os: on OpenBSD implement Executable using Args[0]
OpenBSD no longer has procfs.
Based on a patch by Matthieu Sarter.
Fixes #19453.
Change-Id: Ia09d16f8a1cbef2f8cc1c5f49e9c61ec7d026a40
Reviewed-on: https://go-review.googlesource.com/46004
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/os/executable_path.go b/src/os/executable_path.go
new file mode 100644
index 0000000..057e6a7
--- /dev/null
+++ b/src/os/executable_path.go
@@ -0,0 +1,104 @@
+// Copyright 2017 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.
+
+// +build openbsd
+
+package os
+
+// We query the working directory at init, to use it later to search for the
+// executable file
+// errWd will be checked later, if we need to use initWd
+var initWd, errWd = Getwd()
+
+func executable() (string, error) {
+ var exePath string
+ if len(Args) == 0 || Args[0] == "" {
+ return "", ErrNotExist
+ }
+ if IsPathSeparator(Args[0][0]) {
+ // Args[0] is an absolute path, so it is the executable.
+ // Note that we only need to worry about Unix paths here.
+ exePath = Args[0]
+ } else {
+ for i := 1; i < len(Args[0]); i++ {
+ if IsPathSeparator(Args[0][i]) {
+ // Args[0] is a relative path: prepend the
+ // initial working directory.
+ if errWd != nil {
+ return "", errWd
+ }
+ exePath = initWd + string(PathSeparator) + Args[0]
+ break
+ }
+ }
+ }
+ if exePath != "" {
+ if err := isExecutable(exePath); err != nil {
+ return "", err
+ }
+ return exePath, nil
+ }
+ // Search for executable in $PATH.
+ for _, dir := range splitPathList(Getenv("PATH")) {
+ if len(dir) == 0 {
+ dir = "."
+ }
+ if !IsPathSeparator(dir[0]) {
+ if errWd != nil {
+ return "", errWd
+ }
+ dir = initWd + string(PathSeparator) + dir
+ }
+ exePath = dir + string(PathSeparator) + Args[0]
+ switch isExecutable(exePath) {
+ case nil:
+ return exePath, nil
+ case ErrPermission:
+ return "", ErrPermission
+ }
+ }
+ return "", ErrNotExist
+}
+
+// isExecutable returns an error if a given file is not an executable.
+func isExecutable(path string) error {
+ stat, err := Stat(path)
+ if err != nil {
+ return err
+ }
+ mode := stat.Mode()
+ if !mode.IsRegular() {
+ return ErrPermission
+ }
+ if (mode & 0111) == 0 {
+ return ErrPermission
+ }
+ return nil
+}
+
+// splitPathList splits a path list.
+// This is based on genSplit from strings/strings.go
+func splitPathList(pathList string) []string {
+ if pathList == "" {
+ return nil
+ }
+ n := 1
+ for i := 0; i < len(pathList); i++ {
+ if pathList[i] == PathListSeparator {
+ n++
+ }
+ }
+ start := 0
+ a := make([]string, n)
+ na := 0
+ for i := 0; i+1 <= len(pathList) && na+1 < n; i++ {
+ if pathList[i] == PathListSeparator {
+ a[na] = pathList[start:i]
+ na++
+ start = i + 1
+ }
+ }
+ a[na] = pathList[start:]
+ return a[:na+1]
+}
diff --git a/src/os/executable_procfs.go b/src/os/executable_procfs.go
index 69a70e1..b5fae59 100644
--- a/src/os/executable_procfs.go
+++ b/src/os/executable_procfs.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// +build linux netbsd openbsd dragonfly nacl
+// +build linux netbsd dragonfly nacl
package os
@@ -23,8 +23,6 @@
procfn = "/proc/self/exe"
case "netbsd":
procfn = "/proc/curproc/exe"
- case "openbsd":
- procfn = "/proc/curproc/file"
case "dragonfly":
procfn = "/proc/curproc/file"
}
diff --git a/src/os/executable_test.go b/src/os/executable_test.go
index a4d8909..a6aeb07 100644
--- a/src/os/executable_test.go
+++ b/src/os/executable_test.go
@@ -20,10 +20,6 @@
testenv.MustHaveExec(t) // will also execlude nacl, which doesn't support Executable anyway
ep, err := os.Executable()
if err != nil {
- switch goos := runtime.GOOS; goos {
- case "openbsd": // procfs is not mounted by default
- t.Skipf("Executable failed on %s: %v, expected", goos, err)
- }
t.Fatalf("Executable failed: %v", err)
}
// we want fn to be of the form "dir/prog"
@@ -32,6 +28,13 @@
if err != nil {
t.Fatalf("filepath.Rel: %v", err)
}
+
+ if runtime.GOOS == "openbsd" {
+ // The rest of the test doesn't work on OpenBSD,
+ // which relies on argv[0].
+ t.Skipf("skipping remainder of test on %s", runtime.GOOS)
+ }
+
cmd := &osexec.Cmd{}
// make child start with a relative program path
cmd.Dir = dir
