Fix a pair of bugs relating to properties in ARC.

First, when synthesizing an explicitly strong/retain/copy property
of Class type, don't pretend during compatibility checking that the
property is actually assign.  Instead, resolve incompatibilities
by secretly changing the type of *implicitly* __unsafe_unretained
Class ivars to be strong.  This is moderately evil but better than
what we were doing.

Second, when synthesizing the setter for a strong property of
non-retainable type, be sure to use objc_setProperty.  This is
possible when the property is decorated with the NSObject
attribute.  This is an ugly, ugly corner of the language, and
we probably ought to deprecate it.

The first is rdar://problem/12039404;  the second was noticed by
inspection while fixing the first.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162244 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 1 deletions

diff --git a/lib/Sema/SemaObjCProperty.cpp b/lib/Sema/SemaObjCProperty.cpp
index 27deab226f..8a8927d362 100644
--- a/lib/Sema/SemaObjCProperty.cpp
+++ b/lib/Sema/SemaObjCProperty.cpp
@@ -43,7 +43,7 @@ static Qualifiers::ObjCLifetime getImpliedARCOwnership(
   if (attrs & (ObjCPropertyDecl::OBJC_PR_retain |
                ObjCPropertyDecl::OBJC_PR_strong |
                ObjCPropertyDecl::OBJC_PR_copy)) {
-    return type->getObjCARCImplicitLifetime();
+    return Qualifiers::OCL_Strong;
   } else if (attrs & ObjCPropertyDecl::OBJC_PR_weak) {
     return Qualifiers::OCL_Weak;
   } else if (attrs & ObjCPropertyDecl::OBJC_PR_unsafe_unretained) {
@@ -543,6 +543,23 @@ static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
       ivarLifetime == Qualifiers::OCL_Autoreleasing)
     return;
 
+  // If the ivar is private, and it's implicitly __unsafe_unretained
+  // becaues of its type, then pretend it was actually implicitly
+  // __strong.  This is only sound because we're processing the
+  // property implementation before parsing any method bodies.
+  if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
+      propertyLifetime == Qualifiers::OCL_Strong &&
+      ivar->getAccessControl() == ObjCIvarDecl::Private) {
+    SplitQualType split = ivarType.split();
+    if (split.Quals.hasObjCLifetime()) {
+      assert(ivarType->isObjCARCImplicitlyUnretainedType());
+      split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
+      ivarType = S.Context.getQualifiedType(split);
+      ivar->setType(ivarType);
+      return;
+    }
+  }
+
   switch (propertyLifetime) {
   case Qualifiers::OCL_Strong:
     S.Diag(propertyImplLoc, diag::err_arc_strong_property_ownership)