cmd/cgo: remove -O options when generating compiler errors

The cgo tool generates compiler errors to find out what kind of name it
is using.  Turning on optimization can confuse that process by producing
new unexpected messages.

Fixes #14669.

Change-Id: Idc8e35fd259711ecc9638566b691c11d17140325
Reviewed-on: https://go-review.googlesource.com/23231
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/misc/cgo/errors/issue14669.go b/misc/cgo/errors/issue14669.go
new file mode 100644 (file)
index 0000000..04d2bcb
--- /dev/null
+++ b/misc/cgo/errors/issue14669.go
@@ -0,0 +1,23 @@
+// Copyright 2016 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.
+
+// Issue 14669: test that fails when build with CGO_CFLAGS selecting
+// optimization.
+
+package p
+
+/*
+const int E = 1;
+
+typedef struct s {
+       int       c;
+} s;
+*/
+import "C"
+
+func F() {
+       _ = C.s{
+               c: C.E,
+       }
+}

diff --git a/misc/cgo/errors/test.bash b/misc/cgo/errors/test.bash
index cd358a10f815e0fe13c9c8be143a4f07ee334c7f..643d03820502850015a3081aec4f7cc6db3e9433 100755 (executable)
--- a/misc/cgo/errors/test.bash
+++ b/misc/cgo/errors/test.bash
@@ -45,6 +45,13 @@ expect issue13129.go C.ushort
 check issue13423.go
 expect issue13635.go C.uchar C.schar C.ushort C.uint C.ulong C.longlong C.ulonglong C.complexfloat C.complexdouble
 
+if ! go build issue14669.go; then
+       exit 1
+fi
+if ! CGO_CFLAGS="-O" go build issue14669.go; then
+       exit 1
+fi
+
 if ! go run ptr.go; then
        exit 1
 fi

diff --git a/src/cmd/cgo/gcc.go b/src/cmd/cgo/gcc.go
index 97ef824c9342a727a15b4d799e00cf832e5d6e6b..451798244f6db2a48fd0793a74622faa96b85d92 100644 (file)
--- a/src/cmd/cgo/gcc.go
+++ b/src/cmd/cgo/gcc.go
@@ -1243,12 +1243,20 @@ func (p *Package) gccErrors(stdin []byte) string {
        // TODO(rsc): require failure
        args := p.gccCmd()
 
+       // Optimization options can confuse the error messages; remove them.
+       nargs := make([]string, 0, len(args))
+       for _, arg := range args {
+               if !strings.HasPrefix(arg, "-O") {
+                       nargs = append(nargs, arg)
+               }
+       }
+
        if *debugGcc {
-               fmt.Fprintf(os.Stderr, "$ %s <<EOF\n", strings.Join(args, " "))
+               fmt.Fprintf(os.Stderr, "$ %s <<EOF\n", strings.Join(nargs, " "))
                os.Stderr.Write(stdin)
                fmt.Fprint(os.Stderr, "EOF\n")
        }
-       stdout, stderr, _ := run(stdin, args)
+       stdout, stderr, _ := run(stdin, nargs)
        if *debugGcc {
                os.Stderr.Write(stdout)
                os.Stderr.Write(stderr)