How to detect LLVM and its version through #define directives?

Question

The question is quite clear I think. I'm trying to write a compiler detection header to be able to include in the application information on which compiler was used and which version.

This is part of the code I'm using:

/* GNU C Compiler Detection */
#elif defined __GNUC__
    #ifdef __MINGW32__
        #define COMPILER "MinGW GCC %d.%d.%d"
    #else
        #define COMPILER "GCC %d.%d.%d"
    #endif
    #define COMP_VERSION __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__
#endif

Which could be used like this:

printf("  Compiled using " COMPILER "\n", COMP_VERSION);

Is there any way to detect LLVM and its version? And CLANG?

Answer 1

The __llvm__ and __clang__ macros are the official way to check for an LLVM compiler (llvm-gcc or clang) or clang, respectively.

__has_feature and __has_builtin are the recommended way of checking for optional compiler features when using clang, they are documented here.

Note that you can find a list of the builtin compiler macros for gcc, llvm-gcc, and clang using:

echo | clang -dM -E -

This preprocesses an empty string and spits out all macros defined by the compiler.