tclbasic.c

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	 */

	oldRefPtr = cmdPtr->importRefPtr;
	cmdPtr->importRefPtr = NULL;

	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
	hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &new);
	if (!new) {
	    /*
	     * If the deletion callback recreated the command, just throw
	     * away the new command (if we try to delete it again, we
	     * could get stuck in an infinite loop).
	     */

	     ckfree((char *) Tcl_GetHashValue(hPtr));
	}
    }
    cmdPtr = (Command *) ckalloc(sizeof(Command));
    Tcl_SetHashValue(hPtr, cmdPtr);
    cmdPtr->hPtr = hPtr;
    cmdPtr->nsPtr = nsPtr;
    cmdPtr->refCount = 1;
    cmdPtr->cmdEpoch = 0;
    cmdPtr->compileProc = (CompileProc *) NULL;
    cmdPtr->objProc = proc;
    cmdPtr->objClientData = clientData;
    cmdPtr->proc = TclInvokeObjectCommand;
    cmdPtr->clientData = (ClientData) cmdPtr;
    cmdPtr->deleteProc = deleteProc;
    cmdPtr->deleteData = clientData;
    cmdPtr->flags = 0;
    cmdPtr->importRefPtr = NULL;
    cmdPtr->tracePtr = NULL;

    /*
     * Plug in any existing import references found above.  Be sure
     * to update all of these references to point to the new command.
     */

    if (oldRefPtr != NULL) {
	cmdPtr->importRefPtr = oldRefPtr;
	while (oldRefPtr != NULL) {
	    refCmdPtr = oldRefPtr->importedCmdPtr;
	    dataPtr = (ImportedCmdData*)refCmdPtr->objClientData;
	    dataPtr->realCmdPtr = cmdPtr;
	    oldRefPtr = oldRefPtr->nextPtr;
	}
    }
    
    /*
     * We just created a command, so in its namespace and all of its parent
     * namespaces, it may shadow global commands with the same name. If any
     * shadowed commands are found, invalidate all cached command references
     * in the affected namespaces.
     */
    
    TclResetShadowedCmdRefs(interp, cmdPtr);
    return (Tcl_Command) cmdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * TclInvokeStringCommand --
 *
 *	"Wrapper" Tcl_ObjCmdProc used to call an existing string-based
 *	Tcl_CmdProc if no object-based procedure exists for a command. A
 *	pointer to this procedure is stored as the Tcl_ObjCmdProc in a
 *	Command structure. It simply turns around and calls the string
 *	Tcl_CmdProc in the Command structure.
 *
 * Results:
 *	A standard Tcl object result value.
 *
 * Side effects:
 *	Besides those side effects of the called Tcl_CmdProc,
 *	TclInvokeStringCommand allocates and frees storage.
 *
 *----------------------------------------------------------------------
 */

int
TclInvokeStringCommand(clientData, interp, objc, objv)
    ClientData clientData;	/* Points to command's Command structure. */
    Tcl_Interp *interp;		/* Current interpreter. */
    register int objc;		/* Number of arguments. */
    Tcl_Obj *CONST objv[];	/* Argument objects. */
{
    register Command *cmdPtr = (Command *) clientData;
    register int i;
    int result;

    /*
     * This procedure generates an argv array for the string arguments. It
     * starts out with stack-allocated space but uses dynamically-allocated
     * storage if needed.
     */

#define NUM_ARGS 20
    CONST char *(argStorage[NUM_ARGS]);
    CONST char **argv = argStorage;

    /*
     * Create the string argument array "argv". Make sure argv is large
     * enough to hold the objc arguments plus 1 extra for the zero
     * end-of-argv word.
     */

    if ((objc + 1) > NUM_ARGS) {
	argv = (CONST char **) ckalloc((unsigned)(objc + 1) * sizeof(char *));
    }

    for (i = 0;  i < objc;  i++) {
	argv[i] = Tcl_GetString(objv[i]);
    }
    argv[objc] = 0;

    /*
     * Invoke the command's string-based Tcl_CmdProc.
     */

    result = (*cmdPtr->proc)(cmdPtr->clientData, interp, objc, argv);

    /*
     * Free the argv array if malloc'ed storage was used.
     */

    if (argv != argStorage) {
	ckfree((char *) argv);
    }
    return result;
#undef NUM_ARGS
}

