libltdl/ltdl.h

   1 /* ltdl.h -- generic dlopen functions
   2
   3    Copyright (C) 1998-2000, 2004, 2005,
   4                  2007, 2008 Free Software Foundation, Inc.
   5    Written by Thomas Tanner, 1998
   6
   7    NOTE: The canonical source of this file is maintained with the
   8    GNU Libtool package.  Report bugs to bug-libtool@gnu.org.
   9
  10 GNU Libltdl is free software; you can redistribute it and/or
  11 modify it under the terms of the GNU Lesser General Public
  12 License as published by the Free Software Foundation; either
  13 version 2 of the License, or (at your option) any later version.
  14
  15 As a special exception to the GNU Lesser General Public License,
  16 if you distribute this file as part of a program or library that
  17 is built using GNU Libtool, you may include this file under the
  18 same distribution terms that you use for the rest of that program.
  19
  20 GNU Libltdl is distributed in the hope that it will be useful,
  21 but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 GNU Lesser General Public License for more details.
  24
  25 You should have received a copy of the GNU Lesser General Public
  26 License along with GNU Libltdl; see the file COPYING.LIB.  If not, a
  27 copy can be downloaded from  http://www.gnu.org/licenses/lgpl.html,
  28 or obtained by writing to the Free Software Foundation, Inc.,
  29 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  30 */
  31
  32 /* Only include this header file once. */
  33 #if !defined(LTDL_H)
  34 #define LTDL_H 1
  35
  36 #include <libltdl/lt_system.h>
  37 #include <libltdl/lt_error.h>
  38 #include <libltdl/lt_dlloader.h>
  39
  40 LT_BEGIN_C_DECLS
  41
  42
  43 /* LT_STRLEN can be used safely on NULL pointers.  */
  44 #define LT_STRLEN(s)    (((s) && (s)[0]) ? strlen (s) : 0)
  45
  46 \f
  47 /* --- DYNAMIC MODULE LOADING API --- */
  48
  49
  50 typedef struct lt__handle *lt_dlhandle; /* A loaded module.  */
  51
  52 /* Initialisation and finalisation functions for libltdl. */
  53 LT_SCOPE int        lt_dlinit           (void);
  54 LT_SCOPE int        lt_dlexit           (void);
  55
  56 /* Module search path manipulation.  */
  57 LT_SCOPE int        lt_dladdsearchdir    (const char *search_dir);
  58 LT_SCOPE int        lt_dlinsertsearchdir (const char *before,
  59                                                   const char *search_dir);
  60 LT_SCOPE int        lt_dlsetsearchpath   (const char *search_path);
  61 LT_SCOPE const char *lt_dlgetsearchpath  (void);
  62 LT_SCOPE int        lt_dlforeachfile     (
  63                         const char *search_path,
  64                         int (*func) (const char *filename, void *data),
  65                         void *data);
  66
  67 /* User module loading advisors.  */
  68 LT_SCOPE int        lt_dladvise_init     (lt_dladvise *advise);
  69 LT_SCOPE int        lt_dladvise_destroy  (lt_dladvise *advise);
  70 LT_SCOPE int        lt_dladvise_ext      (lt_dladvise *advise);
  71 LT_SCOPE int        lt_dladvise_resident (lt_dladvise *advise);
  72 LT_SCOPE int        lt_dladvise_local    (lt_dladvise *advise);
  73 LT_SCOPE int        lt_dladvise_global   (lt_dladvise *advise);
  74 LT_SCOPE int        lt_dladvise_preload  (lt_dladvise *advise);
  75
  76 /* Portable libltdl versions of the system dlopen() API. */
  77 LT_SCOPE lt_dlhandle lt_dlopen          (const char *filename);
  78 LT_SCOPE lt_dlhandle lt_dlopenext       (const char *filename);
  79 LT_SCOPE lt_dlhandle lt_dlopenadvise    (const char *filename,
  80                                          lt_dladvise advise);
