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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <unistd.h>
#include <stdio.h>
#include <stdarg.h>
#include "msg.h"
#include "_libld.h"
/*
* GNU ld --wrap support, also known as -z wrap.
*
* We maintain an AVL tree of wrapped symbol names. Every undefined
* symbol is tested against this tree, and those that match have
* their names modified to produce the wrapping effect:
*
* - An undefined reference to XXX is converted to __wrap_XXX
* - An undefined reference to __real_XXX is converted to XXX
*
* This operation has a cost, but that is mitigated by two factors:
*
* - This is a test feature, not used for production code, so somewhat
* longer link times are tolerable.
* - The cost of this feature is only paid when it is used. Otherwise,
* the sole overhead is the cost of testing the NULL AVL tree pointer
* during symbol processing.
*/
/*
* AVL comparison function for WrapSymNode items.
*
* entry:
* n1, n2 - pointers to nodes to be compared
*
* exit:
* Returns -1 if (n1 < n2), 0 if they are equal, and 1 if (n1 > n2)
*/
static int
wrap_cmp(const void *n1, const void *n2)
{
int rc;
rc = strcmp(((WrapSymNode *)n1)->wsn_name,
((WrapSymNode *)n2)->wsn_name);
if (rc > 0)
return (1);
if (rc < 0)
return (-1);
return (0);
}
/*
* Enter a -z wrap symbol into the ofl_wrap AVL tree
*
* entry:
* ofl - Output file descriptor
* name - Name of symbol to be entered. Caller must ensure that
* memory used to hold name remains available for the life
* of the link-edit process.
*
* exit:
* On success, updates ofl->wrap_cache with a pointer to the
* resulting WrapSymNode, and returns that pointer. On failure,
* returns NULL.
*/
WrapSymNode *
ld_wrap_enter(Ofl_desc *ofl, const char *name)
{
WrapSymNode *wsnp, wsn;
avl_index_t where;
size_t name_len, wrapname_len;
char *tmpname;
/* If this is the first wrap symbol, create the AVL tree */
if (ofl->ofl_wrap == NULL) {
ofl->ofl_wrap = libld_calloc(1, sizeof (*ofl->ofl_wrap));
if (ofl->ofl_wrap == NULL)
return (NULL);
avl_create(ofl->ofl_wrap, wrap_cmp, sizeof (WrapSymNode),
SGSOFFSETOF(WrapSymNode, wsn_avlnode));
}
/* Have we already entered this one? */
wsn.wsn_name = name;
if ((wsnp = avl_find(ofl->ofl_wrap, &wsn, &where)) != NULL)
return (wsnp);
/*
* Allocate a new node, along with room for the wrapped name.
* Since strings have byte alignment, we can allocate it immediately
* following the AVL node without the need for alignment padding.
*/
name_len = strlen(wsn.wsn_name);
wrapname_len = MSG_STR_UU_WRAP_U_SIZE + name_len + 1;
if ((wsnp = libld_calloc(1, sizeof (*wsnp) + wrapname_len)) == NULL)
return (NULL);
wsnp->wsn_name = name;
wsnp->wsn_wrapname = tmpname = (char *)(wsnp + 1);
(void) snprintf(tmpname, wrapname_len, MSG_ORIG(MSG_FMT_STRCAT),
MSG_ORIG(MSG_STR_UU_WRAP_U), name);
/* Insert the new node */
avl_insert(ofl->ofl_wrap, wsnp, where);
return (wsnp);
}
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