What predefined macro can I use to detect clang?

Question

I'm trying to detect the compiler used to compile my source code. I can easily find predefined macros to check for MSVC or GCC (see https://github.com/cpredef/predef for example), but I cannot find any macro to check for clang.

Does someone know if clang defines a macro like __CLANG__ in order to know what is currently compiling my code ?

Trauner

predef.sourceforge.net/precomp.html#sec4 – Waterless

Updated list of compiler macros – Saintmihiel

Answer 1

Found the answer using strings + grep :

$ strings /usr/bin/clang | grep __ | grep -i clang
__clang__

Trauner

Answer 2

To get a list of all the predefined macros that the compiler uses, use this:

clang -dM -E -x c /dev/null

You can do the same for gcc.

Am

Answer 3

This question has been answered for years but let me add (for future reference) how it is done in Windows:

echo | clang -dM -E -

same as for GCC:

echo | gcc -dM -E -

Please note: The last dash - is actually important! (Otherwise you get error: no input files for both compilers)

Spadix

FYI, Windows equivalent of /dev/null is NUL: – Reverent

@Reverent Whoa! I didn't know that! That's pretty cool; where'd you find that? – Rightly

It's been there since the DOS days, just most DOS/Windows users never needed it. – Reverent

This is what I usually do in Linux as well. Typing /dev/null is more work. – Hon