/* Look up a versioned symbol in a shared object loaded by `dlopen'.

   Copyright (C) 1995-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <dlfcn.h>

#include <stddef.h>

#include <ldsodefs.h>

#if !defined SHARED && IS_IN (libdl)

void *

weak_function

dlvsym (void *handle, const char *name, const char *version_str)

{

  return __dlvsym (handle, name, version_str, RETURN_ADDRESS (0));

}

#else

struct dlvsym_args

{

  /* The arguments to dlvsym_doit.  */

  void *handle;

  const char *name;

  const char *version;

  void *who;

  /* The return values of dlvsym_doit.  */

  void *sym;

};

static void

dlvsym_doit (void *a)

{

  struct dlvsym_args *args = (struct dlvsym_args *)a;

  args->sym = _dl_vsym (args->handle, args->name, args->version, args->who);

}

void *

__dlvsym (void *handle, const char *name, const char *version_str

	  DL_CALLER_DECL)

{

# ifdef SHARED

  if (!rtld_active ())

    return _dlfcn_hook->dlvsym (handle, name, version_str, DL_CALLER);

# endif

  struct dlvsym_args args;

  args.handle = handle;

  args.name = name;

  args.who = DL_CALLER;

  args.version = version_str;

  /* Protect against concurrent loads and unloads.  */

  __rtld_lock_lock_recursive (GL(dl_load_lock));

  void *result = (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);

  __rtld_lock_unlock_recursive (GL(dl_load_lock));

  return result;

}

# ifdef SHARED

weak_alias (__dlvsym, dlvsym)

# endif

#endif