[MSVC2015] dllexport for defaulted special class members

[DmitryPolukhin]

Summary

Clang doesn't dllexport defaulted special member function defaulted inside class but does it if they defaulted outside class. MSVC doesn't make any distinction where they were defaulted. Also MSVC 2013 and 2015 export different set of members. MSVC2015 doesn't emit trivial defaulted x-tors but does emit copy assign operator.

[rnk]

lib/Sema/SemaDeclCXX.cpp

4814

nit, can you rename this Ctor? I definitely know that that is, but not necessarily CXXC.

13111

Can we add if (InClassDef) ActOnFinishInlineFunctionDef(MD); here instead? If the decl doesn't have dllexport, we will just defer it until its referenced, which seems OK.

[DmitryPolukhin]

Comments resolved, PTAL.

lib/Sema/SemaDeclCXX.cpp

13111

We can move this check here but condition has to be more complicated because MSVC2015 doesn't export trivial defaulted c-tors even if they were explicitly declared dllexport, see my check on line 4822.

[rnk]

lib/Sema/SemaDeclCXX.cpp

13111

Maybe we should handle that case by silently dropping dllexport on trivial defaulted ctors and dtors. Basically I'm trying to keep our dllexport policy decisions local to the dll attribute checking code. We should either consistently call ActOnFinishInlineFunctionDef for special members that were defaulted in the class body, or not do it at all.

[DmitryPolukhin]

• drop dllexport for trivial defaulted x-tors for compatibility with MSVC2015
• move checks to CheckCompletedCXXClass because completed class definition is required to detect if x-tor is trivial

[DmitryPolukhin]

PTAL

lib/Sema/SemaDeclCXX.cpp

13111–13112

I added code to drop dllexport attribute but the check for dropping dllexport attribute is basically the same. Moreover it cannot be done when the attribute is processed because we need full class definition so I moved the check to CheckCompletedCXXClass. Alternatively I can move the check to checkClassLevelDLLAttribute but it will start working for classes without class level dllexport attribute to detect if any class member has member level attribute (it is less efficient because it requires more more loop over all class methods even for all classes).

[rnk]

lgtm

Thanks!

lib/Sema/SemaDeclCXX.cpp

if (MD) {
       if (MD->isInlined()) {
         // MinGW does not import or export inline methods.
         if (!Context.getTargetInfo().getCXXABI().isMicrosoft())
           continue;
 
         // MSVC versions before 2015 don't export the move assignment operators
         // and move constructor, so don't attempt to import/export them if
         // we have a definition.
         auto *CXXC = dyn_cast<CXXConstructorDecl>(MD);
         if ((MD->isMoveAssignmentOperator() ||
              (CXXC && CXXC->isMoveConstructor())) &&
             !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
           continue;
+
+        // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
+        // operator is exported anyway.
+        if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
+            (CXXC || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
+          continue;
       }
     }
 
     if (!cast<NamedDecl>(Member)->isExternallyVisible())
       continue;
 
     if (!getDLLAttr(Member)) {
       auto *NewAttr =
if (MD) {
     const FunctionDecl *Primary = MD;
     if (const FunctionDecl *Pattern = MD->getTemplateInstantiationPattern())
       // Find the uninstantiated declaration that actually had the '= default'
       // on it.
       Pattern->isDefined(Primary);
 
     // If the method was defaulted on its first declaration, we will have
     // already performed the checking in CheckCompletedCXXClass. Such a
-    // declaration doesn't trigger an implicit definition.
-    if (Primary == Primary->getCanonicalDecl())
+    // declaration doesn't trigger an implicit definition. But defaulted methods
+    // marked with dllexport do need implicit definition.
+    bool InClassDef = Primary == Primary->getCanonicalDecl();
+    bool HasDllexport = MD->hasAttr<DLLExportAttr>();
+    if (InClassDef && !HasDllexport)
       return;
 
+    if (!InClassDef)
       CheckExplicitlyDefaultedSpecialMember(MD);
 
     if (MD->isInvalidDecl())
       return;
 
