AST: Mangle reference temporaries reliably

[majnemer]

Summary

Previously, we would generate a single name for all reference
temporaries and allow LLVM to rename them for us. Instead, number the
reference temporaries as we build them in Sema.

[rsmith]

Please also propose this mangling scheme on cxx-abi-dev.

lib/AST/ExprCXX.cpp

1458–1459

auto ES = new (ExtendedBy->getASTContext()) ExtraState;

1464–1465

Maybe stash the ExtraState* in a variable to avoid repeateding geting it here?

lib/Sema/SemaInit.cpp

5767–5771

It's not sufficient to start the numbering from 1 each time: we need to number within the topmost InitializedEntity, not just within the subentity for which we're currently building an initializer. Example:

struct S { const int &a, const int &b; };
S s = { 1, 2 };

lib/Serialization/ASTWriterStmt.cpp

1569–1573

We usually serialize fields in the order they appear in the class (so mangling number would go last). Not a big deal, though.

[majnemer]

Address Richard's review comments

[rsmith]

include/clang/Sema/Initialization.h

424

Maybe make this allocate a mangling number and return it, rather than returning a reference to the member?

lib/Sema/SemaInit.cpp

5381

Maybe pass the ExtendingEntity * into here instead of its decl and a reference to its mangling number?

5791–5808

You could reorder these to first create the MTE and then performReferenceExtension on it, and avoid the special-casing of the ManglingNumber here:

auto *MTE = new (S.Context) MaterializeTemporaryExpr(... /*no extending decl or mangling number*/ ...);
if (auto *ExtendingEntity = getEntityForTemporaryLifetimeExtension(&Entity)) {
  performReferenceExtension(MTE, ExtendingEntity);
  warnOnLifetimeExtension(...);
}

6196–6218

Likewise here.

[majnemer]

Address Richard's review comments.

[rsmith]

Looks great, thanks!

include/clang/Sema/Initialization.h

424

Please give this a name that sounds more like it's changing the state of the object. allocateManglingNumber or something?

lib/AST/MicrosoftMangle.cpp

120

This line looks like it's over 80 characters to me.

[majnemer]

Closed by commit rL207776 (authored by @majnemer).

include/clang/AST/ExprCXX.h

 /// binds to the temporary. \c MaterializeTemporaryExprs are always glvalues
 /// (either an lvalue or an xvalue, depending on the kind of reference binding
 /// to it), maintaining the invariant that references always bind to glvalues.
 ///
 /// Reference binding and copy-elision can both extend the lifetime of a
 /// temporary. When either happens, the expression will also track the
 /// declaration which is responsible for the lifetime extension.
 class MaterializeTemporaryExpr : public Expr {
-public:
+private:
+  struct ExtraState {
     /// \brief The temporary-generating expression whose value will be
     /// materialized.
     Stmt *Temporary;
 
     /// \brief The declaration which lifetime-extended this reference, if any.
     /// Either a VarDecl, or (for a ctor-initializer) a FieldDecl.
     const ValueDecl *ExtendingDecl;
 
+    unsigned ManglingNumber;
+  };
+  llvm::PointerUnion<Stmt *, ExtraState *> State;
+
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
 
+  void initializeExtraState(const ValueDecl *ExtendedBy,
+                            unsigned ManglingNumber);
+
 public:
   MaterializeTemporaryExpr(QualType T, Expr *Temporary,
                            bool BoundToLvalueReference,
-                           const ValueDecl *ExtendedBy)
+                           const ValueDecl *ExtendedBy, unsigned ManglingNumber)
     : Expr(MaterializeTemporaryExprClass, T,
            BoundToLvalueReference? VK_LValue : VK_XValue, OK_Ordinary,
            Temporary->isTypeDependent(), Temporary->isValueDependent(),
            Temporary->isInstantiationDependent(),
            Temporary->containsUnexpandedParameterPack()),
-      Temporary(Temporary), ExtendingDecl(ExtendedBy) {
+        State(Temporary) {
+    initializeExtraState(ExtendedBy, ManglingNumber);
   }
 
   MaterializeTemporaryExpr(EmptyShell Empty)
     : Expr(MaterializeTemporaryExprClass, Empty) { }
 
+  Stmt *getTemporary() const {
+    return State.is<Stmt *>() ? State.get<Stmt *>()
+                              : State.get<ExtraState *>()->Temporary;
+  }
+
   /// \brief Retrieve the temporary-generating subexpression whose value will
   /// be materialized into a glvalue.
-  Expr *GetTemporaryExpr() const { return static_cast<Expr *>(Temporary); }
+  Expr *GetTemporaryExpr() const { return static_cast<Expr *>(getTemporary()); }
 
   /// \brief Retrieve the storage duration for the materialized temporary.
   StorageDuration getStorageDuration() const {
+    const ValueDecl *ExtendingDecl = getExtendingDecl();
     if (!ExtendingDecl)
       return SD_FullExpression;
     // FIXME: This is not necessarily correct for a temporary materialized
     // within a default initializer.
     if (isa<FieldDecl>(ExtendingDecl))
       return SD_Automatic;
     return cast<VarDecl>(ExtendingDecl)->getStorageDuration();
   }
 
