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b9a2658a3e
This patch implements the forwarding to frozen C++03 headers as discussed in https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc. In the RFC, we initially proposed selecting the right headers from the Clang driver, however consensus seemed to steer towards handling this in the library itself. This patch implements that direction. At a high level, the changes basically amount to making each public header look like this: ``` // inside <vector> #ifdef _LIBCPP_CXX03_LANG # include <__cxx03/vector> #else // normal <vector> content #endif ``` In most cases, public headers are simple umbrella headers so there isn't much code in the #else branch. In other cases, the #else branch contains the actual implementation of the header.
64 lines
1.6 KiB
C++
64 lines
1.6 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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#ifndef _LIBCPP_CSTDDEF
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#define _LIBCPP_CSTDDEF
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/*
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cstddef synopsis
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Macros:
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offsetof(type,member-designator)
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NULL
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namespace std
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{
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Types:
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ptrdiff_t
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size_t
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max_align_t // C++11
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nullptr_t
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byte // C++17
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} // std
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*/
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#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
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# include <__cxx03/cstddef>
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#else
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# include <__config>
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# include <version>
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# include <stddef.h>
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# ifndef _LIBCPP_STDDEF_H
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# error <cstddef> tried including <stddef.h> but didn't find libc++'s <stddef.h> header. \
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This usually means that your header search paths are not configured properly. \
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The header search paths should contain the C++ Standard Library headers before \
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any C Standard Library, and you are probably using compiler flags that make that \
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not be the case.
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# endif
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# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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# endif
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# include <__cstddef/byte.h>
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# include <__cstddef/max_align_t.h>
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# include <__cstddef/nullptr_t.h>
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# include <__cstddef/ptrdiff_t.h>
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# include <__cstddef/size_t.h>
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#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
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#endif // _LIBCPP_CSTDDEF
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