+    auto PostAction = [=]{
+      if (InClassDef &&
+          (Member == CXXCopyAssignment ||
+           !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015)))
+        ActOnFinishInlineFunctionDef(MD);
+    };
     switch (Member) {
     case CXXDefaultConstructor:
       DefineImplicitDefaultConstructor(DefaultLoc,
                                        cast<CXXConstructorDecl>(MD));
+      PostAction();
       break;
     case CXXCopyConstructor:
       DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD));
+      PostAction();
       break;
     case CXXCopyAssignment:
       DefineImplicitCopyAssignment(DefaultLoc, MD);
+      PostAction();
       break;
     case CXXDestructor:
       DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(MD));
+      PostAction();
       break;
     case CXXMoveConstructor:
       DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD));
       break;
     case CXXMoveAssignment:
       DefineImplicitMoveAssignment(DefaultLoc, MD);
       break;
     case CXXInvalid:
       llvm_unreachable("Invalid special member.");
     }
   } else {
     Diag(DefaultLoc, diag::err_default_special_members);
   }
 }
 
 static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
   for (Stmt *SubStmt : S->children()) {
     if (!SubStmt)
       continue;

test/CodeGenCXX/dllexport-members.cpp

-// RUN: %clang_cc1 -triple i686-windows-msvc -fms-compatibility   -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M32 %s
-// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-compatibility -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M64 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc   -fms-compatibility -fms-compatibility-version=18 -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M32 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-compatibility -fms-compatibility-version=18 -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M64 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc   -fms-compatibility -fms-compatibility-version=19 -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=M32VS2015 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-compatibility -fms-compatibility-version=19 -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=M64VS2015 %s
 // RUN: %clang_cc1 -triple i686-windows-gnu                       -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G32 %s
 // RUN: %clang_cc1 -triple x86_64-windows-gnu                     -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G64 %s
 
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Exported {};
 struct ExplicitDecl_Exported {};
 struct ExplicitInst_Exported {};
 struct ExplicitSpec_Exported {};

 
 // M32-DAG: define dllexport x86_thiscallcc dereferenceable({{[0-9]+}}) %struct.ExportDefaultedDefs* @"\01??4ExportDefaultedDefs@@QAEAAU0@$$QAU0@@Z"(%struct.ExportDefaultedDefs* %this, %struct.ExportDefaultedDefs* dereferenceable({{[0-9]+}}))
 // M64-DAG: define dllexport                dereferenceable({{[0-9]+}}) %struct.ExportDefaultedDefs* @"\01??4ExportDefaultedDefs@@QEAAAEAU0@$$QEAU0@@Z"(%struct.ExportDefaultedDefs* %this, %struct.ExportDefaultedDefs* dereferenceable({{[0-9]+}}))
 // G32-DAG: define dllexport x86_thiscallcc dereferenceable({{[0-9]+}}) %struct.ExportDefaultedDefs* @_ZN19ExportDefaultedDefsaSEOS_(%struct.ExportDefaultedDefs* %this, %struct.ExportDefaultedDefs* dereferenceable({{[0-9]+}}))
 // G64-DAG: define dllexport                dereferenceable({{[0-9]+}}) %struct.ExportDefaultedDefs* @_ZN19ExportDefaultedDefsaSEOS_(%struct.ExportDefaultedDefs* %this, %struct.ExportDefaultedDefs* dereferenceable({{[0-9]+}}))
 ExportDefaultedDefs& ExportDefaultedDefs::operator=(ExportDefaultedDefs&&) = default;
 
 
+// Export defaulted member function definitions declared inside class.
+struct ExportDefaultedInclassDefs {
+  __declspec(dllexport) ExportDefaultedInclassDefs() = default;
+  // M32VS2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+  // M64VS2013-DAG: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+  // M32VS2015-NOT: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+  // M64VS2015-NOT: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+
+  __declspec(dllexport) ~ExportDefaultedInclassDefs() = default;
+  // M32VS2013-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??1ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+  // M64VS2013-DAG: define weak_odr dllexport                void @"\01??1ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+  // M32VS2015-NOT: define weak_odr dllexport x86_thiscallcc void @"\01??1ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+  // M64VS2015-NOT: define weak_odr dllexport                void @"\01??1ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+
+  __declspec(dllexport) ExportDefaultedInclassDefs(const ExportDefaultedInclassDefs&) = default;
+  // M32VS2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@ABU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M64VS2013-DAG: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@AEBU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M32VS2015-NOT: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@ABU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M64VS2015-NOT: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@AEBU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+
+  __declspec(dllexport) ExportDefaultedInclassDefs& operator=(const ExportDefaultedInclassDefs&) = default;
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc dereferenceable({{[0-9]+}}) %struct.ExportDefaultedInclassDefs* @"\01??4ExportDefaultedInclassDefs@@QAEAAU0@ABU0@@Z"(%struct.ExportDefaultedInclassDefs* %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M64-DAG: define weak_odr dllexport                dereferenceable({{[0-9]+}}) %struct.ExportDefaultedInclassDefs* @"\01??4ExportDefaultedInclassDefs@@QEAAAEAU0@AEBU0@@Z"(%struct.ExportDefaultedInclassDefs* %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+};
+
+
 // Export allocation functions.
 struct ExportAlloc {
   __declspec(dllexport) void* operator new(__SIZE_TYPE__);
   __declspec(dllexport) void* operator new[](__SIZE_TYPE__);
   __declspec(dllexport) void operator delete(void*);
   __declspec(dllexport) void operator delete[](void*);
 };
 

