/* GMODULE - GLIB wrapper code for dynamic module loading

  * Copyright (C) 1998 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 "glib.h"

 #include "gmodule.h"

 #include <errno.h>

 #include <string.h>

 #include <sys/types.h>

 #include <sys/stat.h>

 #include <fcntl.h>

 #ifdef HAVE_UNISTD_H

 #include <unistd.h>

 #endif

 #ifdef G_OS_WIN32

 #include <io.h>		/* For open() and close() prototypes. */

 #endif

 #include "gmoduleconf.h"

 #include "gstdio.h" 

 #ifdef __SYMBIAN32__

 #include "gmodule_wsd.h"

 #endif /* __SYMBIAN32__ */

 /* We maintain a list of modules, so we can reference count them.

  * That's needed because some platforms don't support refernce counts on

  * modules e.g. the shl_* implementation of HP-UX

  * (http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html).

  * Also, the module for the program itself is kept seperatedly for

  * faster access and because it has special semantics.

  */

 /* --- structures --- */

 struct _GModule

 {

   gchar	*file_name;

 #if defined (G_OS_WIN32) && !defined(_WIN64)

   gchar *cp_file_name;

 #endif

   gpointer handle;

   guint ref_count : 31;

   guint is_resident : 1;

   GModuleUnload unload;

   GModule *next;

 };

 /* --- prototypes --- */

 static gpointer		_g_module_open		(const gchar	*file_name,

 						 gboolean	 bind_lazy,

 						 gboolean	 bind_local);

 static void		_g_module_close		(gpointer	 handle,

 						 gboolean	 is_unref);

 static gpointer		_g_module_self		(void);

 static gpointer		_g_module_symbol	(gpointer	 handle,

 						 const gchar	*symbol_name);

 static gchar*		_g_module_build_path	(const gchar	*directory,

 						 const gchar	*module_name);

 static inline void	g_module_set_error	(const gchar	*error);

 static inline GModule*	g_module_find_by_handle (gpointer	 handle);

 static inline GModule*	g_module_find_by_name	(const gchar	*name);

 /* --- variables --- */

 #if EMULATOR

 PLS(modules,gmodule,GModule *)

 PLS(main_module,gmodule,GModule *)

 PLS(module_error_private,gmodule,GStaticPrivate)

 PLS(module_debug_initialized,gmodule,gboolean)

 PLS(module_debug_flags,gmodule,guint)

 #define modules (*FUNCTION_NAME(modules,gmodule)())

 #define main_module (*FUNCTION_NAME(main_module,gmodule)())

 #define module_error_private (*FUNCTION_NAME(module_error_private,gmodule)())

 #define module_debug_initialized (*FUNCTION_NAME(module_debug_initialized,gmodule)())

 #define module_debug_flags (*FUNCTION_NAME(module_debug_flags,gmodule)())

 #else

 static GModule	     *modules = NULL;

 static GModule	     *main_module = NULL;

 static GStaticPrivate module_error_private = G_STATIC_PRIVATE_INIT;

 static gboolean	      module_debug_initialized = FALSE;

 static guint	      module_debug_flags = 0;

 #endif /* EMULATOR */

 /* --- inline functions --- */

 static inline GModule*

 g_module_find_by_handle (gpointer handle)

 {

   GModule *module;

   GModule *retval = NULL;

   if (main_module && main_module->handle == handle)

     retval = main_module;

   else

     for (module = modules; module; module = module->next)

       if (handle == module->handle)

 	{

 	  retval = module;

 	  break;

 	}

   return retval;

 }

 static inline GModule*

 g_module_find_by_name (const gchar *name)

 {

   GModule *module;

   GModule *retval = NULL;

   for (module = modules; module; module = module->next)

     if (strcmp (name, module->file_name) == 0)

 	{

 	  retval = module;

 	  break;

 	}

   return retval;

 }

 static inline void

 g_module_set_error_unduped (gchar *error)

 {

   g_static_private_set (&module_error_private, error, g_free);

   errno = 0;

 }

 static inline void

 g_module_set_error (const gchar *error)

 {

   g_module_set_error_unduped (g_strdup (error));

