In ARC we emit an error when compiling:

@interface Foo : NSObject
@property (readonly) id myProp;
@end

@implementation Foo
@synthesize myProp;
@end

t.m:9:13: error: ARC forbids synthesizing a property of an Objective-C object with unspecified storage attribute
@synthesize myProp;
            ^

which is fine, we want the ownership of the synthesized ivar to be explicit. But we should _not_ emit an error
for the following cases, because we can get the ownership either from the declared ivar or from the property type:

@interface Foo : NSObject {
	__weak id _myProp1;
	id myProp2;
}
@property (readonly) id myProp1;
@property (readonly) id myProp2;
@property (readonly) __strong id myProp3;
@end

@implementation Foo
@synthesize myProp1 = _myProp1;
@synthesize myProp2;
@synthesize myProp3;
@end

rdar://9844006.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136155 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 7 deletions

diff --git a/lib/Sema/SemaObjCProperty.cpp b/lib/Sema/SemaObjCProperty.cpp
index 53de50c16c..8c8af1389b 100644
--- a/lib/Sema/SemaObjCProperty.cpp
+++ b/lib/Sema/SemaObjCProperty.cpp
@@ -594,13 +594,6 @@ Decl *Sema::ActOnPropertyImplDecl(Scope *S,
   ObjCIvarDecl *Ivar = 0;
   // Check that we have a valid, previously declared ivar for @synthesize
   if (Synthesize) {
-    if (getLangOptions().ObjCAutoRefCount &&
-        !property->hasWrittenStorageAttribute() &&
-        property->getType()->isObjCRetainableType()) {
-      Diag(PropertyLoc, diag::err_arc_objc_property_default_assign_on_object);
-      Diag(property->getLocation(), diag::note_property_declare);
-    }
-
     // @synthesize
     if (!PropertyIvar)
       PropertyIvar = PropertyId;
@@ -619,6 +612,13 @@ Decl *Sema::ActOnPropertyImplDecl(Scope *S,
       if (getLangOptions().ObjCAutoRefCount &&
           !PropertyIvarType.getObjCLifetime()) {
 
+        if (!property->hasWrittenStorageAttribute() &&
+            property->getType()->isObjCRetainableType()) {
+          Diag(PropertyLoc,
+               diag::err_arc_objc_property_default_assign_on_object);
+          Diag(property->getLocation(), diag::note_property_declare);
+        }
+
         // retain/copy have retaining lifetime.
         if (kind & (ObjCPropertyDecl::OBJC_PR_retain |
                     ObjCPropertyDecl::OBJC_PR_strong |