dlfcn/dlfcn.h

   1 /* User functions for run-time dynamic loading.
   2    Copyright (C) 1995-1999, 2000 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 dependent definitions and declarations.  */
  26 #include <bits/dlfcn.h>
  27
  28 #ifdef __USE_GNU
  29 /* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
  30    the run-time address of the symbol called NAME in the next shared
  31    object is returned.  The "next" relation is defined by the order
  32    the shared objects were loaded.  */
  33 # define RTLD_NEXT      ((void *) -1l)
  34
  35 /* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
  36    the run-time address of the symbol called NAME in the global scope
  37    is returned.  */
  38 # define RTLD_DEFAULT   ((void *) 0)
  39 #endif
  40
  41 __BEGIN_DECLS
  42
  43 /* Open the shared object FILE and map it in; return a handle that can be
  44    passed to `dlsym' to get symbol values from it.  */
  45 extern void *dlopen (__const char *__file, int __mode) __THROW;
  46
  47 /* Unmap and close a shared object opened by `dlopen'.
  48    The handle cannot be used again after calling `dlclose'.  */
  49 extern int dlclose (void *__handle) __THROW;
  50
  51 /* Find the run-time address in the shared object HANDLE refers to
  52    of the symbol called NAME.  */
  53 extern void *dlsym (void *__restrict __handle,
  54                     __const char *__restrict __name) __THROW;
  55
  56 #ifdef __USE_GNU
  57 /* Find the run-time address in the shared object HANDLE refers to
  58    of the symbol called NAME with VERSION.  */
  59 extern void *dlvsym (void *__restrict __handle,
  60                      __const char *__restrict __name,
  61                      __const char *__restrict __version) __THROW;
  62 #endif
  63
  64 /* When any of the above functions fails, call this function
  65    to return a string describing the error.  Each call resets
  66    the error string so that a following call returns null.  */
  67 extern char *dlerror (void) __THROW;
  68
  69 #ifdef __USE_GNU
  70 /* Structure containing information about object searched using
  71    `dladdr'.  */
  72 typedef struct
  73 {
  74   __const char *dli_fname;      /* File name of defining object.  */
  75   void *dli_fbase;              /* Load address of that object.  */
  76   __const char *dli_sname;      /* Name of nearest symbol.  */
  77   void *dli_saddr;              /* Exact value of nearest symbol.  */
  78 } Dl_info;
  79
  80 /* Fill in *INFO with the following information about ADDRESS.
  81    Returns 0 iff no shared object's segments contain that address.  */
  82 extern int dladdr (const void *__address, Dl_info *__info) __THROW;
  83 #endif
  84
  85 __END_DECLS
  86
  87 #endif  /* dlfcn.h */