libtool/libltdl/loaders/dld_link.c
Gary V. Vaughan 5451db06bd Split lt_dlloader management into a separate file, and factor
`loaders' list management into a new SList ADT.  In the process,
the API for writing loaders is a little cleaner, so all the
existing loaders were tweaked to take advantage of that:

* libltdl/slist.h, libltdl/slist.c: New files implementing a
generic singly linked list container ADT.  The ADT is purely
internal, and none of its API's are visible from an installed
libltdl.
* libltdl/lt_dlloader.h (lt_dlloader): Removed next field again
:-) Renamed to lt_dlvtable for API.  Changed all callers.
(lt_dlloader_get): New function to turn an lt_dlloader into its
associated lt_dlvtable.
(lt_dlloader_add): Removed unused data parameter.  The caller
data belongs to (and is set by) the loader itself, not the
loader's client.  Changed all callers.
(lt_dlloader_name, lt_dlloader_data): Removed.  Use
lt_dlloader_get instead!
* libltdl/lt__private.h: Include slist.h.
(lt__alloc_die_callback): Add missing LT_SCOPE to declaration.
(lt_dlhandle_struct): Use lt_dlvtable instead of opaque
lt_dlloader.
* libltdl/ltdl.c (lt_dlexit): Rewritten for the new loader API.
(loaders, lt_dlloader_add, lt_dlloader_remove, lt_dlloader_next,
lt_dlloader_find): Moved from here...
* libltdl/lt_dlloader.c ((loaders, lt_dlloader_add,
lt_dlloader_remove, lt_dlloader_next, lt_dlloader_find): ...to
here.  And rewritten in terms of new SList interface.
* libltdl/ltdl.c (lt_dlexit, tryall_dlopen): Rewritten in terms of
new lt_dlloader interface.
* libltdl/Makefile.am (libdlloader_la_SOURCES): Add slist.h and
slist.c.  Move lt_dlloader.h from here...
(pkginclude_HEADERS): ...to here.
(libltdl_la_SOURCES): Add lt_dlloader.c and lt_dlloader.h.
2004-07-15 12:33:20 +00:00

141 lines
3.9 KiB
C

/* loader-dld_link.c -- dynamic linking with dld
Copyright (C) 1998, 1999, 2000, 2004 Free Software Foundation, Inc.
Originally by Thomas Tanner <tanner@ffii.org>
NOTE: The canonical source of this file is maintained with the
GNU Libtool package. Report bugs to bug-libtool@gnu.org.
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.
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 it under the same
distribution terms that you use for the rest of that program.
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
*/
#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_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
/* Boilerplate code to set up the vtable for hooking this loader into
libltdl's loader list: */
static lt_module vm_open (lt_user_data loader_data, const char *filename);
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);
/* 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)
{
static lt_dlvtable *vtable = 0;
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_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 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 loader_data, const char *filename)
{
lt_module module = lt__strdup (filename);
if (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 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 loader_data, lt_module module, const char *name)
{
void *address = dld_get_func (name);
if (!address)
{
LT__SETERROR (SYMBOL_NOT_FOUND);
}
return address;
}