dlfcn/dlsym.c

   1 /* Look up a 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
  22 struct dlsym_args
  23 {
  24   /* The arguments to dlsym_doit.  */
  25   void *handle;
  26   const char *name;
  27   void *who;
  28
  29   /* The return value of dlsym_doit.  */
  30   void *sym;
  31 };
  32
  33 static void
  34 dlsym_doit (void *a)
  35 {
  36   struct dlsym_args *args = (struct dlsym_args *) a;
  37
  38   args->sym = _dl_sym (args->handle, args->name, args->who);
  39 }
  40
  41
  42 void *
  43 dlsym (void *handle, const char *name)
  44 {
  45   struct dlsym_args args;
  46   args.who = __builtin_return_address (0);
  47   args.handle = handle;
  48   args.name = name;
  49
  50   return (_dlerror_run (dlsym_doit, &args) ? NULL : args.sym);
  51 }