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/* List Utilities
* Copyright (C) 2009 Chris Hall (GMCH), Highwayman
*
* This file is part of GNU Zebra.
*
* GNU Zebra is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* GNU Zebra is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Zebra; see the file COPYING. If not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <list_util.h>
/*==============================================================================
* Single Base, Single Link
*/
/*------------------------------------------------------------------------------
* Deleting item
*
* Have to chase down list to find item.
*
* Note that p_this:
*
* * starts as pointer to the base pointer, so should really be void**,
* but that causes all sorts of problems with strict-aliasing.
*
* So: have to cast to (void**) before dereferencing to get the address
* of the first item on the list.
*
* * as steps along the list p_this points to the "next pointer" in the
* previous item.
*
* The _sl_p_next() macro adds the offset of the "next pointer" to the
* address of the this item.
*
* * at the end, assigns the item's "next pointer" to the "next pointer"
* field pointed at by p_this.
*
* Note again the cast to (void**).
*
* Returns: 0 => OK -- removed item from list (OR item == NULL)
* -1 => item not found on list
*/
extern int
ssl_del_func(void* p_this, void* item, size_t link_offset)
{
void* this ;
if (item == NULL)
return 0 ;
while ((this = *(void**)p_this) != item)
{
if (this == NULL)
return -1 ;
p_this = _sl_p_next(this, link_offset) ;
} ;
*(void**)p_this = _sl_next(item, link_offset) ;
return 0 ;
} ;
/*==============================================================================
* Single Base, Double Link
*/
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