 }

 /* --- include platform specifc code --- */

 #define	SUPPORT_OR_RETURN(rv)	{ g_module_set_error (NULL); }

 #if	(G_MODULE_IMPL == G_MODULE_IMPL_DL)

 #include "gmodule-dl.c"

 #elif	(G_MODULE_IMPL == G_MODULE_IMPL_DLD)

 #include "gmodule-dld.c"

 #elif	(G_MODULE_IMPL == G_MODULE_IMPL_WIN32)

 #include "gmodule-win32.c"

 #elif	(G_MODULE_IMPL == G_MODULE_IMPL_DYLD)

 #include "gmodule-dyld.c"

 #elif	(G_MODULE_IMPL == G_MODULE_IMPL_AR)

 #include "gmodule-ar.c"

 #else

 #undef	SUPPORT_OR_RETURN

 #define	SUPPORT_OR_RETURN(rv)	{ g_module_set_error ("dynamic modules are " \

                                               "not supported by this system"); return rv; }

 static gpointer

 _g_module_open (const gchar	*file_name,

 		gboolean	 bind_lazy,

 		gboolean	 bind_local)

 {

   return NULL;

 }

 static void

 _g_module_close	(gpointer	 handle,

 		 gboolean	 is_unref)

 {

 }

 static gpointer

 _g_module_self (void)

 {

   return NULL;

 }

 static gpointer

 _g_module_symbol (gpointer	 handle,

 		  const gchar	*symbol_name)

 {

   return NULL;

 }

 static gchar*

 _g_module_build_path (const gchar *directory,

 		      const gchar *module_name)

 {

   return NULL;

 }

 #endif	/* no implementation */

 /* --- functions --- */

 EXPORT_C gboolean

 g_module_supported (void)

 {

   SUPPORT_OR_RETURN (FALSE);

   return TRUE;

 }

 static gchar*

 parse_libtool_archive (const gchar* libtool_name)

 {

   const guint TOKEN_DLNAME = G_TOKEN_LAST + 1;

   const guint TOKEN_INSTALLED = G_TOKEN_LAST + 2;

   const guint TOKEN_LIBDIR = G_TOKEN_LAST + 3;

   gchar *lt_dlname = NULL;

   gboolean lt_installed = TRUE;

   gchar *lt_libdir = NULL;

   gchar *name;

   GTokenType token;

   GScanner *scanner;

   int fd = g_open (libtool_name, O_RDONLY, 0);

   if (fd < 0)

     {

       gchar *display_libtool_name = g_filename_display_name (libtool_name);

       g_module_set_error_unduped (g_strdup_printf ("failed to open libtool archive \"%s\"", display_libtool_name));

       g_free (display_libtool_name);

       return NULL;

     }

   /* search libtool's dlname specification  */

   scanner = g_scanner_new (NULL);

   g_scanner_input_file (scanner, fd);

   scanner->config->symbol_2_token = TRUE;

   g_scanner_scope_add_symbol (scanner, 0, "dlname", 

 			      GUINT_TO_POINTER (TOKEN_DLNAME));

   g_scanner_scope_add_symbol (scanner, 0, "installed", 

 			      GUINT_TO_POINTER (TOKEN_INSTALLED));

   g_scanner_scope_add_symbol (scanner, 0, "libdir", 

 			      GUINT_TO_POINTER (TOKEN_LIBDIR));

   while (!g_scanner_eof (scanner))

     {

       token = g_scanner_get_next_token (scanner);

       if (token == TOKEN_DLNAME || token == TOKEN_INSTALLED || 

 	  token == TOKEN_LIBDIR)

 	{

 	  if (g_scanner_get_next_token (scanner) != '=' ||

 	      g_scanner_get_next_token (scanner) != 

 	      (token == TOKEN_INSTALLED ? 

