objective-C: When implementing custom accessor method for

a property, the -Wdirect-ivar-access should not warn when 
accessing the property's synthesized instance variable.
// rdar://13142820


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175195 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 31 insertions, 2 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index b3ba2dc4ae..0ed460cc5e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -2042,7 +2042,8 @@ Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S,
       MarkAnyDeclReferenced(Loc, IV, true);
       
       ObjCMethodFamily MF = CurMethod->getMethodFamily();
-      if (MF != OMF_init && MF != OMF_dealloc && MF != OMF_finalize)
+      if (MF != OMF_init && MF != OMF_dealloc && MF != OMF_finalize &&
+          !IvarBacksCurrentMethodAccessor(IFace, CurMethod, IV))
         Diag(Loc, diag::warn_direct_ivar_access) << IV->getDeclName();
 
       ObjCIvarRefExpr *Result = new (Context) ObjCIvarRefExpr(IV, IV->getType(),
diff --git a/lib/Sema/SemaExprMember.cpp b/lib/Sema/SemaExprMember.cpp
index f1f8104020..16f4a43bd7 100644
--- a/lib/Sema/SemaExprMember.cpp
+++ b/lib/Sema/SemaExprMember.cpp
@@ -1259,7 +1259,8 @@ Sema::LookupMemberExpr(LookupResult &R, ExprResult &BaseExpr,
       if (ObjCMethodDecl *MD = getCurMethodDecl()) {
         ObjCMethodFamily MF = MD->getMethodFamily();
         warn = (MF != OMF_init && MF != OMF_dealloc && 
-                MF != OMF_finalize);
+                MF != OMF_finalize &&
+                !IvarBacksCurrentMethodAccessor(IDecl, MD, IV));
       }
       if (warn)
         Diag(MemberLoc, diag::warn_direct_ivar_access) << IV->getDeclName();
diff --git a/lib/Sema/SemaObjCProperty.cpp b/lib/Sema/SemaObjCProperty.cpp
index 1fe88a26ab..e238b7ea20 100644
--- a/lib/Sema/SemaObjCProperty.cpp
+++ b/lib/Sema/SemaObjCProperty.cpp
@@ -1541,6 +1541,33 @@ static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
   }
 }
 
+/// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
+/// an ivar synthesized for 'Method' and 'Method' is a property accessor
+/// declared in class 'IFace'.
+bool
+Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
+                                     ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
+  if (!IV->getSynthesize())
+    return false;
+  ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
+                                            Method->isInstanceMethod());
+  if (!IMD || !IMD->isPropertyAccessor())
+    return false;
+  
+  // look up a property declaration whose one of its accessors is implemented
+  // by this method.
+  for (ObjCContainerDecl::prop_iterator P = IFace->prop_begin(),
+       E = IFace->prop_end(); P != E; ++P) {
+    ObjCPropertyDecl *property = *P;
+    if ((property->getGetterName() == IMD->getSelector() ||
+         property->getSetterName() == IMD->getSelector()) &&
+        (property->getPropertyIvarDecl() == IV))
+      return true;
+  }
+  return false;
+}
+
+
 /// \brief Default synthesizes all properties which must be synthesized
 /// in class's \@implementation.
 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl* IMPDecl,