libc/include/namespace.h

1 /* $OpenBSD: namespace.h,v 1.17 2025年10月23日 19:06:10 miod 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 * ISO C11 or higher is required to build libc.
24 * This must come _before_ sys/cdefs.h is included.
25 */
26#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112
27#define _ISOC11_SOURCE 1
28#endif
29
30 /*
31 * For explanations of how to use these, see README
32 * For explanations of why we use them and how they work, see DETAILS
33 */
34
35#include <sys/cdefs.h> /* for __dso_hidden and __{weak,strong}_alias */
36
37#define __dso_protected __attribute__((__visibility__("protected")))
38
39#define HIDDEN(x) _libc_##x
40#define CANCEL(x) _libc_##x##_cancel
41#define WRAP(x) _libc_##x##_wrap
42#define HIDDEN_STRING(x) "_libc_" __STRING(x)
43#define CANCEL_STRING(x) "_libc_" __STRING(x) "_cancel"
44#define WRAP_STRING(x) "_libc_" __STRING(x) "_wrap"
45
46#define PROTO_NORMAL(x) __dso_hidden typeof(x) x asm(HIDDEN_STRING(x))
47#define PROTO_STD_DEPRECATED(x) typeof(x) x __attribute__((deprecated))
48#define PROTO_DEPRECATED(x) typeof(x) x __attribute__((deprecated, weak))
49#define PROTO_CANCEL(x) __dso_hidden typeof(x) HIDDEN(x), \
50 x asm(CANCEL_STRING(x))
51#define PROTO_WRAP(x) PROTO_NORMAL(x), WRAP(x)
52#define PROTO_PROTECTED(x) __dso_protected typeof(x) x
53
54#define DEF_STRONG(x) __strong_alias(x, HIDDEN(x))
55#define DEF_WEAK(x) __weak_alias(x, HIDDEN(x))
56#define DEF_CANCEL(x) __weak_alias(x, CANCEL(x))
57#define DEF_WRAP(x) __weak_alias(x, WRAP(x))
58#define DEF_SYS(x) __strong_alias(_thread_sys_##x, HIDDEN(x))
59
60#if !defined(__clang__)
61 /* our gcc 4.2 handles redirecting builtins via PROTO_NORMAL()'s asm() label */
62#define DEF_BUILTIN(x) DEF_STRONG(x)
63#define BUILTIN
64#else
65 /*
66 * clang can't redirect builtins via asm() labels, so mark
67 * them protected instead.
68 */
69#define DEF_BUILTIN(x) __asm("")
70#define BUILTIN __dso_protected
71#endif
72
73#define MAKE_CLONE(dst, src) __dso_hidden typeof(dst) HIDDEN(dst) \
74 __attribute__((alias (HIDDEN_STRING(src))))
75
76#define __relro __attribute__((section(".data.rel.ro")))
77
78
79 /*
80 * gcc and clang will generate calls to the functions below.
81 * Declare and redirect them here so we always go
82 * directly to our hidden aliases.
83 */
84#include <sys/_types.h>
85 BUILTIN void *memmove(void *, const void *, __size_t);
86 BUILTIN void *memcpy(void *__restrict, const void *__restrict, __size_t);
87 BUILTIN void *memset(void *, int, __size_t);
88 BUILTIN void __stack_smash_handler(const char [], int __unused);
89#if !defined(__clang__)
90 PROTO_NORMAL(memmove);
91 PROTO_NORMAL(memcpy);
92 PROTO_NORMAL(memset);
93 PROTO_NORMAL(__stack_smash_handler);
94#endif
95#undef BUILTIN
96
97#endif /* _LIBC_NAMESPACE_H_ */
98
99