 	       G_TOKEN_IDENTIFIER : G_TOKEN_STRING))

 	    {

 	      gchar *display_libtool_name = g_filename_display_name (libtool_name);

 	      g_module_set_error_unduped (g_strdup_printf ("unable to parse libtool archive \"%s\"", display_libtool_name));

 	      g_free (display_libtool_name);

 	      g_free (lt_dlname);

 	      g_free (lt_libdir);

 	      g_scanner_destroy (scanner);

 	      close (fd);

 	      return NULL;

 	    }

 	  else

 	    {

 	      if (token == TOKEN_DLNAME)

 		{

 		  g_free (lt_dlname);

 		  lt_dlname = g_strdup (scanner->value.v_string);

 		}

 	      else if (token == TOKEN_INSTALLED)

 		lt_installed = 

 		  strcmp (scanner->value.v_identifier, "yes") == 0;

 	      else /* token == TOKEN_LIBDIR */

 		{

 		  g_free (lt_libdir);

 		  lt_libdir = g_strdup (scanner->value.v_string);

 		}

 	    }

 	}      

     }

   if (!lt_installed)

     {

       gchar *dir = g_path_get_dirname (libtool_name);

       g_free (lt_libdir);

       lt_libdir = g_strconcat (dir, G_DIR_SEPARATOR_S ".libs", NULL);

       g_free (dir);

     }

   name = g_strconcat (lt_libdir, G_DIR_SEPARATOR_S, lt_dlname, NULL);

   g_free (lt_dlname);

   g_free (lt_libdir);

   g_scanner_destroy (scanner);

   close (fd);

   return name;

 }

 static inline gboolean

 str_check_suffix (const gchar* string,

 		  const gchar* suffix)

 {

   gsize string_len = strlen (string);    

   gsize suffix_len = strlen (suffix);    

   return string_len >= suffix_len && 

     strcmp (string + string_len - suffix_len, suffix) == 0;

 }

 enum

 {

   G_MODULE_DEBUG_RESIDENT_MODULES = 1 << 0,

   G_MODULE_DEBUG_BIND_NOW_MODULES = 1 << 1

 };

 static void

 _g_module_debug_init (void)

 {

   const GDebugKey keys[] = {

     { "resident-modules", G_MODULE_DEBUG_RESIDENT_MODULES },

     { "bind-now-modules", G_MODULE_DEBUG_BIND_NOW_MODULES }

   };

   const gchar *env;

   env = g_getenv ("G_DEBUG");

   module_debug_flags =

     !env ? 0 : g_parse_debug_string (env, keys, G_N_ELEMENTS (keys));

   module_debug_initialized = TRUE;

 }

 #if EMULATOR

 PLS(g_module_global_lock,gmodule,GStaticRecMutex)

 #define g_module_global_lock (*FUNCTION_NAME(g_module_global_lock,gmodule)())

 #else

 static GStaticRecMutex g_module_global_lock = G_STATIC_REC_MUTEX_INIT;

 #endif /* EMULATOR */

 EXPORT_C GModule*

 g_module_open (const gchar    *file_name,

 	       GModuleFlags    flags)

 {

   GModule *module;

   gpointer handle = NULL;

   gchar *name = NULL;

   SUPPORT_OR_RETURN (NULL);

   g_static_rec_mutex_lock (&g_module_global_lock);

   if (G_UNLIKELY (!module_debug_initialized))

     _g_module_debug_init ();

   if (module_debug_flags & G_MODULE_DEBUG_BIND_NOW_MODULES)

     flags &= ~G_MODULE_BIND_LAZY;

   if (!file_name)

     {      

       if (!main_module)

 	{

 	  handle = _g_module_self ();

 	  if (handle)

 	    {

 	      main_module = g_new (GModule, 1);

 	      main_module->file_name = NULL;

 #if defined (G_OS_WIN32) && !defined(_WIN64)

 	      main_module->cp_file_name = NULL;

 #endif

 	      main_module->handle = handle;

 	      main_module->ref_count = 1;

 	      main_module->is_resident = TRUE;

 	      main_module->unload = NULL;

 	      main_module->next = NULL;

 	    }

 	}

       else

 	main_module->ref_count++;

       g_static_rec_mutex_unlock (&g_module_global_lock);

       return main_module;

     }

   /* we first search the module list by name */

   module = g_module_find_by_name (file_name);

   if (module)

     {

       module->ref_count++;

       g_static_rec_mutex_unlock (&g_module_global_lock);

       return module;

