1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Berkeley Software Design, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef _SYS__VISIBLE_H_
36#define _SYS__VISIBLE_H_
37
38/*-
39 * The following definitions are an extension of the behavior originally
40 * implemented in <sys/_posix.h>, but with a different level of granularity.
41 * POSIX.1 requires that the macros we test be defined before any standard
42 * header file is included.
43 *
44 * Here's a quick run-down of the versions (and some informal names)
45 * defined(_POSIX_SOURCE) 1003.1-1988
46 * encoded as 198808 below
47 * _POSIX_C_SOURCE == 1 1003.1-1990
48 * encoded as 199009 below
49 * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option
50 * encoded as 199209 below
51 * _POSIX_C_SOURCE == 199309 1003.1b-1993
52 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93)
53 * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995,
54 * and the omnibus ISO/IEC 9945-1: 1996
55 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95)
56 * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03)
57 * with _XOPEN_SOURCE=600
58 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7)
59 * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is
60 * 1003.1-2008 with two TCs applied and
61 * _XOPEN_SOURCE=700
62 * _POSIX_C_SOURCE == 202405 1003.1-2004 (1003.1 Issue 8), IEEE Std 1003.1-2024
63 * with _XOPEN_SOURCE=800
64 *
65 * In addition, the X/Open Portability Guide, which is now the Single UNIX
66 * Specification, defines a feature-test macro which indicates the version of
67 * that specification, and which subsumes _POSIX_C_SOURCE.
68 *
69 * Our macros begin with two underscores to avoid namespace screwage.
70 */
71
72/* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
73#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
74#undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */
75#define _POSIX_C_SOURCE 199009
76#endif
77
78/* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
79#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
80#undef _POSIX_C_SOURCE
81#define _POSIX_C_SOURCE 199209
82#endif
83
84/*
85 * Deal with various X/Open Portability Guides and Single UNIX Spec. We use the
86 * '- 0' construct so software that defines _XOPEN_SOURCE to nothing doesn't
87 * cause errors. X/Open CAE Specification, August 1994, System Interfaces and
88 * Headers, Issue 4, Version 2 section 2.2 states an empty definition means the
89 * same thing as _POSIX_C_SOURCE == 2. This broadly mirrors "System V Interface
90 * Definition, Fourth Edition", but earlier editions suggest some ambiguity.
91 * However, FreeBSD has histoically implemented this as a NOP, so we just
92 * document what it should be for now to not break ports gratuitously.
93 */
94#ifdef _XOPEN_SOURCE
95#if _XOPEN_SOURCE - 0 >= 800
96#define __XSI_VISIBLE 800
97#undef _POSIX_C_SOURCE
98#define _POSIX_C_SOURCE 202405
99#elif _XOPEN_SOURCE - 0 >= 700
100#define __XSI_VISIBLE 700
101#undef _POSIX_C_SOURCE
102#define _POSIX_C_SOURCE 200809
103#elif _XOPEN_SOURCE - 0 >= 600
104#define __XSI_VISIBLE 600
105#undef _POSIX_C_SOURCE
106#define _POSIX_C_SOURCE 200112
107#elif _XOPEN_SOURCE - 0 >= 500
108#define __XSI_VISIBLE 500
109#undef _POSIX_C_SOURCE
110#define _POSIX_C_SOURCE 199506
111#else
112/* #define _POSIX_C_SOURCE 199209 */
113#endif
114#endif
115
116/*
117 * Deal with all versions of POSIX. The ordering relative to the tests above is
118 * important.
