Currently, clang generates a new block descriptor global variable for
each new block literal. This commit merges block descriptors that are
identical inside and across translation units using the same approach
taken in r339438.
To enable merging identical block descriptors, the size and signature of
the block and information about the captures are encoded into the name
of the block descriptor variable. Also, the block descriptor variable is
marked as linkonce_odr and unnamed_addr.
rdar://problem/42640703
Differential Revision: https://reviews.llvm.org/D50783
llvm-svn: 340041
These are all emitted into a section with a cstring_literal attribute. The
attribute permits the linker to coalesce the string contents. The address of
the strings are not important.
llvm-svn: 281855
These strings are constants, mark them as such. This doesn't matter too much in
practice on MachO since the constants are placed into a special section and not
referred to directly.
llvm-svn: 281854
This is almost entirely a matter of just flipping a switch. 99% of
the runtime support is available all the way back to when it was
implemented in the non-fragile runtime, i.e. in Lion. However,
fragile runtimes do not recognize ARC-style ivar layout strings,
which means that accessing __strong or __weak ivars reflectively
(e.g. via object_setIvar) will end up accessing the ivar as if it
were __unsafe_unretained. Therefore, when using reflective
technologies like KVC, be sure that your paths always refer to a
property.
rdar://23209307
llvm-svn: 250955
Pete Cooper