}

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
)

	// See https://golang.org/issue/22858.
	out, err := exec.Command(swig, "-version").CombinedOutput()
	if err != nil {
		t.Skipf("failed to get swig version:%s\n%s", err, string(out))
	}

	re := regexp.MustCompile(`[vV]ersion +(\d+)([.]\d+)?([.]\d+)?`)
	matches := re.FindSubmatch(out)
	if matches == nil {
		// Can't find version number; hope for the best.
		t.Logf("failed to find swig version, continuing")
		return
	}

0000190 00 00 00 00 00 00 00 00 00 00 00 72 2f 72 2e 7a
00001a0 69 70 50 4b 05 06 00 00 00 00 01 00 01 00 35 00
00001b0 00 00 6d 01 00 00 00 00`
	s = regexp.MustCompile(`[0-9a-f]{7}`).ReplaceAllString(s, "")
	s = regexp.MustCompile(`\s+`).ReplaceAllString(s, "")
	b, err := hex.DecodeString(s)
	if err != nil {
		panic(err)
	}
	return b
}

func returnRecursiveZip() (r io.ReaderAt, size int64) {

		if got := out.String(); text != got {
			t.Errorf("want full output %q, got %q", text, got)
		}
	}
	wantErr = regexp.MustCompile("^no exit code")
	check("abc")
	check("exitcode")
	check("exitcode=")
	check("exitcode=123\n")
	wantErr = regexp.MustCompile("^bad exit code: .* value out of range")
	check("exitcode=999999999999999999999999")

// It might be at the beginning but it might be in the middle of the printed instruction.
var fileLineRE = regexp.MustCompile(`(?:^|\()(testdata[/\\][\da-z]+\.s:\d+)(?:$|\)|:)`)

// Same as in test/run.go
var (
	errRE       = regexp.MustCompile(`// ERROR ?(.*)`)
	errQuotesRE = regexp.MustCompile(`"([^"]*)"`)
)

func testErrors(t *testing.T, goarch, file string, flags ...string) {

func contextName(c *build.Context) string {
	s := c.GOOS + "-" + c.GOARCH
	if c.CgoEnabled {
		s += "-cgo"
	}
	if c.Dir != "" {
		s += fmt.Sprintf(" [%s]", c.Dir)
	}
	return s
}

var internalPkg = regexp.MustCompile(`(^|/)internal($|/)`)

var exitCode = 0

func Check(t *testing.T) {
	checkFiles, err := filepath.Glob(filepath.Join(testenv.GOROOT(t), "api/go1*.txt"))
	if err != nil {
		t.Fatal(err)
	}

	// This is the only case we use a group, and we'll use this
	// group to extract the numeric code.
	fmt.Fprintf(&exitReStr, "%s([0-9]+)$", exitStr)
	exitRe := regexp.MustCompile(exitReStr.String())

	return &exitCodeFilter{w: w, exitRe: exitRe}, exitStr
}

func (f *exitCodeFilter) Write(data []byte) (int, error) {
	n := len(data)
	f.buf.Write(data)

pkg regexp, func Match(string, []uint8) (bool, error)
pkg regexp, func MatchReader(string, io.RuneReader) (bool, error)
pkg regexp, func MatchString(string, string) (bool, error)
pkg regexp, func MustCompile(string) *Regexp
pkg regexp, func MustCompilePOSIX(string) *Regexp
pkg regexp, func QuoteMeta(string) string
pkg regexp, method (*Regexp) Expand([]uint8, []uint8, []uint8, []int) []uint8