}

var warmupCache = sync.OnceFunc(func() {
	// Warm up the import cache in parallel.
	var wg sync.WaitGroup
	for _, context := range contexts {
		context := context
		wg.Add(1)
		go func() {
			defer wg.Done()
			_ = NewWalker(context, filepath.Join(testenv.GOROOT(nil), "src"))
		}()
	}
	wg.Wait()
})

func TestIssue21181(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping with -short")
	}

			}()
		}
		runtime.GOMAXPROCS(threads)
		argv := append(os.Args, "-test.run=^$")
		if err := syscall.Exec(os.Args[0], argv, os.Environ()); err != nil {
			t.Fatal(err)
		}
	}

	var cmds []*exec.Cmd
	defer func() {
		for _, cmd := range cmds {
			cmd.Process.Kill()
		}
	}()

	args := append(append([]string(nil), os.Args[1:]...), "-test.run=^Test18146$")
	for n := attempts; n > 0; n-- {

	fw *flate.Writer
}

func (w *pooledFlateWriter) Write(p []byte) (n int, err error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	if w.fw == nil {
		return 0, errors.New("Write after Close")
	}
	return w.fw.Write(p)
}

func (w *pooledFlateWriter) Close() error {
	w.mu.Lock()
	defer w.mu.Unlock()
	var err error
	if w.fw != nil {
		err = w.fw.Close()
		flateWriterPool.Put(w.fw)
		w.fw = nil
	}

		if err := os.Symlink(srcPath, dstPath); err == nil {
			return nil
		}

		// Otherwise, copy the bytes.
		src, err := os.Open(srcPath)
		if err != nil {
			return err
		}
		defer src.Close()

		dst, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
		if err != nil {
			return err
		}

		_, err = io.Copy(dst, src)
		if closeErr := dst.Close(); err == nil {

)

func testBuildID(t *testing.T) {
	f, err := elf.Open("/proc/self/exe")
	if err != nil {
		if os.IsNotExist(err) {
			t.Skip("no /proc/self/exe")
		}
		t.Fatal("opening /proc/self/exe: ", err)
	}
	defer f.Close()

	c := 0
sections:
	for i, s := range f.Sections {
		if s.Type != elf.SHT_NOTE {
			continue
		}

		d, err := s.Data()
		if err != nil {

		if _, err := os.Stat("/etc/alpine-release"); err == nil {
			t.Skip("skipping failing test on alpine - go.dev/issue/19938")
		}
	}

	// Launch some threads in C.
	const cts = 5
	C.trial(cts)
	defer C.cleanup()

	vs := []struct {
		call           string
		fn             func() error
		filter, expect string
	}{

	case "all", "ret":
		ctxt.Retpoline = true
	}

	ctxt.Bso = bufio.NewWriter(os.Stdout)
	defer ctxt.Bso.Flush()

	architecture.Init(ctxt)

	// Create object file, write header.
	buf, err := bio.Create(*flags.OutputFile)
	if err != nil {
		log.Fatal(err)
	}
	defer buf.Close()

	if !*flags.SymABIs {
		buf.WriteString(objabi.HeaderString())
		fmt.Fprintf(buf, "!\n")
	}

	return
}

// url may contain a #fragment, and the fragment is then noted as needing to exist.
func crawl(url string, sourceURL string) {
	if strings.Contains(url, "/devel/release") {
		return
	}
	mu.Lock()
	defer mu.Unlock()
	if u, frag, ok := strings.Cut(url, "#"); ok {
		url = u
		if frag != "" {
			uf := urlFrag{url, frag}
			neededFrags[uf] = append(neededFrags[uf], sourceURL)
		}
	}
	if crawled[url] {
		return

func TestAddr2Line(t *testing.T) {
	testenv.MustHaveGoBuild(t)

	tmpDir, err := os.MkdirTemp("", "TestAddr2Line")
	if err != nil {
		t.Fatal("TempDir failed: ", err)
	}
	defer os.RemoveAll(tmpDir)

	// Build copy of test binary with debug symbols,
	// since the one running now may not have them.
	exepath := filepath.Join(tmpDir, "testaddr2line_test.exe")

	fmt.Fprintf(&buf, "\n")

	override := make(map[string]string)

	// Allow source file to specify override mappings.
	// For example, the socket data structures refer
	// to in_addr and in_addr6 structs but we want to be
	// able to treat them as byte arrays, so the godefs
	// inputs in package syscall say
	//
	//	// +godefs map struct_in_addr [4]byte