   /// \brief Get the declaration which triggered the lifetime-extension of this
   /// temporary, if any.
-  const ValueDecl *getExtendingDecl() const { return ExtendingDecl; }
+  const ValueDecl *getExtendingDecl() const {
+    return State.is<Stmt *>() ? nullptr
+                              : State.get<ExtraState *>()->ExtendingDecl;
+  }
+
+  void setExtendingDecl(const ValueDecl *ExtendedBy, unsigned ManglingNumber) {
+    initializeExtraState(ExtendedBy, ManglingNumber);
+  }
 
-  void setExtendingDecl(const ValueDecl *ExtendedBy) {
-    ExtendingDecl = ExtendedBy;
+  unsigned getManglingNumber() const {
+    return State.is<Stmt *>() ? 0 : State.get<ExtraState *>()->ManglingNumber;
   }
 
   /// \brief Determine whether this materialized temporary is bound to an
   /// lvalue reference; otherwise, it's bound to an rvalue reference.
   bool isBoundToLvalueReference() const {
     return getValueKind() == VK_LValue;
   }
 
   SourceLocation getLocStart() const LLVM_READONLY {
-    return Temporary->getLocStart();
+    return getTemporary()->getLocStart();
   }
   SourceLocation getLocEnd() const LLVM_READONLY {
-    return Temporary->getLocEnd();
+    return getTemporary()->getLocEnd();
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == MaterializeTemporaryExprClass;
   }
 
   // Iterators
-  child_range children() { return child_range(&Temporary, &Temporary + 1); }
+  child_range children() {
+    if (State.is<Stmt *>())
+      return child_range(State.getAddrOfPtr1(), State.getAddrOfPtr1() + 1);
+
+    auto ES = State.get<ExtraState *>();
+    return child_range(&ES->Temporary, &ES->Temporary + 1);
+  }
 };
 
 }  // end namespace clang
 
 #endif

include/clang/AST/Mangle.h

public:
   virtual void mangleCXXName(const NamedDecl *D, raw_ostream &) = 0;
   virtual void mangleThunk(const CXXMethodDecl *MD,
                           const ThunkInfo &Thunk,
                           raw_ostream &) = 0;
   virtual void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
                                   const ThisAdjustment &ThisAdjustment,
                                   raw_ostream &) = 0;
   virtual void mangleReferenceTemporary(const VarDecl *D,
+                                        unsigned ManglingNumber,
                                         raw_ostream &) = 0;
   virtual void mangleCXXRTTI(QualType T, raw_ostream &) = 0;
   virtual void mangleCXXRTTIName(QualType T, raw_ostream &) = 0;
   virtual void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type,
                              raw_ostream &) = 0;
   virtual void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type,
                              raw_ostream &) = 0;
   virtual void mangleStringLiteral(const StringLiteral *SL, raw_ostream &) = 0;

include/clang/Sema/Initialization.h

private:
 
   /// \brief If non-NULL, the parent entity in which this
   /// initialization occurs.
   const InitializedEntity *Parent;
 
   /// \brief The type of the object or reference being initialized.
   QualType Type;
 
+  /// \brief The mangling number for the next reference temporary to be created.
+  mutable unsigned ManglingNumber;
+
   struct LN {
     /// \brief When Kind == EK_Result, EK_Exception, EK_New, the
     /// location of the 'return', 'throw', or 'new' keyword,
     /// respectively. When Kind == EK_Temporary, the location where
     /// the temporary is being created.
     unsigned Location;
 
     /// \brief Whether the entity being initialized may end up using the
union {
     /// \brief When Kind == EK_ArrayElement, EK_VectorElement, or
     /// EK_ComplexElement, the index of the array or vector element being
     /// initialized. 
     unsigned Index;
 
     struct C Capture;
   };
 
-  InitializedEntity() { }
+  InitializedEntity() : ManglingNumber(1) {}
 
   /// \brief Create the initialization entity for a variable.
   InitializedEntity(VarDecl *Var)
-    : Kind(EK_Variable), Parent(0), Type(Var->getType()),
+    : Kind(EK_Variable), Parent(0), Type(Var->getType()), ManglingNumber(1),
       VariableOrMember(Var) { }
   
   /// \brief Create the initialization entity for the result of a
   /// function, throwing an object, performing an explicit cast, or
   /// initializing a parameter for which there is no declaration.
   InitializedEntity(EntityKind Kind, SourceLocation Loc, QualType Type,
                     bool NRVO = false)
-    : Kind(Kind), Parent(0), Type(Type)
+    : Kind(Kind), Parent(0), Type(Type), ManglingNumber(1)
   {
     LocAndNRVO.Location = Loc.getRawEncoding();
     LocAndNRVO.NRVO = NRVO;
   }
   
   /// \brief Create the initialization entity for a member subobject.
   InitializedEntity(FieldDecl *Member, const InitializedEntity *Parent) 
     : Kind(EK_Member), Parent(Parent), Type(Member->getType()),
-      VariableOrMember(Member) { }
+      ManglingNumber(1), VariableOrMember(Member) { }
   
   /// \brief Create the initialization entity for an array element.
   InitializedEntity(ASTContext &Context, unsigned Index, 
                     const InitializedEntity &Parent);
 
