case len(text) == 0:
sh.ShowCmd("", "echo -n > %s # internal", file)
case bytes.IndexByte(text, '\n') == len(text)-1:
// One line. Use a simpler "echo" command.
sh.ShowCmd("", "echo '%s' > %s # internal", bytes.TrimSuffix(text, []byte("\n")), file)
default:
// Use the most general form.
sh.ShowCmd("", "cat >%s << 'EOF' # internal\n%sEOF", file, text)
}
}
if cfg.BuildN {
return nil
}
return os.WriteFile(file, text, 0666)
}
// Install the cgo export header file, if there is one.
func (b *Builder) installHeader(ctx context.Context, a *Action) error {
sh := b.Shell(a)
@ -2180,370 +2007,6 @@ func isObject(s string) bool {
return false
}
// mayberemovefile removes a file only if it is a regular file
// When running as a user with sufficient privileges, we may delete
// even device files, for example, which is not intended.
func mayberemovefile(s string) {
if fi, err := os.Lstat(s); err == nil && !fi.Mode().IsRegular() {
return
}
os.Remove(s)
}
// fmtCmd formats a command in the manner of fmt.Sprintf but also:
//
// fmtCmd replaces the value of b.WorkDir with $WORK.
func (sh *Shell) fmtCmd(dir string, format string, args ...any) string {
cmd := fmt.Sprintf(format, args...)
if sh.workDir != "" && !strings.HasPrefix(cmd, "cat ") {
cmd = strings.ReplaceAll(cmd, sh.workDir, "$WORK")
escaped := strconv.Quote(sh.workDir)
escaped = escaped[1 : len(escaped)-1] // strip quote characters
if escaped != sh.workDir {
cmd = strings.ReplaceAll(cmd, escaped, "$WORK")
}
}
return cmd
}
// ShowCmd prints the given command to standard output
// for the implementation of -n or -x.
//
// ShowCmd also replaces the name of the current script directory with dot (.)
// but only when it is at the beginning of a space-separated token.
//
// If dir is not "" or "/" and not the current script directory, ShowCmd first
// prints a "cd" command to switch to dir and updates the script directory.
func (sh *Shell) ShowCmd(dir string, format string, args ...any) {
// Use the output lock directly so we can manage scriptDir.
sh.printLock.Lock()
defer sh.printLock.Unlock()
cmd := sh.fmtCmd(dir, format, args...)
if dir != "" && dir != "/" {
if dir != sh.scriptDir {
// Show changing to dir and update the current directory.
sh.printLocked(sh.fmtCmd("", "cd %s\n", dir))
sh.scriptDir = dir
}
// Replace scriptDir is our working directory. Replace it
// with "." in the command.
dot := " ."
if dir[len(dir)-1] == filepath.Separator {
dot += string(filepath.Separator)
}
cmd = strings.ReplaceAll(" "+cmd, " "+dir, dot)[1:]
}
sh.printLocked(cmd + "\n")
}
// reportCmd reports the output and exit status of a command. The cmdOut and
// cmdErr arguments are the output and exit error of the command, respectively.
//
// The exact reporting behavior is as follows:
//
// cmdOut cmdErr Result
// "" nil print nothing, return nil
// !="" nil print output, return nil
// "" !=nil print nothing, return cmdErr (later printed)
// !="" !=nil print nothing, ignore err, return output as error (later printed)
//
// reportCmd returns a non-nil error if and only if cmdErr != nil. It assumes
// that the command output, if non-empty, is more detailed than the command
// error (which is usually just an exit status), so prefers using the output as
// the ultimate error. Typically, the caller should return this error from an
// Action, which it will be printed by the Builder.
//
// reportCmd formats the output as "# desc" followed by the given output. The
// output is expected to contain references to 'dir', usually the source
// directory for the package that has failed to build. reportCmd rewrites
// mentions of dir with a relative path to dir when the relative path is
// shorter. This is usually more pleasant. For example, if fmt doesn't compile
// and we are in src/html, the output is
//
// $ go build
// # fmt
// ../fmt/print.go:1090: undefined: asdf
// $
//
// instead of
//
// $ go build
// # fmt
// /usr/gopher/go/src/fmt/print.go:1090: undefined: asdf
// $
//
// reportCmd also replaces references to the work directory with $WORK, replaces
// cgo file paths with the original file path, and replaces cgo-mangled names
// with "C.name".
