}
	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
		t.Logf("%s", out)
		t.Fatal(err)
	}

	darwin := "0"
	if runtime.GOOS == "darwin" {
		darwin = "1"
	}
	cmd = exec.Command(bin[0], append(bin[1:], darwin)...)

	if out, err := cmd.CombinedOutput(); err != nil {
		t.Logf("%s", out)
		t.Fatal(err)
	}
}

func TestSignalForwarding(t *testing.T) {

	}
}

func TestBuildForTvOS(t *testing.T) {
	testenv.MustHaveCGO(t)
	testenv.MustHaveGoBuild(t)

	// Only run this on darwin, where we can cross build for tvOS.
	if runtime.GOOS != "darwin" {
		t.Skip("skipping on non-darwin platform")
	}
	if testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
		t.Skip("skipping in -short mode with $GO_BUILDER_NAME empty")
	}

	// run this test on just a small set of platforms (no need to test it
	// across the board given the nature of the test).
	pair := runtime.GOOS + "-" + runtime.GOARCH
	switch pair {
	case "darwin-amd64", "darwin-arm64", "linux-amd64", "freebsd-amd64":
	default:
		t.Skip("no need for test on " + pair)
	}
	switch runtime.GOOS {
	case "openbsd", "windows":
		t.Skip("c-archive unsupported")
	}

		cc = append(cc, s[start:])
	}

	switch GOOS {
	case "darwin", "ios":
		// For Darwin/ARM.
		// TODO(crawshaw): can we do better?
		cc = append(cc, []string{"-framework", "CoreFoundation", "-framework", "Foundation"}...)
	case "android":
		cc = append(cc, "-pie")
	}
	libgodir := GOOS + "_" + GOARCH
	switch GOOS {
	case "darwin", "ios":
		if GOARCH == "arm64" {
			libgodir += "_shared"
		}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build darwin || dragonfly || freebsd || netbsd || openbsd

// BSD system call wrappers shared by *BSD based systems
// including OS X (Darwin) and FreeBSD.  Like the other
// syscall_*.go files it is compiled as Go code but also
// used as input to mksyscall which parses the //sys

		mode = "asan"
	}
	modeFlag := "-" + mode

	// Check that cgo is enabled.
	// Note: On macOS, -race does not require cgo. -asan and -msan still do.
	if !cfg.BuildContext.CgoEnabled && (cfg.Goos != "darwin" || cfg.BuildASan || cfg.BuildMSan) {
		if runtime.GOOS != cfg.Goos || runtime.GOARCH != cfg.Goarch {
			fmt.Fprintf(os.Stderr, "go: %s requires cgo\n", modeFlag)
		} else {

	}

	if *useGdb {
		debugger = "gdb"
		_, err := exec.LookPath(gdb)
		if err != nil {
			if runtime.GOOS != "darwin" {
				skipReasons += "not run because gdb not on path; "
			} else {
				// On Darwin, MacPorts installs gdb as "ggdb".
				_, err = exec.LookPath("ggdb")
				if err != nil {

Operators have the same meaning as in Go.

For example, the following build constraint constrains a file to
build when the "linux" and "386" constraints are satisfied, or when
"darwin" is satisfied and "cgo" is not:

	//go:build (linux && 386) || (darwin && !cgo)

It is an error for a file to have more than one //go:build line.

During a particular build, the following build tags are satisfied:

// go run mksysnum.go /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.1.sdk/usr/include/sys/syscall.h
// Code generated by the command above; see README.md. DO NOT EDIT.

//go:build arm64 && darwin

package unix

// Deprecated: Use libSystem wrappers instead of direct syscalls.
const (
	SYS_SYSCALL                        = 0
	SYS_EXIT                           = 1
	SYS_FORK                           = 2

// a boolean indicating if it is an LLVM objdump.
func findObjdump(paths []string) (string, bool, bool) {
	objdumpNames := []string{"llvm-objdump", "objdump"}
	if runtime.GOOS == "darwin" {
		objdumpNames = append(objdumpNames, "gobjdump")
	}

	for _, objdumpName := range objdumpNames {
		if objdump, objdumpFound := findExe(objdumpName, paths); objdumpFound {