   /// \brief Create the initialization entity for a lambda capture.
   InitializedEntity(IdentifierInfo *VarID, QualType FieldType, SourceLocation Loc)
-    : Kind(EK_LambdaCapture), Parent(0), Type(FieldType) 
+    : Kind(EK_LambdaCapture), Parent(0), Type(FieldType), ManglingNumber(1)
   {
     Capture.VarID = VarID;
     Capture.Location = Loc.getRawEncoding();
   }
   
 public:
   /// \brief Create the initialization entity for a variable.
   static InitializedEntity InitializeVariable(VarDecl *Var) {
SourceLocation getCaptureLoc() const {
     assert(getKind() == EK_LambdaCapture && "Not a lambda capture!");
     return SourceLocation::getFromRawEncoding(Capture.Location);
   }
   
   void setParameterCFAudited() {
     Kind = EK_Parameter_CF_Audited;
   }
 
+  unsigned &getManglingNumber() const { return ManglingNumber; }
+
   /// Dump a representation of the initialized entity to standard error,
   /// for debugging purposes.
   void dump() const;
 
 private:
   unsigned dumpImpl(raw_ostream &OS) const;
 };
   

lib/AST/ExprCXX.cpp

 FunctionParmPackExpr *
 FunctionParmPackExpr::CreateEmpty(const ASTContext &Context,
                                   unsigned NumParams) {
   return new (Context.Allocate(sizeof(FunctionParmPackExpr) +
                                sizeof(ParmVarDecl*) * NumParams))
     FunctionParmPackExpr(QualType(), 0, SourceLocation(), 0, 0);
 }
 
+void MaterializeTemporaryExpr::initializeExtraState(const ValueDecl *ExtendedBy,
+                                                    unsigned ManglingNumber) {
+  // We only need extra state if we have to remember more than just the Stmt.
+  if (!ExtendedBy)
+    return;
+
+  // We may need to allocate extra storage for the mangling number and the
+  // extended-by ValueDecl.
+  if (!State.is<ExtraState *>()) {
+    auto ES = new (ExtendedBy->getASTContext()) ExtraState;
+    ES->Temporary = State.get<Stmt *>();
+    State = ES;
+  }
+
+  auto ES = State.get<ExtraState *>();
+  ES->ExtendingDecl = ExtendedBy;
+  ES->ManglingNumber = ManglingNumber;
+}
+
 TypeTraitExpr::TypeTraitExpr(QualType T, SourceLocation Loc, TypeTrait Kind,
                              ArrayRef<TypeSourceInfo *> Args,
                              SourceLocation RParenLoc,
                              bool Value)
   : Expr(TypeTraitExprClass, T, VK_RValue, OK_Ordinary,
          /*TypeDependent=*/false,
          /*ValueDependent=*/false,
          /*InstantiationDependent=*/false,

lib/AST/ItaniumMangle.cpp

bool shouldMangleStringLiteral(const StringLiteral *) override {
     return false;
   }
   void mangleCXXName(const NamedDecl *D, raw_ostream &) override;
   void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
                    raw_ostream &) override;
   void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
                           const ThisAdjustment &ThisAdjustment,
                           raw_ostream &) override;
-  void mangleReferenceTemporary(const VarDecl *D, raw_ostream &) override;
+  void mangleReferenceTemporary(const VarDecl *D, unsigned ManglingNumber,
+                                raw_ostream &) override;
   void mangleCXXVTable(const CXXRecordDecl *RD, raw_ostream &) override;
   void mangleCXXVTT(const CXXRecordDecl *RD, raw_ostream &) override;
   void mangleCXXCtorVTable(const CXXRecordDecl *RD, int64_t Offset,
                            const CXXRecordDecl *Type, raw_ostream &) override;
   void mangleCXXRTTI(QualType T, raw_ostream &) override;
   void mangleCXXRTTIName(QualType T, raw_ostream &) override;
   void mangleTypeName(QualType T, raw_ostream &) override;
   void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type,
ItaniumMangleContextImpl::mangleItaniumThreadLocalWrapper(const VarDecl *D,
                                                           raw_ostream &Out) {
   //  <special-name> ::= TW <object name>
   CXXNameMangler Mangler(*this, Out);
   Mangler.getStream() << "_ZTW";
   Mangler.mangleName(D);
 }
 
 void ItaniumMangleContextImpl::mangleReferenceTemporary(const VarDecl *D,
+                                                        unsigned ManglingNumber,
                                                         raw_ostream &Out) {
   // We match the GCC mangling here.
   //  <special-name> ::= GR <object name>
   CXXNameMangler Mangler(*this, Out);
   Mangler.getStream() << "_ZGR";
   Mangler.mangleName(D);
+  assert(ManglingNumber > 0 && "Reference temporary mangling number is zero!");
+  if (ManglingNumber > 1)
+    Mangler.mangleNumber(ManglingNumber - 2);
 }
 
 void ItaniumMangleContextImpl::mangleCXXVTable(const CXXRecordDecl *RD,
                                                raw_ostream &Out) {
   // <special-name> ::= TV <type>  # virtual table
   CXXNameMangler Mangler(*this, Out);
   Mangler.getStream() << "_ZTV";
   Mangler.mangleNameOrStandardSubstitution(RD);

