blob: ce24748f4e33af58498ab15b7de6dbb9c7ff1b50 [file] [log] [blame]
// Copyright 2011 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.
// Package run implements the ``go run'' command.
package run
import (
var CmdRun = &base.Command{
UsageLine: "run [build flags] [-exec xprog] gofiles... [arguments...]",
Short: "compile and run Go program",
Long: `
Run compiles and runs the main package comprising the named Go source files.
A Go source file is defined to be a file ending in a literal ".go" suffix.
By default, 'go run' runs the compiled binary directly: 'a.out arguments...'.
If the -exec flag is given, 'go run' invokes the binary using xprog:
'xprog a.out arguments...'.
If the -exec flag is not given, GOOS or GOARCH is different from the system
default, and a program named go_$GOOS_$GOARCH_exec can be found
on the current search path, 'go run' invokes the binary using that program,
for example 'go_nacl_386_exec a.out arguments...'. This allows execution of
cross-compiled programs when a simulator or other execution method is
For more about build flags, see 'go help build'.
See also: go build.
func init() {
CmdRun.Run = runRun // break init loop
CmdRun.Flag.Var((*base.StringsFlag)(&work.ExecCmd), "exec", "")
func printStderr(args ...interface{}) (int, error) {
return fmt.Fprint(os.Stderr, args...)
func runRun(cmd *base.Command, args []string) {
var b work.Builder
b.Print = printStderr
i := 0
for i < len(args) && strings.HasSuffix(args[i], ".go") {
files, cmdArgs := args[:i], args[i:]
if len(files) == 0 {
base.Fatalf("go run: no go files listed")
for _, file := range files {
if strings.HasSuffix(file, "_test.go") {
// GoFilesPackage is going to assign this to TestGoFiles.
// Reject since it won't be part of the build.
base.Fatalf("go run: cannot run *_test.go files (%s)", file)
p := load.GoFilesPackage(files)
if p.Error != nil {
base.Fatalf("%s", p.Error)
p.Internal.OmitDebug = true
if len(p.DepsErrors) > 0 {
// Since these are errors in dependencies,
// the same error might show up multiple times,
// once in each package that depends on it.
// Only print each once.
printed := map[*load.PackageError]bool{}
for _, err := range p.DepsErrors {
if !printed[err] {
printed[err] = true
base.Errorf("%s", err)
if p.Name != "main" {
base.Fatalf("go run: cannot run non-main package")
p.Target = "" // must build - not up to date
var src string
if len(p.GoFiles) > 0 {
src = p.GoFiles[0]
} else if len(p.CgoFiles) > 0 {
src = p.CgoFiles[0]
} else {
// this case could only happen if the provided source uses cgo
// while cgo is disabled.
hint := ""
if !cfg.BuildContext.CgoEnabled {
hint = " (cgo is disabled)"
base.Fatalf("go run: no suitable source files%s", hint)
p.Internal.ExeName = src[:len(src)-len(".go")] // name temporary executable for first go file
a1 := b.LinkAction(work.ModeBuild, work.ModeBuild, p)
a := &work.Action{Mode: "go run", Func: buildRunProgram, Args: cmdArgs, Deps: []*work.Action{a1}}
// buildRunProgram is the action for running a binary that has already
// been compiled. We ignore exit status.
func buildRunProgram(b *work.Builder, a *work.Action) error {
cmdline := str.StringList(work.FindExecCmd(), a.Deps[0].Target, a.Args)
if cfg.BuildN || cfg.BuildX {
b.Showcmd("", "%s", strings.Join(cmdline, " "))
if cfg.BuildN {
return nil
return nil