Define weak and __weak to mean ARC-style weak references, even in MRC.
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
diff --git a/clang/lib/ARCMigrate/ARCMT.cpp b/clang/lib/ARCMigrate/ARCMT.cpp
index 7eb01fb..82d8acd 100644
--- a/clang/lib/ARCMigrate/ARCMT.cpp
+++ b/clang/lib/ARCMigrate/ARCMT.cpp
@@ -206,7 +206,8 @@
WarnOpts.push_back("error=arc-unsafe-retained-assign");
CInvok->getDiagnosticOpts().Warnings = std::move(WarnOpts);
- CInvok->getLangOpts()->ObjCARCWeak = HasARCRuntime(origCI);
+ CInvok->getLangOpts()->ObjCWeakRuntime = HasARCRuntime(origCI);
+ CInvok->getLangOpts()->ObjCWeak = CInvok->getLangOpts()->ObjCWeakRuntime;
return CInvok.release();
}