url, frag string
}

var (
	mu          sync.Mutex
	crawled     = make(map[string]bool)      // URL without fragment -> true
	neededFrags = make(map[urlFrag][]string) // URL#frag -> who needs it
)

var aRx = regexp.MustCompile(`<a href=['"]?(/[^\s'">]+)`)

// Owned by crawlLoop goroutine:
var (
	linkSources = make(map[string][]string) // url no fragment -> sources
	fragExists  = make(map[urlFrag]bool)
	problems    []string
)

	{faces, "☹", -1, []string{"☺☻", ""}},
	{faces, "~", -1, []string{faces}},
	{faces, "", -1, []string{"☺", "☻", "☹"}},
	{"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
	{"1 2", " ", 3, []string{"1", "2"}},
	{"123", "", 2, []string{"1", "23"}},
	{"123", "", 17, []string{"1", "2", "3"}},
	{"bT", "T", math.MaxInt / 4, []string{"b", ""}},
	{"\xff-\xff", "", -1, []string{"\xff", "-", "\xff"}},
	{"\xff-\xff", "-", -1, []string{"\xff", "\xff"}},
}

	cmd := testenv.Command(t, testenv.GoToolPath(t), "tool", "nm", dbgExePath)
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("%v: %v\n%s", cmd, err, string(out))
	}
	syms := make(map[string]string)
	scanner := bufio.NewScanner(bytes.NewReader(out))
	for scanner.Scan() {
		f := strings.Fields(scanner.Text())
		if len(f) < 3 {
			continue
		}
		syms[f[2]] = f[0]
	}

	for name, id := range goIdent {
		if id.Name == name && strings.Contains(name, "_Ctype_union") {
			if def := typedef[name]; def != nil {
				id.Name = gofmt(def)
			}
		}
	}

	conf.Fprint(&buf, fset, f.AST)

	return buf.String()
}

var gofmtBuf strings.Builder

// gofmt returns the gofmt-formatted string for an AST node.
func gofmt(n interface{}) string {
	gofmtBuf.Reset()

	Register map[string]int16
	// Table of register prefix names. These are things like R for R(0) and SPR for SPR(268).
	RegisterPrefix map[string]bool
	// RegisterNumber converts R(10) into arm.REG_R10.
	RegisterNumber func(string, int16) (int16, bool)
	// Instruction is a jump.
	IsJump func(word string) bool
}

// nilRegisterNumber is the register number function for architectures
// that do not accept the R(N) notation. It always returns failure.

func (f *fileListEntry) String() string {
	return fs.FormatDirEntry(f)
}

// toValidName coerces name to be a valid name for fs.FS.Open.
func toValidName(name string) string {
	name = strings.ReplaceAll(name, `\`, `/`)
	p := path.Clean(name)

	p = strings.TrimPrefix(p, "/")

	for strings.HasPrefix(p, "../") {
		p = p[len("../"):]
	}

	return p
}

func (f *Format) mayOnlyBe(f2 Format) { *f &= f2 }
func (f *Format) mustNotBe(f2 Format) { *f &^= f2 }

var formatNames = map[Format]string{
	formatV7: "V7", FormatUSTAR: "USTAR", FormatPAX: "PAX", FormatGNU: "GNU", formatSTAR: "STAR",
}

func (f Format) String() string {
	var ss []string
	for f2 := Format(1); f2 < formatMax; f2 <<= 1 {
		if f.has(f2) {
			ss = append(ss, formatNames[f2])
		}
	}
	switch len(ss) {

	// Output: ["Achtung! Achtung"]
}

func ExampleTrimFunc() {
	fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsLetter)))
	fmt.Println(string(bytes.TrimFunc([]byte("\"go-gopher!\""), unicode.IsLetter)))
	fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsPunct)))
	fmt.Println(string(bytes.TrimFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
	// Output:
	// -gopher!
	// "go-gopher!"

	const input = "1234 5678 1234567901234567890"
	scanner := bufio.NewScanner(strings.NewReader(input))
	// Create a custom split function by wrapping the existing ScanWords function.
	split := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		advance, token, err = bufio.ScanWords(data, atEOF)
		if err == nil && token != nil {
			_, err = strconv.ParseInt(string(token), 10, 32)
		}
		return
	}

import (
	big "."
	"runtime"
)

func fibber(c chan *big.Int, out chan string, n int64) {
	// Keep the fibbers in dedicated operating system
	// threads, so that this program tests coordination
	// between pthreads and not just goroutines.
	runtime.LockOSThread()

	i := big.NewInt(n)
	if n == 0 {
		c <- i
	}
	for {
		j := <-c
		out <- j.String()
		i.Add(i, j)
		c <- i
	}
}

func main() {