}

func fnop(*ast.File) bool { return false }

func parseFixPrint(t *testing.T, fn func(*ast.File) bool, desc, in string, mustBeGofmt bool) (out string, fixed, ok bool) {
	file, err := parser.ParseFile(fset, desc, in, parserMode)
	if err != nil {
		t.Errorf("parsing: %v", err)
		return
	}

	outb, err := gofmtFile(file)
	if err != nil {
		t.Errorf("printing: %v", err)
		return
	}

// the same source and formatted appropriately.
func ExtractDoc(content, name string) (string, error) {
	if content == "" {
		return "", fmt.Errorf("empty Go source file")
	}
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, "", content, parser.ParseComments|parser.PackageClauseOnly)
	if err != nil {
		return "", fmt.Errorf("not a Go source file")
	}
	if f.Doc == nil {
		return "", fmt.Errorf("Go source file has no package doc comment")

			type R interface {} // must not shadow R in first line of this function body
		}
		`,
	}

	fset := token.NewFileSet()
	var files []*ast.File
	for i, src := range sources {
		file, err := parser.ParseFile(fset, "p", src, parser.ParseComments)
		if err != nil {
			t.Fatalf("could not parse file %d: %s", i, err)
		}

		// Materialized aliases give a different (better)

			defer wg.Done()
			src, err := open(filepath)
			if err != nil {
				errors[i] = err // open provides operation and filename in error
				return
			}
			files[i], errors[i] = parser.ParseFile(p.fset, filepath, src, parser.SkipObjectResolution)
			src.Close() // ignore Close error - parsing may have succeeded which is all we need
		}(i, p.joinPath(dir, filename))
	}
	wg.Wait()

		if err := checkOtherFile(pass, name); err != nil {
			return nil, err
		}
	}
	for _, name := range pass.IgnoredFiles {
		if strings.HasSuffix(name, ".go") {
			f, err := parser.ParseFile(pass.Fset, name, nil, parser.ParseComments)
			if err != nil {
				// Not valid Go source code - not our job to diagnose, so ignore.
				return nil, nil
			}
			checkGoFile(pass, f)
		} else {

	}
}

func mkbuiltin(w io.Writer) {
	pkg := "runtime"
	fset := token.NewFileSet()
	path := filepath.Join("..", "..", "compile", "internal", "typecheck", "_builtin", "runtime.go")
	f, err := parser.ParseFile(fset, path, nil, 0)
	if err != nil {
		log.Fatal(err)
	}

	decls := make(map[string]bool)

	fmt.Fprintf(w, "var builtins = [...]struct{ name string; abi int }{\n")
	for _, decl := range f.Decls {

func TestDocs(t *testing.T) {
	want := formatDesc(t)

	src, err := os.ReadFile("doc.go")
	if err != nil {
		t.Fatal(err)
	}
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, "doc.go", src, parser.ParseComments)
	if err != nil {
		t.Fatal(err)
	}
	fdoc := f.Doc
	if fdoc == nil {
		t.Fatal("no doc comment in doc.go")
	}

		// TODO(gri) Do this more efficiently.
		var buf bytes.Buffer
		err := config.Fprint(&buf, fset, file)
		if err != nil {
			return err
		}
		file, err = parser.ParseFile(fset, "", buf.Bytes(), parserMode)
		if err != nil {
			// We should never get here. If we do, provide good diagnostic.
			return fmt.Errorf("format.Node internal error (%s)", err)
		}
		ast.SortImports(fset, file)

			continue
		}
		text, err := os.ReadFile(filepath.Join("testdata", f.Name()))
		if err != nil {
			t.Fatalf("can't read testdata/%s: %v", f.Name(), err)
		}
		fset := token.NewFileSet()
		code, err := parser.ParseFile(fset, f.Name(), text, 0)
		if err != nil {
			t.Fatalf("can't parse testdata/%s: %v", f.Name(), err)
		}
		srcs = append(srcs, filepath.Join("testdata", f.Name()))
		foundTest := false

		if err := checkOtherFile(pass, name); err != nil {
			return nil, err
		}
	}
	for _, name := range pass.IgnoredFiles {
		if strings.HasSuffix(name, ".go") {
			f, err := parser.ParseFile(pass.Fset, name, nil, parser.ParseComments)
			if err != nil {
				// Not valid Go source code - not our job to diagnose, so ignore.
				continue
			}
			checkGoFile(pass, f)
		} else {