c++ - 代码块主页不会加载?
问题描述
代码:
// -*- C++ -*- forwarding header.
// Copyright (C) 1997-2016 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This 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 General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file include/cwchar
* This is a Standard C++ Library file. You should @c \#include this file
* in your programs, rather than any of the @a *.h implementation files.
*
* This is the C++ version of the Standard C Library header @c wchar.h,
* and its contents are (mostly) the same as that header, but are all
* contained in the namespace @c std (except for names which are defined
* as macros in C).
*/
//
// ISO C++ 14882: 21.4
//
#pragma GCC system_header
#include <bits/c++config.h>
#if _GLIBCXX_HAVE_WCHAR_H
#include <wchar.h>
#endif
#ifndef _GLIBCXX_CWCHAR
#define _GLIBCXX_CWCHAR 1
// Need to do a bit of trickery here with mbstate_t as char_traits
// assumes it is in wchar.h, regardless of wchar_t specializations.
#ifndef _GLIBCXX_HAVE_MBSTATE_T
extern "C"
{
typedef struct
{
int __fill[6];
} mbstate_t;
}
#endif
namespace std
{
using ::mbstate_t;
} // namespace std
// Get rid of those macros defined in <wchar.h> in lieu of real functions.
#undef btowc
#undef fgetwc
#undef fgetws
#undef fputwc
#undef fputws
#undef fwide
#undef fwprintf
#undef fwscanf
#undef getwc
#undef getwchar
#undef mbrlen
#undef mbrtowc
#undef mbsinit
#undef mbsrtowcs
#undef putwc
#undef putwchar
#undef swprintf
#undef swscanf
#undef ungetwc
#undef vfwprintf
#if _GLIBCXX_HAVE_VFWSCANF
# undef vfwscanf
#endif
#undef vswprintf
#if _GLIBCXX_HAVE_VSWSCANF
# undef vswscanf
#endif
#undef vwprintf
#if _GLIBCXX_HAVE_VWSCANF
# undef vwscanf
#endif
#undef wcrtomb
#undef wcscat
#undef wcschr
#undef wcscmp
#undef wcscoll
#undef wcscpy
#undef wcscspn
#undef wcsftime
#undef wcslen
#undef wcsncat
#undef wcsncmp
#undef wcsncpy
#undef wcspbrk
#undef wcsrchr
#undef wcsrtombs
#undef wcsspn
#undef wcsstr
#undef wcstod
#if _GLIBCXX_HAVE_WCSTOF
# undef wcstof
#endif
#undef wcstok
#undef wcstol
#undef wcstoul
#undef wcsxfrm
#undef wctob
#undef wmemchr
#undef wmemcmp
#undef wmemcpy
#undef wmemmove
#undef wmemset
#undef wprintf
#undef wscanf
#if _GLIBCXX_USE_WCHAR_T
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
using ::wint_t;
using ::vfwscanf;
using ::btowc;
using ::fgetwc;
using ::fgetws;
using ::fputwc;
using ::fputws;
using ::fwide;
using ::fwprintf;
using ::fwscanf;
using ::getwc;
using ::getwchar;
using ::mbrlen;
using ::mbrtowc;
using ::mbsinit;
using ::mbsrtowcs;
using ::putwc;
using ::putwchar;
#ifndef _GLIBCXX_HAVE_BROKEN_VSWPRINTF
using ::swprintf;
#endif
using ::swscanf;
using ::ungetwc;
using ::vfwprintf;
#ifndef _GLIBCXX_HAVE_WFWSCANF;
if _GLIBCXX_HAVE_VFWSCANF
using ::vfwscanf;
#endif
#ifndef _GLIBCXX_HAVE_BROKEN_VSWPRINTF
using ::vswprintf;
#endif
#if _GLIBCXX_HAVE_VSWSCANF
using ::vswscanf;
#endif
using ::vwprintf;
#if _GLIBCXX_HAVE_VWSCANF
using ::vwscanf;
#endif
using ::wcrtomb;
using ::wcscat;
using ::wcscmp;
using ::wcscoll;
using ::wcscpy;
using ::wcscspn;
using ::wcsftime;
using ::wcslen;
using ::wcsncat;
using ::wcsncmp;
using ::wcsncpy;
using ::wcsrtombs;
using ::wcsspn;