     }

   /* check whether we have a readable file right away */

   if (g_file_test (file_name, G_FILE_TEST_IS_REGULAR))

     name = g_strdup (file_name);

   /* try completing file name with standard library suffix */

   if (!name)

     {

       name = g_strconcat (file_name, "." G_MODULE_SUFFIX, NULL);

       if (!g_file_test (name, G_FILE_TEST_IS_REGULAR))

 	{

 	  g_free (name);

 	  name = NULL;

 	}

     }

   /* try completing by appending libtool suffix */

   if (!name)

     {

       name = g_strconcat (file_name, ".la", NULL);

       if (!g_file_test (name, G_FILE_TEST_IS_REGULAR))

 	{

 	  g_free (name);

 	  name = NULL;

 	}

     }

   /* we can't access() the file, lets hope the platform backends finds

    * it via library paths

    */

   if (!name)

     {

       gchar *dot = strrchr (file_name, '.');

       gchar *slash = strrchr (file_name, G_DIR_SEPARATOR);

       /* make sure the name has a suffix */

       if (!dot || dot < slash)

 	name = g_strconcat (file_name, "." G_MODULE_SUFFIX, NULL);

       else

 	name = g_strdup (file_name);

     }

   /* ok, try loading the module */

   if (name)

     {

       /* if it's a libtool archive, figure library file to load */

       if (str_check_suffix (name, ".la")) /* libtool archive? */

 	{

 	  gchar *real_name = parse_libtool_archive (name);

 	  /* real_name might be NULL, but then module error is already set */

 	  if (real_name)

 	    {

 	      g_free (name);

 	      name = real_name;

             }

 	}

       if (name)

 	handle = _g_module_open (name, (flags & G_MODULE_BIND_LAZY) != 0,

 			(flags & G_MODULE_BIND_LOCAL) != 0);

     }

   else

     {

       gchar *display_file_name = g_filename_display_name (file_name);

       g_module_set_error_unduped (g_strdup_printf ("unable to access file \"%s\"", display_file_name));

       g_free (display_file_name);

     }

   g_free (name);

   if (handle)

     {

       gchar *saved_error;

       GModuleCheckInit check_init;

       const gchar *check_failed = NULL;

       /* search the module list by handle, since file names are not unique */

       module = g_module_find_by_handle (handle);

       if (module)

 	{

 	  _g_module_close (module->handle, TRUE);

 	  module->ref_count++;

 	  g_module_set_error (NULL);

 	  g_static_rec_mutex_unlock (&g_module_global_lock);

 	  return module;

 	}

       saved_error = g_strdup (g_module_error ());

       g_module_set_error (NULL);

       module = g_new (GModule, 1);

       module->file_name = g_strdup (file_name);

 #if defined (G_OS_WIN32) && !defined(_WIN64)

       module->cp_file_name = g_locale_from_utf8 (file_name, -1,

 						 NULL, NULL, NULL);

 #endif

       module->handle = handle;

       module->ref_count = 1;

       module->is_resident = FALSE;

       module->unload = NULL;

       module->next = modules;

       modules = module;

       /* check initialization */

       if (g_module_symbol (module, "g_module_check_init", (gpointer) &check_init) && check_init != NULL)

 	check_failed = check_init (module);

       /* we don't call unload() if the initialization check failed. */

       if (!check_failed)

 	g_module_symbol (module, "g_module_unload", (gpointer) &module->unload);

       if (check_failed)

 	{

 	  gchar *error;

 	  error = g_strconcat ("GModule (", 

                                file_name ? file_name : "NULL", 

                                ") initialization check failed: ", 

                                check_failed, NULL);

 	  g_module_close (module);

 	  module = NULL;

 	  g_module_set_error (error);

 	  g_free (error);

 	}

       else

 	g_module_set_error (saved_error);

       g_free (saved_error);

     }

   if (module != NULL &&

       (module_debug_flags & G_MODULE_DEBUG_RESIDENT_MODULES))

     g_module_make_resident (module);

   g_static_rec_mutex_unlock (&g_module_global_lock);

   return module;

 }

 #if defined (G_OS_WIN32) && !defined(_WIN64)

