* invoked step trace */
    int curFlags;		/* Trace flags for the current command */
    int curCode;		/* Return code for the current command */
    size_t refCount;		/* Used to ensure this structure is not
				 * deleted too early. Keeps track of how many
				 * pieces of code have a pointer to this
				 * structure. */
    char command[TCLFLEXARRAY];		/* Space for Tcl command to invoke. Actual
				 * size will be as large as necessary to hold
				 * command. This field must be the last in the
				 * structure, so that it can be larger than 1
				 * byte. */
} TraceCommandInfo;

/*

 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void *
Tcl_CommandTraceInfo(
    Tcl_Interp *interp,		/* Interpreter containing command. */
    const char *cmdName,	/* Name of command. */
    TCL_UNUSED(int) /*flags*/,
    Tcl_CommandTraceProc *proc,	/* Function assocated with trace. */
    void *prevClientData)	/* If non-NULL, gives last value returned by
				 * this function, so this call will return the

	/*
	 * Second, create the tcl callback, if required.
	 */

	if (call) {
	    Tcl_DString cmd, sub;
	    int i;
	    int saveInterpFlags;

	    Tcl_DStringInit(&cmd);
	    Tcl_DStringAppend(&cmd, tcmdPtr->command, tcmdPtr->length);

	    /*
	     * Append command with arguments.
	     */

    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateObjTrace/Tcl_CreateObjTrace2 --
 *
 *	Arrange for a function to be called to trace command execution.
 *
 * Results:
 *	The return value is a token for the trace, which may be passed to
 *	Tcl_DeleteTrace to eliminate the trace.
 *
 * Side effects:
 *	From now on, proc will be called just before a command function is
 *	called to execute a Tcl command. Calls to proc will have the following
 *	form:
 *
 *	void proc(void   *	 clientData,
 *		  Tcl_Interp *	 interp,
 *		  int		 level,
 *		  const char *	 command,
 *		  Tcl_Command	 commandInfo,
 *		  int		 objc,
 *		  Tcl_Obj *const objv[]);
 *

 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void *
Tcl_VarTraceInfo2(
    Tcl_Interp *interp,		/* Interpreter containing variable. */
    const char *part1,		/* Name of variable or array. */
    const char *part2,		/* Name of element within array; NULL means
				 * trace applies to scalar variable or array
				 * as-a-whole. */
    int flags,			/* OR-ed combination of TCL_GLOBAL_ONLY,