shadowm@nanacore:~% cat test.cpp
#include <iostream>

#define GCC_VERSION (__GNUC__ * 10000 \
                 + __GNUC_MINOR__ * 100 \
                 + __GNUC_PATCHLEVEL__)

int main(int, char**)
{
        std::cerr << GCC_VERSION << '\n';
}

shadowm@nanacore:~% clang++ test.cpp -o test
shadowm@nanacore:~% ./test
40201