test/CodeGenCXX/dllexport.cpp

-// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O1 -mconstructor-aliases -disable-llvm-optzns -o - %s -w -fms-compatibility-version=19.00 | FileCheck --check-prefix=MSC --check-prefix=M32 -check-prefix=MSVC2015 %s
-// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O1 -mconstructor-aliases -disable-llvm-optzns -o - %s -w -fms-compatibility-version=18.00 | FileCheck --check-prefix=MSC --check-prefix=M32 -check-prefix=MSVC2013 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O1 -mconstructor-aliases -disable-llvm-optzns -o - %s -w -fms-compatibility-version=19.00 | FileCheck --check-prefix=MSC --check-prefix=M32 -check-prefix=MSVC2015 -check-prefix=M32MSVC2015 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O1 -mconstructor-aliases -disable-llvm-optzns -o - %s -w -fms-compatibility-version=18.00 | FileCheck --check-prefix=MSC --check-prefix=M32 -check-prefix=MSVC2013 -check-prefix=M32MSVC2013 %s
 
-// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O0 -o - %s -w -fms-compatibility-version=19.00 | FileCheck --check-prefix=MSC --check-prefix=M64 -check-prefix=MSVC2015 %s
-// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O0 -o - %s -w -fms-compatibility-version=18.00 | FileCheck --check-prefix=MSC --check-prefix=M64 -check-prefix=MSVC2013 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O0 -o - %s -w -fms-compatibility-version=19.00 | FileCheck --check-prefix=MSC --check-prefix=M64 -check-prefix=MSVC2015 -check-prefix=M64MSVC2015 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O0 -o - %s -w -fms-compatibility-version=18.00 | FileCheck --check-prefix=MSC --check-prefix=M64 -check-prefix=MSVC2013 -check-prefix=M64MSVC2013 %s
 
 // RUN: %clang_cc1 -triple i686-windows-gnu    -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O0 -o - %s -w | FileCheck --check-prefix=GNU --check-prefix=G32 %s
 // RUN: %clang_cc1 -triple x86_64-windows-gnu  -emit-llvm -std=c++1y -fno-threadsafe-statics -fms-extensions -O0 -o - %s -w | FileCheck --check-prefix=GNU --check-prefix=G64 %s
 
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Exported {};
 struct ExplicitDecl_Exported {};
 struct ExplicitInst_Exported {};

 // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??_FB@PR23801@@QAEXXZ"({{.*}}) {{#[0-9]+}} comdat
 
 struct __declspec(dllexport) T {
   // Copy assignment operator:
   // M32-DAG: define weak_odr dllexport x86_thiscallcc dereferenceable({{[0-9]+}}) %struct.T* @"\01??4T@@QAEAAU0@ABU0@@Z"
 
   // Explicitly defaulted copy constructur:
   T(const T&) = default;
-  // M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.T* @"\01??0T@@QAE@ABU0@@Z"
+  // M32MSVC2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.T* @"\01??0T@@QAE@ABU0@@Z"
 
   void a() {}
   // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?a@T@@QAEXXZ"
 
   static int b;
   // M32-DAG: @"\01?b@T@@2HA" = external dllexport global i32
 
   static int c;
namespace UseDtorAlias {
   A::~A() { }
   B::~B() { }
   // Emit a alias definition of B's constructor.
   // M32-DAG: @"\01??1B@UseDtorAlias@@QAE@XZ" = dllexport alias {{.*}} @"\01??1A@UseDtorAlias@@QAE@XZ"
 }
 
