result := drain(input)
		if result != test.output {
			t.Errorf("%s: got %q expected %q", test.name, result, test.output)
		}
	}
}

// lines joins the arguments together as complete lines.
func lines(a ...string) string {
	return strings.Join(a, "\n") + "\n"
}

// drain returns a single string representing the processed input tokens.
func drain(input *Input) string {
	var buf strings.Builder
	for {

	fis, err := td.Readdir(0)
	if err != nil {
		t.Fatal(err)
	}
	for _, fi := range fis {
		if !fi.IsDir() {
			continue
		}

		// TODO(gri) remove extra pkg directory eventually
		goldenFile := filepath.Join("testdata", "src", "pkg", fi.Name(), "golden.txt")
		w := NewWalker(nil, "testdata/src/pkg")
		pkg, _ := w.import_(fi.Name())
		w.export(pkg)

		if *updateGolden {
			os.Remove(goldenFile)

	testdata, err := os.ReadDir("testdata")
	if err != nil {
		f.Fatalf("failed to read testdata directory: %s", err)
	}
	for _, de := range testdata {
		if de.IsDir() {
			continue
		}
		b, err := os.ReadFile(filepath.Join("testdata", de.Name()))
		if err != nil {
			f.Fatalf("failed to read testdata: %s", err)
		}
		f.Add(b)
	}

	f.Fuzz(func(t *testing.T, b []byte) {
		r, err := NewReader(bytes.NewReader(b), int64(len(b)))

	output, err := exec.Command(swig, "-go", "-swiglib").Output()
	if err != nil {
		t.Skip("swig is missing Go support")
	}
	swigDir := strings.TrimSpace(string(output))

	_, err = os.Stat(filepath.Join(swigDir, "go"))
	if err != nil {
		t.Skip("swig is missing Go support")
	}

	// Check that swig has a new enough version.
	// See https://golang.org/issue/22858.

		s := r.data[r.step]
		n = copy(p, s)
		r.step++
	} else {
		err = io.EOF
	}
	return
}

func readRuneSegments(t *testing.T, segments []string) {
	got := ""
	want := strings.Join(segments, "")
	r := NewReader(&StringReader{data: segments})
	for {
		r, _, err := r.ReadRune()
		if err != nil {
			if err != io.EOF {
				return
			}
			break
		}
		got += string(r)
	}

		case '/':
			//-style comment (no newline at the end)
			c = c[2:] + "\n"
		case '*':
			/*-style comment */
			c = c[2 : len(c)-2]
		}
		pieces = append(pieces, c)
	}
	return strings.Join(pieces, "")
}

func (f *File) validateIdents(x interface{}, context astContext) {
	if x, ok := x.(*ast.Ident); ok {
		if f.isMangledName(x.Name) {

		z, err = NewReader(rat, size)
		raw = make([]byte, size)
		if _, err := rat.ReadAt(raw, 0); err != nil {
			t.Errorf("ReadAt error=%v", err)
			return
		}
	} else {
		path := filepath.Join("testdata", zt.Name)
		if zt.Obscured {
			tf, err := obscuretestdata.DecodeToTempFile(path)
			if err != nil {
				t.Errorf("obscuretestdata.DecodeToTempFile(%s): %v", path, err)
				return
			}

assignment of regular parameters.
</p>

<pre>
func Split(s string, pos int) (string, string) {
	return s[0:pos], s[pos:]
}

func Join(s, t string) string {
	return s + t
}

if Join(Split(value, len(value)/2)) != value {
	log.Panic("test fails")
}
</pre>

<p>
A method call <code>x.m()</code> is valid if the <a href="#Method_sets">method set</a>

pkg syscall (netbsd-arm64-cgo), const IPV6_HOPOPTS ideal-int
pkg syscall (netbsd-arm64-cgo), const IPV6_IPSEC_POLICY = 28
pkg syscall (netbsd-arm64-cgo), const IPV6_IPSEC_POLICY ideal-int
pkg syscall (netbsd-arm64-cgo), const IPV6_JOIN_GROUP = 12
pkg syscall (netbsd-arm64-cgo), const IPV6_LEAVE_GROUP = 13
pkg syscall (netbsd-arm64-cgo), const IPV6_MAXHLIM = 255
pkg syscall (netbsd-arm64-cgo), const IPV6_MAXHLIM ideal-int

		if err != nil || srcPath == srcRoot {
			return err
		}

		suffix := strings.TrimPrefix(srcPath, srcRoot)
		for len(suffix) > 0 && suffix[0] == filepath.Separator {
			suffix = suffix[1:]
		}
		dstPath := filepath.Join(dstRoot, suffix)

		perm := info.Mode() & os.ModePerm
		if info.Mode()&os.ModeSymlink != 0 {
			info, err = os.Stat(srcPath)
			if err != nil {
				return err
			}
			perm = info.Mode() & os.ModePerm
		}