3 files changed, 64 insertions, 5 deletions

diff --git a/include/clang/Sema/ScopeInfo.h b/include/clang/Sema/ScopeInfo.h
index c49dee7b41..feda9c96b8 100644
--- a/include/clang/Sema/ScopeInfo.h
+++ b/include/clang/Sema/ScopeInfo.h
@@ -169,6 +169,7 @@ public:
     WeakObjectProfileTy(const DeclRefExpr *RE);
     WeakObjectProfileTy(const ObjCIvarRefExpr *RE);
 
+    const NamedDecl *getBase() const { return Base.getPointer(); }
     const NamedDecl *getProperty() const { return Property; }
 
     /// Returns true if the object base specifies a known object in memory,
diff --git a/lib/Sema/AnalysisBasedWarnings.cpp b/lib/Sema/AnalysisBasedWarnings.cpp
index b039bc6f92..a20817f965 100644
--- a/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/lib/Sema/AnalysisBasedWarnings.cpp
@@ -904,17 +904,24 @@ public:
 };
 }
 
-static bool isInLoop(const ParentMap &PM, const Stmt *S) {
+static bool isInLoop(const ASTContext &Ctx, const ParentMap &PM,
+                     const Stmt *S) {
   assert(S);
 
   do {
     switch (S->getStmtClass()) {
-    case Stmt::DoStmtClass:
     case Stmt::ForStmtClass:
     case Stmt::WhileStmtClass:
     case Stmt::CXXForRangeStmtClass:
     case Stmt::ObjCForCollectionStmtClass:
       return true;
+    case Stmt::DoStmtClass: {
+      const Expr *Cond = cast<DoStmt>(S)->getCond();
+      llvm::APSInt Val;
+      if (!Cond->EvaluateAsInt(Val, Ctx))
+        return true;
+      return Val.getBoolValue();
+    }
     default:
       break;
     }
@@ -932,6 +939,8 @@ static void diagnoseRepeatedUseOfWeak(Sema &S,
   typedef sema::FunctionScopeInfo::WeakObjectUseMap WeakObjectUseMap;
   typedef sema::FunctionScopeInfo::WeakUseVector WeakUseVector;
 
+  ASTContext &Ctx = S.getASTContext();
+
   const WeakObjectUseMap &WeakMap = CurFn->getWeakObjectUses();
 
   // Extract all weak objects that are referenced more than once.
@@ -952,16 +961,32 @@ static void diagnoseRepeatedUseOfWeak(Sema &S,
       continue;
 
     // If there was only one read, followed by any number of writes, and the
-    // read is not within a loop, don't warn.
+    // read is not within a loop, don't warn. Additionally, don't warn in a
+    // loop if the base object is a local variable -- local variables are often
+    // changed in loops.
     if (UI == Uses.begin()) {
       WeakUseVector::const_iterator UI2 = UI;
       for (++UI2; UI2 != UE; ++UI2)
         if (UI2->isUnsafe())
           break;
 
-      if (UI2 == UE)
-        if (!isInLoop(PM, UI->getUseExpr()))
+      if (UI2 == UE) {
+        if (!isInLoop(Ctx, PM, UI->getUseExpr()))
           continue;
+
+        const WeakObjectProfileTy &Profile = I->first;
+        if (!Profile.isExactProfile())
+          continue;
+
+        const NamedDecl *Base = Profile.getBase();
+        if (!Base)
+          Base = Profile.getProperty();
+        assert(Base && "A profile always has a base or property.");
+
+        if (const VarDecl *BaseVar = dyn_cast<VarDecl>(Base))
+          if (BaseVar->hasLocalStorage() && !isa<ParmVarDecl>(Base))
+            continue;
+      }
     }
 
     UsesByStmt.push_back(StmtUsesPair(UI->getUseExpr(), I));
diff --git a/test/SemaObjC/arc-repeated-weak.mm b/test/SemaObjC/arc-repeated-weak.mm
index 1539a9bcae..e652bee82d 100644
--- a/test/SemaObjC/arc-repeated-weak.mm
+++ b/test/SemaObjC/arc-repeated-weak.mm
@@ -257,6 +257,38 @@ void readOnlyLoop(Test *a) {
   }
 }
 
+void readInIterationLoop() {
+  for (Test *a in get())
+    use(a.weakProp); // no-warning
+}
+
+void readDoubleLevelAccessInLoop() {
+  for (Test *a in get()) {
+    use(a.strongProp.weakProp); // no-warning
+  }
+}
+
+void readParameterInLoop(Test *a) {
+  for (id unused in get()) {
+    use(a.weakProp); // expected-warning{{weak property 'weakProp' is accessed multiple times in this function}}
+    (void)unused;
+  }
+}
+
+void readGlobalInLoop() {
+  static __weak id a;
+  for (id unused in get()) {
+    use(a); // expected-warning{{weak variable 'a' is accessed multiple times in this function}}
+    (void)unused;
+  }
+}
+
+void doWhileLoop(Test *a) {
+  do {
+    use(a.weakProp); // no-warning
+  } while(0);
+}
+
 
 @interface Test (Methods)
 @end
@@ -351,3 +383,4 @@ void doubleLevelAccessIvar(Test *a, Test *b) {
 
   use(a.strongProp.weakProp); // no-warning
 }
+