//
// desc is optional. If "", a.Package.Desc() is used.
//
// dir is optional. If "", a.Package.Dir is used.
func (sh *Shell) reportCmd(desc, dir string, cmdOut []byte, cmdErr error) error {
if len(cmdOut) == 0 && cmdErr == nil {
// Common case
return nil
}
if len(cmdOut) == 0 && cmdErr != nil {
// Just return the error.
//
// TODO: This is what we've done for a long time, but it may be a
// mistake because it loses all of the extra context and results in
// ultimately less descriptive output. We should probably just take the
// text of cmdErr as the output in this case and do everything we
// otherwise would. We could chain the errors if we feel like it.
return cmdErr
}
// Fetch defaults from the package.
var p *load.Package
a := sh.action
if a != nil {
p = a.Package
}
var importPath string
if p != nil {
importPath = p.ImportPath
if desc == "" {
desc = p.Desc()
}
if dir == "" {
dir = p.Dir
}
}
out := string(cmdOut)
if !strings.HasSuffix(out, "\n") {
out = out + "\n"
}
// Replace workDir with $WORK
out = replacePrefix(out, sh.workDir, "$WORK")
// Rewrite mentions of dir with a relative path to dir
// when the relative path is shorter.
for {
// Note that dir starts out long, something like
// /foo/bar/baz/root/a
// The target string to be reduced is something like
// (blah-blah-blah) /foo/bar/baz/root/sibling/whatever.go:blah:blah
// /foo/bar/baz/root/a doesn't match /foo/bar/baz/root/sibling, but the prefix
// /foo/bar/baz/root does. And there may be other niblings sharing shorter
// prefixes, the only way to find them is to look.
// This doesn't always produce a relative path --
// /foo is shorter than ../../.., for example.
if reldir := base.ShortPath(dir); reldir != dir {
out = replacePrefix(out, dir, reldir)
if filepath.Separator == '\\' {
// Don't know why, sometimes this comes out with slashes, not backslashes.
wdir := strings.ReplaceAll(dir, "\\", "/")
out = replacePrefix(out, wdir, reldir)
}
}
dirP := filepath.Dir(dir)
if dir == dirP {
break
}
dir = dirP
}
// Fix up output referring to cgo-generated code to be more readable.
// Replace x.go:19[/tmp/.../x.cgo1.go:18] with x.go:19.
// Replace *[100]_Ctype_foo with *[100]C.foo.
// If we're using -x, assume we're debugging and want the full dump, so disable the rewrite.
if !cfg.BuildX && cgoLine.MatchString(out) {
out = cgoLine.ReplaceAllString(out, "")
out = cgoTypeSigRe.ReplaceAllString(out, "C.")
}
// Usually desc is already p.Desc(), but if not, signal cmdError.Error to
// add a line explicitly metioning the import path.
needsPath := importPath != "" && p != nil && desc != p.Desc()
err := &cmdError{desc, out, importPath, needsPath}
if cmdErr != nil {
// The command failed. Report the output up as an error.
return err
}
// The command didn't fail, so just print the output as appropriate.
if a != nil && a.output != nil {
// The Action is capturing output.
a.output = append(a.output, err.Error()...)
} else {
// Write directly to the Builder output.
sh.Print(err.Error())
}
return nil
}
// replacePrefix is like strings.ReplaceAll, but only replaces instances of old
// that are preceded by ' ', '\t', or appear at the beginning of a line.
func replacePrefix(s, old, new string) string {
n := strings.Count(s, old)
if n == 0 {
return s
}
s = strings.ReplaceAll(s, " "+old, " "+new)
s = strings.ReplaceAll(s, "\n"+old, "\n"+new)
s = strings.ReplaceAll(s, "\n\t"+old, "\n\t"+new)
if strings.HasPrefix(s, old) {
s = new + s[len(old):]
}
return s
}
type cmdError struct {
desc string
text string
importPath string
needsPath bool // Set if desc does not already include the import path
}
func (e *cmdError) Error() string {
var msg string
if e.needsPath {
// Ensure the import path is part of the message.
