glibc/math/lgamma-compat.h

74 lines
2.7 KiB
C

/* ABI compatibility for lgamma functions.
Copyright (C) 2015-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef LGAMMA_COMPAT_H
#define LGAMMA_COMPAT_H 1
#include <shlib-compat.h>
/* XSI POSIX requires lgamma to set signgam, but ISO C does not permit
this. Namespace issues can be avoided if the functions set
__signgam and signgam is a weak alias, but this only works if both
signgam and __signgam were exported from the glibc version the
program was linked against. Before glibc 2.23, lgamma functions
set signgam which was not a weak alias for __signgam, so old
binaries have dynamic symbols for signgam only and the versions of
lgamma used for old binaries must set both signgam and __signgam.
Those versions also do a check of _LIB_VERSION != _ISOC_ to match
old glibc.
Users of this file define USE_AS_COMPAT to 0 when building the main
version of lgamma, 1 when building the compatibility version. */
#define LGAMMA_OLD_VER GLIBC_2_0
#define LGAMMA_NEW_VER GLIBC_2_23
#define HAVE_LGAMMA_COMPAT SHLIB_COMPAT (libm, LGAMMA_OLD_VER, LGAMMA_NEW_VER)
/* Whether to build this version at all. */
#define BUILD_LGAMMA (HAVE_LGAMMA_COMPAT || !USE_AS_COMPAT)
/* The name to use for this version. */
#if USE_AS_COMPAT
# define LGFUNC(FUNC) FUNC ## _compat
#else
# define LGFUNC(FUNC) FUNC
#endif
/* If there is a compatibility version, gamma (not an ISO C function,
so never a problem for it to set signgam) points directly to it
rather than having separate versions. */
#define GAMMA_ALIAS (USE_AS_COMPAT ? HAVE_LGAMMA_COMPAT : !HAVE_LGAMMA_COMPAT)
/* How to call the underlying lgamma_r function. */
#define CALL_LGAMMA(TYPE, FUNC, ARG) \
({ \
TYPE lgamma_tmp; \
int local_signgam; \
if (USE_AS_COMPAT) \
{ \
lgamma_tmp = FUNC ((ARG), &local_signgam); \
if (_LIB_VERSION != _ISOC_) \
signgam = __signgam = local_signgam; \
} \
else \
lgamma_tmp = FUNC ((ARG), &__signgam); \
lgamma_tmp; \
})
#endif /* lgamma-compat.h. */