How to #ifdef by CompilerType ? GCC or VC++

问题:

I used #ifdef Win32 for safe calls alike sprintf_s but now I want to build project with MinGW and it's just wrong now. I need to use #ifdef VC++ or somehow like that. Is it possible?

回答1:

See the "Microsoft-Specific Predefined Macros" table of Visual C predefined macros

You could check for _MSC_VER.

回答2:

#ifdef __clang__
/*code specific to clang compiler*/
#elif __GNUC__
/*code for GNU C compiler */
#elif _MSC_VER
/*usually has the version number in _MSC_VER*/
/*code specific to MSVC compiler*/
#elif __BORLANDC__
/*code specific to borland compilers*/
#elif __MINGW32__
/*code specific to mingw compilers*/
#endif

回答3:

Preferably, you should resort to using portable symbols. I understand sometimes those symbols may not be defined, so you can see the Predef project for an extensive list of preprocessor macros regarding standards, compilers, libraries, operating systems and architectures that aren't portable.

However, the function you specifically mention in this question has been included within the C11 standard as a part of Annex K.3, the bounds-checking interfaces (library).

K.3.1.1p2 states:

The functions, macros, and types declared or defined in K.3 and its subclauses are declared and defined by their respective headers if __STDC_WANT_LIB_EXT1__ is defined as a macro which expands to the integer constant 1 at the point in the source file where the appropriate header is first included

Thus, you should place preference upon checking __STDC_WANT_LIB_EXT1__, and only use compiler-specific symbols when that doesn't exist.