// gccCmd returns the gcc command line to use for compiling
// the input.
func (p *Package) gccCmd() []string {
	c := append(gccBaseCmd,
		"-w",          // no warnings
		"-Wno-error",  // warnings are not errors
		"-o"+gccTmp(), // write object to tmp
		"-gdwarf-2",   // generate DWARF v2 debugging symbols
		"-c",          // do not link
		"-xc",         // input language is C
	)
	if p.GccIsClang {
		c = append(c,