lib/AST/MicrosoftMangle.cpp

void mangleCXXVBTable(const CXXRecordDecl *Derived,
                         raw_ostream &Out) override;
   void mangleCXXRTTI(QualType T, raw_ostream &) override;
   void mangleCXXRTTIName(QualType T, raw_ostream &) override;
   void mangleTypeName(QualType T, raw_ostream &) override;
   void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type,
                      raw_ostream &) override;
   void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type,
                      raw_ostream &) override;
-  void mangleReferenceTemporary(const VarDecl *, raw_ostream &) override;
+  void mangleReferenceTemporary(const VarDecl *, unsigned ManglingNumber, raw_ostream &) override;
   void mangleStaticGuardVariable(const VarDecl *D, raw_ostream &Out) override;
   void mangleDynamicInitializer(const VarDecl *D, raw_ostream &Out) override;
   void mangleDynamicAtExitDestructor(const VarDecl *D,
                                      raw_ostream &Out) override;
   void mangleStringLiteral(const StringLiteral *SL, raw_ostream &Out) override;
   bool getNextDiscriminator(const NamedDecl *ND, unsigned &disc) {
     // Lambda closure types are already numbered.
     if (isLambda(ND))

 void MicrosoftMangleContextImpl::mangleCXXDtor(const CXXDestructorDecl *D,
                                                CXXDtorType Type,
                                                raw_ostream &Out) {
   MicrosoftCXXNameMangler mangler(*this, Out, D, Type);
   mangler.mangle(D);
 }
 
 void MicrosoftMangleContextImpl::mangleReferenceTemporary(const VarDecl *VD,
+                                                          unsigned,
                                                           raw_ostream &) {
   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
     "cannot mangle this reference temporary yet");
   getDiags().Report(VD->getLocation(), DiagID);
 }
 
 void MicrosoftMangleContextImpl::mangleStaticGuardVariable(const VarDecl *VD,
                                                            raw_ostream &Out) {

lib/CodeGen/CodeGenModule.cpp

llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary(
   if (Slot)
     return Slot;
 
   // FIXME: If an externally-visible declaration extends multiple temporaries,
   // we need to give each temporary the same name in every translation unit (and
   // we also need to make the temporaries externally-visible).
   SmallString<256> Name;
   llvm::raw_svector_ostream Out(Name);
-  getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out);
+  getCXXABI().getMangleContext().mangleReferenceTemporary(
+      VD, E->getManglingNumber(), Out);
   Out.flush();
 
   APValue *Value = 0;
   if (E->getStorageDuration() == SD_Static) {
     // We might have a cached constant initializer for this temporary. Note
     // that this might have a different value from the value computed by
     // evaluating the initializer if the surrounding constant expression
     // modifies the temporary.

lib/Sema/SemaCast.cpp

static TryCastResult TryConstCast(Sema &Self, ExprResult &SrcExpr,
   // Since we're dealing in canonical types, the remainder must be the same.
   if (SrcType != DestType)
     return TC_NotApplicable;
 
   if (NeedToMaterializeTemporary)
     // This is a const_cast from a class prvalue to an rvalue reference type.
     // Materialize a temporary to store the result of the conversion.
     SrcExpr = new (Self.Context) MaterializeTemporaryExpr(
-        SrcType, SrcExpr.take(), /*IsLValueReference*/ false,
-        /*ExtendingDecl*/ 0);
+        SrcType, SrcExpr.take(), /*IsLValueReference=*/false,
+        /*ExtendingDecl=*/nullptr, /*ManglingNumber=*/0);
 
   return TC_Success;
 }
 
 // Checks for undefined behavior in reinterpret_cast.
 // The cases that is checked for is:
 // *reinterpret_cast<T*>(&a)
 // reinterpret_cast<T&>(a)

lib/Sema/SemaExpr.cpp

QualType Sema::CheckAddressOfOperand(ExprResult &OrigOp, SourceLocation OpLoc) {
   if (lval == Expr::LV_ClassTemporary || lval == Expr::LV_ArrayTemporary) { 
     bool sfinae = (bool)isSFINAEContext();
     Diag(OpLoc, isSFINAEContext() ? diag::err_typecheck_addrof_temporary
                                   : diag::ext_typecheck_addrof_temporary)
       << op->getType() << op->getSourceRange();
     if (sfinae)
       return QualType();
     // Materialize the temporary as an lvalue so that we can take its address.
-    OrigOp = op = new (Context)
-        MaterializeTemporaryExpr(op->getType(), OrigOp.take(), true, 0);
+    OrigOp = op = new (Context) MaterializeTemporaryExpr(
+        op->getType(), OrigOp.take(), /*BoundToLvalueReference=*/true,
+        /*ExtendingDecl=*/nullptr, /*ManglingNumber=*/0);
   } else if (isa<ObjCSelectorExpr>(op)) {
     return Context.getPointerType(op->getType());
   } else if (lval == Expr::LV_MemberFunction) {
     // If it's an instance method, make a member pointer.
     // The expression must have exactly the form &A::foo.
 
     // If the underlying expression isn't a decl ref, give up.
     if (!isa<DeclRefExpr>(op)) {

lib/Sema/SemaInit.cpp

InitializedEntityOutlivesFullExpression(const InitializedEntity &Entity) {
   }
 
   llvm_unreachable("unknown entity kind");
 }
 
 /// Determine the declaration which an initialized entity ultimately refers to,
 /// for the purpose of lifetime-extending a temporary bound to a reference in
 /// the initialization of \p Entity.
-static const ValueDecl *
-getDeclForTemporaryLifetimeExtension(const InitializedEntity &Entity,
-                                     const ValueDecl *FallbackDecl = 0) {
+static const InitializedEntity *getEntityForTemporaryLifetimeExtension(
+    const InitializedEntity *Entity,
+    const InitializedEntity *FallbackDecl = 0) {
   // C++11 [class.temporary]p5:
-  switch (Entity.getKind()) {
+  switch (Entity->getKind()) {
   case InitializedEntity::EK_Variable:
     //   The temporary [...] persists for the lifetime of the reference
-    return Entity.getDecl();
+    return Entity;
 
   case InitializedEntity::EK_Member:
     // For subobjects, we look at the complete object.
-    if (Entity.getParent())
-      return getDeclForTemporaryLifetimeExtension(*Entity.getParent(),
-                                                  Entity.getDecl());
+    if (Entity->getParent())
+      return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
+                                                    Entity);
 
