Enable ARC on the fragile runtime.

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

1 files changed, 7 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index ddac815038d..a44cdf8c345 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -3063,7 +3063,8 @@ enum FragileClassFlags {
   FragileABI_Class_Factory                 = 0x00001,
   FragileABI_Class_Meta                    = 0x00002,
   FragileABI_Class_HasCXXStructors         = 0x02000,
-  FragileABI_Class_Hidden                  = 0x20000
+  FragileABI_Class_Hidden                  = 0x20000,
+  FragileABI_Class_CompiledByARC           = 0x04000000
 };
 
 enum NonFragileClassFlags {
@@ -3125,6 +3126,10 @@ void CGObjCMac::GenerateClass(const ObjCImplementationDecl *ID) {
   unsigned Flags = FragileABI_Class_Factory;
   if (ID->hasNonZeroConstructors() || ID->hasDestructors())
     Flags |= FragileABI_Class_HasCXXStructors;
+
+  if (CGM.getLangOpts().ObjCAutoRefCount)
+    Flags |= FragileABI_Class_CompiledByARC;
+
   CharUnits Size =
     CGM.getContext().getASTObjCImplementationLayout(ID).getSize();
 
@@ -4847,7 +4852,7 @@ CGObjCCommonMac::BuildIvarLayout(const ObjCImplementationDecl *OMD,
 
     if (isNonFragileABI()) {
       baseOffset = beginOffset; // InstanceStart
-    } else if (auto superClass = OMD->getSuperClass()) {
+    } else if (auto superClass = OI->getSuperClass()) {
       auto startOffset =
         CGM.getContext().getASTObjCInterfaceLayout(superClass).getSize();
       baseOffset = startOffset.RoundUpToAlignment(CGM.getPointerAlign());