root/libltdl/loaders/load_add_on.c

/* */

DEFINITIONS

1. get_vtable
2. vl_exit
3. vm_open
4. vm_close
5. vm_sym

   1 /* loader-load_add_on.c --  dynamic linking for BeOS
   2 
   3    Copyright (C) 1998, 1999, 2000, 2004, 2006,
   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 #include "lt__private.h"
  33 #include "lt_dlloader.h"
  34 
  35 /* Use the preprocessor to rename non-static symbols to avoid namespace
  36    collisions when the loader code is statically linked into libltdl.
  37    Use the "<module_name>_LTX_" prefix so that the symbol addresses can
  38    be fetched from the preloaded symbol list by lt_dlsym():  */
  39 #define get_vtable      load_add_on_LTX_get_vtable
  40 
  41 LT_BEGIN_C_DECLS
  42 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
  43 LT_END_C_DECLS
  44 
  45 
  46 /* Boilerplate code to set up the vtable for hooking this loader into
  47    libltdl's loader list:  */
  48 static int       vl_exit  (lt_user_data loader_data);
  49 static lt_module vm_open  (lt_user_data loader_data, const char *filename,
  50                            lt_dladvise advise);
  51 static int       vm_close (lt_user_data loader_data, lt_module module);
  52 static void *    vm_sym   (lt_user_data loader_data, lt_module module,
  53                           const char *symbolname);
  54 
  55 static lt_dlvtable *vtable = 0;
  56 
  57 /* Return the vtable for this loader, only the name and sym_prefix
  58    attributes (plus the virtual function implementations, obviously)
  59    change between loaders.  */
  60 lt_dlvtable *
  61 get_vtable (lt_user_data loader_data)
  62 {
  63   if (!vtable)
  64     {
  65       vtable = lt__zalloc (sizeof *vtable);
  66     }
  67 
  68   if (vtable && !vtable->name)
  69     {
  70       vtable->name              = "lt_load_add_on";
  71       vtable->module_open       = vm_open;
  72       vtable->module_close      = vm_close;
  73       vtable->find_sym          = vm_sym;
  74       vtable->dlloader_exit     = vl_exit;
  75       vtable->dlloader_data     = loader_data;
  76       vtable->priority          = LT_DLLOADER_APPEND;
  77     }
  78 
  79   if (vtable && (vtable->dlloader_data != loader_data))
  80     {
  81       LT__SETERROR (INIT_LOADER);
  82       return 0;
  83     }
  84 
  85   return vtable;
  86 }
  87 
  88 
  89 
  90 /* --- IMPLEMENTATION --- */
  91 
  92 
  93 #include <kernel/image.h>
  94 
  95 /* A function called through the vtable when this loader is no
  96    longer needed by the application.  */
  97 static int
  98 vl_exit (lt_user_data LT__UNUSED loader_data)
  99 {
 100   vtable = NULL;
 101   return 0;
 102 }
 103 
 104 /* A function called through the vtable to open a module with this
 105    loader.  Returns an opaque representation of the newly opened
 106    module for processing with this loader's other vtable functions.  */
 107 static lt_module
 108 vm_open (lt_user_data LT__UNUSED loader_data, const char *filename,
 109          lt_dladvise LT__UNUSED advise)
 110 {
 111   image_id image = 0;
 112 
 113   if (filename)
 114     {
 115       image = load_add_on (filename);
 116     }
 117   else
 118     {
 119       image_info info;
 120       int32 cookie = 0;
 121       if (get_next_image_info (0, &cookie, &info) == B_OK)
 122         image = load_add_on (info.name);
 123     }
 124 
 125   if (image <= 0)
 126     {
 127       LT__SETERROR (CANNOT_OPEN);
 128       image = 0;
 129     }
 130 
 131   return (lt_module) image;
 132 }
 133 
 134 
 135 /* A function called through the vtable when a particular module
 136    should be unloaded.  */
 137 static int
 138 vm_close (lt_user_data LT__UNUSED loader_data, lt_module module)
 139 {
 140   int errors = 0;
 141 
 142   if (unload_add_on ((image_id) module) != B_OK)
 143     {
 144       LT__SETERROR (CANNOT_CLOSE);
 145       ++errors;
 146     }
 147 
 148   return errors;
 149 }
 150 
 151 
 152 /* A function called through the vtable to get the address of
 153    a symbol loaded from a particular module.  */
 154 static void *
 155 vm_sym (lt_user_data LT__UNUSED loader_data, lt_module module, const char *name)
 156 {
 157   void *address = 0;
 158   image_id image = (image_id) module;
 159 
 160   if (get_image_symbol (image, name, B_SYMBOL_TYPE_ANY, address) != B_OK)
 161     {
 162       LT__SETERROR (SYMBOL_NOT_FOUND);
 163       address = 0;
 164     }
 165 
 166   return address;
 167 }

/* */