cgo: put CFLAGS before filename argument

This means that the -x flag can work, which could enable
support for other languages (e.g. objective-C).

R=iant, rsc
CC=golang-dev
https://golang.org/cl/4476049

diff --git a/src/cmd/cgo/gcc.go b/src/cmd/cgo/gcc.go
index ae5ca2c7da0de877b3d872a59431a66ea4bd6099..ac656134598a944392f0c0fbc7893e7ef72dced3 100644 (file)
--- a/src/cmd/cgo/gcc.go
+++ b/src/cmd/cgo/gcc.go
@@ -604,7 +604,7 @@ const gccTmp = "_obj/_cgo_.o"
 // gccCmd returns the gcc command line to use for compiling
 // the input.
 func (p *Package) gccCmd() []string {
-       return []string{
+       c := []string{
                p.gccName(),
                p.gccMachine(),
                "-Wall",                             // many warnings
@@ -614,15 +614,17 @@ func (p *Package) gccCmd() []string {
                "-fno-eliminate-unused-debug-types", // gets rid of e.g. untyped enum otherwise
                "-c",                                // do not link
                "-xc",                               // input language is C
-               "-",                                 // read input from standard input
        }
+       c = append(c, p.GccOptions...)
+       c = append(c, "-") //read input from standard input
+       return c
 }
 
 // gccDebug runs gcc -gdwarf-2 over the C program stdin and
 // returns the corresponding DWARF data and any messages
 // printed to standard error.
 func (p *Package) gccDebug(stdin []byte) *dwarf.Data {
-       runGcc(stdin, append(p.gccCmd(), p.GccOptions...))
+       runGcc(stdin, p.gccCmd())
 
        // Try to parse f as ELF and Mach-O and hope one works.
        var f interface {
@@ -649,8 +651,8 @@ func (p *Package) gccDebug(stdin []byte) *dwarf.Data {
 // #defines that gcc encountered while processing the input
 // and its included files.
 func (p *Package) gccDefines(stdin []byte) string {
-       base := []string{p.gccName(), p.gccMachine(), "-E", "-dM", "-xc", "-"}
-       stdout, _ := runGcc(stdin, append(base, p.GccOptions...))
+       base := []string{p.gccName(), p.gccMachine(), "-E", "-dM", "-xc"}
+       stdout, _ := runGcc(stdin, append(append(base, p.GccOptions...), "-"))
        return stdout
 }
 
@@ -659,7 +661,7 @@ func (p *Package) gccDefines(stdin []byte) string {
 // gcc to fail.
 func (p *Package) gccErrors(stdin []byte) string {
        // TODO(rsc): require failure
-       args := append(p.gccCmd(), p.GccOptions...)
+       args := p.gccCmd()
        if *debugGcc {
                fmt.Fprintf(os.Stderr, "$ %s <<EOF\n", strings.Join(args, " "))
                os.Stderr.Write(stdin)