case "line":
		in.line()
	case "undef":
		in.undef()
	default:
		in.Error("unexpected token after '#':", in.Stack.Text())
	}
	return true
}

// macroName returns the name for the macro being referenced.
func (in *Input) macroName() string {
	// We use the Stack's input method; no macro processing at this stage.
	tok := in.Stack.Next()
	if tok != scanner.Ident {

	ROT                                   // @> Used on ARM for shift type 4, rotate right.
	Include                               // included file started here
	BuildComment                          // //go:build or +build comment
	macroName                             // name of macro that should not be expanded
)

// IsRegisterShift reports whether the token is one of the ARM register shift operators.
func IsRegisterShift(r ScanToken) bool {