Edit File: dld_link.c
/* loader-dld_link.c -- dynamic linking with dld Copyright (C) 1998, 1999, 2000, 2004, 2006, 2007, 2008 Free Software Foundation, Inc. Written by Thomas Tanner, 1998 NOTE: The canonical source of this file is maintained with the GNU Libtool package. Report bugs to bug-libtool@gnu.org. GNU Libltdl 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. As a special exception to the GNU Lesser General Public License, if you distribute this file as part of a program or library that is built using GNU Libtool, you may include this file under the same distribution terms that you use for the rest of that program. GNU Libltdl 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 GNU Libltdl; see the file COPYING.LIB. If not, a copy can be downloaded from http://www.gnu.org/licenses/lgpl.html, or obtained by writing to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "lt__private.h" #include "lt_dlloader.h" /* Use the preprocessor to rename non-static symbols to avoid namespace collisions when the loader code is statically linked into libltdl. Use the "<module_name>_LTX_" prefix so that the symbol addresses can be fetched from the preloaded symbol list by lt_dlsym(): */ #define get_vtable dld_link_LTX_get_vtable LT_BEGIN_C_DECLS LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data); LT_END_C_DECLS /* Boilerplate code to set up the vtable for hooking this loader into libltdl's loader list: */ static int vl_exit (lt_user_data loader_data); static lt_module vm_open (lt_user_data loader_data, const char *filename, lt_dladvise advise); static int vm_close (lt_user_data loader_data, lt_module module); static void * vm_sym (lt_user_data loader_data, lt_module module, const char *symbolname); static lt_dlvtable *vtable = 0; /* Return the vtable for this loader, only the name and sym_prefix attributes (plus the virtual function implementations, obviously) change between loaders. */ lt_dlvtable * get_vtable (lt_user_data loader_data) { if (!vtable) { vtable = lt__zalloc (sizeof *vtable); } if (vtable && !vtable->name) { vtable->name = "lt_dld_link"; vtable->module_open = vm_open; vtable->module_close = vm_close; vtable->find_sym = vm_sym; vtable->dlloader_exit = vl_exit; vtable->dlloader_data = loader_data; vtable->priority = LT_DLLOADER_APPEND; } if (vtable && (vtable->dlloader_data != loader_data)) { LT__SETERROR (INIT_LOADER); return 0; } return vtable; } /* --- IMPLEMENTATION --- */ #if defined(HAVE_DLD_H) # include <dld.h> #endif /* A function called through the vtable when this loader is no longer needed by the application. */ static int vl_exit (lt_user_data LT__UNUSED loader_data) { vtable = NULL; return 0; } /* A function called through the vtable to open a module with this loader. Returns an opaque representation of the newly opened module for processing with this loader's other vtable functions. */ static lt_module vm_open (lt_user_data LT__UNUSED loader_data, const char *filename, lt_dladvise LT__UNUSED advise) { lt_module module = lt__strdup (filename); if (module && dld_link (filename) != 0) { LT__SETERROR (CANNOT_OPEN); FREE (module); } return module; } /* A function called through the vtable when a particular module should be unloaded. */ static int vm_close (lt_user_data LT__UNUSED loader_data, lt_module module) { int errors = 0; if (dld_unlink_by_file ((char*)(module), 1) != 0) { LT__SETERROR (CANNOT_CLOSE); ++errors; } else { FREE (module); } return errors; } /* A function called through the vtable to get the address of a symbol loaded from a particular module. */ static void * vm_sym (lt_user_data LT__UNUSED loader_data, lt_module LT__UNUSED module, const char *name) { void *address = dld_get_func (name); if (!address) { LT__SETERROR (SYMBOL_NOT_FOUND); } return address; }