/* GMODULE - GLIB wrapper code for dynamic module loading

  * Copyright (C) 1998, 2000 Tim Janik

  * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.

  * 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.

  *

  * 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.

  */

 /*

  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS

  * file for a list of people on the GLib Team.  See the ChangeLog

  * files for a list of changes.  These files are distributed with

  * GLib at ftp://ftp.gtk.org/pub/gtk/. 

  */

 /* 

  * MT safe

  */

 #include "config.h"

 #include <dlfcn.h>

 /* Perl includes <nlist.h> and <link.h> instead of <dlfcn.h> on some systmes? */

 /* dlerror() is not implemented on all systems

  */

 #ifndef	G_MODULE_HAVE_DLERROR

 #  ifdef __NetBSD__

 #    define dlerror()	g_strerror (errno)

 #  else /* !__NetBSD__ */

 /* could we rely on errno's state here? */

 #    define dlerror()	"unknown dl-error"

 #  endif /* !__NetBSD__ */

 #endif	/* G_MODULE_HAVE_DLERROR */

 /* some flags are missing on some systems, so we provide

  * harmless defaults.

  * The Perl sources say, RTLD_LAZY needs to be defined as (1),

  * at least for Solaris 1.

  *

  * Mandatory:

  * RTLD_LAZY   - resolve undefined symbols as code from the dynamic library

  *		 is executed.

  * RTLD_NOW    - resolve all undefined symbols before dlopen returns, and fail

  *		 if this cannot be done.

  * Optionally:

  * RTLD_GLOBAL - the external symbols defined in the library will be made

  *		 available to subsequently loaded libraries.

  */

 #ifndef	RTLD_LAZY

 #define	RTLD_LAZY	1

 #endif	/* RTLD_LAZY */

 #ifndef	RTLD_NOW

 #define	RTLD_NOW	0

 #endif	/* RTLD_NOW */

 /* some systems (OSF1 V5.0) have broken RTLD_GLOBAL linkage */

 #ifdef G_MODULE_BROKEN_RTLD_GLOBAL

 #undef	RTLD_GLOBAL

 #endif /* G_MODULE_BROKEN_RTLD_GLOBAL */

 #ifndef	RTLD_GLOBAL

 #define	RTLD_GLOBAL	0

 #endif	/* RTLD_GLOBAL */

 /* --- functions --- */

 static gchar*

 fetch_dlerror (gboolean replace_null)

 {

   gchar *msg = dlerror ();

   /* make sure we always return an error message != NULL, if

    * expected to do so. */

   if (!msg && replace_null)

     return "unknown dl-error";

   return msg;

 }

 static gpointer

 _g_module_open (const gchar *file_name,

 		gboolean     bind_lazy,

 		gboolean     bind_local)

 {

   gpointer handle;

   handle = dlopen (file_name,

 		   (bind_local ? 0 : RTLD_GLOBAL) | (bind_lazy ? RTLD_LAZY : RTLD_NOW));

   if (!handle)

     g_module_set_error (fetch_dlerror (TRUE));

   return handle;

 }

 static gpointer

 _g_module_self (void)

 {

   gpointer handle;

   /* to query symbols from the program itself, special link options

    * are required on some systems.

    */

   handle = dlopen (NULL, RTLD_GLOBAL | RTLD_LAZY);

   if (!handle)

     g_module_set_error (fetch_dlerror (TRUE));

   return handle;

 }

 static void

 _g_module_close (gpointer handle,

 		 gboolean is_unref)

 {

   /* are there any systems out there that have dlopen()/dlclose()

    * without a reference count implementation?

    */

   is_unref |= 1;

   if (is_unref)

     {

       if (dlclose (handle) != 0)

 	g_module_set_error (fetch_dlerror (TRUE));

     }

 }

 static gpointer

 _g_module_symbol (gpointer     handle,

 		  const gchar *symbol_name)

 {

   gpointer p;

   gchar *msg;

   fetch_dlerror (FALSE);

   p = dlsym (handle, symbol_name);

   msg = fetch_dlerror (FALSE);

   if (msg)

     g_module_set_error (msg);

   return p;

 }

 static gchar*

 _g_module_build_path (const gchar *directory,

 		      const gchar *module_name)

 {

   if (directory && *directory) {

     #ifdef __SYMBIAN32__

 	return g_strconcat (directory, "\\", module_name, "." G_MODULE_SUFFIX, NULL);

     #else

     if (strncmp (module_name, "lib", 3) == 0)

       return g_strconcat (directory, "/", module_name, NULL);

     else

       return g_strconcat (directory, "/lib", module_name, "." G_MODULE_SUFFIX, NULL);

     #endif /* __SYMBIAN32__ */

   } else if (strncmp (module_name, "lib", 3) == 0)

     return g_strdup (module_name);

   else

     #ifdef __SYMBIAN32__

     return g_strconcat (module_name, "." G_MODULE_SUFFIX, NULL);

     #else

     return g_strconcat ("lib", module_name, "." G_MODULE_SUFFIX, NULL);

     #endif /* __SYMBIAN32__ */

 }