.
[glibc/history.git] / bits / dlfcn.h
blob67fd96a22afacbfe8eb2e1501d0a3a87bd7d5fac
1 /* System dependent definitions for run-time dynamic loading.
2 Copyright (C) 1996-2001, 2004 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #ifndef _DLFCN_H
21 # error "Never use <bits/dlfcn.h> directly; include <dlfcn.h> instead."
22 #endif
24 /* The MODE argument to `dlopen' contains one of the following: */
25 #define RTLD_LAZY 0x00001 /* Lazy function call binding. */
26 #define RTLD_NOW 0x00002 /* Immediate function call binding. */
27 #define RTLD_BINDING_MASK 0x3 /* Mask of binding time value. */
28 #define RTLD_NOLOAD 0x00004 /* Do not load the object. */
29 #define RTLD_DEEPBIND 0x00008 /* Use deep binding. */
31 /* If the following bit is set in the MODE argument to `dlopen',
32 the symbols of the loaded object and its dependencies are made
33 visible as if the object were linked directly into the program. */
34 #define RTLD_GLOBAL 0x00100
36 /* Unix98 demands the following flag which is the inverse to RTLD_GLOBAL.
37 The implementation does this by default and so we can define the
38 value to zero. */
39 #define RTLD_LOCAL 0
41 /* Do not delete object when closed. */
42 #define RTLD_NODELETE 0x01000
44 #ifdef __USE_GNU
45 /* To support profiling of shared objects it is a good idea to call
46 the function found using `dlsym' using the following macro since
47 these calls do not use the PLT. But this would mean the dynamic
48 loader has no chance to find out when the function is called. The
49 macro applies the necessary magic so that profiling is possible.
50 Rewrite
51 foo = (*fctp) (arg1, arg2);
52 into
53 foo = DL_CALL_FCT (fctp, (arg1, arg2));
55 # define DL_CALL_FCT(fctp, args) \
56 (_dl_mcount_wrapper_check ((void *) (fctp)), (*(fctp)) args)
58 __BEGIN_DECLS
60 /* This function calls the profiling functions. */
61 extern void _dl_mcount_wrapper_check (void *__selfpc) __THROW;
63 __END_DECLS
65 #endif