libgo/go/internal/testenv/testenv_windows.go

   1 // Copyright 2016 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package testenv
   6
   7 import (
   8         "io/ioutil"
   9         "os"
  10         "path/filepath"
  11         "sync"
  12         "syscall"
  13 )
  14
  15 var symlinkOnce sync.Once
  16 var winSymlinkErr error
  17
  18 func initWinHasSymlink() {
  19         tmpdir, err := ioutil.TempDir("", "symtest")
  20         if err != nil {
  21                 panic("failed to create temp directory: " + err.Error())
  22         }
  23         defer os.RemoveAll(tmpdir)
  24
  25         err = os.Symlink("target", filepath.Join(tmpdir, "symlink"))
  26         if err != nil {
  27                 err = err.(*os.LinkError).Err
  28                 switch err {
  29                 case syscall.EWINDOWS, syscall.ERROR_PRIVILEGE_NOT_HELD:
  30                         winSymlinkErr = err
  31                 }
  32         }
  33 }
  34
  35 func hasSymlink() (ok bool, reason string) {
  36         symlinkOnce.Do(initWinHasSymlink)
  37
  38         switch winSymlinkErr {
  39         case nil:
  40                 return true, ""
  41         case syscall.EWINDOWS:
  42                 return false, ": symlinks are not supported on your version of Windows"
  43         case syscall.ERROR_PRIVILEGE_NOT_HELD:
  44                 return false, ": you don't have enough privileges to create symlinks"
  45         }
  46
  47         return false, ""
  48 }