{"id":1847,"date":"2014-06-05T11:06:17","date_gmt":"2014-06-05T09:06:17","guid":{"rendered":"http:\/\/mariusbancila.ro\/blog\/?p=1847"},"modified":"2014-06-23T12:34:35","modified_gmt":"2014-06-23T10:34:35","slug":"crt-refactored-in-visual-studio-14","status":"publish","type":"post","link":"https:\/\/mariusbancila.ro\/blog\/2014\/06\/05\/crt-refactored-in-visual-studio-14\/","title":{"rendered":"CRT Refactored in Visual Studio “14”"},"content":{"rendered":"
Visual Studio “14” CTP ships with a refactored C Runtime. The first thing you’ll notice is that msvcrXX.dll<\/tt> has been replaced by three new DLLs: appcrtXX.dll<\/tt>, desktopcrtXX.dll<\/tt> and vcruntimeXX.ddl<\/tt> (where XX stands for the version number so in this version it’s appcrt140.dll<\/tt>, desktopcrt140.dll<\/tt> and vcruntime140.dll<\/tt>).<\/p>\n
Breaking CRT routines in several DLLs is not the only change. The CRT has been rewritten for safety and const correctness. Many of the routines have been re-written in C++. Here is a random example: the _open<\/tt> function, that was available in open.c<\/tt> was implemented like this in Visual Studio 2013:<\/p>\n
int __cdecl _topen (\r\n const _TSCHAR *path,\r\n int oflag,\r\n ...\r\n )\r\n{\r\n va_list ap;\r\n int pmode = 0;\r\n int fh = -1;\r\n errno_t retval = 0;\r\n int unlock_flag = 0;\r\n\r\n _VALIDATE_RETURN( (path != NULL), EINVAL, -1);\r\n\r\n va_start(ap, oflag);\r\n pmode = va_arg(ap, int);\r\n va_end(ap);\r\n\r\n __try {\r\n\/* Last parameter passed as 0 because we don't want to\r\nvalidate pmode from open *\/\r\n retval = _tsopen_nolock( &unlock_flag,\r\n &fh,\r\n path,\r\n oflag,\r\n _SH_DENYNO,\r\n pmode,\r\n 0 );\r\n }\r\n __finally {\r\n if ( unlock_flag )\r\n {\r\n if (retval)\r\n {\r\n _osfile(fh) &= ~FOPEN;\r\n }\r\n _unlock_fh(fh);\r\n }\r\n }\r\n\r\n if (retval)\r\n {\r\n errno = retval;\r\n return -1;\r\n }\r\n\r\n return fh;\r\n}<\/pre>\n
In Visual Studio “14” CTP it is available in function appcrt\\open.cpp<\/tt> and looks like this:<\/p>\n
template <typename Character>\r\nstatic int __cdecl common_open(\r\n Character const* const path,\r\n int const oflag,\r\n int const pmode\r\n ) throw()\r\n{\r\n typedef __crt_char_traits<Character> traits;\r\n\r\n _VALIDATE_RETURN(path != nullptr, EINVAL, -1);\r\n\r\n int fh = -1;\r\n int unlock_flag = 0;\r\n errno_t error_code = 0;\r\n __try\r\n {\r\n error_code = traits::tsopen_nolock(&unlock_flag, &fh, path, oflag, _SH_DENYNO, pmode, 0);\r\n }\r\n __finally\r\n {\r\n if (unlock_flag)\r\n {\r\n if (error_code)\r\n {\r\n _osfile(fh) &= ~FOPEN;\r\n }\r\n\r\n __acrt_lowio_unlock_fh(fh);\r\n }\r\n }\r\n\r\n if (error_code != 0)\r\n {\r\n errno = error_code;\r\n return -1;\r\n }\r\n\r\n return fh;\r\n}<\/pre>\n
UPDATE<\/strong><\/p>\n
To read more about the refactoring see the VC++ team’s blog posts:<\/p>\n
![\"crtdlls\"](\"http:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2014\/06\/crtdlls.png\")
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