/*
 *----------------------------------------------------------------------
 *
 * TclInvokeObjectCommand --
 *
 *	"Wrapper" Tcl_CmdProc used to call an existing object-based
 *	Tcl_ObjCmdProc if no string-based procedure exists for a command.
 *	A pointer to this procedure is stored as the Tcl_CmdProc in a
 *	Command structure. It simply turns around and calls the object
 *	Tcl_ObjCmdProc in the Command structure.
 *
 * Results:
 *	A standard Tcl string result value.
 *
 * Side effects:
 *	Besides those side effects of the called Tcl_CmdProc,
 *	TclInvokeStringCommand allocates and frees storage.
 *
 *----------------------------------------------------------------------
 */

int
TclInvokeObjectCommand(clientData, interp, argc, argv)
    ClientData clientData;	/* Points to command's Command structure. */
    Tcl_Interp *interp;		/* Current interpreter. */
    int argc;			/* Number of arguments. */
    register CONST char **argv;	/* Argument strings. */
{
    Command *cmdPtr = (Command *) clientData;
    register Tcl_Obj *objPtr;
    register int i;
    int length, result;

    /*
     * This procedure generates an objv array for object arguments that hold
     * the argv strings. It starts out with stack-allocated space but uses
     * dynamically-allocated storage if needed.
     */

#define NUM_ARGS 20
    Tcl_Obj *(argStorage[NUM_ARGS]);
    register Tcl_Obj **objv = argStorage;

    /*
     * Create the object argument array "objv". Make sure objv is large
     * enough to hold the objc arguments plus 1 extra for the zero
     * end-of-objv word.
     */

    if ((argc + 1) > NUM_ARGS) {
	objv = (Tcl_Obj **)
	    ckalloc((unsigned)(argc + 1) * sizeof(Tcl_Obj *));
    }

    for (i = 0;  i < argc;  i++) {
	length = strlen(argv[i]);
	TclNewObj(objPtr);
	TclInitStringRep(objPtr, argv[i], length);
	Tcl_IncrRefCount(objPtr);
	objv[i] = objPtr;
    }
    objv[argc] = 0;

    /*
     * Invoke the command's object-based Tcl_ObjCmdProc.
     */

    result = (*cmdPtr->objProc)(cmdPtr->objClientData, interp, argc, objv);

    /*
     * Move the interpreter's object result to the string result, 
     * then reset the object result.
     */

    Tcl_SetResult(interp, TclGetString(Tcl_GetObjResult(interp)),
	    TCL_VOLATILE);
    
    /*
     * Decrement the ref counts for the argument objects created above,
     * then free the objv array if malloc'ed storage was used.
     */

    for (i = 0;  i < argc;  i++) {
	objPtr = objv[i];
	Tcl_DecrRefCount(objPtr);
    }
    if (objv != argStorage) {
	ckfree((char *) objv);
    }
    return result;
#undef NUM_ARGS
}

/*
 *----------------------------------------------------------------------
 *
 * TclRenameCommand --
 *
 *      Called to give an existing Tcl command a different name. Both the
 *      old command name and the new command name can have "::" namespace
 *      qualifiers. If the new command has a different namespace context,
 *      the command will be moved to that namespace and will execute in
 *	the context of that new namespace.
 *
 *      If the new command name is NULL or the null string, the command is
 *      deleted.
 *
 * Results:
 *      Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *      If anything goes wrong, an error message is returned in the
 *      interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

int
TclRenameCommand(interp, oldName, newName)
    Tcl_Interp *interp;                 /* Current interpreter. */
    char *oldName;                      /* Existing command name. */
    char *newName;                      /* New command name. */
{
    Interp *iPtr = (Interp *) interp;
    CONST char *newTail;
    Namespace *cmdNsPtr, *newNsPtr, *dummy1, *dummy2;
    Tcl_Command cmd;
    Command *cmdPtr;
    Tcl_HashEntry *hPtr, *oldHPtr;
    int new, result;
    Tcl_Obj* oldFullName;
    Tcl_DString newFullName;

    /*
     * Find the existing command. An error is returned if cmdName can't
     * be found.
     */

    cmd = Tcl_FindCommand(interp, oldName, (Tcl_Namespace *) NULL,
	/*flags*/ 0);
    cmdPtr = (Command *) cmd;
    if (cmdPtr == NULL) {
	Tcl_AppendStringsToObj(Tcl_GetObjResult(interp), "can't ",
                ((newName == NULL)||(*newName == '\0'))? "delete":"rename",
                " \"", oldName, "\": command doesn't exist", (char *) NULL);
	return TCL_ERROR;
    }
    cmdNsPtr = cmdPtr->nsPtr;
    oldFullName = Tcl_NewObj();
    Tcl_IncrRefCount( oldFullName );
    Tcl_GetCommandFullName( interp, cmd, oldFullName );

