Fix a major swiftcall ABI bug with trivial C++ class types.
The problem with the previous logic was that there might not be any
explicit copy/move constructor declarations, e.g. if the type is
trivial and we've never type-checked a copy of it. Relying on Sema's
computation seems much more reliable.
Also, I believe Richard's recommendation is exactly the rule we use
now on the Itanium ABI, modulo the trivial_abi attribute (which this
change of course fixes our handling of in Swift).
This does mean that we have a less portable rule for deciding
indirectness for swiftcall. I would prefer it if we just applied the
Itanium rule universally under swiftcall, but in the meantime, I need
to fix this bug.
This only arises when defining functions with class-type arguments
in C++, as we do in the Swift runtime. It doesn't affect normal Swift
operation because we don't import code as C++.
llvm-svn: 328942
2 files changed