sl@0: /* GMODULE - GLIB wrapper code for dynamic module loading
sl@0:  * Copyright (C) 1998, 2000 Tim Janik
sl@0:  * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.
sl@0:  * This library is free software; you can redistribute it and/or
sl@0:  * modify it under the terms of the GNU Lesser General Public
sl@0:  * License as published by the Free Software Foundation; either
sl@0:  * version 2 of the License, or (at your option) any later version.
sl@0:  *
sl@0:  * This library is distributed in the hope that it will be useful,
sl@0:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
sl@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
sl@0:  * Lesser General Public License for more details.
sl@0:  *
sl@0:  * You should have received a copy of the GNU Lesser General Public
sl@0:  * License along with this library; if not, write to the
sl@0:  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
sl@0:  * Boston, MA 02111-1307, USA.
sl@0:  */
sl@0: 
sl@0: /*
sl@0:  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
sl@0:  * file for a list of people on the GLib Team.  See the ChangeLog
sl@0:  * files for a list of changes.  These files are distributed with
sl@0:  * GLib at ftp://ftp.gtk.org/pub/gtk/. 
sl@0:  */
sl@0: 
sl@0: /* 
sl@0:  * MT safe
sl@0:  */
sl@0: #include "config.h"
sl@0: 
sl@0: #include <dlfcn.h>
sl@0: 
sl@0: /* Perl includes <nlist.h> and <link.h> instead of <dlfcn.h> on some systmes? */
sl@0: 
sl@0: 
sl@0: /* dlerror() is not implemented on all systems
sl@0:  */
sl@0: #ifndef	G_MODULE_HAVE_DLERROR
sl@0: #  ifdef __NetBSD__
sl@0: #    define dlerror()	g_strerror (errno)
sl@0: #  else /* !__NetBSD__ */
sl@0: /* could we rely on errno's state here? */
sl@0: #    define dlerror()	"unknown dl-error"
sl@0: #  endif /* !__NetBSD__ */
sl@0: #endif	/* G_MODULE_HAVE_DLERROR */
sl@0: 
sl@0: /* some flags are missing on some systems, so we provide
sl@0:  * harmless defaults.
sl@0:  * The Perl sources say, RTLD_LAZY needs to be defined as (1),
sl@0:  * at least for Solaris 1.
sl@0:  *
sl@0:  * Mandatory:
sl@0:  * RTLD_LAZY   - resolve undefined symbols as code from the dynamic library
sl@0:  *		 is executed.
sl@0:  * RTLD_NOW    - resolve all undefined symbols before dlopen returns, and fail
sl@0:  *		 if this cannot be done.
sl@0:  * Optionally:
sl@0:  * RTLD_GLOBAL - the external symbols defined in the library will be made
sl@0:  *		 available to subsequently loaded libraries.
sl@0:  */
sl@0: #ifndef	RTLD_LAZY
sl@0: #define	RTLD_LAZY	1
sl@0: #endif	/* RTLD_LAZY */
sl@0: #ifndef	RTLD_NOW
sl@0: #define	RTLD_NOW	0
sl@0: #endif	/* RTLD_NOW */
sl@0: /* some systems (OSF1 V5.0) have broken RTLD_GLOBAL linkage */
sl@0: #ifdef G_MODULE_BROKEN_RTLD_GLOBAL
sl@0: #undef	RTLD_GLOBAL
sl@0: #endif /* G_MODULE_BROKEN_RTLD_GLOBAL */
sl@0: #ifndef	RTLD_GLOBAL
sl@0: #define	RTLD_GLOBAL	0
sl@0: #endif	/* RTLD_GLOBAL */
sl@0: 
sl@0: 
sl@0: /* --- functions --- */
sl@0: static gchar*
sl@0: fetch_dlerror (gboolean replace_null)
sl@0: {
sl@0:   gchar *msg = dlerror ();
sl@0: 
sl@0:   /* make sure we always return an error message != NULL, if
sl@0:    * expected to do so. */
sl@0: 
sl@0:   if (!msg && replace_null)
sl@0:     return "unknown dl-error";
sl@0: 
sl@0:   return msg;
sl@0: }
sl@0: 
sl@0: static gpointer
sl@0: _g_module_open (const gchar *file_name,
sl@0: 		gboolean     bind_lazy,
sl@0: 		gboolean     bind_local)
sl@0: {
sl@0:   gpointer handle;
sl@0:   
sl@0:   handle = dlopen (file_name,
sl@0: 		   (bind_local ? 0 : RTLD_GLOBAL) | (bind_lazy ? RTLD_LAZY : RTLD_NOW));
sl@0:   if (!handle)
sl@0:     g_module_set_error (fetch_dlerror (TRUE));
sl@0:   
sl@0:   return handle;
sl@0: }
sl@0: 
sl@0: static gpointer
sl@0: _g_module_self (void)
sl@0: {
sl@0:   gpointer handle;
sl@0:   
sl@0:   /* to query symbols from the program itself, special link options
sl@0:    * are required on some systems.
sl@0:    */
sl@0:   
sl@0:   handle = dlopen (NULL, RTLD_GLOBAL | RTLD_LAZY);
sl@0:   if (!handle)
sl@0:     g_module_set_error (fetch_dlerror (TRUE));
sl@0:   
sl@0:   return handle;
sl@0: }
sl@0: 
sl@0: static void
sl@0: _g_module_close (gpointer handle,
sl@0: 		 gboolean is_unref)
sl@0: {
sl@0:   /* are there any systems out there that have dlopen()/dlclose()
sl@0:    * without a reference count implementation?
sl@0:    */
sl@0:   is_unref |= 1;
sl@0:   
sl@0:   if (is_unref)
sl@0:     {
sl@0:       if (dlclose (handle) != 0)
sl@0: 	g_module_set_error (fetch_dlerror (TRUE));
sl@0:     }
sl@0: }
sl@0: 
sl@0: static gpointer
sl@0: _g_module_symbol (gpointer     handle,
sl@0: 		  const gchar *symbol_name)
sl@0: {
sl@0:   gpointer p;
sl@0:   gchar *msg;
sl@0: 
sl@0:   fetch_dlerror (FALSE);
sl@0:   p = dlsym (handle, symbol_name);
sl@0:   msg = fetch_dlerror (FALSE);
sl@0:   if (msg)
sl@0:     g_module_set_error (msg);
sl@0:   
sl@0:   return p;
sl@0: }
sl@0: 
sl@0: static gchar*
sl@0: _g_module_build_path (const gchar *directory,
sl@0: 		      const gchar *module_name)
sl@0: {
sl@0:   if (directory && *directory) {
sl@0:     #ifdef __SYMBIAN32__
sl@0: 	return g_strconcat (directory, "\\", module_name, "." G_MODULE_SUFFIX, NULL);
sl@0:     #else
sl@0:     if (strncmp (module_name, "lib", 3) == 0)
sl@0:       return g_strconcat (directory, "/", module_name, NULL);
sl@0:     else
sl@0:       return g_strconcat (directory, "/lib", module_name, "." G_MODULE_SUFFIX, NULL);
sl@0:     #endif /* __SYMBIAN32__ */
sl@0:   } else if (strncmp (module_name, "lib", 3) == 0)
sl@0:     return g_strdup (module_name);
sl@0:   else
sl@0:     #ifdef __SYMBIAN32__
sl@0:     return g_strconcat (module_name, "." G_MODULE_SUFFIX, NULL);
sl@0:     #else
sl@0:     return g_strconcat ("lib", module_name, "." G_MODULE_SUFFIX, NULL);
sl@0:     #endif /* __SYMBIAN32__ */
sl@0: }