The -dealloc method in CIFilter is highly unusual in that it will release
instance variables belonging to its *subclasses* if the variable name
starts with "input" or backs a property whose name starts with "input".
Subclasses should not release these ivars in their own -dealloc method --
doing so could result in an over release.
Before this commit, the DeallocChecker would warn about missing releases for
such "input" properties -- which could cause users of the analyzer to add
over releases to silence the warning.
To avoid this, DeallocChecker now treats CIFilter "input-prefixed" ivars
as MustNotReleaseDirectly and so will not require a release. Further, it
will now warn when such an ivar is directly released in -dealloc.
rdar://problem/25364901
llvm-svn: 264463
This prevents false negatives when a -dealloc method, for example, removes itself as
as an observer with [[NSNotificationCenter defaultCenter] removeObserver:self]. It is
unlikely that passing 'self' to a system header method will release 'self''s instance
variables, so this is unlikely to produce false positives.
A challenge here is that while CheckObjCDealloc no longer treats these calls as
escaping, the rest of the analyzer still does. In particular, this means that loads
from the same instance variable before and after a call to a system header will
result in different symbols being loaded by the region store. To account for this,
the checker now treats different ivar symbols with the same instance and ivar decl as
the same for the purpose of release checking and more eagerly removes a release
requirement when an instance variable is assumed to be nil. This was not needed before
because when an ivar escaped its release requirement was always removed -- now the
requirement is not removed for calls to system headers.
llvm-svn: 262261
Devin Coughlin