cmd/go: use temporary file for output of gcc command on Windows
On Windows, some of gcc command (like msys2 native) output NUL as a file.
Fixes #36000
Change-Id: I02c632fa2d710a011d79f24d5beee4bc57ad994e
Reviewed-on: https://go-review.googlesource.com/c/go/+/233977
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go
index 6ab3498..071c9d2 100644
--- a/src/cmd/go/internal/work/exec.go
+++ b/src/cmd/go/internal/work/exec.go
@@ -2434,13 +2434,25 @@
if b.flagCache == nil {
b.flagCache = make(map[[2]string]bool)
}
+
+ tmp := os.DevNull
+ if runtime.GOOS == "windows" {
+ f, err := ioutil.TempFile(b.WorkDir, "")
+ if err != nil {
+ return false
+ }
+ f.Close()
+ tmp = f.Name()
+ defer os.Remove(tmp)
+ }
+
// We used to write an empty C file, but that gets complicated with
// go build -n. We tried using a file that does not exist, but that
// fails on systems with GCC version 4.2.1; that is the last GPLv2
// version of GCC, so some systems have frozen on it.
// Now we pass an empty file on stdin, which should work at least for
// GCC and clang.
- cmdArgs := str.StringList(compiler, flag, "-c", "-x", "c", "-", "-o", os.DevNull)
+ cmdArgs := str.StringList(compiler, flag, "-c", "-x", "c", "-", "-o", tmp)
if cfg.BuildN || cfg.BuildX {
b.Showcmd(b.WorkDir, "%s || true", joinUnambiguously(cmdArgs))
if cfg.BuildN {
diff --git a/src/cmd/go/testdata/script/issue36000.txt b/src/cmd/go/testdata/script/issue36000.txt
new file mode 100644
index 0000000..4173275
--- /dev/null
+++ b/src/cmd/go/testdata/script/issue36000.txt
@@ -0,0 +1,6 @@
+# Tests golang.org/issue/36000
+
+[!cgo] skip
+
+# go env with CGO flags should not make NUL file
+go env CGO_CFLAGS
