r251874 reworked the way we handle properties declared within
Objective-C class extensions, which had the effective of tightening up
property checking in a number of places. In this particular class of
cases, we end up complaining about "atomic" mismatches between an
implicitly-atomic, readonly property and a nonatomic, readwrite
property, which doesn't make sense because "atomic" is essentially
irrelevant to readonly properties.
Therefore, suppress this diagnostic when the readonly property is
implicitly atomic. Fixes rdar://problem/23803109.
llvm-svn: 255174
A 'readonly' Objective-C property declared in the primary class can
effectively be shadowed by a 'readwrite' property declared within an
extension of that class, so long as the types and attributes of the
two property declarations are compatible.
Previously, this functionality was implemented by back-patching the
original 'readonly' property to make it 'readwrite', destroying source
information and causing some hideously redundant, incorrect
code. Simplify the implementation to express how this should actually
be modeled: as a separate property declaration in the extension that
shadows (via the name lookup rules) the declaration in the primary
class. While here, correct some broken Fix-Its, eliminate a pile of
redundant code, clean up the ARC migrator's handling of properties
declared in extensions, and fix debug info's naming of methods that
come from categories.
A wonderous side effect of doing this write is that it eliminates the
"AddedObjCPropertyInClassExtension" method from the AST mutation
listener, which in turn eliminates the last place where we rewrite
entire declarations in a chained PCH file or a module file. This
change (which fixes rdar://problem/18475765) will allow us to
eliminate the rewritten-decls logic from the serialization library,
and fixes a crash (rdar://problem/23247794) illustrated by the
test/PCH/chain-categories.m example.
llvm-svn: 251874
Previously, __weak was silently accepted and ignored in MRC mode.
That makes this a potentially source-breaking change that we have to
roll out cautiously. Accordingly, for the time being, actual support
for __weak references in MRC is experimental, and the compiler will
reject attempts to actually form such references. The intent is to
eventually enable the feature by default in all non-GC modes.
(It is, of course, incompatible with ObjC GC's interpretation of
__weak.)
If you like, you can enable this feature with
-Xclang -fobjc-weak
but like any -Xclang option, this option may be removed at any point,
e.g. if/when it is eventually enabled by default.
This patch also enables the use of the ARC __unsafe_unretained qualifier
in MRC. Unlike __weak, this is being enabled immediately. Since
variables are essentially __unsafe_unretained by default in MRC,
the only practical uses are (1) communication and (2) changing the
default behavior of by-value block capture.
As an implementation matter, this means that the ObjC ownership
qualifiers may appear in any ObjC language mode, and so this patch
removes a number of checks for getLangOpts().ObjCAutoRefCount
that were guarding the processing of these qualifiers. I don't
expect this to be a significant drain on performance; it may even
be faster to just check for these qualifiers directly on a type
(since it's probably in a register anyway) than to do N dependent
loads to grab the LangOptions.
rdar://9674298
llvm-svn: 251041
property declaration has a memory management
attribute (retain, copy, etc.). Sich properties
are usually overridden to become 'readwrite'
via a class extension (which require the memory
management attribute specified). In the absence of class
extension override, memory management attribute is
needed to produce correct Code Gen. for the
property getter in any case and this warning becomes
confusing to user. // rdar://15641300
llvm-svn: 197251
class extensions a little. clang now allows readonly property
with no ownership rule (assign, unsafe_unretained, weak, retain,
strong, or copy) with a readwrite property with an ownership rule.
// rdar://12103400
llvm-svn: 162319
Douglas Gregor