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,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:如果'if'|
之前出现预期的unqualified-id这只是试图构建和运行“ hello world”启动页面,不知道该怎么办,修复了调试器的一些错误,但这只是一种痛苦,因为我的知识渊博,从未有过之前
解决方法
第164行是此处指示的行:
#ifndef _GLIBCXX_HAVE_WFWSCANF;
if _GLIBCXX_HAVE_VFWSCANF // this one
using ::vfwscanf;
#endif
您似乎不小心将#
前面的if
移开了。
您应该使用文件权限将整个树标记为只读,以避免这种情况。
出于某些奇怪的原因,有两条错误的行进入了编译器的cwchar文件。
#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,并且肯定不包含该错误行:
#if _GLIBCXX_HAVE_VFWSCANF
using ::vfwscanf;
#endif
没有足够的#endif
来使#ifndef _GLIBCXX_HAVE_WFWSCANF;
有效。另外,您的复制粘贴代码似乎从一开始就缺少#endif
:
#endif // _GLIBCXX_USE_WCHAR_T
#endif // C++11
#endif
为什么会产生错误,如果定义了_GLIBCXX_HAVE_VFWSCANF
,则非预处理程序if
语句将像这样展开:
if 1
using ::vfwscanf;
#endif
也许在用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安装有问题吗?很难猜。
无论哪种方式,我都会删除错误的行,并将#endif
添加到末尾(如果缺少的话)。如果编译器文件中显示更多错误,我将考虑重新安装mingw。