xref: /openbsd-src/lib/libc/include/namespace.h (revision 7350f337b9e3eb4461d99580e625c7ef148d107c)
1 /*	$OpenBSD: namespace.h,v 1.14 2019/06/02 01:03:01 guenther Exp $	*/
2 
3 #ifndef _LIBC_NAMESPACE_H_
4 #define _LIBC_NAMESPACE_H_
5 
6 /*
7  * Copyright (c) 2015 Philip Guenther <guenther@openbsd.org>
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 
22 /*
23  * For explanations of how to use these, see README
24  * For explanations of why we use them and how they work, see DETAILS
25  */
26 
27 #include <sys/cdefs.h>	/* for __dso_hidden and __{weak,strong}_alias */
28 
29 #define	__dso_protected		__attribute__((__visibility__("protected")))
30 
31 #define	HIDDEN(x)		_libc_##x
32 #define	CANCEL(x)		_libc_##x##_cancel
33 #define	WRAP(x)			_libc_##x##_wrap
34 #define	HIDDEN_STRING(x)	"_libc_" __STRING(x)
35 #define	CANCEL_STRING(x)	"_libc_" __STRING(x) "_cancel"
36 #define	WRAP_STRING(x)		"_libc_" __STRING(x) "_wrap"
37 
38 #define	PROTO_NORMAL(x)		__dso_hidden typeof(x) x asm(HIDDEN_STRING(x))
39 #define	PROTO_STD_DEPRECATED(x)	typeof(x) x __attribute__((deprecated))
40 #define	PROTO_DEPRECATED(x)	typeof(x) x __attribute__((deprecated, weak))
41 #define	PROTO_CANCEL(x)		__dso_hidden typeof(x) HIDDEN(x), \
42 					x asm(CANCEL_STRING(x))
43 #define	PROTO_WRAP(x)		PROTO_NORMAL(x), WRAP(x)
44 #define	PROTO_PROTECTED(x)	__dso_protected typeof(x) x
45 
46 #define	DEF_STRONG(x)		__strong_alias(x, HIDDEN(x))
47 #define	DEF_WEAK(x)		__weak_alias(x, HIDDEN(x))
48 #define	DEF_CANCEL(x)		__weak_alias(x, CANCEL(x))
49 #define	DEF_WRAP(x)		__weak_alias(x, WRAP(x))
50 #define	DEF_SYS(x)		__strong_alias(_thread_sys_##x, HIDDEN(x))
51 #ifdef __clang__
52 #define	DEF_BUILTIN(x)		__asm("")
53 #define	BUILTIN			__dso_protected
54 #else
55 #define	DEF_BUILTIN(x)		DEF_STRONG(x)
56 #define	BUILTIN
57 #endif
58 
59 #define	MAKE_CLONE(dst, src)	__dso_hidden typeof(dst) HIDDEN(dst) \
60 				__attribute__((alias (HIDDEN_STRING(src))))
61 
62 #define	__relro			__attribute__((section(".data.rel.ro")))
63 
64 
65 /*
66  * gcc and clang will generate calls to the functions below.
67  * Declare and redirect them here so we always go
68  * directly to our hidden aliases.
69  */
70 #include <sys/_types.h>
71 BUILTIN void	*memmove(void *, const void *, __size_t);
72 BUILTIN void	*memcpy(void *__restrict, const void *__restrict, __size_t);
73 BUILTIN void	*memset(void *, int, __size_t);
74 BUILTIN void	__stack_smash_handler(const char [], int __unused);
75 #ifndef __clang__
76 PROTO_NORMAL(memmove);
77 PROTO_NORMAL(memcpy);
78 PROTO_NORMAL(memset);
79 PROTO_NORMAL(__stack_smash_handler);
80 #endif
81 #undef	BUILTIN
82 
83 #endif  /* _LIBC_NAMESPACE_H_ */
84 
85