     //   except:
     //   -- A temporary bound to a reference member in a constructor's
     //      ctor-initializer persists until the constructor exits.
-    return Entity.getDecl();
+    return Entity;
 
   case InitializedEntity::EK_Parameter:
   case InitializedEntity::EK_Parameter_CF_Audited:
     //   -- A temporary bound to a reference parameter in a function call
     //      persists until the completion of the full-expression containing
     //      the call.
   case InitializedEntity::EK_Result:
     //   -- The lifetime of a temporary bound to the returned value in a
     //      function return statement is not extended; the temporary is
     //      destroyed at the end of the full-expression in the return statement.
   case InitializedEntity::EK_New:
     //   -- A temporary bound to a reference in a new-initializer persists
     //      until the completion of the full-expression containing the
     //      new-initializer.
-    return 0;
+    return nullptr;
 
   case InitializedEntity::EK_Temporary:
   case InitializedEntity::EK_CompoundLiteralInit:
   case InitializedEntity::EK_RelatedResult:
     // We don't yet know the storage duration of the surrounding temporary.
     // Assume it's got full-expression duration for now, it will patch up our
     // storage duration if that's not correct.
-    return 0;
+    return nullptr;
 
   case InitializedEntity::EK_ArrayElement:
     // For subobjects, we look at the complete object.
-    return getDeclForTemporaryLifetimeExtension(*Entity.getParent(),
+    return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
                                                   FallbackDecl);
 
   case InitializedEntity::EK_Base:
   case InitializedEntity::EK_Delegating:
     // We can reach this case for aggregate initialization in a constructor:
     //   struct A { int &&r; };
     //   struct B : A { B() : A{0} {} };
     // In this case, use the innermost field decl as the context.
     return FallbackDecl;
 
   case InitializedEntity::EK_BlockElement:
   case InitializedEntity::EK_LambdaCapture:
   case InitializedEntity::EK_Exception:
   case InitializedEntity::EK_VectorElement:
   case InitializedEntity::EK_ComplexElement:
-    return 0;
+    return nullptr;
   }
   llvm_unreachable("unknown entity kind");
 }
 
-static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD);
+static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD,
+                                     unsigned &ManglingNumber);
 
 /// Update a glvalue expression that is used as the initializer of a reference
 /// to note that its lifetime is extended.
 /// \return \c true if any temporary had its lifetime extended.
-static bool performReferenceExtension(Expr *Init, const ValueDecl *ExtendingD) {
+static bool performReferenceExtension(Expr *Init, const ValueDecl *ExtendingD,
+                                      unsigned &ManglingNumber) {
   if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
     if (ILE->getNumInits() == 1 && ILE->isGLValue()) {
       // This is just redundant braces around an initializer. Step over it.
       Init = ILE->getInit(0);
     }
   }
 
   // Walk past any constructs which we can lifetime-extend across.
do {
     // FIXME: Per DR1213, subscripting on an array temporary produces an xvalue.
     // It's unclear if binding a reference to that xvalue extends the array
     // temporary.
   } while (Init != Old);
 
   if (MaterializeTemporaryExpr *ME = dyn_cast<MaterializeTemporaryExpr>(Init)) {
     // Update the storage duration of the materialized temporary.
     // FIXME: Rebuild the expression instead of mutating it.
-    ME->setExtendingDecl(ExtendingD);
-    performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingD);
+    ME->setExtendingDecl(ExtendingD, ManglingNumber);
+    ++ManglingNumber;
+    performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingD,
+                             ManglingNumber);
     return true;
   }
 
   return false;
 }
 
 /// Update a prvalue expression that is going to be materialized as a
 /// lifetime-extended temporary.
-static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD) {
+static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD,
+                                     unsigned &ManglingNumber) {
   // Dig out the expression which constructs the extended temporary.
   SmallVector<const Expr *, 2> CommaLHSs;
   SmallVector<SubobjectAdjustment, 2> Adjustments;
   Init = const_cast<Expr *>(
       Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments));
 
   if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
     Init = BTE->getSubExpr();
 
   if (CXXStdInitializerListExpr *ILE =
           dyn_cast<CXXStdInitializerListExpr>(Init)) {
-    performReferenceExtension(ILE->getSubExpr(), ExtendingD);
+    performReferenceExtension(ILE->getSubExpr(), ExtendingD, ManglingNumber);
     return;
   }
 
   if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
     if (ILE->getType()->isArrayType()) {
       for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
-        performLifetimeExtension(ILE->getInit(I), ExtendingD);
+        performLifetimeExtension(ILE->getInit(I), ExtendingD, ManglingNumber);
       return;
     }
 
     if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) {
       assert(RD->isAggregate() && "aggregate init on non-aggregate");
 
