}
	}
	return nil
}

// walk recursively descends path, calling walkFn.
func walk(path string, info fs.FileInfo, walkFn WalkFunc) error {
	if !info.IsDir() {
		return walkFn(path, info, nil)
	}

	names, err := readDirNames(path)
	err1 := walkFn(path, info, err)
	// If err != nil, walk can't walk into this directory.
	// err1 != nil means walkFn want walk to skip this directory or stop walking.

		if err := walk(filename, fi, walkFn); err != nil {
			if !fi.IsDir() || err != filepath.SkipDir {
				return err
			}
		}
	}
	return nil
}

// Walk walks the file tree rooted at root, calling walkFn for each file or
// directory in the tree, including root.
func Walk(root string, walkFn filepath.WalkFunc) error {
	Trace("Walk", root)
	info, err := Lstat(root)
	if err != nil {

func listStdPkgs(goroot string) ([]string, error) {
	// Based on cmd/go's matchPackages function.
	var pkgs []string

	src := filepath.Join(goroot, "src") + string(filepath.Separator)
	walkFn := func(path string, d fs.DirEntry, err error) error {
		if err != nil || !d.IsDir() || path == src {
			return nil
		}

		base := filepath.Base(path)

			return nil
		}

		if s.walkMu != nil {
			s.walkMu.Lock()
		}
		entries, err := s.ListDir(ctx, "", opts.Bucket, current, -1)
		if s.walkMu != nil {
			s.walkMu.Unlock()
		}
		if err != nil {
			// Folder could have gone away in-between
			if err != errVolumeNotFound && err != errFileNotFound {
				internalLogOnceIf(ctx, err, "metacache-walk-scan-dir")
			}

		if n.Elt != nil {
			Walk(v, n.Elt)
		}

	case *FuncLit:
		Walk(v, n.Type)
		Walk(v, n.Body)

	case *CompositeLit:
		if n.Type != nil {
			Walk(v, n.Type)
		}
		walkList(v, n.Elts)

	case *ParenExpr:
		Walk(v, n.X)

	case *SelectorExpr:
		Walk(v, n.X)
		Walk(v, n.Sel)

	case *IndexExpr:
		Walk(v, n.X)
		Walk(v, n.Index)

	case *IndexListExpr:
		Walk(v, n.X)

}

func walkPkgDirs(dir string, pkgh func(dir string, filenames []string), errh func(args ...interface{})) {
	w := walker{pkgh, errh}
	w.walk(dir)
}

type walker struct {
	pkgh func(dir string, filenames []string)
	errh func(args ...any)
}

func (w *walker) walk(dir string) {
	files, err := os.ReadDir(dir)
	if err != nil {
		w.errh(err)
		return
	}

	extraCalls map[*ir.Func][]nowritebarrierrecCall

	// curfn is the current function during AST walks.
	curfn *ir.Func
}

type nowritebarrierrecCall struct {
	target *ir.Func // caller or callee
	lineno src.XPos // line of call
}

// newNowritebarrierrecChecker creates a nowritebarrierrecChecker. It
// must be called before walk.
func newNowritebarrierrecChecker() *nowritebarrierrecChecker {
	c := &nowritebarrierrecChecker{

	truth, ok := isTrue(indirectInterface(val))
	if !ok {
		s.errorf("if/with can't use %v", val)
	}
	if truth {
		if typ == parse.NodeWith {
			s.walk(val, list)
		} else {
			s.walk(dot, list)
		}
	} else if elseList != nil {
		s.walk(dot, elseList)
	}
}

// IsTrue reports whether the value is 'true', in the sense of not the zero of its type,

  // for such regions to a new unique-id. This is required because walk() walks
  // the attached regions first before visiting the op, so there is no
  // opportunity during the walk to seed region arguments. Also note that walk
  // eventually also visits the Op on which the walk() is called, so make sure
  // we do not overwrite the function argument mapping here.
  func_op.walk([&](Operation* op) {
    if (op == func_op) return;

package ast_test

import (
	"go/ast"
	"go/parser"
	"go/token"
	"testing"
)

func TestPreorderBreak(t *testing.T) {
	// This test checks that Preorder correctly handles a break statement while
	// in the middle of walking a node. Previously, incorrect handling of the
	// boolean returned by the yield function resulted in the iterator calling
	// yield for sibling nodes even after yield had returned false. With that