// Clearly distinguish the description from the import path.
msg = fmt.Sprintf("# %s\n# [%s]\n", e.importPath, e.desc)
} else {
msg = "# " + e.desc + "\n"
}
return msg + e.text
}
func (e *cmdError) ImportPath() string {
return e.importPath
}
var cgoLine = lazyregexp.New(`\[[^\[\]]+\.(cgo1|cover)\.go:[0-9]+(:[0-9]+)?\]`)
var cgoTypeSigRe = lazyregexp.New(`\b_C2?(type|func|var|macro)_\B`)
// run runs the command given by cmdline in the directory dir.
// If the command fails, run prints information about the failure
// and returns a non-nil error.
func (sh *Shell) run(dir string, desc string, env []string, cmdargs ...any) error {
out, err := sh.runOut(dir, env, cmdargs...)
if desc == "" {
desc = sh.fmtCmd(dir, "%s", strings.Join(str.StringList(cmdargs...), " "))
}
return sh.reportCmd(desc, dir, out, err)
}
// runOut runs the command given by cmdline in the directory dir.
// It returns the command output and any errors that occurred.
// It accumulates execution time in a.
func (sh *Shell) runOut(dir string, env []string, cmdargs ...any) ([]byte, error) {
a := sh.action
cmdline := str.StringList(cmdargs...)
for _, arg := range cmdline {
// GNU binutils commands, including gcc and gccgo, interpret an argument
// @foo anywhere in the command line (even following --) as meaning
// "read and insert arguments from the file named foo."
// Don't say anything that might be misinterpreted that way.
if strings.HasPrefix(arg, "@") {
return nil, fmt.Errorf("invalid command-line argument %s in command: %s", arg, joinUnambiguously(cmdline))
}
}
if cfg.BuildN || cfg.BuildX {
var envcmdline string
for _, e := range env {
if j := strings.IndexByte(e, '='); j != -1 {
if strings.ContainsRune(e[j+1:], '\'') {
envcmdline += fmt.Sprintf("%s=%q", e[:j], e[j+1:])
} else {
envcmdline += fmt.Sprintf("%s='%s'", e[:j], e[j+1:])
}
envcmdline += " "
}
}
envcmdline += joinUnambiguously(cmdline)
sh.ShowCmd(dir, "%s", envcmdline)
if cfg.BuildN {
return nil, nil
}
}
var buf bytes.Buffer
path, err := cfg.LookPath(cmdline[0])
if err != nil {
return nil, err
}
cmd := exec.Command(path, cmdline[1:]...)
if cmd.Path != "" {
cmd.Args[0] = cmd.Path
}
cmd.Stdout = &buf
cmd.Stderr = &buf
cleanup := passLongArgsInResponseFiles(cmd)
defer cleanup()
if dir != "." {
cmd.Dir = dir
}
cmd.Env = cmd.Environ() // Pre-allocate with correct PWD.
// Add the TOOLEXEC_IMPORTPATH environment variable for -toolexec tools.
// It doesn't really matter if -toolexec isn't being used.
// Note that a.Package.Desc is not really an import path,
// but this is consistent with 'go list -f {{.ImportPath}}'.
// Plus, it is useful to uniquely identify packages in 'go list -json'.
if a != nil && a.Package != nil {
cmd.Env = append(cmd.Env, "TOOLEXEC_IMPORTPATH="+a.Package.Desc())
}
cmd.Env = append(cmd.Env, env...)
start := time.Now()
err = cmd.Run()
if a != nil && a.json != nil {
aj := a.json
aj.Cmd = append(aj.Cmd, joinUnambiguously(cmdline))
aj.CmdReal += time.Since(start)
if ps := cmd.ProcessState; ps != nil {
aj.CmdUser += ps.UserTime()
aj.CmdSys += ps.SystemTime()
}
}
// err can be something like 'exit status 1'.
// Add information about what program was running.
// Note that if buf.Bytes() is non-empty, the caller usually
// shows buf.Bytes() and does not print err at all, so the
// prefix here does not make most output any more verbose.
if err != nil {
err = errors.New(cmdline[0] + ": " + err.Error())
}
return buf.Bytes(), err
}
// joinUnambiguously prints the slice, quoting where necessary to make the
// output unambiguous.