       // If we lifetime-extend a braced initializer which is initializing an
       // aggregate, and that aggregate contains reference members which are
       // bound to temporaries, those temporaries are also lifetime-extended.
       if (RD->isUnion() && ILE->getInitializedFieldInUnion() &&
           ILE->getInitializedFieldInUnion()->getType()->isReferenceType())
-        performReferenceExtension(ILE->getInit(0), ExtendingD);
+        performReferenceExtension(ILE->getInit(0), ExtendingD, ManglingNumber);
       else {
         unsigned Index = 0;
         for (const auto *I : RD->fields()) {
           if (Index >= ILE->getNumInits())
             break;
           if (I->isUnnamedBitfield())
             continue;
           Expr *SubInit = ILE->getInit(Index);
           if (I->getType()->isReferenceType())
-            performReferenceExtension(SubInit, ExtendingD);
+            performReferenceExtension(SubInit, ExtendingD, ManglingNumber);
           else if (isa<InitListExpr>(SubInit) ||
                    isa<CXXStdInitializerListExpr>(SubInit))
             // This may be either aggregate-initialization of a member or
             // initialization of a std::initializer_list object. Either way,
             // we should recursively lifetime-extend that initializer.
-            performLifetimeExtension(SubInit, ExtendingD);
+            performLifetimeExtension(SubInit, ExtendingD, ManglingNumber);
           ++Index;
         }
       }
     }
   }
 }
 
 static void warnOnLifetimeExtension(Sema &S, const InitializedEntity &Entity,
case SK_BindReference:
 
       // Check exception specifications
       if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
         return ExprError();
 
       // Even though we didn't materialize a temporary, the binding may still
       // extend the lifetime of a temporary. This happens if we bind a reference
       // to the result of a cast to reference type.
-      if (const ValueDecl *ExtendingDecl =
-              getDeclForTemporaryLifetimeExtension(Entity)) {
-        if (performReferenceExtension(CurInit.get(), ExtendingDecl))
+      if (const InitializedEntity *ExtendingEntity =
+              getEntityForTemporaryLifetimeExtension(&Entity)) {
+        const ValueDecl *ExtendingDecl = ExtendingEntity->getDecl();
+        if (performReferenceExtension(CurInit.get(), ExtendingDecl,
+                                      ExtendingEntity->getManglingNumber()))
           warnOnLifetimeExtension(S, Entity, CurInit.get(), false,
                                   ExtendingDecl);
       }
 
       break;
 
     case SK_BindReferenceToTemporary: {
       // Make sure the "temporary" is actually an rvalue.
       assert(CurInit.get()->isRValue() && "not a temporary");
 
       // Check exception specifications
       if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
         return ExprError();
 
+      unsigned ManglingNumber = 1;
+      const ValueDecl *ExtendingDecl = nullptr;
+
       // Maybe lifetime-extend the temporary's subobjects to match the
       // entity's lifetime.
-      const ValueDecl *ExtendingDecl =
-          getDeclForTemporaryLifetimeExtension(Entity);
-      if (ExtendingDecl) {
-        performLifetimeExtension(CurInit.get(), ExtendingDecl);
+      const InitializedEntity *ExtendingEntity =
+          getEntityForTemporaryLifetimeExtension(&Entity);
+      if (ExtendingEntity) {
+        unsigned &ExtendingEntityManglingNumber =
+            ExtendingEntity->getManglingNumber();
+        ManglingNumber = ExtendingEntityManglingNumber++;
+
+        ExtendingDecl = ExtendingEntity->getDecl();
+        performLifetimeExtension(CurInit.get(), ExtendingDecl,
+                                 ExtendingEntityManglingNumber);
         warnOnLifetimeExtension(S, Entity, CurInit.get(), false, ExtendingDecl);
       }
 
       // Materialize the temporary into memory.
       MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr(
           Entity.getType().getNonReferenceType(), CurInit.get(),
-          Entity.getType()->isLValueReferenceType(), ExtendingDecl);
+          Entity.getType()->isLValueReferenceType(), ExtendingDecl,
+          ManglingNumber);
 
       // If we're binding to an Objective-C object that has lifetime, we
       // need cleanups. Likewise if we're extending this temporary to automatic
       // storage duration -- we need to register its cleanup during the
       // full-expression's cleanups.
       if ((S.getLangOpts().ObjCAutoRefCount &&
            MTE->getType()->isObjCLifetimeType()) ||
           (MTE->getStorageDuration() == SD_Automatic &&
case SK_ProduceObjCObject:
                                                  CurInit.take(), 0, VK_RValue));
       break;
 
     case SK_StdInitializerList: {
       S.Diag(CurInit.get()->getExprLoc(),
              diag::warn_cxx98_compat_initializer_list_init)
         << CurInit.get()->getSourceRange();
 
+      unsigned ManglingNumber = 1;
+      const ValueDecl *ExtendingDecl = nullptr;
+
       // Maybe lifetime-extend the array temporary's subobjects to match the
       // entity's lifetime.
-      const ValueDecl *ExtendingDecl =
-          getDeclForTemporaryLifetimeExtension(Entity);
-      if (ExtendingDecl) {
-        performLifetimeExtension(CurInit.get(), ExtendingDecl);
+      const InitializedEntity *ExtendingEntity =
+          getEntityForTemporaryLifetimeExtension(&Entity);
+      if (ExtendingEntity) {
+        unsigned &ExtendingEntityManglingNumber =
+            ExtendingEntity->getManglingNumber();
+        ManglingNumber = ExtendingEntityManglingNumber++;
+
+        ExtendingDecl = ExtendingEntity->getDecl();
+        performLifetimeExtension(CurInit.get(), ExtendingDecl,
+                                 ExtendingEntityManglingNumber);
         warnOnLifetimeExtension(S, Entity, CurInit.get(), true, ExtendingDecl);
       }
 
