bit by allowing __weak and __strong to be added/dropped as part of
implicit conversions (qualification conversions in C++). A little
history: GCC lets one add/remove/change GC qualifiers just about
anywhere, implicitly. Clang did roughly the same before, but we
recently normalized the semantics of qualifiers across the board to
get a semantics that we could reason about (yay). Unfortunately, this
tightened the screws a bit too much for GC qualifiers, where it's
common to add/remove these qualifiers at will.
Overall, we're still in better shape than we were before: we don't
permit directly changing the GC qualifier (e.g., __weak -> __strong),
so type safety is improved. More importantly, we're internally
consistent in our handling of qualifiers, and the logic that allows
adding/removing GC qualifiers (but not adding/removing address
spaces!) only touches two obvious places.
Fixes <rdar://problem/9402499>.
llvm-svn: 131065
the qualifiers (e.g., GC qualifiers) on the type we're converting
from, rather than just blindly adopting the qualifiers of the type
we're converting to or dropping qualifiers altogether.
As an added bonus, properly diagnose GC qualifier mismatches to
eliminate a crash in the overload resolution failure diagnostics.
llvm-svn: 130255
Douglas Gregor