glib/gmodule/gmodule.c
changeset 18 47c74d1534e1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/glib/gmodule/gmodule.c	Fri Apr 16 16:46:38 2010 +0300
@@ -0,0 +1,713 @@
+/* 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__