1/* ABI compatibility for lgamma functions.
2 Copyright (C) 2015-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
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.
9
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.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef LGAMMA_COMPAT_H
20#define LGAMMA_COMPAT_H 1
21
22#include <math-svid-compat.h>
23#include <shlib-compat.h>
24
25/* XSI POSIX requires lgamma to set signgam, but ISO C does not permit
26 this. Namespace issues can be avoided if the functions set
27 __signgam and signgam is a weak alias, but this only works if both
28 signgam and __signgam were exported from the glibc version the
29 program was linked against. Before glibc 2.23, lgamma functions
30 set signgam which was not a weak alias for __signgam, so old
31 binaries have dynamic symbols for signgam only and the versions of
32 lgamma used for old binaries must set both signgam and __signgam.
33 Those versions also do a check of _LIB_VERSION != _ISOC_ to match
34 old glibc.
35
36 Users of this file define USE_AS_COMPAT to 0 when building the main
37 version of lgamma, 1 when building the compatibility version. */
38
39#define LGAMMA_OLD_VER GLIBC_2_0
40#define LGAMMA_NEW_VER GLIBC_2_23
41#define HAVE_LGAMMA_COMPAT SHLIB_COMPAT (libm, LGAMMA_OLD_VER, LGAMMA_NEW_VER)
42
43/* Whether to build this version at all. */
44#define BUILD_LGAMMA \
45 (LIBM_SVID_COMPAT && (HAVE_LGAMMA_COMPAT || !USE_AS_COMPAT))
46
47/* The name to use for this version. */
48#if USE_AS_COMPAT
49# define LGFUNC(FUNC) FUNC ## _compat
50#else
51# define LGFUNC(FUNC) FUNC
52#endif
53
54/* If there is a compatibility version, gamma (not an ISO C function,
55 so never a problem for it to set signgam) points directly to it
56 rather than having separate versions. */
57#define GAMMA_ALIAS (USE_AS_COMPAT ? HAVE_LGAMMA_COMPAT : !HAVE_LGAMMA_COMPAT)
58
59/* How to call the underlying lgamma_r function. */
60#define CALL_LGAMMA(TYPE, FUNC, ARG) \
61 ({ \
62 TYPE lgamma_tmp; \
63 int local_signgam; \
64 if (USE_AS_COMPAT) \
65 { \
66 lgamma_tmp = FUNC ((ARG), &local_signgam); \
67 if (_LIB_VERSION != _ISOC_) \
68 signgam = __signgam = local_signgam; \
69 } \
70 else \
71 lgamma_tmp = FUNC ((ARG), &__signgam); \
72 lgamma_tmp; \
73 })
74
75#endif /* lgamma-compat.h. */
76