glibc/include/stdc-predef.h
Joseph Myers 8807e560c0 Define __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__
TS 18661-1 and C2X specify predefined macros __STDC_IEC_60559_BFP__
and __STDC_IEC_60559_COMPLEX__, making __STDC_IEC_559__ and
__STDC_IEC_559_COMPLEX__ obsolescent (but still included in the
standard).  Now that we have all the functions from TS 18661-1, define
these macros in stdc-predef.h, under the same conditions in which the
older macros are defined, since support for the floating-point
features in TS 18661-1 is now at the same level as that for those in
C11 and before (all library functions and other library APIs present,
but no standard pragma support).

The macros are defined for now with their TS 18661-1 values.  C2X will
give them new values (listed as yyyymmL in the working drafts until
the final standard), at which point there will be the question of what
value to use in stdc-predef.h (where it could depend on
__STDC_VERSION__, but not on feature test macros defined by the user).
My inclination then would be to use the C2X value unconditionally
rather than using an older value to indicate TS support, and only have
any C standard version conditionals for the value when subsequent C
standard versions define further values.

(Note that I'm also inclined, when we implement the C2X change to the
return types of fromfp functions, to make that change unconditional
much like the change made to the types of totalorder functions, with
the old version only supported with compat symbols for already-linked
programs and not as an API for newly built objects.  So using the C2X
value would also accurately reflect not supporting the versions of
APIs in the TS where those ended up being incompatible with the first
version actually added to the standard.)

Tested for x86_64.
2021-09-24 20:11:56 +00:00

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2.4 KiB
C

/* Copyright (C) 1991-2021 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
<https://www.gnu.org/licenses/>. */
#ifndef _STDC_PREDEF_H
#define _STDC_PREDEF_H 1
/* This header is separate from features.h so that the compiler can
include it implicitly at the start of every compilation. It must
not itself include <features.h> or any other header that includes
<features.h> because the implicit include comes before any feature
test macros that may be defined in a source file before it first
explicitly includes a system header. GCC knows the name of this
header in order to preinclude it. */
/* glibc's intent is to support the IEC 559 math functionality, real
and complex. If the GCC (4.9 and later) predefined macros
specifying compiler intent are available, use them to determine
whether the overall intent is to support these features; otherwise,
presume an older compiler has intent to support these features and
define these macros by default. */
#ifdef __GCC_IEC_559
# if __GCC_IEC_559 > 0
# define __STDC_IEC_559__ 1
# define __STDC_IEC_60559_BFP__ 201404L
# endif
#else
# define __STDC_IEC_559__ 1
# define __STDC_IEC_60559_BFP__ 201404L
#endif
#ifdef __GCC_IEC_559_COMPLEX
# if __GCC_IEC_559_COMPLEX > 0
# define __STDC_IEC_559_COMPLEX__ 1
# define __STDC_IEC_60559_COMPLEX__ 201404L
# endif
#else
# define __STDC_IEC_559_COMPLEX__ 1
# define __STDC_IEC_60559_COMPLEX__ 201404L
#endif
/* wchar_t uses Unicode 10.0.0. Version 10.0 of the Unicode Standard is
synchronized with ISO/IEC 10646:2017, fifth edition, plus
the following additions from Amendment 1 to the fifth edition:
- 56 emoji characters
- 285 hentaigana
- 3 additional Zanabazar Square characters */
#define __STDC_ISO_10646__ 201706L
#endif