       // Materialize the temporary into memory.
       MaterializeTemporaryExpr *MTE = new (S.Context)
           MaterializeTemporaryExpr(CurInit.get()->getType(), CurInit.get(),
-                                   /*lvalue reference*/ false, ExtendingDecl);
+                                   /*BoundToLvalueReference=*/false,
+                                   ExtendingDecl, ManglingNumber);
 
       // Wrap it in a construction of a std::initializer_list<T>.
       CurInit = S.Owned(
           new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE));
 
       // Bind the result, in case the library has given initializer_list a
       // non-trivial destructor.
       if (shouldBindAsTemporary(Entity))

lib/Serialization/ASTReaderStmt.cpp

void ASTStmtReader::VisitFunctionParmPackExpr(FunctionParmPackExpr *E) {
   E->NameLoc = ReadSourceLocation(Record, Idx);
   ParmVarDecl **Parms = reinterpret_cast<ParmVarDecl**>(E+1);
   for (unsigned i = 0, n = E->NumParameters; i != n; ++i)
     Parms[i] = ReadDeclAs<ParmVarDecl>(Record, Idx);
 }
 
 void ASTStmtReader::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) {
   VisitExpr(E);
-  E->Temporary = Reader.ReadSubExpr();
-  E->ExtendingDecl = ReadDeclAs<ValueDecl>(Record, Idx);
+  E->State = Reader.ReadSubExpr();
+  auto VD = ReadDeclAs<ValueDecl>(Record, Idx);
+  unsigned ManglingNumber = Record[Idx++];
+  E->initializeExtraState(VD, ManglingNumber);
 }
 
 void ASTStmtReader::VisitOpaqueValueExpr(OpaqueValueExpr *E) {
   VisitExpr(E);
   E->SourceExpr = Reader.ReadSubExpr();
   E->Loc = ReadSourceLocation(Record, Idx);
 }
 

lib/Serialization/ASTWriterStmt.cpp

void ASTStmtWriter::VisitFunctionParmPackExpr(FunctionParmPackExpr *E) {
   Writer.AddSourceLocation(E->getParameterPackLocation(), Record);
   for (FunctionParmPackExpr::iterator I = E->begin(), End = E->end();
        I != End; ++I)
     Writer.AddDeclRef(*I, Record);
   Code = serialization::EXPR_FUNCTION_PARM_PACK;
 }
 
 void ASTStmtWriter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) {
   VisitExpr(E);
-  Writer.AddStmt(E->Temporary);
-  Writer.AddDeclRef(E->ExtendingDecl, Record);
+  Writer.AddStmt(E->getTemporary());
+  Writer.AddDeclRef(E->getExtendingDecl(), Record);
+  Record.push_back(E->getManglingNumber());
   Code = serialization::EXPR_MATERIALIZE_TEMPORARY;
 }
 
 void ASTStmtWriter::VisitOpaqueValueExpr(OpaqueValueExpr *E) {
   VisitExpr(E);
   Writer.AddStmt(E->getSourceExpr());
   Writer.AddSourceLocation(E->getLocation(), Record);
   Code = serialization::EXPR_OPAQUE_VALUE;
 }

test/CodeGenCXX/const-init-cxx1y.cpp

 // CHECK: @_ZGRN34HiddenVariableTemplateWithConstRef1iIvEE = linkonce_odr hidden constant i32 5, align 4
 // CHECK: @_ZN34HiddenVariableTemplateWithConstRef3useE = constant i32* @_ZGRN34HiddenVariableTemplateWithConstRef1iIvEE
 namespace HiddenVariableTemplateWithConstRef {
   template <typename T>
   __attribute__((visibility("hidden"))) const int &i = 5;
   const int &use = i<void>;
 }
 
-// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE = linkonce_odr constant i32 1
-// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE2 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE }
+// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE1 = linkonce_odr constant i32 1
+// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE0 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE1 }
 // CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE3 = linkonce_odr constant i32 2
-// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE4 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE3 }
+// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE2 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE3 }
 // CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE5 = linkonce_odr constant i32 3
-// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE6 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE5 }
+// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE4 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE5 }
 // CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE7 = linkonce_odr constant i32 4
-// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE8 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE7 }
-// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE9 = linkonce_odr global {{.*}} { {{.*}} @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE2, {{.*}} @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE4, {{.*}} @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE6, {{.*}} @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE8 }
-// CHECK: @_ZN24VariableTemplateWithPack1pE = global {{.*}} @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE9
+// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE6 = linkonce_odr global {{.*}} { i32* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE7 }
+// CHECK: @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE = linkonce_odr global %"struct.VariableTemplateWithPack::S" { {{.*}}* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE0, {{.*}}* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE2, {{.*}}* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE4, {{.*}}* @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE6 }
+// CHECK: @_ZN24VariableTemplateWithPack1pE = global {{.*}} @_ZGRN24VariableTemplateWithPack1sIJLi1ELi2ELi3ELi4EEEE
 namespace VariableTemplateWithPack {
   struct A {
     const int &r;
   };
   struct S {
     A &&a, &&b, &&c, &&d;
   };
   template <int... N>

test/CodeGenCXX/cxx0x-initializer-stdinitializerlist-pr12086.cpp

#endif
   };
 }
 
 constexpr int a = 2, b = 4, c = 6;
 std::initializer_list<std::initializer_list<int>> nested = {
   {1, a}, {3, b}, {5, c}
 };
 
