elf/dlfcn.h

   1 /* User functions for run-time dynamic loading.
   2    Copyright (C) 1995, 1996, 1997 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _DLFCN_H
  21 #define _DLFCN_H 1
  22
  23 #include <features.h>
  24
  25 /* Collect various system dependand definitions and declarations.  */
  26 #include <bits/dlfcn.h>
  27
  28 /* If the first argument of `dlsym' is set to RTLD_NEXT the run-time
  29    address of the symbol called NAME in the next shared object is
  30    returned.  The "next" relation is defined by the order the shared
  31    objects were loaded.  */
  32 #define RTLD_NEXT       ((void *) -1l)
  33
  34 __BEGIN_DECLS
  35
  36 /* Open the shared object FILE and map it in; return a handle that can be
  37    passed to `dlsym' to get symbol values from it.  */
  38 extern void *dlopen __P ((__const char *__file, int __mode));
  39
  40 /* Unmap and close a shared object opened by `dlopen'.
  41    The handle cannot be used again after calling `dlclose'.  */
  42 extern int dlclose __P ((void *__handle));
  43
  44 /* Find the run-time address in the shared object HANDLE refers to
  45    of the symbol called NAME.  */
  46 extern void *dlsym __P ((void *__handle, __const char *__name));
  47
  48 #ifdef __USE_GNU
  49 /* Find the run-time address in the shared object HANDLE refers to
  50    of the symbol called NAME with VERSION.  */
  51 extern void *__dlvsym __P ((void *__handle, __const char *__name,
  52                             __const char *__version));
  53 extern void *dlvsym __P ((void *__handle, __const char *__name,
  54                           __const char *__version));
  55 #endif
  56
  57 /* When any of the above functions fails, call this function
  58    to return a string describing the error.  Each call resets
  59    the error string so that a following call returns null.  */
  60 extern char *dlerror __P ((void));
  61
  62 /* Fill in *INFO with the following information about ADDRESS.
  63    Returns 0 iff no shared object's segments contain that address.  */
  64 typedef struct
  65   {
  66     __const char *dli_fname;    /* File name of defining object.  */
  67     void *dli_fbase;            /* Load address of that object.  */
  68     __const char *dli_sname;    /* Name of nearest symbol.  */
  69     void *dli_saddr;            /* Exact value of nearest symbol.  */
  70   } Dl_info;
  71 extern int dladdr __P ((void *__address, Dl_info *__info));
  72
  73 __END_DECLS
  74
  75 #endif  /* dlfcn.h */