    /*
     * If the new command name is NULL or empty, delete the command. Do this
     * with Tcl_DeleteCommandFromToken, since we already have the command.
     */
    
    if ((newName == NULL) || (*newName == '\0')) {
	Tcl_DeleteCommandFromToken(interp, cmd);
	result = TCL_OK;
	goto done;
    }

    /*
     * Make sure that the destination command does not already exist.
     * The rename operation is like creating a command, so we should
     * automatically create the containing namespaces just like
     * Tcl_CreateCommand would.
     */

    TclGetNamespaceForQualName(interp, newName, (Namespace *) NULL,
       CREATE_NS_IF_UNKNOWN, &newNsPtr, &dummy1, &dummy2, &newTail);

    if ((newNsPtr == NULL) || (newTail == NULL)) {
	Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
		 "can't rename to \"", newName, "\": bad command name",
    	    	 (char *) NULL);
	result = TCL_ERROR;
	goto done;
    }
    if (Tcl_FindHashEntry(&newNsPtr->cmdTable, newTail) != NULL) {
	Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
		 "can't rename to \"", newName,
		 "\": command already exists", (char *) NULL);
	result = TCL_ERROR;
	goto done;
    }

    /*
     * Warning: any changes done in the code here are likely
     * to be needed in Tcl_HideCommand() code too.
     * (until the common parts are extracted out)     --dl
     */

    /*
     * Put the command in the new namespace so we can check for an alias
     * loop. Since we are adding a new command to a namespace, we must
     * handle any shadowing of the global commands that this might create.
     */
    
    oldHPtr = cmdPtr->hPtr;
    hPtr = Tcl_CreateHashEntry(&newNsPtr->cmdTable, newTail, &new);
    Tcl_SetHashValue(hPtr, (ClientData) cmdPtr);
    cmdPtr->hPtr = hPtr;
    cmdPtr->nsPtr = newNsPtr;
    TclResetShadowedCmdRefs(interp, cmdPtr);

    /*
     * Now check for an alias loop. If we detect one, put everything back
     * the way it was and report the error.
     */

    result = TclPreventAliasLoop(interp, interp, (Tcl_Command) cmdPtr);
    if (result != TCL_OK) {
        Tcl_DeleteHashEntry(cmdPtr->hPtr);
        cmdPtr->hPtr = oldHPtr;
        cmdPtr->nsPtr = cmdNsPtr;
	goto done;
    }

    /*
     * Script for rename traces can delete the command "oldName".
     * Therefore increment the reference count for cmdPtr so that
     * it's Command structure is freed only towards the end of this
     * function by calling TclCleanupCommand.
     *
     * The trace procedure needs to get a fully qualified name for
     * old and new commands [Tcl bug #651271], or else there's no way
     * for the trace procedure to get the namespace from which the old
     * command is being renamed!
     */

    Tcl_DStringInit( &newFullName );
    Tcl_DStringAppend( &newFullName, newNsPtr->fullName, -1 );
    if ( newNsPtr != iPtr->globalNsPtr ) {
	Tcl_DStringAppend( &newFullName, "::", 2 );
    }
    Tcl_DStringAppend( &newFullName, newTail, -1 );
    cmdPtr->refCount++;
    CallCommandTraces( iPtr, cmdPtr,
		       Tcl_GetString( oldFullName ),
		       Tcl_DStringValue( &newFullName ),
		       TCL_TRACE_RENAME);
    Tcl_DStringFree( &newFullName );

    /*
     * The new command name is okay, so remove the command from its
     * current namespace. This is like deleting the command, so bump
     * the cmdEpoch to invalidate any cached references to the command.
     */
    
    Tcl_DeleteHashEntry(oldHPtr);
    cmdPtr->cmdEpoch++;

    /*
     * If the command being renamed has a compile procedure, increment the
     * interpreter's compileEpoch to invalidate its compiled code. This
     * makes sure that we don't later try to execute old code compiled for
     * the now-renamed command.
     */

    if (cmdPtr->compileProc != NULL) {
	iPtr->compileEpoch++;
    }

    /*
     * Now free the Command structure, if the "oldName" command has
     * been deleted by invocation of rename traces.
     */
    TclCleanupCommand(cmdPtr);
    result = TCL_OK;

    done:
    TclDecrRefCount( oldFullName );
    return result;
}

/*
 *----------------------------------------------------------------------