// TODO: See issue 5279. The printing of commands needs a complete redo.
func joinUnambiguously(a []string) string {
var buf strings.Builder
for i, s := range a {
if i > 0 {
buf.WriteByte(' ')
}
q := strconv.Quote(s)
// A gccgo command line can contain -( and -).
// Make sure we quote them since they are special to the shell.
// The trimpath argument can also contain > (part of =>) and ;. Quote those too.
if s == "" || strings.ContainsAny(s, " ()>;") || len(q) > len(s)+2 {
buf.WriteString(q)
} else {
buf.WriteString(s)
}
}
return buf.String()
}
// cCompilerEnv returns environment variables to set when running the
// C compiler. This is needed to disable escape codes in clang error
// messages that confuse tools like cgo.
@ -2551,43 +2014,6 @@ func (b *Builder) cCompilerEnv() []string {
return []string{"TERM=dumb"}
}
// Mkdir makes the named directory.
func (sh *Shell) Mkdir(dir string) error {
// Make Mkdir(a.Objdir) a no-op instead of an error when a.Objdir == "".
if dir == "" {
return nil
}
// We can be a little aggressive about being
// sure directories exist. Skip repeated calls.
return sh.mkdirCache.Do(dir, func() error {
if cfg.BuildN || cfg.BuildX {
sh.ShowCmd("", "mkdir -p %s", dir)
if cfg.BuildN {
return nil
}
}
return os.MkdirAll(dir, 0777)
})
}
// Symlink creates a symlink newname -> oldname.
func (sh *Shell) Symlink(oldname, newname string) error {
// It's not an error to try to recreate an existing symlink.
if link, err := os.Readlink(newname); err == nil && link == oldname {
return nil
}
if cfg.BuildN || cfg.BuildX {
sh.ShowCmd("", "ln -s %s %s", oldname, newname)
if cfg.BuildN {
return nil
}
}
return os.Symlink(oldname, newname)
}
// mkAbs returns an absolute path corresponding to
// evaluating f in the directory dir.
// We always pass absolute paths of source files so that

590
src/cmd/go/internal/work/shell.go
View File

@ -5,10 +5,26 @@
package work
import (
"bytes"
"cmd/go/internal/base"
"cmd/go/internal/cache"
"cmd/go/internal/cfg"
"cmd/go/internal/load"
"cmd/go/internal/par"
"cmd/go/internal/str"
"errors"
"fmt"
"internal/lazyregexp"
"io"
"io/fs"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
"sync"
"time"
)
// A Shell runs shell commands and performs shell-like file system operations.
@ -86,3 +102,577 @@ func (b *Builder) Shell(a *Action) *Shell {
func (b *Builder) BackgroundShell() *Shell {
return b.backgroundSh
}
// moveOrCopyFile is like 'mv src dst' or 'cp src dst'.
func (sh *Shell) moveOrCopyFile(dst, src string, perm fs.FileMode, force bool) error {
if cfg.BuildN {
sh.ShowCmd("", "mv %s %s", src, dst)
return nil
}
// If we can update the mode and rename to the dst, do it.
// Otherwise fall back to standard copy.
// If the source is in the build cache, we need to copy it.
if strings.HasPrefix(src, cache.DefaultDir()) {
return sh.CopyFile(dst, src, perm, force)
}
// On Windows, always copy the file, so that we respect the NTFS
// permissions of the parent folder. https://golang.org/issue/22343.
// What matters here is not cfg.Goos (the system we are building
// for) but runtime.GOOS (the system we are building on).
if runtime.GOOS == "windows" {
return sh.CopyFile(dst, src, perm, force)
}
// If the destination directory has the group sticky bit set,
// we have to copy the file to retain the correct permissions.
// https://golang.org/issue/18878
if fi, err := os.Stat(filepath.Dir(dst)); err == nil {
if fi.IsDir() && (fi.Mode()&fs.ModeSetgid) != 0 {
return sh.CopyFile(dst, src, perm, force)
}
}
// The perm argument is meant to be adjusted according to umask,
// but we don't know what the umask is.
// Create a dummy file to find out.
