Index: cfe/trunk/lib/CodeGen/CGClass.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGClass.cpp
+++ cfe/trunk/lib/CodeGen/CGClass.cpp
@@ -2873,6 +2873,11 @@
   if (getLangOpts().AppleKext)
     return false;
 
+  // If the member function is marked 'final', we know that it can't be
+  // overridden and can therefore devirtualize it.
+  if (MD->hasAttr<FinalAttr>())
+    return true;
+
   // If the most derived class is marked final, we know that no subclass can
   // override this member function and so we can devirtualize it. For example:
   //
@@ -2883,14 +2888,17 @@
   //   b->f();
   // }
   //
-  const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType();
-  if (MostDerivedClassDecl->hasAttr<FinalAttr>())
-    return true;
+  if (const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType()) {
+    if (BestDynamicDecl->hasAttr<FinalAttr>())
+      return true;
 
-  // If the member function is marked 'final', we know that it can't be
-  // overridden and can therefore devirtualize it.
-  if (MD->hasAttr<FinalAttr>())
-    return true;
+    // There may be a method corresponding to MD in a derived class. If that
+    // method is marked final, we can devirtualize it.
+    const CXXMethodDecl *DevirtualizedMethod =
+        MD->getCorrespondingMethodInClass(BestDynamicDecl);
+    if (DevirtualizedMethod->hasAttr<FinalAttr>())
+      return true;
+  }
 
   // Similarly, if the class itself is marked 'final' it can't be overridden
   // and we can therefore devirtualize the member function call.
Index: cfe/trunk/test/CodeGenCXX/devirtualize-virtual-function-calls-final.cpp
===================================================================
--- cfe/trunk/test/CodeGenCXX/devirtualize-virtual-function-calls-final.cpp
+++ cfe/trunk/test/CodeGenCXX/devirtualize-virtual-function-calls-final.cpp
@@ -225,3 +225,19 @@
     return -static_cast<RA&>(*x);
   }
 }
+
+namespace Test10 {
+  struct A {
+    virtual int f();
+  };
+
+  struct B : A {
+    int f() final;
+  };
+
+  // CHECK-LABEL: define i32 @_ZN6Test101fEPNS_1BE
+  int f(B *b) {
+    // CHECK: call i32 @_ZN6Test101B1fEv
+    return static_cast<A *>(b)->f();
+  }
+}
Index: cfe/trunk/test/CodeGenCXX/ubsan-devirtualized-calls.cpp
===================================================================
--- cfe/trunk/test/CodeGenCXX/ubsan-devirtualized-calls.cpp
+++ cfe/trunk/test/CodeGenCXX/ubsan-devirtualized-calls.cpp
@@ -16,9 +16,6 @@
   void f1() override {}
 };
 
-// PR13127 documents some missed devirtualization opportunities, including
-// devirt for methods marked 'final'. We can enable the checks marked 'PR13127'
-// if we implement this in the frontend.
 struct Derived3 : Base1 {
   void f1() override /* nofinal */ {}
 };
@@ -30,10 +27,10 @@
 // CHECK: [[UBSAN_TI_DERIVED1_1:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived1 to i8*
 // CHECK: [[UBSAN_TI_DERIVED2_1:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived2 to i8*
 // CHECK: [[UBSAN_TI_DERIVED2_2:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived2 to i8*
-// PR13127: [[UBSAN_TI_DERIVED3:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived3 to i8*
-// PR13127: [[UBSAN_TI_BASE1:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI5Base1 to i8*
-// PR13127: [[UBSAN_TI_DERIVED4_1:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived4 to i8*
-// PR13127: [[UBSAN_TI_DERIVED4_2:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived4 to i8*
+// CHECK: [[UBSAN_TI_DERIVED3:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived3 to i8*
+// CHECK: [[UBSAN_TI_BASE1:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI5Base1 to i8*
+// CHECK: [[UBSAN_TI_DERIVED4_1:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived4 to i8*
+// CHECK: [[UBSAN_TI_DERIVED4_2:@[0-9]+]] = private unnamed_addr global {{.*}} i8* bitcast {{.*}} @_ZTI8Derived4 to i8*
 
 // CHECK-LABEL: define void @_Z2t1v
 void t1() {
@@ -59,26 +56,26 @@
   // CHECK-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED2_2]] {{.*}}, i{{[0-9]+}} %[[D2_2]]
 }
 
-// PR13127-LABEL: define void @_Z2t4v
+// CHECK-LABEL: define void @_Z2t4v
 void t4() {
   Base1 p;
   Derived3 *badp = static_cast<Derived3 *>(&p); //< Check that &p isa Derived3.
-  // PR13127: %[[P1:[0-9]+]] = ptrtoint %struct.Derived3* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
-  // PR13127-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED3]] {{.*}}, i{{[0-9]+}} %[[P1]]
+  // CHECK: %[[P1:[0-9]+]] = ptrtoint %struct.Derived3* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
+  // CHECK-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED3]] {{.*}}, i{{[0-9]+}} %[[P1]]
 
   static_cast<Base1 *>(badp)->f1(); //< No devirt, test 'badp isa Base1'.
-  // PR13127: %[[BADP1:[0-9]+]] = ptrtoint %struct.Base1* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
-  // PR13127-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_BASE1]] {{.*}}, i{{[0-9]+}} %[[BADP1]]
+  // CHECK: %[[BADP1:[0-9]+]] = ptrtoint %struct.Base1* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
+  // CHECK-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_BASE1]] {{.*}}, i{{[0-9]+}} %[[BADP1]]
 }
 
-// PR13127-LABEL: define void @_Z2t5v
+// CHECK-LABEL: define void @_Z2t5v
 void t5() {
   Base1 p;
   Derived4 *badp = static_cast<Derived4 *>(&p); //< Check that &p isa Derived4.
-  // PR13127: %[[P1:[0-9]+]] = ptrtoint %struct.Derived4* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
-  // PR13127-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED4_1]] {{.*}}, i{{[0-9]+}} %[[P1]]
+  // CHECK: %[[P1:[0-9]+]] = ptrtoint %struct.Derived4* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
+  // CHECK-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED4_1]] {{.*}}, i{{[0-9]+}} %[[P1]]
 
   static_cast<Base1 *>(badp)->f1(); //< Devirt Base1::f1 to Derived4::f1.
-  // PR13127: %[[BADP1:[0-9]+]] = ptrtoint %struct.Derived4* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
-  // PR13127-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED4_2]] {{.*}}, i{{[0-9]+}} %[[BADP1]]
+  // CHECK: %[[BADP1:[0-9]+]] = ptrtoint %struct.Derived4* {{%[0-9]+}} to i{{[0-9]+}}, !nosanitize
+  // CHECK-NEXT: call void @__ubsan_handle_dynamic_type_cache{{[_a-z]*}}({{.*}} [[UBSAN_TI_DERIVED4_2]] {{.*}}, i{{[0-9]+}} %[[BADP1]]
 }