  81 LT_SCOPE void *     lt_dlsym            (lt_dlhandle handle, const char *name);
  82 LT_SCOPE const char *lt_dlerror         (void);
  83 LT_SCOPE int        lt_dlclose          (lt_dlhandle handle);
  84
  85
  86
  87 /* --- PRELOADED MODULE SUPPORT --- */
  88
  89
  90 /* A preopened symbol. Arrays of this type comprise the exported
  91    symbols for a dlpreopened module. */
  92 typedef struct {
  93   const char *name;
  94   void       *address;
  95 } lt_dlsymlist;
  96
  97 typedef int lt_dlpreload_callback_func (lt_dlhandle handle);
  98
  99 LT_SCOPE int    lt_dlpreload         (const lt_dlsymlist *preloaded);
 100 LT_SCOPE int    lt_dlpreload_default (const lt_dlsymlist *preloaded);
 101 LT_SCOPE int    lt_dlpreload_open    (const char *originator,
 102                                       lt_dlpreload_callback_func *func);
 103
 104 #define lt_preloaded_symbols    lt__PROGRAM__LTX_preloaded_symbols
 105 #define LTDL_SET_PRELOADED_SYMBOLS()                    LT_STMT_START{  \
 106         extern const lt_dlsymlist lt_preloaded_symbols[];               \
 107         lt_dlpreload_default(lt_preloaded_symbols);                     \
 108                                                         }LT_STMT_END
 109
 110
 111
 112 \f
 113 /* --- MODULE INFORMATION --- */
 114
 115
 116 /* Associating user data with loaded modules. */
 117 typedef void * lt_dlinterface_id;
 118 typedef int lt_dlhandle_interface (lt_dlhandle handle, const char *id_string);
 119
 120 LT_SCOPE lt_dlinterface_id lt_dlinterface_register (const char *id_string,
 121                                           lt_dlhandle_interface *iface);
 122 LT_SCOPE void   lt_dlinterface_free (lt_dlinterface_id key);
 123 LT_SCOPE void * lt_dlcaller_set_data  (lt_dlinterface_id key,
 124                                           lt_dlhandle handle, void *data);
 125 LT_SCOPE void * lt_dlcaller_get_data  (lt_dlinterface_id key,
 126                                           lt_dlhandle handle);
 127
 128
 129 /* Read only information pertaining to a loaded module. */
 130 typedef struct {
 131   char *        filename;       /* file name */
 132   char *        name;           /* module name */
 133   int           ref_count;      /* number of times lt_dlopened minus
 134                                    number of times lt_dlclosed. */
 135   unsigned int  is_resident:1;  /* module can't be unloaded. */
 136   unsigned int  is_symglobal:1; /* module symbols can satisfy
 137                                    subsequently loaded modules.  */
 138   unsigned int  is_symlocal:1;  /* module symbols are only available
 139                                    locally. */
 140 } lt_dlinfo;
 141
 142 LT_SCOPE const lt_dlinfo *lt_dlgetinfo      (lt_dlhandle handle);
 143
 144 LT_SCOPE lt_dlhandle    lt_dlhandle_iterate (lt_dlinterface_id iface,
 145                                              lt_dlhandle place);
 146 LT_SCOPE lt_dlhandle    lt_dlhandle_fetch   (lt_dlinterface_id iface,
 147                                              const char *module_name);
 148 LT_SCOPE int            lt_dlhandle_map     (lt_dlinterface_id iface,
 149                                 int (*func) (lt_dlhandle handle, void *data),
 150                                 void *data);
 151
 152
 153
 154 /* Deprecated module residency management API. */
 155 LT_SCOPE int        lt_dlmakeresident   (lt_dlhandle handle);
 156 LT_SCOPE int        lt_dlisresident     (lt_dlhandle handle);
 157
 158 #define lt_ptr void *
 159
 160 LT_END_C_DECLS
 161
 162 #endif /*!defined(LTDL_H)*/