dlfcn/dlfcn.h

   1 /* User functions for run-time dynamic loading.
   2    Copyright (C) 1995-1999, 2000, 2001 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 #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
  29 #ifdef __USE_GNU
  30 /* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
  31    the run-time address of the symbol called NAME in the next shared
  32    object is returned.  The "next" relation is defined by the order
  33    the shared objects were loaded.  */
  34 # define RTLD_NEXT      ((void *) -1l)
  35
  36 /* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
  37    the run-time address of the symbol called NAME in the global scope
  38    is returned.  */
  39 # define RTLD_DEFAULT   ((void *) 0)
  40 #endif
  41
  42
  43 __BEGIN_DECLS
  44
  45 /* Open the shared object FILE and map it in; return a handle that can be
  46    passed to `dlsym' to get symbol values from it.  */
  47 extern void *dlopen (__const char *__file, int __mode) __THROW;
  48
  49 /* Unmap and close a shared object opened by `dlopen'.
  50    The handle cannot be used again after calling `dlclose'.  */
  51 extern int dlclose (void *__handle) __THROW;
  52
  53 /* Find the run-time address in the shared object HANDLE refers to
  54    of the symbol called NAME.  */
  55 extern void *dlsym (void *__restrict __handle,
  56                     __const char *__restrict __name) __THROW;
  57
  58 #ifdef __USE_GNU
  59 /* Find the run-time address in the shared object HANDLE refers to
  60    of the symbol called NAME with VERSION.  */
  61 extern void *dlvsym (void *__restrict __handle,
  62                      __const char *__restrict __name,
  63                      __const char *__restrict __version) __THROW;
  64 #endif
  65
  66 /* When any of the above functions fails, call this function
  67    to return a string describing the error.  Each call resets
  68    the error string so that a following call returns null.  */
  69 extern char *dlerror (void) __THROW;
  70
  71
  72 #ifdef __USE_GNU
  73 /* Structure containing information about object searched using
  74    `dladdr'.  */
  75 typedef struct
  76 {
  77   __const char *dli_fname;      /* File name of defining object.  */
  78   void *dli_fbase;              /* Load address of that object.  */
  79   __const char *dli_sname;      /* Name of nearest symbol.  */
  80   void *dli_saddr;              /* Exact value of nearest symbol.  */
  81 } Dl_info;
  82
  83 /* Fill in *INFO with the following information about ADDRESS.
  84    Returns 0 iff no shared object's segments contain that address.  */
  85 extern int dladdr (__const void *__address, Dl_info *__info) __THROW;
  86 #endif
  87
  88 __END_DECLS
  89
  90 #endif  /* dlfcn.h */