// This avoids build tags and works even on systems like Plan 9
// where the file mask computation incorporates other information.
mode := perm
f, err := os.OpenFile(filepath.Clean(dst)+"-go-tmp-umask", os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
if err == nil {
fi, err := f.Stat()
if err == nil {
mode = fi.Mode() & 0777
}
name := f.Name()
f.Close()
os.Remove(name)
}
if err := os.Chmod(src, mode); err == nil {
if err := os.Rename(src, dst); err == nil {
if cfg.BuildX {
sh.ShowCmd("", "mv %s %s", src, dst)
}
return nil
}
}
return sh.CopyFile(dst, src, perm, force)
}
// copyFile is like 'cp src dst'.
func (sh *Shell) CopyFile(dst, src string, perm fs.FileMode, force bool) error {
if cfg.BuildN || cfg.BuildX {
sh.ShowCmd("", "cp %s %s", src, dst)
if cfg.BuildN {
return nil
}
}
sf, err := os.Open(src)
if err != nil {
return err
}
defer sf.Close()
// Be careful about removing/overwriting dst.
// Do not remove/overwrite if dst exists and is a directory
// or a non-empty non-object file.
if fi, err := os.Stat(dst); err == nil {
if fi.IsDir() {
return fmt.Errorf("build output %q already exists and is a directory", dst)
}
if !force && fi.Mode().IsRegular() && fi.Size() != 0 && !isObject(dst) {
return fmt.Errorf("build output %q already exists and is not an object file", dst)
}
}
// On Windows, remove lingering ~ file from last attempt.
if runtime.GOOS == "windows" {
if _, err := os.Stat(dst + "~"); err == nil {
os.Remove(dst + "~")
}
}
mayberemovefile(dst)
df, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
if err != nil && runtime.GOOS == "windows" {
// Windows does not allow deletion of a binary file
// while it is executing. Try to move it out of the way.
// If the move fails, which is likely, we'll try again the
// next time we do an install of this binary.
if err := os.Rename(dst, dst+"~"); err == nil {
os.Remove(dst + "~")
}
df, err = os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
}
if err != nil {
return fmt.Errorf("copying %s: %w", src, err) // err should already refer to dst
}
_, err = io.Copy(df, sf)
df.Close()
if err != nil {
mayberemovefile(dst)
return fmt.Errorf("copying %s to %s: %v", src, dst, err)
}
return nil
}
// mayberemovefile removes a file only if it is a regular file
// When running as a user with sufficient privileges, we may delete
// even device files, for example, which is not intended.
func mayberemovefile(s string) {
if fi, err := os.Lstat(s); err == nil && !fi.Mode().IsRegular() {
return
}
os.Remove(s)
}
// writeFile writes the text to file.
func (sh *Shell) writeFile(file string, text []byte) error {
if cfg.BuildN || cfg.BuildX {
switch {
case len(text) == 0:
sh.ShowCmd("", "echo -n > %s # internal", file)
case bytes.IndexByte(text, '\n') == len(text)-1:
// One line. Use a simpler "echo" command.
sh.ShowCmd("", "echo '%s' > %s # internal", bytes.TrimSuffix(text, []byte("\n")), file)
default:
// Use the most general form.
sh.ShowCmd("", "cat >%s << 'EOF' # internal\n%sEOF", file, text)
}
}
if cfg.BuildN {
return nil
}
return os.WriteFile(file, text, 0666)
}
// Mkdir makes the named directory.
func (sh *Shell) Mkdir(dir string) error {
// Make Mkdir(a.Objdir) a no-op instead of an error when a.Objdir == "".
if dir == "" {
return nil
}
// We can be a little aggressive about being
// sure directories exist. Skip repeated calls.
return sh.mkdirCache.Do(dir, func() error {
if cfg.BuildN || cfg.BuildX {
sh.ShowCmd("", "mkdir -p %s", dir)
if cfg.BuildN {
return nil
}
}
return os.MkdirAll(dir, 0777)
})
}
// RemoveAll is like 'rm -rf'. It attempts to remove all paths even if there's
// an error, and returns the first error.
func (sh *Shell) RemoveAll(paths ...string) error {
if cfg.BuildN || cfg.BuildX {
// Don't say we are removing the directory if we never created it.
show := func() bool {
for _, path := range paths {
if _, ok := sh.mkdirCache.Get(path); ok {
return true
}
if _, err := os.Stat(path); !os.IsNotExist(err) {
return true
}
}
return false
}
if show() {
sh.ShowCmd("", "rm -rf %s", strings.Join(paths, " "))
}
}
if cfg.BuildN {
return nil
}
var err error
for _, path := range paths {
if err2 := os.RemoveAll(path); err2 != nil && err == nil {
err = err2
}
}
return err
}
// Symlink creates a symlink newname -> oldname.