119 */
120#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
121#define _POSIX_C_SOURCE 198808
122#endif
123#ifdef _POSIX_C_SOURCE
124#if _POSIX_C_SOURCE >= 202405
125#define __POSIX_VISIBLE 202405
126#define __ISO_C_VISIBLE 2017
127#elif _POSIX_C_SOURCE >= 200809
128#define __POSIX_VISIBLE 200809
129#define __ISO_C_VISIBLE 1999
130#elif _POSIX_C_SOURCE >= 200112
131#define __POSIX_VISIBLE 200112
132#define __ISO_C_VISIBLE 1999
133#elif _POSIX_C_SOURCE >= 199506
134#define __POSIX_VISIBLE 199506
135#define __ISO_C_VISIBLE 1990
136#elif _POSIX_C_SOURCE >= 199309
137#define __POSIX_VISIBLE 199309
138#define __ISO_C_VISIBLE 1990
139#elif _POSIX_C_SOURCE >= 199209
140#define __POSIX_VISIBLE 199209
141#define __ISO_C_VISIBLE 1990
142#elif _POSIX_C_SOURCE >= 199009
143#define __POSIX_VISIBLE 199009
144#define __ISO_C_VISIBLE 1990
145#else
146#define __POSIX_VISIBLE 198808
147#define __ISO_C_VISIBLE 0
148#endif /* _POSIX_C_SOURCE */
149
150/*
151 * When we've explicitly asked for a newer C version, make the C variable
152 * visible by default. Also honor the glibc _ISOC{11,23}_SOURCE macros
153 * extensions. Both glibc and OpenBSD do this, even when a more strict
154 * _POSIX_C_SOURCE has been requested, and it makes good sense (especially for
155 * pre POSIX 2024, since C11 is much nicer than the old C99 base). Continue the
156 * practice with C23, though don't do older standards. Also, GLIBC doesn't have
157 * a _ISOC17_SOURCE, so it's not implemented here. glibc has earlier ISOCxx defines,
158 * but we don't implement those as they are not relevant enough.
159 */
160#if _ISOC23_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L)
161#undef __ISO_C_VISIBLE
162#define __ISO_C_VISIBLE 2023
163#elif _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
164#undef __ISO_C_VISIBLE
165#define __ISO_C_VISIBLE 2011
166#endif
167#else /* _POSIX_C_SOURCE */
168/*-
169 * Deal with _ANSI_SOURCE:
170 * If it is defined, and no other compilation environment is explicitly
171 * requested, then define our internal feature-test macros to zero. This
172 * makes no difference to the preprocessor (undefined symbols in preprocessing
173 * expressions are defined to have value zero), but makes it more convenient for
174 * a test program to print out the values.
175 *
176 * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
177 * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
178 * environment (and in fact we will never get here).
179 */
180#if defined(_ANSI_SOURCE) /* Hide almost everything. */
181#define __POSIX_VISIBLE 0
182#define __XSI_VISIBLE 0
183#define __BSD_VISIBLE 0
184#define __ISO_C_VISIBLE 1990
185#define __EXT1_VISIBLE 0
186#elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */
187#define __POSIX_VISIBLE 0
188#define __XSI_VISIBLE 0
189#define __BSD_VISIBLE 0
190#define __ISO_C_VISIBLE 1999
191#define __EXT1_VISIBLE 0
192#elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */
193#define __POSIX_VISIBLE 0
194#define __XSI_VISIBLE 0
195#define __BSD_VISIBLE 0
196#define __ISO_C_VISIBLE 2011
197#define __EXT1_VISIBLE 0
198#elif defined(_C23_SOURCE) /* Localism to specify strict C23 env. */
199#define __POSIX_VISIBLE 0
200#define __XSI_VISIBLE 0
201#define __BSD_VISIBLE 0
202#define __ISO_C_VISIBLE 2023
203#define __EXT1_VISIBLE 0
204#else /* Default environment: show everything. */
205#define __POSIX_VISIBLE 202405
206#define __XSI_VISIBLE 800
207#define __BSD_VISIBLE 1
208#define __ISO_C_VISIBLE 2023
209#define __EXT1_VISIBLE 1
210#endif
211#endif /* _POSIX_C_SOURCE */
212
213/* User override __EXT1_VISIBLE */
214#if defined(__STDC_WANT_LIB_EXT1__)
215#undef __EXT1_VISIBLE
216#if __STDC_WANT_LIB_EXT1__
217#define __EXT1_VISIBLE 1
218#else
219#define __EXT1_VISIBLE 0
220#endif
221#endif /* __STDC_WANT_LIB_EXT1__ */
222
223#endif /* !_SYS__VISIBLE_H_ */