编译Hello World程序的时候编译错误。

Scott

编译出错，编译错误信息如下：
G:\Qt\Tools\mingw492_32\i686-w64-mingw32\include\crtdefs.h:26: error: 'size_t' does not name a type
typedef size_t rsize_t;

G:\Qt\Tools\mingw492_32\i686-w64-mingw32\include\stddef.h:20: error: 'errno_t' does not name a type
   errno_t __cdecl _set_errno(int _Value);

G:\Qt\Tools\mingw492_32\i686-w64-mingw32\include\stddef.h:21: error: 'errno_t' does not name a type
   errno_t __cdecl _get_errno(int *_Value);

G:\Qt\Tools\mingw492_32\i686-w64-mingw32\include\stddef.h:218: error: '__MINGW_EXTENSION' does not name a type
__MINGW_EXTENSION typedef __SIZE_TYPE__ size_t;

G:\Ubuntu\MinGW\include\stdlib.h:352: error: 'size_t' does not name a type
_CRTIMP size_t __cdecl __MINGW_NOTHROW wcstombs (char*, const wchar_t*, size_t);

G:\Ubuntu\MinGW\include\stdlib.h:362: error: 'size_t' was not declared in this scope
_CRTIMP void* __cdecl __MINGW_NOTHROW calloc (size_t, size_t) __MINGW_ATTRIB_MALLOC;

请问是什么问题，该怎么办？