func (sh *Shell) Symlink(oldname, newname string) error {
// It's not an error to try to recreate an existing symlink.
if link, err := os.Readlink(newname); err == nil && link == oldname {
return nil
}
if cfg.BuildN || cfg.BuildX {
sh.ShowCmd("", "ln -s %s %s", oldname, newname)
if cfg.BuildN {
return nil
}
}
return os.Symlink(oldname, newname)
}
// fmtCmd formats a command in the manner of fmt.Sprintf but also:
//
// fmtCmd replaces the value of b.WorkDir with $WORK.
func (sh *Shell) fmtCmd(dir string, format string, args ...any) string {
cmd := fmt.Sprintf(format, args...)
if sh.workDir != "" && !strings.HasPrefix(cmd, "cat ") {
cmd = strings.ReplaceAll(cmd, sh.workDir, "$WORK")
escaped := strconv.Quote(sh.workDir)
escaped = escaped[1 : len(escaped)-1] // strip quote characters
if escaped != sh.workDir {
cmd = strings.ReplaceAll(cmd, escaped, "$WORK")
}
}
return cmd
}
// ShowCmd prints the given command to standard output
// for the implementation of -n or -x.
//
// ShowCmd also replaces the name of the current script directory with dot (.)
// but only when it is at the beginning of a space-separated token.
//
// If dir is not "" or "/" and not the current script directory, ShowCmd first
// prints a "cd" command to switch to dir and updates the script directory.
func (sh *Shell) ShowCmd(dir string, format string, args ...any) {
// Use the output lock directly so we can manage scriptDir.
sh.printLock.Lock()
defer sh.printLock.Unlock()
cmd := sh.fmtCmd(dir, format, args...)
if dir != "" && dir != "/" {
if dir != sh.scriptDir {
// Show changing to dir and update the current directory.
sh.printLocked(sh.fmtCmd("", "cd %s\n", dir))
sh.scriptDir = dir
}
// Replace scriptDir is our working directory. Replace it
// with "." in the command.
dot := " ."
if dir[len(dir)-1] == filepath.Separator {
dot += string(filepath.Separator)
}
cmd = strings.ReplaceAll(" "+cmd, " "+dir, dot)[1:]
}
sh.printLocked(cmd + "\n")
}
// reportCmd reports the output and exit status of a command. The cmdOut and
// cmdErr arguments are the output and exit error of the command, respectively.
//
// The exact reporting behavior is as follows:
//
// cmdOut cmdErr Result
// "" nil print nothing, return nil
// !="" nil print output, return nil
// "" !=nil print nothing, return cmdErr (later printed)
// !="" !=nil print nothing, ignore err, return output as error (later printed)
//
// reportCmd returns a non-nil error if and only if cmdErr != nil. It assumes
// that the command output, if non-empty, is more detailed than the command
// error (which is usually just an exit status), so prefers using the output as
// the ultimate error. Typically, the caller should return this error from an
// Action, which it will be printed by the Builder.
//
// reportCmd formats the output as "# desc" followed by the given output. The
// output is expected to contain references to 'dir', usually the source
// directory for the package that has failed to build. reportCmd rewrites
// mentions of dir with a relative path to dir when the relative path is
// shorter. This is usually more pleasant. For example, if fmt doesn't compile
// and we are in src/html, the output is
//
// $ go build
// # fmt
// ../fmt/print.go:1090: undefined: asdf
// $
//
// instead of
//
// $ go build
// # fmt
// /usr/gopher/go/src/fmt/print.go:1090: undefined: asdf
// $
//
// reportCmd also replaces references to the work directory with $WORK, replaces
// cgo file paths with the original file path, and replaces cgo-mangled names
// with "C.name".
//
// desc is optional. If "", a.Package.Desc() is used.
//
// dir is optional. If "", a.Package.Dir is used.
func (sh *Shell) reportCmd(desc, dir string, cmdOut []byte, cmdErr error) error {
if len(cmdOut) == 0 && cmdErr == nil {
// Common case
return nil
}
if len(cmdOut) == 0 && cmdErr != nil {
// Just return the error.