 struct __declspec(dllexport) DefaultedCtorsDtors {
   DefaultedCtorsDtors() = default;
-  // M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.DefaultedCtorsDtors* @"\01??0DefaultedCtorsDtors@@QAE@XZ"
+  // M32MSVC2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.DefaultedCtorsDtors* @"\01??0DefaultedCtorsDtors@@QAE@XZ"
   ~DefaultedCtorsDtors() = default;
-  // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??1DefaultedCtorsDtors@@QAE@XZ"
+  // M32MSVC2013-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??1DefaultedCtorsDtors@@QAE@XZ"
+};
+
+// Export defaulted member function definitions declared inside class.
+struct __declspec(dllexport) ExportDefaultedInclassDefs {
+  ExportDefaultedInclassDefs() = default;
+  // M32VS2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+  // M64VS2013-DAG: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+  // M32VS2015-NOT: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+  // M64VS2015-NOT: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* returned %this)
+
+  ~ExportDefaultedInclassDefs() = default;
+  // M32VS2013-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??1ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+  // M64VS2013-DAG: define weak_odr dllexport                void @"\01??1ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+  // M32VS2015-NOT: define weak_odr dllexport x86_thiscallcc void @"\01??1ExportDefaultedInclassDefs@@QAE@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+  // M64VS2015-NOT: define weak_odr dllexport                void @"\01??1ExportDefaultedInclassDefs@@QEAA@XZ"(%struct.ExportDefaultedInclassDefs* %this)
+
+  ExportDefaultedInclassDefs(const ExportDefaultedInclassDefs&) = default;
+  // M32VS2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@ABU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M64VS2013-DAG: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@AEBU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M32VS2015-NOT: define weak_odr dllexport x86_thiscallcc %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QAE@ABU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M64VS2015-NOT: define weak_odr dllexport                %struct.ExportDefaultedInclassDefs* @"\01??0ExportDefaultedInclassDefs@@QEAA@AEBU0@@Z"(%struct.ExportDefaultedInclassDefs* returned %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+
+  ExportDefaultedInclassDefs& operator=(const ExportDefaultedInclassDefs&) = default;
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc dereferenceable({{[0-9]+}}) %struct.ExportDefaultedInclassDefs* @"\01??4ExportDefaultedInclassDefs@@QAEAAU0@ABU0@@Z"(%struct.ExportDefaultedInclassDefs* %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
+  // M64-DAG: define weak_odr dllexport                dereferenceable({{[0-9]+}}) %struct.ExportDefaultedInclassDefs* @"\01??4ExportDefaultedInclassDefs@@QEAAAEAU0@AEBU0@@Z"(%struct.ExportDefaultedInclassDefs* %this, %struct.ExportDefaultedInclassDefs* dereferenceable({{[0-9]+}}))
 };
 
 namespace ReferencedInlineMethodInNestedClass {
   struct __declspec(dllexport) S {
     void foo() {
       t->bar();
     }
     struct T {

 template <typename T> struct ExplicitInstConstexprMembers {
   // Copy assignment operator
   // M32-DAG: define weak_odr dllexport x86_thiscallcc dereferenceable(1) %struct.ExplicitInstConstexprMembers* @"\01??4?$ExplicitInstConstexprMembers@X@@QAEAAU0@ABU0@@Z"
 
   constexpr ExplicitInstConstexprMembers() {}
   // M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExplicitInstConstexprMembers* @"\01??0?$ExplicitInstConstexprMembers@X@@QAE@XZ"
 
   ExplicitInstConstexprMembers(const ExplicitInstConstexprMembers&) = default;
-  // M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExplicitInstConstexprMembers* @"\01??0?$ExplicitInstConstexprMembers@X@@QAE@ABU0@@Z"
+  // M32MSVC2013-DAG: define weak_odr dllexport x86_thiscallcc %struct.ExplicitInstConstexprMembers* @"\01??0?$ExplicitInstConstexprMembers@X@@QAE@ABU0@@Z"
 
   constexpr int f() const { return 42; }
   // M32-DAG: define weak_odr dllexport x86_thiscallcc i32 @"\01?f@?$ExplicitInstConstexprMembers@X@@QBEHXZ"
 };
 template struct __declspec(dllexport) ExplicitInstConstexprMembers<void>;
 
 template <typename T> struct ExplicitInstantiationDeclTemplate { void f() {} };
 extern template struct __declspec(dllexport) ExplicitInstantiationDeclTemplate<int>;