dlfcn/dlvsym.c

   1 /* Look up a versioned symbol in a shared object loaded by `dlopen'.
   2    Copyright (C) 1995, 1996, 1997, 1998, 1999 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 #include <dlfcn.h>
  21 #include <stddef.h>
  22
  23 struct dlvsym_args
  24 {
  25   /* The arguments to dlvsym_doit.  */
  26   void *handle;
  27   const char *name;
  28   const char *version;
  29   void *who;
  30
  31   /* The return values of dlvsym_doit.  */
  32   void *sym;
  33 };
  34
  35
  36 static void
  37 dlvsym_doit (void *a)
  38 {
  39   struct dlvsym_args *args = (struct dlvsym_args *)a;
  40
  41   args->sym = _dl_vsym (args->handle, args->name, args->version, args->who);
  42 }
  43
  44 void *
  45 __dlvsym (void *handle, const char *name, const char *version_str)
  46 {
  47   struct dlvsym_args args;
  48
  49   args.handle = handle;
  50   args.name = name;
  51   args.who = __builtin_return_address (0);
  52   args.version = version_str;
  53
  54   return (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);
  55 }
  56 weak_alias (__dlvsym, dlvsym)