glibc/elf/dl-dst.h

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/* Handling of dynamic sring tokens.
Copyright (C) 1999-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include "trusted-dirs.h"
/* Determine the number of DST elements in the name. Only if IS_PATH is
nonzero paths are recognized (i.e., multiple, ':' separated filenames). */
#define DL_DST_COUNT(name, is_path) \
({ \
size_t __cnt = 0; \
const char *__sf = strchr (name, '$'); \
\
if (__glibc_unlikely (__sf != NULL)) \
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__cnt = _dl_dst_count (__sf, is_path); \
\
__cnt; })
#ifdef SHARED
# define IS_RTLD(l) (l) == &GL(dl_rtld_map)
#else
# define IS_RTLD(l) 0
#endif
/* Guess from the number of DSTs the length of the result string. */
#define DL_DST_REQUIRED(l, name, len, cnt) \
({ \
size_t __len = (len); \
size_t __cnt = (cnt); \
\
if (__cnt > 0) \
{ \
size_t dst_len; \
/* Now we make a guess how many extra characters on top of the \
length of S we need to represent the result. We know that \
we have CNT replacements. Each at most can use \
MAX (MAX (strlen (ORIGIN), strlen (_dl_platform)), \
strlen (DL_DST_LIB)) \
minus 4 (which is the length of "$LIB"). \
\
First get the origin string if it is not available yet. \
This can only happen for the map of the executable or, when \
auditing, in ld.so. */ \
if ((l)->l_origin == NULL) \
{ \
assert ((l)->l_name[0] == '\0' || IS_RTLD (l)); \
(l)->l_origin = _dl_get_origin (); \
dst_len = ((l)->l_origin && (l)->l_origin != (char *) -1 \
? strlen ((l)->l_origin) : 0); \
} \
else \
dst_len = (l)->l_origin == (char *) -1 \
? 0 : strlen ((l)->l_origin); \
dst_len = MAX (MAX (dst_len, GLRO(dl_platformlen)), \
strlen (DL_DST_LIB)); \
if (dst_len > 4) \
__len += __cnt * (dst_len - 4); \
} \
\
__len; })