return
	}
	cc1 := defaultcc[""]
	if cc1 == "" {
		cc1 = "gcc"
		for _, os := range clangos {
			if gohostos == os {
				cc1 = "clang"
				break
			}
		}
	}
	cc, err := quotedSplit(cc1)
	if err != nil {
		fatalf("split CC: %v", err)
	}
	var ccHelp = append(cc, "--help")

	if output, err := exec.Command(ccHelp[0], ccHelp[1:]...).CombinedOutput(); err != nil {
		outputHdr := ""