Methods now include a selector and extended type encoding, rather than a
method name and lgacy type encoding. Older ones are auto-upgraded.
Expose the extended type encoding via a function that JavaScriptCore
expects to exist.
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.
Some applications still include the old objc-class.h header expecting
to obtain the declarations contained in objc/message.h and
objc/runtime.h nowadays. This commit adds this header to achieve
out-of-the-box compatibility with these applications.
Some applications still include the old objc-runtime.h header expecting
to obtain the declarations contained in objc/message.h and
objc/runtime.h nowadays. This commit adds this header to achieve
out-of-the-box compatibility with these applications.
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`.
An interesting feature of the AArch64 ABI simplifies this code relative to other platforms. AArch64 reserves an extra register (x8) for the address of struct returns, giving the
clang trunk if -fobjc-runtime-1.7 is specified and provides significantly
better interoperability with foreign exceptions.
Note: Most of the exception tests will not pass with gcc or clang < 3.3. They
test things that are impossible to implement quite correctly with the
GCC-compatible exception ABI.
Also updated the release notes to reflect recent improvements.
David Chisnall
David Chisnall
David Chisnall
Dustin L. Howett
David Chisnall
Zenny Chen
Daniel Ferreira
Daniel Ferreira
theraven
thebeing