libtool/libltdl/loader-shl_load.c

/* loader-shl_load.c --  dynamic linking with shl_load (HP-UX)
   Copyright (C) 1998, 1999, 2000, 2004 Free Software Foundation, Inc.
   Originally by Thomas Tanner <tanner@ffii.org>

   NOTE: The canonical source of this file is maintained with the
   GNU Libtool package.  Report bugs to bug-libtool@gnu.org.

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

As a special exception to the GNU Lesser General Public License,
if you distribute this file as part of a program or library that
is built using GNU libtool, you may include it under the same
distribution terms that you use for the rest of that program.

This 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 this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307  USA

*/

#include "lt__private.h"
#include "lt_dlloader.h"

#if defined(HAVE_DL_H)
#  include <dl.h>
#endif

/* some flags are missing on some systems, so we provide
 * harmless defaults.
 *
 * Mandatory:
 * BIND_IMMEDIATE  - Resolve symbol references when the library is loaded.
 * BIND_DEFERRED   - Delay code symbol resolution until actual reference.
 *
 * Optionally:
 * BIND_FIRST	   - Place the library at the head of the symbol search
 * 		     order.
 * BIND_NONFATAL   - The default BIND_IMMEDIATE behavior is to treat all
 * 		     unsatisfied symbols as fatal.  This flag allows
 * 		     binding of unsatisfied code symbols to be deferred
 * 		     until use.
 *		     [Perl: For certain libraries, like DCE, deferred
 *		     binding often causes run time problems. Adding
 *		     BIND_NONFATAL to BIND_IMMEDIATE still allows
 *		     unresolved references in situations like this.]
 * BIND_NOSTART	   - Do not call the initializer for the shared library
 *		     when the library is loaded, nor on a future call to
 *		     shl_unload().
 * BIND_VERBOSE	   - Print verbose messages concerning possible
 *		     unsatisfied symbols.
 *
 * hp9000s700/hp9000s800:
 * BIND_RESTRICTED - Restrict symbols visible by the library to those
 *		     present at library load time.
 * DYNAMIC_PATH	   - Allow the loader to dynamically search for the
 *		     library specified by the path argument.
 */

#if !defined(DYNAMIC_PATH)
#  define DYNAMIC_PATH		0
#endif
#if !defined(BIND_RESTRICTED)
#  define BIND_RESTRICTED	0
#endif

#define	LT_BIND_FLAGS	(BIND_IMMEDIATE | BIND_NONFATAL | DYNAMIC_PATH)

static lt_module
sys_shl_open (lt_user_data loader_data, const char *filenam)
{
  static shl_t self = (shl_t) 0;
  lt_module module = shl_load (filename, LT_BIND_FLAGS, 0L);

  /* Since searching for a symbol against a NULL module handle will also
     look in everything else that was already loaded and exported with
     the -E compiler flag, we always cache a handle saved before any
     modules are loaded.  */
  if (!self)
    {
      void *address;
      shl_findsym (&self, "main", TYPE_UNDEFINED, &address);
    }

  if (!filename)
    {
      module = self;
    }
  else
    {
      module = shl_load (filename, LT_BIND_FLAGS, 0L);

      if (!module)
	{
	  LT__MUTEX_SETERROR (CANNOT_OPEN);
	}
    }

  return module;
}

static int
sys_shl_close (lt_user_data loader_data, lt_module module)
{
  int errors = 0;

  if (module && (shl_unload ((shl_t) (module)) != 0))
    {
      LT__MUTEX_SETERROR (CANNOT_CLOSE);
      ++errors;
    }

  return errors;
}

static void *
sys_shl_sym (lt_user_data loader_data, lt_module module, const char *symbol)
{
  void *address = 0;

  /* sys_shl_open should never return a NULL module handle */
  if (module == (lt_module) 0)
  {
    LT__MUTEX_SETERROR (INVALID_HANDLE);
  }
  else if (!shl_findsym((shl_t*) &module, symbol, TYPE_UNDEFINED, &address))
    {
      if (!address)
	{
	  LT__MUTEX_SETERROR (SYMBOL_NOT_FOUND);
	}
    }

  return address;
}

struct lt_user_dlloader lt__sys_shl = {
  0, sys_shl_open, sys_shl_close, sys_shl_sym, 0, 0
};