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Diffstat (limited to 'REORG.TODO/math/lgamma-compat.h')
| -rw-r--r-- | REORG.TODO/math/lgamma-compat.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/REORG.TODO/math/lgamma-compat.h b/REORG.TODO/math/lgamma-compat.h new file mode 100644 index 0000000000..90a423756a --- /dev/null +++ b/REORG.TODO/math/lgamma-compat.h @@ -0,0 +1,73 @@ +/* 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. */ |