//
// TODO: This is what we've done for a long time, but it may be a
// mistake because it loses all of the extra context and results in
// ultimately less descriptive output. We should probably just take the
// text of cmdErr as the output in this case and do everything we
// otherwise would. We could chain the errors if we feel like it.
return cmdErr
}
// Fetch defaults from the package.
var p *load.Package
a := sh.action
if a != nil {
p = a.Package
}
var importPath string
if p != nil {
importPath = p.ImportPath
if desc == "" {
desc = p.Desc()
}
if dir == "" {
dir = p.Dir
}
}
out := string(cmdOut)
if !strings.HasSuffix(out, "\n") {
out = out + "\n"
}
// Replace workDir with $WORK
out = replacePrefix(out, sh.workDir, "$WORK")
// Rewrite mentions of dir with a relative path to dir
// when the relative path is shorter.
for {
// Note that dir starts out long, something like
// /foo/bar/baz/root/a
// The target string to be reduced is something like
// (blah-blah-blah) /foo/bar/baz/root/sibling/whatever.go:blah:blah
// /foo/bar/baz/root/a doesn't match /foo/bar/baz/root/sibling, but the prefix
// /foo/bar/baz/root does. And there may be other niblings sharing shorter
// prefixes, the only way to find them is to look.
// This doesn't always produce a relative path --
// /foo is shorter than ../../.., for example.
if reldir := base.ShortPath(dir); reldir != dir {
out = replacePrefix(out, dir, reldir)
if filepath.Separator == '\\' {
// Don't know why, sometimes this comes out with slashes, not backslashes.
wdir := strings.ReplaceAll(dir, "\\", "/")
out = replacePrefix(out, wdir, reldir)
}
}
dirP := filepath.Dir(dir)
if dir == dirP {
break
}
dir = dirP
}
// Fix up output referring to cgo-generated code to be more readable.
// Replace x.go:19[/tmp/.../x.cgo1.go:18] with x.go:19.
// Replace *[100]_Ctype_foo with *[100]C.foo.
// If we're using -x, assume we're debugging and want the full dump, so disable the rewrite.
if !cfg.BuildX && cgoLine.MatchString(out) {
out = cgoLine.ReplaceAllString(out, "")
out = cgoTypeSigRe.ReplaceAllString(out, "C.")
}
// Usually desc is already p.Desc(), but if not, signal cmdError.Error to
// add a line explicitly metioning the import path.
needsPath := importPath != "" && p != nil && desc != p.Desc()
err := &cmdError{desc, out, importPath, needsPath}
if cmdErr != nil {
// The command failed. Report the output up as an error.
return err
}
// The command didn't fail, so just print the output as appropriate.
if a != nil && a.output != nil {
// The Action is capturing output.
a.output = append(a.output, err.Error()...)
} else {
// Write directly to the Builder output.
sh.Print(err.Error())
}
return nil
}
// replacePrefix is like strings.ReplaceAll, but only replaces instances of old
// that are preceded by ' ', '\t', or appear at the beginning of a line.
func replacePrefix(s, old, new string) string {
n := strings.Count(s, old)
if n == 0 {
return s
}
s = strings.ReplaceAll(s, " "+old, " "+new)
s = strings.ReplaceAll(s, "\n"+old, "\n"+new)
s = strings.ReplaceAll(s, "\n\t"+old, "\n\t"+new)
if strings.HasPrefix(s, old) {
s = new + s[len(old):]
}
return s
}
type cmdError struct {
desc string
text string
importPath string
needsPath bool // Set if desc does not already include the import path
}
func (e *cmdError) Error() string {
var msg string
if e.needsPath {
// Ensure the import path is part of the message.
// Clearly distinguish the description from the import path.
msg = fmt.Sprintf("# %s\n# [%s]\n", e.importPath, e.desc)
} else {
msg = "# " + e.desc + "\n"
}
return msg + e.text
}
func (e *cmdError) ImportPath() string {
return e.importPath
}
var cgoLine = lazyregexp.New(`\[[^\[\]]+\.(cgo1|cover)\.go:[0-9]+(:[0-9]+)?\]`)
var cgoTypeSigRe = lazyregexp.New(`\b_C2?(type|func|var|macro)_\B`)
// run runs the command given by cmdline in the directory dir.
