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Edit File: libc-header-start.h
/* Handle feature test macros at the start of a header. Copyright (C) 2016-2021 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/>. */ /* This header is internal to glibc and should not be included outside of glibc headers. Headers including it must define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION first. This header cannot have multiple include guards because ISO C feature test macros depend on the definition of the macro when an affected header is included, not when the first system header is included. */ #ifndef __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION # error "Never include <bits/libc-header-start.h> directly." #endif #undef __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION #include <features.h> /* ISO/IEC TR 24731-2:2010 defines the __STDC_WANT_LIB_EXT2__ macro. */ #undef __GLIBC_USE_LIB_EXT2 #if (defined __USE_GNU \ || (defined __STDC_WANT_LIB_EXT2__ && __STDC_WANT_LIB_EXT2__ > 0)) # define __GLIBC_USE_LIB_EXT2 1 #else # define __GLIBC_USE_LIB_EXT2 0 #endif /* ISO/IEC TS 18661-1:2014 defines the __STDC_WANT_IEC_60559_BFP_EXT__ macro. Most but not all symbols enabled by that macro in TS 18661-1 are enabled unconditionally in C2X. In C2X, the symbols in Annex F still require a new feature test macro __STDC_WANT_IEC_60559_EXT__ instead (C2X does not define __STDC_WANT_IEC_60559_BFP_EXT__), while a few features from TS 18661-1 are not included in C2X (and thus should depend on __STDC_WANT_IEC_60559_BFP_EXT__ even when C2X features are enabled). __GLIBC_USE (IEC_60559_BFP_EXT) controls those features from TS 18661-1 not included in C2X. __GLIBC_USE (IEC_60559_BFP_EXT_C2X) controls those features from TS 18661-1 that are also included in C2X (with no feature test macro required in C2X). __GLIBC_USE (IEC_60559_EXT) controls those features from TS 18661-1 that are included in C2X but conditional on __STDC_WANT_IEC_60559_EXT__. (There are currently no features conditional on __STDC_WANT_IEC_60559_EXT__ that are not in TS 18661-1.) */ #undef __GLIBC_USE_IEC_60559_BFP_EXT #if defined __USE_GNU || defined __STDC_WANT_IEC_60559_BFP_EXT__ # define __GLIBC_USE_IEC_60559_BFP_EXT 1 #else # define __GLIBC_USE_IEC_60559_BFP_EXT 0 #endif #undef __GLIBC_USE_IEC_60559_BFP_EXT_C2X #if __GLIBC_USE (IEC_60559_BFP_EXT) || __GLIBC_USE (ISOC2X) # define __GLIBC_USE_IEC_60559_BFP_EXT_C2X 1 #else # define __GLIBC_USE_IEC_60559_BFP_EXT_C2X 0 #endif #undef __GLIBC_USE_IEC_60559_EXT #if __GLIBC_USE (IEC_60559_BFP_EXT) || defined __STDC_WANT_IEC_60559_EXT__ # define __GLIBC_USE_IEC_60559_EXT 1 #else # define __GLIBC_USE_IEC_60559_EXT 0 #endif /* ISO/IEC TS 18661-4:2015 defines the __STDC_WANT_IEC_60559_FUNCS_EXT__ macro. Other than the reduction functions, the symbols from this TS are enabled unconditionally in C2X. */ #undef __GLIBC_USE_IEC_60559_FUNCS_EXT #if defined __USE_GNU || defined __STDC_WANT_IEC_60559_FUNCS_EXT__ # define __GLIBC_USE_IEC_60559_FUNCS_EXT 1 #else # define __GLIBC_USE_IEC_60559_FUNCS_EXT 0 #endif #undef __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X #if __GLIBC_USE (IEC_60559_FUNCS_EXT) || __GLIBC_USE (ISOC2X) # define __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X 1 #else # define __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X 0 #endif /* ISO/IEC TS 18661-3:2015 defines the __STDC_WANT_IEC_60559_TYPES_EXT__ macro. */ #undef __GLIBC_USE_IEC_60559_TYPES_EXT #if defined __USE_GNU || defined __STDC_WANT_IEC_60559_TYPES_EXT__ # define __GLIBC_USE_IEC_60559_TYPES_EXT 1 #else # define __GLIBC_USE_IEC_60559_TYPES_EXT 0 #endif