testName, err := filepath.Rel("./testdata", testPath)
		if err != nil {
			t.Fatalf("failed to relativize testdata path: %v", err)
		}
		t.Run(testName, func(t *testing.T) {
			tr, exp, err := testtrace.ParseFile(testPath)
			if err != nil {
				t.Fatalf("failed to parse test file at %s: %v", testPath, err)
			}
			testReader(t, tr, exp)
		})
	}
}

func FuzzReader(f *testing.F) {

}

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
	}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package route

import (
	"syscall"
	"unsafe"
)

func (typ RIBType) parseable() bool { return true }

// RouteMetrics represents route metrics.
type RouteMetrics struct {
	PathMTU int // path maximum transmission unit
}

// SysType implements the SysType method of Sys interface.

// 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)

		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 {

			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()

	// check if the verbosity level in klog is high enough and print a stack trace.
	f := flag.CommandLine.Lookup("v")
	if f != nil {
		// assume that the "v" flag contains a parseable Int32 as per klog's "Level" type alias,
		// thus no error from ParseInt is handled here.
		if v, e := strconv.ParseInt(f.Value.String(), 10, 32); e == nil {

	}
}

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")
	}