This change set incorporates a number of changes that all needed to
happen together:
* The imp is now the first field of the `objc_method` structure. This
makes it possible to extend the structure without breaking anything
that relies on being able to access the IMP.
* There is no owner in the slot, so we must use other mechanisms for
determining the owner of a method (e.g. whether the same method appears
in the superclass)
* Again, because there is no owner in the slot, we can't use this as a
fast path for finding the C++ construct / destruct methods. These are
now cached in the class structure when they are found.
* The version field is gone from the slot and now we provide a global
version. This is based on the observation that method replacements
are relatively infrequent and the overhead of invalidating all method
caches is cheaper than adding extra state for every (class, method)
pair.
* A number of the runtime functions are simplified because replacing
the IMP in a `Method` now implicitly updates the dtable.
With the old ABI, we generated a copy of every protocol in every
compilation unit that declared it. We now emit protocols only if they
are referenced (and have the linker deduplicate them).
This test was previously failing with the Apple runtime.
macOS ships with libc++abi, which doesn't provide the hooks required
for interop, so this was causing all of the tests to fail to link in
the Travis macOS test. We're now correctly detecting that it won't
work on macOS and disabling those tests.
correct.
Instance variables are not normally zero-sized, but some are. Examples
include zero-length arrays at the end of a class, and bitfields.
Fixes#30Fixes#31
When we were trying to get or set an ivar on a class that had
no ivars defined, we'd dereference a NULL ivar list while
determining the ownership qualifier.
at the start of the structure, making it easier to change the layout in
the future.
Also clean up the growth of various fields and consolidate some of the
metadata into a pointer to the `struct objc_method`.
David Chisnall
David Chisnall
David Chisnall
David Lobron
Niels Grewe