// MustHaveCGO calls t.Skip if cgo is not available.
func MustHaveCGO(t testing.TB) {
	if !HasCGO() {
		t.Skipf("skipping test: no cgo")
	}
}

// CanInternalLink reports whether the current system can link programs with
// internal linking.
func CanInternalLink(withCgo bool) bool {
	return !platform.MustLinkExternal(runtime.GOOS, runtime.GOARCH, withCgo)
}

	// TODO: maybe there is some way to tell the external linker not to put
	// those symbols in the executable's symbol table? Prefix the symbol name
	// with "." or "L" to pretend it is a label?
	if !testenv.CanInternalLink(false) {
		return
	}

	syms, err := f.Symbols()
	if err != nil {
		t.Fatalf("error reading symbols: %v", err)
	}
	for _, sym := range syms {
		if strings.Contains(sym.Name, "stmp") {

		}
		if string(out) != "hello\n" && string(out) != "hello\r\n" {
			t.Errorf("unexpected output (%s):\n%s", mode, out)
		}

		// Test internal linking mode.

		if !testenv.CanInternalLink(true) {
			continue
		}
		cmd = testenv.Command(t, testenv.GoToolPath(t), "build", "-buildmode="+mode, "-ldflags=-debugtramp=2 -linkmode=internal", "-o", exe, src)
		out, err = cmd.CombinedOutput()
		if err != nil {