4 files changed, 76 insertions, 3 deletions

diff --git a/clang/include/clang/Sema/ScopeInfo.h b/clang/include/clang/Sema/ScopeInfo.h
index 0592265ccdf..7fbe07dc942 100644
--- a/clang/include/clang/Sema/ScopeInfo.h
+++ b/clang/include/clang/Sema/ScopeInfo.h
@@ -25,6 +25,7 @@ namespace clang {
 class Decl;
 class BlockDecl;
 class CXXMethodDecl;
+class ObjCPropertyDecl;
 class IdentifierInfo;
 class LabelDecl;
 class ReturnStmt;
@@ -34,6 +35,7 @@ class VarDecl;
 class DeclRefExpr;
 class ObjCIvarRefExpr;
 class ObjCPropertyRefExpr;
+class ObjCMessageExpr;
 
 namespace sema {
 
@@ -166,6 +168,7 @@ public:
 
   public:
     WeakObjectProfileTy(const ObjCPropertyRefExpr *RE);
+    WeakObjectProfileTy(const Expr *Base, const ObjCPropertyDecl *Property);
     WeakObjectProfileTy(const DeclRefExpr *RE);
     WeakObjectProfileTy(const ObjCIvarRefExpr *RE);
 
@@ -261,6 +264,9 @@ public:
   template <typename ExprT>
   inline void recordUseOfWeak(const ExprT *E, bool IsRead = true);
 
+  void recordUseOfWeak(const ObjCMessageExpr *Msg,
+                       const ObjCPropertyDecl *Prop);
+
   /// Record that a given expression is a "safe" access of a weak object (e.g.
   /// assigning it to a strong variable.)
   ///
diff --git a/clang/lib/Sema/ScopeInfo.cpp b/clang/lib/Sema/ScopeInfo.cpp
index 76f967d588b..c1d66299058 100644
--- a/clang/lib/Sema/ScopeInfo.cpp
+++ b/clang/lib/Sema/ScopeInfo.cpp
@@ -103,6 +103,14 @@ FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
   }
 }
 
+FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE,
+                                                const ObjCPropertyDecl *Prop)
+    : Base(0, true), Property(Prop) {
+  if (BaseE)
+    Base = getBaseInfo(BaseE);
+  // else, this is a message accessing a property on super.
+}
+
 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
                                                       const DeclRefExpr *DRE)
   : Base(0, true), Property(DRE->getDecl()) {
@@ -114,6 +122,14 @@ FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
   : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) {
 }
 
+void FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg,
+                                        const ObjCPropertyDecl *Prop) {
+  assert(Msg && Prop);
+  WeakUseVector &Uses =
+    WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)];
+  Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0));
+}
+
 void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {
   E = E->IgnoreParenCasts();
 
@@ -138,11 +154,21 @@ void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {
   // Has this weak object been seen before?
   FunctionScopeInfo::WeakObjectUseMap::iterator Uses;
   if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E))
-    Uses = WeakObjectUses.find(FunctionScopeInfo::WeakObjectProfileTy(RefExpr));
+    Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr));
   else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E))
-    Uses = WeakObjectUses.find(FunctionScopeInfo::WeakObjectProfileTy(IvarE));
+    Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE));
   else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
-    Uses = WeakObjectUses.find(FunctionScopeInfo::WeakObjectProfileTy(DRE));
+    Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));
+  else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(MsgE)) {
+    Uses = WeakObjectUses.end();
+    if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) {
+      if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) {
+        Uses =
+          WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(),
+                                                  Prop));
+      }
+    }
+  }
   else
     return;
 
diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index 1bb4df04836..3f9c14c6852 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -2434,6 +2434,24 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
     // In ARC, check for message sends which are likely to introduce
     // retain cycles.
     checkRetainCycles(Result);
+
+    if (!isImplicit && Method) {
+      if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) {
+        bool IsWeak =
+          Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak;
+        if (!IsWeak && Sel.isUnarySelector())
+          IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
+
+        if (IsWeak) {
+          DiagnosticsEngine::Level Level =
+            Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak,
+                                     LBracLoc);
+          if (Level != DiagnosticsEngine::Ignored)
+            getCurFunction()->recordUseOfWeak(Result, Prop);
+
+        }
+      }
+    }
   }
       
   return MaybeBindToTemporary(Result);
diff --git a/clang/test/SemaObjC/arc-repeated-weak.mm b/clang/test/SemaObjC/arc-repeated-weak.mm
index 1c6578ef131..ca13e20dcf2 100644
--- a/clang/test/SemaObjC/arc-repeated-weak.mm
+++ b/clang/test/SemaObjC/arc-repeated-weak.mm
@@ -99,6 +99,29 @@ void globals() {
   use(a); // expected-note{{also accessed here}}
 }
 
+void messageGetter(Test *a) {
+  use([a weakProp]); // expected-warning{{weak property 'weakProp' is accessed multiple times}}
+  use([a weakProp]); // expected-note{{also accessed here}}
+}
+
+void messageSetter(Test *a) {
+  [a setWeakProp:get()]; // no-warning
+  [a setWeakProp:get()]; // no-warning
+}
+
+void messageSetterAndGetter(Test *a) {
+  [a setWeakProp:get()]; // expected-note{{also accessed here}}
+  use([a weakProp]); // expected-warning{{weak property 'weakProp' is accessed multiple times}}
+}
+
+void mixDotAndMessageSend(Test *a, Test *b) {
+  use(a.weakProp); // expected-warning{{weak property 'weakProp' is accessed multiple times}}
+  use([a weakProp]); // expected-note{{also accessed here}}
+
+  use([b weakProp]); // expected-warning{{weak property 'weakProp' is accessed multiple times}}
+  use(b.weakProp); // expected-note{{also accessed here}}
+}
+
 
 void assignToStrongWrongInit(Test *a) {
   id val = a.weakProp; // expected-note{{also accessed here}}