2 * Helper header for LD_PRELOAD related headers macros. Must be loaded _first_
5 * Copyright (C) 2012-2013 Simon Ruderich
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 /* Necessary for RTLD_NEXT. */
33 /* Load the function name using dlsym() and return it. Terminate program on
34 * failure. Split in function and macro to reduce code inserted into the
35 * function using the macro. */
36 static void *dlsym_function(char const *name) {
39 int saved_errno = errno; /* just in case */
41 /* Clear possibly existing error. */
43 result = dlsym(RTLD_NEXT, name);
44 /* Not much we can do. Most likely the other output functions failed to
46 if (dlerror() != NULL) {
54 #define DLSYM_FUNCTION(pointer, name) \
56 *(void **) (&(pointer)) = dlsym_function(name); \