Tcl_Obj *litList;	/* List to hold the literals. */
    Tcl_Obj *funcList;	/* List to hold the functon names. */
    Tcl_Parse *exprParsePtr = (Tcl_Parse *)TclStackAlloc(interp, sizeof(Tcl_Parse));
				/* Holds the Tcl_Tokens of substitutions. */

    TclNewObj(litList);
    TclNewObj(funcList);
    if ((numBytes == TCL_INDEX_NONE)
	    || ((sizeof(int) != sizeof(size_t)) && (numBytes > (size_t)INT_MIN))) {
	numBytes = (start ? strlen(start) : 0);
    }

    code = ParseExpr(interp, start, numBytes, &opTree, litList, funcList,
	    exprParsePtr, 1 /* parseOnly */);
    Tcl_DecrRefCount(funcList);
    Tcl_DecrRefCount(litList);