Compiler version, name, and OS detection in C++

Question

I need to detect the OS name, compiler name, and version of the compiler with C++, as I need to change the setup for each case.

How can I do that?

Answer 1

For most compilers you can find a list of predefined macros.

• VS http://msdn.microsoft.com/en-us/library/b0084kay%28v=vs.80%29.aspx
• gcc http://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html

Answer 2

I recommend define platform in build scripts by providing -D_i386 -DENDIAN=1234 -D_linux. But if you still think another predef project is your friend:

http://sourceforge.net/apps/mediawiki/predef/index.php?title=Main_Page

Answer 3

You won't be able to detect the operating system at compile-time. You will, however, be able to determine the compiler- virtually all compilers define macros indicating their presence, like __GNUC__ or something like that for GCC and MSVC has __MSC_VER__ or something similar. You'll have to check their documentation for the actual macro names, I've forgotten.

Edit: For clarification, you can check what system's headers are included. For example, the Windows headers define a number of macros like WINNT_VER which give the minimum version of Windows to be targetted. But you can't detect the compiler's executing OS.

Answer 4

Usually you leave that task to the build environment. Either using commands like uname if you can assume a posixy set up, or by any other mean which is deemed suitable.