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ba87515fea
Currently, the library-internal feature test macros are only defined if the feature is not available, and always have the prefix `_LIBCPP_HAS_NO_`. This patch changes that, so that they are always defined and have the prefix `_LIBCPP_HAS_` instead. This changes the canonical use of these macros to `#if _LIBCPP_HAS_FEATURE`, which means that using an undefined macro (e.g. due to a missing include) is diagnosed now. While this is rather unlikely currently, a similar change in `<__configuration/availability.h>` caught a few bugs. This also improves readability, since it removes the double-negation of `#ifndef _LIBCPP_HAS_NO_FEATURE`. The current patch only touches the macros defined in `<__config>`. If people are happy with this approach, I'll make a follow-up PR to also change the macros defined in `<__config_site>`.
29 lines
1.1 KiB
C++
29 lines
1.1 KiB
C++
// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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export namespace std {
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// Note the Standard does not mark these symbols optional, but libc++'s header
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// does. So this seems strictly not to be conforming.
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// mbstate_t is conditionally here, but always present in cwchar.cppm. To avoid
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// conflicing declarations omit the using here.
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// size_t is conditionally here, but always present in cstddef.cppm. To avoid
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// conflicing declarations omit the using here.
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#if _LIBCPP_HAS_C8RTOMB_MBRTOC8
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using std::mbrtoc8 _LIBCPP_USING_IF_EXISTS;
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using std::c8rtomb _LIBCPP_USING_IF_EXISTS;
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#endif
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using std::mbrtoc16 _LIBCPP_USING_IF_EXISTS;
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using std::c16rtomb _LIBCPP_USING_IF_EXISTS;
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using std::mbrtoc32 _LIBCPP_USING_IF_EXISTS;
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using std::c32rtomb _LIBCPP_USING_IF_EXISTS;
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} // namespace std
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