// If the command fails, run prints information about the failure
// and returns a non-nil error.
func (sh *Shell) run(dir string, desc string, env []string, cmdargs ...any) error {
out, err := sh.runOut(dir, env, cmdargs...)
if desc == "" {
desc = sh.fmtCmd(dir, "%s", strings.Join(str.StringList(cmdargs...), " "))
}
return sh.reportCmd(desc, dir, out, err)
}
// runOut runs the command given by cmdline in the directory dir.
// It returns the command output and any errors that occurred.
// It accumulates execution time in a.
func (sh *Shell) runOut(dir string, env []string, cmdargs ...any) ([]byte, error) {
a := sh.action
cmdline := str.StringList(cmdargs...)
for _, arg := range cmdline {
// GNU binutils commands, including gcc and gccgo, interpret an argument
// @foo anywhere in the command line (even following --) as meaning
// "read and insert arguments from the file named foo."
// Don't say anything that might be misinterpreted that way.
if strings.HasPrefix(arg, "@") {
return nil, fmt.Errorf("invalid command-line argument %s in command: %s", arg, joinUnambiguously(cmdline))
}
}
if cfg.BuildN || cfg.BuildX {
var envcmdline string
for _, e := range env {
if j := strings.IndexByte(e, '='); j != -1 {
if strings.ContainsRune(e[j+1:], '\'') {
envcmdline += fmt.Sprintf("%s=%q", e[:j], e[j+1:])
} else {
envcmdline += fmt.Sprintf("%s='%s'", e[:j], e[j+1:])
}
envcmdline += " "
}
}
envcmdline += joinUnambiguously(cmdline)
sh.ShowCmd(dir, "%s", envcmdline)
if cfg.BuildN {
return nil, nil
}
}
var buf bytes.Buffer
path, err := cfg.LookPath(cmdline[0])
if err != nil {
return nil, err
}
cmd := exec.Command(path, cmdline[1:]...)
if cmd.Path != "" {
cmd.Args[0] = cmd.Path
}
cmd.Stdout = &buf
cmd.Stderr = &buf
cleanup := passLongArgsInResponseFiles(cmd)
defer cleanup()
if dir != "." {
cmd.Dir = dir
}
cmd.Env = cmd.Environ() // Pre-allocate with correct PWD.
// Add the TOOLEXEC_IMPORTPATH environment variable for -toolexec tools.
// It doesn't really matter if -toolexec isn't being used.
// Note that a.Package.Desc is not really an import path,
// but this is consistent with 'go list -f {{.ImportPath}}'.
// Plus, it is useful to uniquely identify packages in 'go list -json'.
if a != nil && a.Package != nil {
cmd.Env = append(cmd.Env, "TOOLEXEC_IMPORTPATH="+a.Package.Desc())
}
cmd.Env = append(cmd.Env, env...)
start := time.Now()
err = cmd.Run()
if a != nil && a.json != nil {
aj := a.json
aj.Cmd = append(aj.Cmd, joinUnambiguously(cmdline))
aj.CmdReal += time.Since(start)
if ps := cmd.ProcessState; ps != nil {
aj.CmdUser += ps.UserTime()
aj.CmdSys += ps.SystemTime()
}
}
// err can be something like 'exit status 1'.
// Add information about what program was running.
// Note that if buf.Bytes() is non-empty, the caller usually
// shows buf.Bytes() and does not print err at all, so the
// prefix here does not make most output any more verbose.
if err != nil {
err = errors.New(cmdline[0] + ": " + err.Error())
}
return buf.Bytes(), err
}
// joinUnambiguously prints the slice, quoting where necessary to make the
// output unambiguous.
// TODO: See issue 5279. The printing of commands needs a complete redo.
func joinUnambiguously(a []string) string {
var buf strings.Builder
for i, s := range a {
if i > 0 {
buf.WriteByte(' ')
}
q := strconv.Quote(s)
// A gccgo command line can contain -( and -).
// Make sure we quote them since they are special to the shell.
// The trimpath argument can also contain > (part of =>) and ;. Quote those too.
if s == "" || strings.ContainsAny(s, " ()>;") || len(q) > len(s)+2 {
buf.WriteString(q)
} else {
buf.WriteString(s)
}
}
return buf.String()
}