 #undef g_module_open

 GModule*

 g_module_open (const gchar    *file_name,

 	       GModuleFlags    flags)

 {

   gchar *utf8_file_name = g_locale_to_utf8 (file_name, -1, NULL, NULL, NULL);

   GModule *retval = g_module_open_utf8 (utf8_file_name, flags);

   g_free (utf8_file_name);

   return retval;

 }

 #endif

 EXPORT_C gboolean

 g_module_close (GModule	       *module)

 {

   SUPPORT_OR_RETURN (FALSE);

   g_return_val_if_fail (module != NULL, FALSE);

   g_return_val_if_fail (module->ref_count > 0, FALSE);

   g_static_rec_mutex_lock (&g_module_global_lock);

   module->ref_count--;

   if (!module->ref_count && !module->is_resident && module->unload)

     {

       GModuleUnload unload;

       unload = module->unload;

       module->unload = NULL;

       unload (module);

     }

   if (!module->ref_count && !module->is_resident)

     {

       GModule *last;

       GModule *node;

       last = NULL;

       node = modules;

       while (node)

 	{

 	  if (node == module)

 	    {

 	      if (last)

 		last->next = node->next;

 	      else

 		modules = node->next;

 	      break;

 	    }

 	  last = node;

 	  node = last->next;

 	}

       module->next = NULL;

       _g_module_close (module->handle, FALSE);

       g_free (module->file_name);

 #if defined (G_OS_WIN32) && !defined(_WIN64)

       g_free (module->cp_file_name);

 #endif

       g_free (module);

     }

   g_static_rec_mutex_unlock (&g_module_global_lock);

   return g_module_error() == NULL;

 }

 EXPORT_C void

 g_module_make_resident (GModule *module)

 {

   g_return_if_fail (module != NULL);

   module->is_resident = TRUE;

 }

 EXPORT_C G_CONST_RETURN gchar*

 g_module_error (void)

 {

   return g_static_private_get (&module_error_private);

 }

 EXPORT_C gboolean

 g_module_symbol (GModule	*module,

 		 const gchar	*symbol_name,

 		 gpointer	*symbol)

 {

   const gchar *module_error;

   if (symbol)

     *symbol = NULL;

   SUPPORT_OR_RETURN (FALSE);

   g_return_val_if_fail (module != NULL, FALSE);

   g_return_val_if_fail (symbol_name != NULL, FALSE);

   g_return_val_if_fail (symbol != NULL, FALSE);

   g_static_rec_mutex_lock (&g_module_global_lock);

 #ifdef	G_MODULE_NEED_USCORE

   {

     gchar *name;

     name = g_strconcat ("_", symbol_name, NULL);

     *symbol = _g_module_symbol (module->handle, name);

     g_free (name);

   }

 #else	/* !G_MODULE_NEED_USCORE */

   *symbol = _g_module_symbol (module->handle, symbol_name);

 #endif	/* !G_MODULE_NEED_USCORE */

   module_error = g_module_error ();

   if (module_error)

     {

       gchar *error;

       error = g_strconcat ("`", symbol_name, "': ", module_error, NULL);

       g_module_set_error (error);

       g_free (error);

       *symbol = NULL;

     }

   g_static_rec_mutex_unlock (&g_module_global_lock);

   return !module_error;

 }

 EXPORT_C G_CONST_RETURN gchar*

 g_module_name (GModule *module)

 {

   g_return_val_if_fail (module != NULL, NULL);

   if (module == main_module)

     return "main";

   return module->file_name;

 }

 #if defined (G_OS_WIN32) && !defined(_WIN64)

 #undef g_module_name

 G_CONST_RETURN gchar*

 g_module_name (GModule *module)

 {

   g_return_val_if_fail (module != NULL, NULL);

   if (module == main_module)

     return "main";

   return module->cp_file_name;

 }

 #endif

 EXPORT_C gchar*

 g_module_build_path (const gchar *directory,

 		     const gchar *module_name)

 {

   g_return_val_if_fail (module_name != NULL, NULL);

   return _g_module_build_path (directory, module_name);

 }

 #define __GMODULE_C__