elf/dlfcn.h

   1 /* dlfcn.h -- User functions for run-time dynamic loading.
   2 Copyright (C) 1995, 1996 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
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #ifndef _DLFCN_H
  21 #define _DLFCN_H 1
  22
  23
  24 /* The MODE argument to `dlopen' contains one of the following: */
  25 #define RTLD_LAZY       0x001   /* Lazy function call binding.  */
  26 #define RTLD_NOW        0x002   /* Immediate function call binding.  */
  27 #define RTLD_BINDING_MASK 0x3   /* Mask of binding time value.  */
  28
  29 /* If the following bit is set in the MODE argument to `dlopen',
  30    the symbols of the loaded object and its dependencies are made
  31    visible as if the object were linked directly into the program.  */
  32 #define RTLD_GLOBAL     0x100
  33
  34 /* Open the shared object FILE and map it in; return a handle that can be
  35    passed to `dlsym' to get symbol values from it.  */
  36 extern void *dlopen (const char *__file, int __mode);
  37
  38 /* Unmap and close a shared object opened by `dlopen'.
  39    The handle cannot be used again after calling `dlclose'.  */
  40 extern int dlclose (void *__handle);
  41
  42 /* Find the run-time address in the shared object HANDLE refers to
  43    of the symbol called NAME.  */
  44 extern void *dlsym (void *__handle, const char *__name);
  45
  46 /* When any of the above functions fails, call this function
  47    to return a string describing the error.  Each call resets
  48    the error string so that a following call returns null.  */
  49 extern char *dlerror (void);
  50
  51 /* Fill in *INFO with the following information about ADDRESS.
  52    Returns 0 iff no shared object's segments contain that address.  */
  53 typedef struct
  54   {
  55     const char *dli_fname;      /* File name of defining object.  */
  56     void *dli_fbase;            /* Load address of that object.  */
  57     const char *dli_sname;      /* Name of nearest symbol.  */
  58     void *dli_saddr;            /* Exact value of nearest symbol.  */
  59   } Dl_info;
  60 extern int dladdr (void *__address, Dl_info *__info);
  61
  62 #endif  /* dlfcn.h */