Index: lib/CodeGen/MicrosoftCXXABI.cpp
===================================================================
--- lib/CodeGen/MicrosoftCXXABI.cpp
+++ lib/CodeGen/MicrosoftCXXABI.cpp
@@ -3800,6 +3800,12 @@
 
 static void emitCXXDestructor(CodeGenModule &CGM, const CXXDestructorDecl *dtor,
                               StructorType dtorType) {
+  // If the class has dllimport attribute and has a virual base, the destructor
+  // is equivalent to the virtual base destrutor.
+  if (dtor->getParent()->getNumVBases() && dtor->hasAttr<DLLImportAttr>() &&
+      (dtorType == StructorType::Complete || dtorType == StructorType::Base) &&
+      CGM.TryEmitBaseDestructorAsAlias(dtor))
+    return;
   // The complete destructor is equivalent to the base destructor for
   // classes with no virtual bases, so try to emit it as an alias.
   if (!dtor->getParent()->getNumVBases() &&
Index: test/CodeGenCXX/dllimport-base.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/dllimport-base.cpp
@@ -0,0 +1,51 @@
+// RUN: %clang_cc1 -triple i386-pc-windows -emit-llvm -fms-compatibility %s -x c++ -o - | FileCheck %s
+
+// CHECK: declare dllimport x86_thiscallcc void @"\01??1VirtualClass@test1@@UAE@XZ"
+// CHECK: declare dllimport x86_thiscallcc void @"\01??1VirtualClass@test2@@UAE@XZ"
+// CHECK-NOT: ??_DVirtualClass@@QEAAXXZ
+
+namespace test1 {
+struct __declspec(dllimport) VirtualClass {
+public:
+  virtual ~VirtualClass(){};
+};
+
+int main() {
+  VirtualClass c;
+  return 0;
+}
+} // namespace test1
+
+namespace test2 {
+class BaseClass {
+public:
+  virtual ~BaseClass(){};
+};
+
+class __declspec(dllimport) VirtualClass : public BaseClass {
+public:
+  virtual ~VirtualClass(){};
+};
+
+int main() {
+  VirtualClass c;
+  return 0;
+}
+} // namespace test2
+
+namespace test3 {
+class BaseClass {
+public:
+  virtual ~BaseClass(){};
+};
+
+class __declspec(dllimport) VirtualClass : public virtual BaseClass {
+public:
+  virtual ~VirtualClass(){};
+};
+
+int main() {
+  VirtualClass c;
+  return 0;
+}
+} // namespace test3
Index: test/CodeGenCXX/dllimport-dtor-thunks.cpp
===================================================================
--- test/CodeGenCXX/dllimport-dtor-thunks.cpp
+++ test/CodeGenCXX/dllimport-dtor-thunks.cpp
@@ -44,6 +44,6 @@
 // CHECK:  call void @"\01??1ImportOverrideVDtor@@UEAA@XZ"(%struct.ImportOverrideVDtor* %{{.*}})
 // CHECK:  call void @"\01??1ImportIntroVDtor@@UEAA@XZ"(%struct.ImportIntroVDtor* %{{.*}})
 
-// CHECK-LABEL: define linkonce_odr void @"\01??_DImportVBaseOverrideVDtor@@QEAAXXZ"
+// CHECK-LABEL: declare dllimport void @"\01??_DImportVBaseOverrideVDtor@@QEAAXXZ"
 // CHECK-LABEL: declare dllimport void @"\01??1ImportOverrideVDtor@@UEAA@XZ"
 // CHECK-LABEL: declare dllimport void @"\01??1ImportIntroVDtor@@UEAA@XZ"
Index: test/CodeGenCXX/dllimport-virtual-base.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/dllimport-virtual-base.cpp
@@ -0,0 +1,67 @@
+// RUN: %clang_cc1 -triple i386-pc-windows -emit-llvm -fms-compatibility %s -x c++ -o - | FileCheck %s
+
+namespace test1 {
+struct BaseClass {
+  ~BaseClass();
+};
+
+struct __declspec(dllimport) Concrete : virtual BaseClass {
+};
+
+Concrete c;
+} // namespace test1
+
+namespace test2 {
+class BaseClass {
+public:
+  virtual ~BaseClass(){};
+};
+
+class __declspec(dllimport) VirtualClass : public virtual BaseClass {
+public:
+  virtual ~VirtualClass(){};
+};
+
+int main() {
+  VirtualClass c;
+  return 0;
+}
+} // namespace test2
+
+namespace test3 {
+class IVirtualBase {
+public:
+  virtual ~IVirtualBase(){};
+  virtual void speak() = 0;
+};
+
+class VirtualClass : public virtual IVirtualBase {
+public:
+  virtual ~VirtualClass(){};
+  virtual void eat() = 0;
+};
+
+class __declspec(dllimport) ConcreteClass : public VirtualClass {
+public:
+  ConcreteClass(int nn);
+  void speak();
+  void eat();
+  virtual ~ConcreteClass();
+
+private:
+  int n;
+};
+
+int main() {
+  ConcreteClass c(10);
+  c.speak();
+  c.eat();
+  return 0;
+}
+} // namespace test3
+
+// CHECK-LABEL: declare dllimport x86_thiscallcc %"struct.test1::Concrete"* @"\01??0Concrete@test1@@QAE@XZ"
+// CHECK-LABEL: declare dllimport x86_thiscallcc %"class.test2::VirtualClass"* @"\01??0VirtualClass@test2@@QAE@XZ"
+// CHECK-LABEL: declare dllimport x86_thiscallcc %"class.test3::ConcreteClass"* @"\01??0ConcreteClass@test3@@QAE@H@Z"
+// CHECK-NOT: ??_DVirtualClass@@QEAAXXZ
+// CHECK-NOT: ??_DConcreteClass@@QEAAXXZ