ObjectiveC. Remove false positive warning for missing property

backing ivar by not issuing this warning if ivar is referenced
somewhere and accessor makes method calls. // rdar://15727325

llvm-svn: 198367

2 files changed, 11 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 7024cf6cb35..edbd7141844 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -3521,8 +3521,13 @@ void Sema::DiagnoseUnusedBackingIvarInAccessor(Scope *S) {
   const ObjCPropertyDecl *PDecl;
   const ObjCIvarDecl *IV = GetIvarBackingPropertyAccessor(CurMethod, PDecl);
   if (IV && !IV->getBackingIvarReferencedInAccessor()) {
-    Diag(getCurMethodDecl()->getLocation(), diag::warn_unused_property_backing_ivar)
-    << IV->getDeclName();
-    Diag(PDecl->getLocation(), diag::note_property_declare);
+    // Do not issue this warning if backing ivar is used somewhere and accessor
+    // implementation makes a call to a method. This is to prevent false positive in
+    // some corner cases.
+    if (!IV->isReferenced() || !CurMethod->getMethodCallsMethod()) {
+      Diag(getCurMethodDecl()->getLocation(), diag::warn_unused_property_backing_ivar)
+        << IV->getDeclName();
+      Diag(PDecl->getLocation(), diag::note_property_declare);
+    }
   }
 }
diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index ca67094f80f..8b1befe4f85 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -2643,7 +2643,9 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
       }
     }
   }
-      
+  if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
+    CurMeth->setMethodCallsMethod(true);
+  
   return MaybeBindToTemporary(Result);
 }