elf/dl-dst.h

   1 /* Handling of dynamic sring tokens.
   2    Copyright (C) 1999, 2001, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* Determine the number of DST elements in the name.  Only if IS_PATH is
  21    nonzero paths are recognized (i.e., multiple, ':' separated filenames).  */
  22 #define DL_DST_COUNT(name, is_path) \
  23   ({                                                                          \
  24     size_t __cnt = 0;                                                         \
  25     const char *__sf = strchr (name, '$');                                    \
  26                                                                               \
  27     if (__builtin_expect (__sf != NULL, 0))                                   \
  28       __cnt = INTUSE(_dl_dst_count) (__sf, is_path);                          \
  29                                                                               \
  30     __cnt; })
  31
  32 /* Prototype for used function.  */
  33 extern size_t _dl_dst_count (const char *name, int is_path);
  34 extern size_t _dl_dst_count_internal (const char *name, int is_path);
  35
  36
  37 /* Guess from the number of DSTs the length of the result string.  */
  38 #define DL_DST_REQUIRED(l, name, len, cnt) \
  39   ({                                                                          \
  40     size_t origin_len;                                                        \
  41     size_t __len = (len);                                                     \
  42                                                                               \
  43     /* Now we make a guess how many extra characters on top of the length     \
  44        of S we need to represent the result.  We know that we have CNT        \
  45        replacements.  Each at most can use                                    \
  46          MAX (strlen (ORIGIN), strlen (_dl_platform))                         \
  47        minus 7 (which is the length of "$ORIGIN").                            \
  48                                                                               \
  49        First get the origin string if it is not available yet.  This can      \
  50        only happen for the map of the executable.  */                         \
  51     if ((l)->l_origin == NULL)                                                \
  52       {                                                                       \
  53         assert ((l)->l_name[0] == '\0');                                      \
  54         (l)->l_origin = _dl_get_origin ();                                    \
  55         origin_len = ((l)->l_origin && (l)->l_origin != (char *) -1           \
  56                       ? strlen ((l)->l_origin) : 0);                          \
  57       }                                                                       \
  58     else                                                                      \
  59       origin_len = (l)->l_origin == (char *) -1 ? 0 : strlen ((l)->l_origin); \
  60                                                                               \
  61     __len + cnt * (MAX (origin_len, GL(dl_platformlen)) - 7); })
  62
  63 /* Find origin of the executable.  */
  64 extern const char *_dl_get_origin (void);
  65 extern const char *_dl_get_origin_internal (void);
  66
  67 #ifdef IS_IN_rtld
  68 # define _dl_get_origin INTUSE(_dl_get_origin)
  69 #endif
  70
  71 /* Prototype for used function.  */
  72 extern char *_dl_dst_substitute (struct link_map *l, const char *name,
  73                                  char *result, int is_path);
  74 extern char *_dl_dst_substitute_internal (struct link_map *l, const char *name,
  75                                           char *result, int is_path);