gmodule/gmodule.h

   1 /* GMODULE - GLIB wrapper code for dynamic module loading
   2  * Copyright (C) 1998 Tim Janik
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GLib Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 #ifndef __GMODULE_H__
  26 #define __GMODULE_H__
  27
  28 #include <glib.h>
  29
  30 G_BEGIN_DECLS
  31
  32 /* exporting and importing functions, this is special cased
  33  * to feature Windows dll stubs.
  34  */
  35 #define G_MODULE_IMPORT         extern
  36 #ifdef G_PLATFORM_WIN32
  37 #  define       G_MODULE_EXPORT         __declspec(dllexport)
  38 #elif __GNUC__ >= 4
  39 #  define       G_MODULE_EXPORT         __attribute__((visibility("default")))
  40 #else /* !G_PLATFORM_WIN32 && __GNUC__ < 4 */
  41 #  define       G_MODULE_EXPORT
  42 #endif /* !G_PLATFORM_WIN32 */
  43
  44 /**
  45  * GModuleFlags:
  46  * @G_MODULE_BIND_LAZY: specifies that symbols are only resolved when
  47  *     needed. The default action is to bind all symbols when the module
  48  *     is loaded.
  49  * @G_MODULE_BIND_LOCAL: specifies that symbols in the module should
  50  *     not be added to the global name space. The default action on most
  51  *     platforms is to place symbols in the module in the global name space,
  52  *     which may cause conflicts with existing symbols.
  53  * @G_MODULE_BIND_MASK: mask for all flags.
  54  *
  55  * Flags passed to g_module_open().
  56  * Note that these flags are not supported on all platforms.
  57  */
  58 typedef enum
  59 {
  60   G_MODULE_BIND_LAZY    = 1 << 0,
  61   G_MODULE_BIND_LOCAL   = 1 << 1,
  62   G_MODULE_BIND_MASK    = 0x03
  63 } GModuleFlags;
  64
  65 typedef struct _GModule                  GModule;
  66 typedef const gchar* (*GModuleCheckInit) (GModule       *module);
  67 typedef void         (*GModuleUnload)    (GModule       *module);
  68
  69 /* return TRUE if dynamic module loading is supported */
  70 GLIB_AVAILABLE_IN_ALL
  71 gboolean        g_module_supported         (void) G_GNUC_CONST;
  72
  73 /* open a module 'file_name' and return handle, which is NULL on error */
  74 GLIB_AVAILABLE_IN_ALL
  75 GModule*              g_module_open          (const gchar  *file_name,
  76                                               GModuleFlags  flags);
  77
  78 /* close a previously opened module, returns TRUE on success */
  79 GLIB_AVAILABLE_IN_ALL
  80 gboolean              g_module_close         (GModule      *module);
  81
  82 /* make a module resident so g_module_close on it will be ignored */
  83 GLIB_AVAILABLE_IN_ALL
  84 void                  g_module_make_resident (GModule      *module);
  85
  86 /* query the last module error as a string */
  87 GLIB_AVAILABLE_IN_ALL
  88 const gchar *         g_module_error         (void);
  89
  90 /* retrieve a symbol pointer from 'module', returns TRUE on success */
  91 GLIB_AVAILABLE_IN_ALL
  92 gboolean              g_module_symbol        (GModule      *module,
  93                                               const gchar  *symbol_name,
  94                                               gpointer     *symbol);
  95
  96 /* retrieve the file name from an existing module */
  97 GLIB_AVAILABLE_IN_ALL
  98 const gchar *         g_module_name          (GModule      *module);
  99
 100 /* Build the actual file name containing a module. 'directory' is the
 101  * directory where the module file is supposed to be, or NULL or empty
 102  * in which case it should either be in the current directory or, on
 103  * some operating systems, in some standard place, for instance on the
 104  * PATH. Hence, to be absoultely sure to get the correct module,
 105  * always pass in a directory. The file name consists of the directory,
 106  * if supplied, and 'module_name' suitably decorated according to
 107  * the operating system's conventions (for instance lib*.so or *.dll).
 108  *
 109  * No checks are made that the file exists, or is of correct type.
 110  */
 111 GLIB_AVAILABLE_IN_ALL
 112 gchar*                g_module_build_path    (const gchar  *directory,
 113                                               const gchar  *module_name);
 114
 115 G_END_DECLS
 116
 117 #endif /* __GMODULE_H__ */