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jfr.im git - solanum.git/blob - libltdl/lt_dlloader.c
1 /* lt_dlloader.c -- dynamic library loader interface
3 Copyright (C) 2004, 2007, 2008 Free Software Foundation, Inc.
4 Written by Gary V. Vaughan, 2004
6 NOTE: The canonical source of this file is maintained with the
7 GNU Libtool package. Report bugs to bug-libtool@gnu.org.
9 GNU Libltdl is free software; you can redistribute it and/or
10 modify it under the terms of the GNU Lesser General Public
11 License as published by the Free Software Foundation; either
12 version 2 of the License, or (at your option) any later version.
14 As a special exception to the GNU Lesser General Public License,
15 if you distribute this file as part of a program or library that
16 is built using GNU Libtool, you may include this file under the
17 same distribution terms that you use for the rest of that program.
19 GNU Libltdl is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 GNU Lesser General Public License for more details.
24 You should have received a copy of the GNU Lesser General Public
25 License along with GNU Libltdl; see the file COPYING.LIB. If not, a
26 copy can be downloaded from http://www.gnu.org/licenses/lgpl.html,
27 or obtained by writing to the Free Software Foundation, Inc.,
28 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
31 #include "lt__private.h"
32 #include "lt_dlloader.h"
34 #define RETURN_SUCCESS 0
35 #define RETURN_FAILURE 1
37 static void * loader_callback (SList
*item
, void *userdata
);
39 /* A list of all the dlloaders we know about, each stored as a boxed
41 static SList
*loaders
= 0;
44 /* Return NULL, unless the loader in this ITEM has a matching name,
45 in which case we return the matching item so that its address is
46 passed back out (for possible freeing) by slist_remove. */
48 loader_callback (SList
*item
, void *userdata
)
50 const lt_dlvtable
*vtable
= (const lt_dlvtable
*) item
->userdata
;
51 const char * name
= (const char *) userdata
;
55 return streq (vtable
->name
, name
) ? (void *) item
: NULL
;
59 /* Hook VTABLE into our global LOADERS list according to its own
60 PRIORITY field value. */
62 lt_dlloader_add (const lt_dlvtable
*vtable
)
66 if ((vtable
== 0) /* diagnose invalid vtable fields */
67 || (vtable
->module_open
== 0)
68 || (vtable
->module_close
== 0)
69 || (vtable
->find_sym
== 0)
70 || ((vtable
->priority
!= LT_DLLOADER_PREPEND
) &&
71 (vtable
->priority
!= LT_DLLOADER_APPEND
)))
73 LT__SETERROR (INVALID_LOADER
);
74 return RETURN_FAILURE
;
77 item
= slist_box (vtable
);
82 /* Let the caller know something went wrong if lt__alloc_die
84 return RETURN_FAILURE
;
87 if (vtable
->priority
== LT_DLLOADER_PREPEND
)
89 loaders
= slist_cons (item
, loaders
);
93 assert (vtable
->priority
== LT_DLLOADER_APPEND
);
94 loaders
= slist_concat (loaders
, item
);
97 return RETURN_SUCCESS
;
100 #ifdef LT_DEBUG_LOADERS
102 loader_dump_callback (SList
*item
, void *userdata
)
104 const lt_dlvtable
*vtable
= (const lt_dlvtable
*) item
->userdata
;
105 fprintf (stderr
, ", %s", (vtable
&& vtable
->name
) ? vtable
->name
: "(null)");
110 lt_dlloader_dump (void)
112 fprintf (stderr
, "loaders: ");
115 fprintf (stderr
, "(empty)");
119 const lt_dlvtable
*head
= (const lt_dlvtable
*) loaders
->userdata
;
120 fprintf (stderr
, "%s", (head
&& head
->name
) ? head
->name
: "(null)");
121 if (slist_tail (loaders
))
122 slist_foreach (slist_tail (loaders
), loader_dump_callback
, NULL
);
124 fprintf (stderr
, "\n");
128 /* An iterator for the global loader list: if LOADER is NULL, then
129 return the first element, otherwise the following element. */
131 lt_dlloader_next (lt_dlloader loader
)
133 SList
*item
= (SList
*) loader
;
134 return (lt_dlloader
) (item
? item
->next
: loaders
);
138 /* Non-destructive unboxing of a loader. */
140 lt_dlloader_get (lt_dlloader loader
)
142 return (const lt_dlvtable
*) (loader
? ((SList
*) loader
)->userdata
: NULL
);
146 /* Return the contents of the first item in the global loader list
147 with a matching NAME after removing it from that list. If there
148 was no match, return NULL; if there is an error, return NULL and
149 set an error for lt_dlerror; do not set an error if only resident
150 modules need this loader; in either case, the loader list is not
151 changed if NULL is returned. */
153 lt_dlloader_remove (const char *name
)
155 const lt_dlvtable
* vtable
= lt_dlloader_find (name
);
156 static const char id_string
[] = "lt_dlloader_remove";
157 lt_dlinterface_id iface
;
158 lt_dlhandle handle
= 0;
160 int in_use_by_resident
= 0;
164 LT__SETERROR (INVALID_LOADER
);
168 /* Fail if there are any open modules which use this loader. */
169 iface
= lt_dlinterface_register (id_string
, NULL
);
170 while ((handle
= lt_dlhandle_iterate (iface
, handle
)))
172 lt_dlhandle cur
= handle
;
173 if (cur
->vtable
== vtable
)
176 if (lt_dlisresident (handle
))
177 in_use_by_resident
= 1;
180 lt_dlinterface_free (iface
);
183 if (!in_use_by_resident
)
184 LT__SETERROR (REMOVE_LOADER
);
188 /* Call the loader finalisation function. */
189 if (vtable
&& vtable
->dlloader_exit
)
191 if ((*vtable
->dlloader_exit
) (vtable
->dlloader_data
) != 0)
193 /* If there is an exit function, and it returns non-zero
194 then it must set an error, and we will not remove it
200 /* If we got this far, remove the loader from our global list. */
201 return (lt_dlvtable
*)
202 slist_unbox ((SList
*) slist_remove (&loaders
, loader_callback
, (void *) name
));
207 lt_dlloader_find (const char *name
)
209 return lt_dlloader_get (slist_find (loaders
, loader_callback
, (void *) name
));