"fmt"
	"os"
	"path/filepath"
	"runtime"
)

// AppendPWD returns the result of appending PWD=dir to the environment base.
//
// The resulting environment makes os.Getwd more efficient for a subprocess
// running in dir, and also improves the accuracy of paths relative to dir
// if one or more elements of dir is a symlink.
func AppendPWD(base []string, dir string) []string {
	// POSIX requires PWD to be absolute.

var fixDocs = flag.Bool("fixdocs", false, "if true, update alldocs.go")

func TestDocsUpToDate(t *testing.T) {
	testenv.MustHaveGoBuild(t)
	if !*fixDocs {
		t.Parallel()
	}

	// We run 'go help documentation' as a subprocess instead of
	// calling help.Help directly because it may be sensitive to
	// init-time configuration
	cmd := testenv.Command(t, testGo, "help", "documentation")
	// Unset GO111MODULE so that the 'go get' section matches

		}
	}
}

// The prime sieve: Daisy-chain Filter processes together.
func Sieve(primes chan<- int) {
	ch := make(chan int) // Create a new channel.
	go Generate(ch)      // Start Generate() as a subprocess.
	for {
		// Note that ch is different on each iteration.
		prime := <-ch
		primes <- prime
		ch1 := make(chan int)
		go Filter(ch, ch1, prime)
		ch = ch1
	}
}

func main() {

	os.Setenv(targetEnv, gotoolchain)
	if dir == "" {
		os.Unsetenv("GOROOT")
	} else {
		os.Setenv("GOROOT", dir)
	}

	// On Windows, there is no syscall.Exec, so the best we can do
	// is run a subprocess and exit with the same status.
	// Doing the same on Unix would be a problem because it wouldn't
	// propagate signals and such, but there are no signals on Windows.
	// We also use the exec case when GODEBUG=gotoolchainexec=0,

def run_shell(cmd, allow_non_zero=False, stderr=None):
  if stderr is None:
    stderr = sys.stdout
  if allow_non_zero:
    try:
      output = subprocess.check_output(cmd, stderr=stderr)
    except subprocess.CalledProcessError as e:
      output = e.output
  else:
    output = subprocess.check_output(cmd, stderr=stderr)
  return output.decode('UTF-8').strip()


def cygpath(path):
  """Convert path from posix to windows."""

	}
	defer pr.Close()

	// Wait for "x\nx\n" to indicate almost-readiness.
	buf := make([]byte, 4)
	_, err = io.ReadFull(pr, buf)
	if err != nil || string(buf) != "x\nx\n" {
		t.Fatal("subprocess failed; output:\n", string(buf))
	}

	// The child blockers print "x\n" and then block on a lock. Receiving
	// those bytes only indicates that the child is _about to block_. Since

	link := filepath.Join(t.TempDir(), "link")
	if err := os.Symlink(cwd, link); err != nil {
		t.Fatal(err)
	}

	// Now link is another equally-valid name for cwd. If we set Dir to one and
	// PWD to the other, the subprocess should report the PWD version.
	cases := []struct {
		name string
		dir  string
		pwd  string
	}{
		{name: "original PWD", pwd: cwd},
		{name: "link PWD", pwd: link},

// for the resulting error.
func MustHaveExec(t testing.TB) {
	tryExecOnce.Do(func() {
		tryExecErr = tryExec()
	})
	if tryExecErr != nil {
		t.Skipf("skipping test: cannot exec subprocess on %s/%s: %v", runtime.GOOS, runtime.GOARCH, tryExecErr)
	}
}

var (
	tryExecOnce sync.Once
	tryExecErr  error
)

func tryExec() error {
	switch runtime.GOOS {
	case "wasip1", "js", "ios":

	if err != nil {
		t.Fatal(err)
	}

	t.Logf("running %s", cmd)
	err = cmd.Start()
	if err != nil {
		t.Fatalf("starting subprocess: %s", err)
	}
	w.Close()
	t.Cleanup(func() {
		stdin.Close()
		if err := cmd.Wait(); err != nil {
			t.Errorf("suprocess failed with: %s", err)
		}
	})

	buf := make([]byte, 2)
	n, err := io.ReadFull(r, buf)

type TintPointer struct {
	p *Tint
}

func (*TintPointer) m() {}

func TestFinalizerRegisterABI(t *testing.T) {
	testenv.MustHaveExec(t)

	// Actually run the test in a subprocess because we don't want
	// finalizers from other tests interfering.
	if os.Getenv("TEST_FINALIZER_REGABI") != "1" {
		cmd := testenv.CleanCmdEnv(exec.Command(os.Args[0], "-test.run=^TestFinalizerRegisterABI$", "-test.v"))