Unfortunately, adding a DEBUG_ASSERT_MSG_FMT isn't actually possible
right now because of compiler bugs:
https://github.com/dolphin-emu/dolphin/pull/9284
We could require a newer version of GCC (10) but that would require
updating GCC on the build machines.
For what it's worth, older versions of GCC (8, 9) are broken in
many ways: adding constexpr to some Matrix functions causes GCC 8
to generate bugged code that causes the Wii IR pointer to disappear,
which means that the generated builds are already unusable
(see https://dolp.in/i12324).
Additionally, we've already had to add workarounds for those versions
in the format macros to fix compilation bugs. This time, it looks like
workarounds won't cut it; even applying the workaround
described in https://github.com/fmtlib/fmt/pull/1580 does not help.
We want to use positional arguments in translatable strings
that have more than one argument so that translators can change
the order of them, but the question is: Should we also use
positional arguments in translatable strings with only one
argument? I think it makes most sense that way, partially
so that translators don't even have to be aware of the
non-positional syntax and partially because "translatable
strings use positional arguments" is an easier rule for us
to remember than "transitional strings which have more than
one argument use positional arguments". But let me know if
you have a different opinion.
Unfortunately, compilers will issue warnings when using offsetof with
non-standard layout types even when offsetof actually works fine here;
just having a virtual function is enough to trigger the warning...
Let's just stop the scan threads explicitly in destructors instead of
relying on member destruction order.
This moves the scan thread logic and variables into a separate
ScanThread class. By turning ScanThread instances into members of the
most derived class, this ensures that the scan thread is always
properly stopped when the most derived class is destructed and fixes
a race condition that could cause the scan thread to call virtual
member functions from a derived class whose members have already
been destructed.
A drawback of this approach is that the scan thread must be the last
member variable, so this commit also adds static assertions to ensure
that the assumption stays valid.