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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.
49 lines
1.2 KiB
C++
49 lines
1.2 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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/*
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stddef.h synopsis
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Macros:
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offsetof(type,member-designator)
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NULL
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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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*/
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#if defined(__cplusplus) && __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
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# include <__cxx03/stddef.h>
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#else
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# include <__config>
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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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// Note: This include is outside of header guards because we sometimes get included multiple times
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// with different defines and the underlying <stddef.h> will know how to deal with that.
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# include_next <stddef.h>
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# ifndef _LIBCPP_STDDEF_H
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# define _LIBCPP_STDDEF_H
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# ifdef __cplusplus
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typedef decltype(nullptr) nullptr_t;
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# endif
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# endif // defined(__cplusplus) && __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
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#endif // _LIBCPP_STDDEF_H
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