using ::wcstod;
#if _GLIBCXX_HAVE_WCSTOF
using ::wcstof;
#endif
using ::wcstok;
using ::wcstol;
using ::wcstoul;
using ::wcsxfrm;
using ::wctob;
using ::wmemcmp;
using ::wmemcpy;
using ::wmemmove;
using ::wmemset;
using ::wprintf;
using ::wscanf;
using ::wcschr;
using ::wcspbrk;
using ::wcsrchr;
using ::wcsstr;
using ::wmemchr;
#ifndef __CORRECT_ISO_CPP_WCHAR_H_PROTO
inline wchar_t*
wcschr(wchar_t* __p, wchar_t __c)
{ return wcschr(const_cast<const wchar_t*>(__p), __c); }
inline wchar_t*
wcspbrk(wchar_t* __s1, const wchar_t* __s2)
{ return wcspbrk(const_cast<const wchar_t*>(__s1), __s2); }
inline wchar_t*
wcsrchr(wchar_t* __p, wchar_t __c)
{ return wcsrchr(const_cast<const wchar_t*>(__p), __c); }
inline wchar_t*
wcsstr(wchar_t* __s1, const wchar_t* __s2)
{ return wcsstr(const_cast<const wchar_t*>(__s1), __s2); }
inline wchar_t*
wmemchr(wchar_t* __p, wchar_t __c, size_t __n)
{ return wmemchr(const_cast<const wchar_t*>(__p), __c, __n); }
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#if _GLIBCXX_USE_C99_WCHAR
#undef wcstold
#undef wcstoll
#undef wcstoull
namespace __gnu_cxx
{
#if _GLIBCXX_USE_C99_CHECK || _GLIBCXX_USE_C99_DYNAMIC
extern "C" long double
(wcstold)(const wchar_t * __restrict, wchar_t ** __restrict) throw ();
#endif
#if !_GLIBCXX_USE_C99_DYNAMIC
using ::wcstold;
#endif
#if _GLIBCXX_USE_C99_LONG_LONG_CHECK || _GLIBCXX_USE_C99_LONG_LONG_DYNAMIC
extern "C" long long int
(wcstoll)(const wchar_t * __restrict, wchar_t ** __restrict, int) throw ();
extern "C" unsigned long long int
(wcstoull)(const wchar_t * __restrict, wchar_t ** __restrict, int) throw ();
#endif
#if !_GLIBCXX_USE_C99_LONG_LONG_DYNAMIC
using ::wcstoll;
using ::wcstoull;
#endif
} // namespace __gnu_cxx
namespace std
{
using ::__gnu_cxx::wcstold;
using ::__gnu_cxx::wcstoll;
using ::__gnu_cxx::wcstoull;
} // namespace
#endif
#endif //_GLIBCXX_USE_WCHAR_T
#if __cplusplus >= 201103L
#ifdef _GLIBCXX_USE_WCHAR_T
namespace std
{
#if _GLIBCXX_HAVE_WCSTOF
using std::wcstof;
#endif
#if _GLIBCXX_HAVE_VFWSCANF
using std::vfwscanf;
#endif
#if _GLIBCXX_HAVE_VSWSCANF
using std::vswscanf;
#endif
#if _GLIBCXX_HAVE_VWSCANF
using std::vwscanf;
#endif
#if _GLIBCXX_USE_C99_WCHAR
using std::wcstold;
using std::wcstoll;
using std::wcstoull;
#endif
} // namespace
#endif // _GLIBCXX_USE_WCHAR_T
#endif // C++11
错误:c:\mingw\lib\gcc\mingw32\6.3.0\include\c++\cwchar|164|错误:'if' 之前的预期不合格 ID|
这只是试图构建和运行“hello world”启动页面,不知道该怎么做,用调试器修复了一些错误,但这只是一个痛苦,超出了我的知识深度,以前从未有过
解决方案
出于某种奇怪的原因,编译器的 cwchar 文件中有两条错误的行。
#ifndef _GLIBCXX_HAVE_WFWSCANF; // This looks erroneous
if _GLIBCXX_HAVE_VFWSCANF // Should be preprocessor if (#if)
using ::vfwscanf;
#endif
我下载并检查了gcc-c++-6.3.0-1-mingw32
cwchar 文件,当然它不包含错误的行:
#if _GLIBCXX_HAVE_VFWSCANF
using ::vfwscanf;
#endif
没有足够#endif
的 s#ifndef _GLIBCXX_HAVE_WFWSCANF;
有效。此外,您复制粘贴的代码似乎#endif
从一开始就缺少:
#endif // _GLIBCXX_USE_WCHAR_T
#endif // C++11
#endif
对于产生错误的原因,如果_GLIBCXX_HAVE_VFWSCANF
定义了,非预处理器if
语句将像这样扩展:
if 1
using ::vfwscanf;
#endif
也许在使用 IDE 查看编译器错误时,您不小心做了一些退格、剪切或复制粘贴,或者您的 mingw 安装有某种错误?很难猜。
无论哪种方式,我都会删除错误的行并将其添加#endif
到末尾,如果它丢失了。如果编译器的文件中出现更多错误,我会考虑重新安装 mingw。
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