cc.go

func stealDefinesFromCC() (defs string, ok bool) {
	cc, ok := os.LookupEnv("CC")
	if !ok { // second chance for CPP
		cc, ok = os.LookupEnv("CPP")
		if !ok {
			return
		}
	}
	cmd := exec.Command(cc, "-dM", "-E", "-x", "c", "/dev/null")
	buf, err := cmd.CombinedOutput()
	if err != nil {
		log.Println("[WARN]:", err)
		return
	}
	defs = string(buf)
	return defs, true
}