There are two problems, one is that it assumes -flto is the argument
to do LTO/WPO, which isn't true of ICC and MSVC (and presumably)
others. It's also incorrect because it assumes that the compiler and
linker will always be the same, which isn't necessarily true. You
could combine GCC with Apple's linker, or clang with link.exe, which
use different arguments.
There is a pretty big error in here, trying to return a tuple
comperhension: (a for a in []) is not a tuple, it's a generator. This
has profound type annotations: generators don't support most tuple or
list methods, and they can only be iterated once. Beyond that tuples are
meant for heterogenous types, ie, position matters for types. I've
converted the output to a list in all cases.