libcxx/include/__mbstate_t.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___MBSTATE_T_H
  11 #define _LIBCPP___MBSTATE_T_H
  12
  13 #include <__config>
  14
  15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16 #  pragma GCC system_header
  17 #endif
  18
  19 // The goal of this header is to provide mbstate_t without requiring all of
  20 // <uchar.h> or <wchar.h>. It's also used by the libc++ versions of <uchar.h>
  21 // and <wchar.h> to get mbstate_t when the C library doesn't provide <uchar.h>
  22 // or <wchar.h>, hence the #include_next of those headers instead of #include.
  23 // (e.g. if <wchar.h> isn't present in the C library, the libc++ <wchar.h>
  24 // will include this header. This header needs to not turn around and cyclically
  25 // include <wchar.h>, but fall through to <uchar.h>.)
  26 //
  27 // This does not define std::mbstate_t -- this only brings in the declaration
  28 // in the global namespace.
  29
  30 // We define this here to support older versions of glibc <wchar.h> that do
  31 // not define this for clang. This is also set in libc++'s <wchar.h> header,
  32 // and we need to do so here too to avoid a different function signature given
  33 // a different include order.
  34 #ifdef __cplusplus
  35 #  define __CORRECT_ISO_CPP_WCHAR_H_PROTO
  36 #endif
  37
  38 #if _LIBCPP_HAS_MUSL_LIBC
  39 #  define __NEED_mbstate_t
  40 #  include <bits/alltypes.h>
  41 #  undef __NEED_mbstate_t
  42 #elif __has_include(<bits/types/mbstate_t.h>)
  43 #  include <bits/types/mbstate_t.h> // works on most Unixes
  44 #elif __has_include(<sys/_types/_mbstate_t.h>)
  45 #  include <sys/_types/_mbstate_t.h> // works on Darwin
  46 #elif _LIBCPP_HAS_WIDE_CHARACTERS && __has_include_next(<wchar.h>)
  47 #  include_next <wchar.h> // fall back to the C standard provider of mbstate_t
  48 #elif __has_include_next(<uchar.h>)
  49 #  include_next <uchar.h> // <uchar.h> is also required to make mbstate_t visible
  50 #else
  51 #  error "We don't know how to get the definition of mbstate_t without <wchar.h> on your platform."
  52 #endif
  53
  54 #endif // _LIBCPP___MBSTATE_T_H