a.apply(n, "Type", nil, n.Type)
		a.apply(n, "Tag", nil, n.Tag)
		a.apply(n, "Comment", nil, n.Comment)

	case *ast.FieldList:
		a.applyList(n, "List")

	// Expressions
	case *ast.BadExpr, *ast.Ident, *ast.BasicLit:
		// nothing to do

	case *ast.Ellipsis:
		a.apply(n, "Elt", nil, n.Elt)

	case *ast.FuncLit:
		a.apply(n, "Type", nil, n.Type)
		a.apply(n, "Body", nil, n.Body)

		walkBeforeAfter(&n.Type, before, after)
		walkBeforeAfter(&n.Tag, before, after)
	case *ast.FieldList:
		for _, field := range n.List {
			walkBeforeAfter(field, before, after)
		}
	case *ast.BadExpr:
	case *ast.Ident:
	case *ast.Ellipsis:
		walkBeforeAfter(&n.Elt, before, after)
	case *ast.BasicLit:
	case *ast.FuncLit:
		walkBeforeAfter(&n.Type, before, after)
		walkBeforeAfter(&n.Body, before, after)

				check.trace(e0.Pos(), "=> %s // %s", T, goTypeName(T))
			} else {
				check.trace(e0.Pos(), "=> %s (under = %s) // %s", T, under, goTypeName(T))
			}
		}()
	}

	switch e := e0.(type) {
	case *syntax.BadExpr:
		// ignore - error reported before

	case *syntax.Name:
		var x operand
		check.ident(&x, e, def, true)

		switch x.mode {
		case typexpr:
			typ := x.typ
			setDefType(def, typ)

	// already held it's assumed that the first caller exits the program
	// so other calls can hang forever without an issue.
	lock(&raceFiniLock)

	// __tsan_fini will run C atexit functions and C++ destructors,
	// which can theoretically call back into Go.
	// Tell the scheduler we entering external code.
	entersyscall()

	// We're entering external code that may call ExitProcess on

				check.trace(e0.Pos(), "=> %s // %s", T, goTypeName(T))
			} else {
				check.trace(e0.Pos(), "=> %s (under = %s) // %s", T, under, goTypeName(T))
			}
		}()
	}

	switch e := e0.(type) {
	case *ast.BadExpr:
		// ignore - error reported before

	case *ast.Ident:
		var x operand
		check.ident(&x, e, def, true)

		switch x.mode {
		case typexpr:
			typ := x.typ
			setDefType(def, typ)

var helperCommands = map[string]func(...string){
	"echo":          cmdEcho,
	"echoenv":       cmdEchoEnv,
	"cat":           cmdCat,
	"pipetest":      cmdPipeTest,
	"stdinClose":    cmdStdinClose,
	"exit":          cmdExit,
	"describefiles": cmdDescribeFiles,
	"stderrfail":    cmdStderrFail,
	"yes":           cmdYes,
	"hang":          cmdHang,
}

func cmdEcho(args ...string) {
	iargs := []any{}
	for _, s := range args {

	// 	//p.print(newline)
	// }
}

func (p *printer) printRawNode(n Node) {
	switch n := n.(type) {
	case nil:
		// we should not reach here but don't crash

	// expressions and types
	case *BadExpr:
		p.print(_Name, "<bad expr>")

	case *Name:
		p.print(_Name, n.Value) // _Name requires actual value following immediately

	case *BasicLit:

		t.Errorf("for File.FileEnd, got %s, want %s", got, want)
	}
}

// TestIncompleteSelection ensures that an incomplete selector
// expression is parsed as a (blank) *ast.SelectorExpr, not a
// *ast.BadExpr.
func TestIncompleteSelection(t *testing.T) {
	for _, src := range []string{
		"package p; var _ = fmt.",             // at EOF
		"package p; var _ = fmt.\ntype X int", // not at EOF
	} {

		rtyp = ptyp.X
		if unpackParams {
			for _, arg := range syntax.UnpackListExpr(ptyp.Index) {
				var par *syntax.Name
				switch arg := arg.(type) {
				case *syntax.Name:
					par = arg
				case *syntax.BadExpr:
					// ignore - error already reported by parser
				case nil:
					check.error(ptyp, InvalidSyntaxTree, "parameterized receiver contains nil parameters")
				default:

		rtyp = ix.X
		if unpackParams {
			for _, arg := range ix.Indices {
				var par *ast.Ident
				switch arg := arg.(type) {
				case *ast.Ident:
					par = arg
				case *ast.BadExpr:
					// ignore - error already reported by parser
				case nil:
					check.error(ix.Orig, InvalidSyntaxTree, "parameterized receiver contains nil parameters")
				default: