Details posted here: https://reviews.llvm.org/D119051#3747201
3 cases that were inconsistent with the MSABI without this patch applied:
https://godbolt.org/z/GY48qxh3G - field with protected member https://godbolt.org/z/Mb1PYhjrP - non-static data member initializer https://godbolt.org/z/sGvxcEPjo - defaulted copy constructor
I'm not sure what's suitable/sufficient testing for this - I did verify
the three cases above. Though if it helps to add them as explicit tests,
I can do that too.
Also, I was wondering if the other use of isTrivialForAArch64MSVC in
isPermittedToBeHomogenousAggregate could be another source of bugs - I
tried changing the function to unconditionally call
isTrivialFor(AArch64)MSVC without testing AArch64 first, but no tests
fail, so it looks like this is undertested in any case. But I had
trouble figuring out how to exercise this functionality properly to add
test coverage and then compare that to MSVC itself... - I got very
confused/turned around trying to test this, so I've given up enough to
send what I have out for review, but happy to look further into this
with help.
I'm amused that this class is passed directly, but if you pass the field by itself, it is passed indirectly. :shrug: