#define TclInvalidateStringRep(objPtr) \
    if (objPtr->bytes != NULL) { \
	if (objPtr->bytes != tclEmptyStringRep) { \
	    ckfree((char *) objPtr->bytes); \
	} \
	objPtr->bytes = NULL; \
    }

#define TclHasStringRep(objPtr) \
    objPtr->bytes != NULL

/*
 *----------------------------------------------------------------
 * Macros used by the Tcl core to grow Tcl_Token arrays. They use the same
 * growth algorithm as used in tclStringObj.c for growing strings. The ANSI C
 * "prototype" for this macro is:
 *

    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{

    Interp *iPtr = (Interp *) interp;
    CmdFrame *invoker = NULL;
    int word = 0;
    int havelevel = 0;
    int result;
    CallFrame *savedVarFramePtr, *framePtr;
    Tcl_Obj *objPtr;

    if (objc < 2) {
    /* to do 
    *    simplify things by interpreting the argument as a command when there
    *    is only one argument.  This requires a TIP since currently a single
    *    argument is interpreted as a level indicator if possible.
    */
    uplevelSyntax:
	Tcl_WrongNumArgs(interp, 1, objv, "?level? command ?arg ...?");
	return TCL_ERROR;
    } else if (objc == 2) {
    } else if (!TclHasStringRep(objv[1]) && objc == 2) {
	int status ,llength;
	status = Tcl_ListObjLength(interp, objv[1], &llength);
	if (status == TCL_OK && llength > 1) {
	    /* the first argument can't interpreted as a level. Avoid
	     * generating a string representation of the script. */
	    result = TclGetFrame(interp, "1", &framePtr);
	    if (result == -1) {
		return TCL_ERROR;
	    }
	    havelevel = 1;
	    objc -= 1;
	    objv += 1;
	    goto havelevel;
	}
    }

    if (!havelevel) {
	/*
	 * Find the level to use for executing the command.
	 */
    /*
     * Find the level to use for executing the command.
     */

	result = TclObjGetFrame(interp, objv[1], &framePtr);
	if (result == -1) {
	    return TCL_ERROR;
	}
	objc -= result + 1;
	if (objc == 0) {
	    goto uplevelSyntax;
	}
	objv += result + 1;
    }

    result = TclObjGetFrame(interp, objv[1], &framePtr);
    if (result == -1) {
	return TCL_ERROR;
    }
    objc -= result + 1;
    if (objc == 0) {
	goto uplevelSyntax;
    }
    objv += result + 1;

    havelevel:

    /*
     * Modify the interpreter state to execute in the given frame.
     */

    savedVarFramePtr = iPtr->varFramePtr;
    iPtr->varFramePtr = framePtr;