-// CHECK-STATIC-BL: @_ZGR6nested = private constant [2 x i32] [i32 1, i32 2], align 4
+// CHECK-STATIC-BL: @_ZGR6nested0 = private constant [2 x i32] [i32 1, i32 2], align 4
 // CHECK-STATIC-BL: @_ZGR6nested1 = private constant [2 x i32] [i32 3, i32 4], align 4
 // CHECK-STATIC-BL: @_ZGR6nested2 = private constant [2 x i32] [i32 5, i32 6], align 4
-// CHECK-STATIC-BL: @_ZGR6nested3 = private constant [3 x {{.*}}] [
-// CHECK-STATIC-BL:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested, i32 0, i32 0), i64 2 },
+// CHECK-STATIC-BL: @_ZGR6nested = private constant [3 x {{.*}}] [
+// CHECK-STATIC-BL:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i32 0, i32 0), i64 2 },
 // CHECK-STATIC-BL:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i32 0, i32 0), i64 2 },
 // CHECK-STATIC-BL:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i32 0, i32 0), i64 2 }
 // CHECK-STATIC-BL: ], align 8
-// CHECK-STATIC-BL: @nested = global {{.*}} { {{.*}} getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested3, i32 0, i32 0), i64 3 }, align 8
+// CHECK-STATIC-BL: @nested = global {{.*}} { {{.*}} getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i32 0, i32 0), i64 3 }, align 8
 
 // CHECK-DYNAMIC-BL: @nested = global
 // CHECK-DYNAMIC-BL: @_ZGR6nested = private global [3 x
+// CHECK-DYNAMIC-BL: @_ZGR6nested0 = private global [2 x i32] zeroinitializer
 // CHECK-DYNAMIC-BL: @_ZGR6nested1 = private global [2 x i32] zeroinitializer
 // CHECK-DYNAMIC-BL: @_ZGR6nested2 = private global [2 x i32] zeroinitializer
-// CHECK-DYNAMIC-BL: @_ZGR6nested3 = private global [2 x i32] zeroinitializer
-// CHECK-DYNAMIC-BL: store i32 1, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0)
-// CHECK-DYNAMIC-BL: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 1)
-// CHECK-DYNAMIC-BL: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0),
+// CHECK-DYNAMIC-BL: store i32 1, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 0, i64 0)
+// CHECK-DYNAMIC-BL: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 0, i64 1)
+// CHECK-DYNAMIC-BL: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 0, i64 0),
 // CHECK-DYNAMIC-BL:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0, i32 0), align 8
 // CHECK-DYNAMIC-BL: store i64 2, i64* getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0, i32 1), align 8
-// CHECK-DYNAMIC-BL: store i32 3, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0)
-// CHECK-DYNAMIC-BL: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 1)
-// CHECK-DYNAMIC-BL: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0),
+// CHECK-DYNAMIC-BL: store i32 3, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0)
+// CHECK-DYNAMIC-BL: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 1)
+// CHECK-DYNAMIC-BL: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0),
 // CHECK-DYNAMIC-BL:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 1, i32 0), align 8
 // CHECK-DYNAMIC-BL: store i64 2, i64* getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 1, i32 1), align 8
-// CHECK-DYNAMIC-BL: store i32 5, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 0, i64 0)
-// CHECK-DYNAMIC-BL: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 0, i64 1)
-// CHECK-DYNAMIC-BL: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 0, i64 0),
+// CHECK-DYNAMIC-BL: store i32 5, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0)
+// CHECK-DYNAMIC-BL: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 1)
+// CHECK-DYNAMIC-BL: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0),
 // CHECK-DYNAMIC-BL:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 2, i32 0), align 8
 // CHECK-DYNAMIC-BL: store i64 2, i64* getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 2, i32 1), align 8
 // CHECK-DYNAMIC-BL: store {{.*}}* getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0),
 // CHECK-DYNAMIC-BL:       {{.*}}** getelementptr inbounds ({{.*}}* @nested, i32 0, i32 0), align 8
 // CHECK-DYNAMIC-BL: store i64 3, i64* getelementptr inbounds ({{.*}}* @nested, i32 0, i32 1), align 8
 
-// CHECK-STATIC-BE: @_ZGR6nested = private constant [2 x i32] [i32 1, i32 2], align 4
+// CHECK-STATIC-BE: @_ZGR6nested0 = private constant [2 x i32] [i32 1, i32 2], align 4
 // CHECK-STATIC-BE: @_ZGR6nested1 = private constant [2 x i32] [i32 3, i32 4], align 4
 // CHECK-STATIC-BE: @_ZGR6nested2 = private constant [2 x i32] [i32 5, i32 6], align 4
-// CHECK-STATIC-BE: @_ZGR6nested3 = private constant [3 x {{.*}}] [
-// CHECK-STATIC-BE:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested, i32 0, i32 0),
-// CHECK-STATIC-BE:            i32* bitcast (i8* getelementptr (i8* bitcast ([2 x i32]* @_ZGR6nested to i8*), i64 8) to i32*) }
+// CHECK-STATIC-BE: @_ZGR6nested = private constant [3 x {{.*}}] [
+// CHECK-STATIC-BE:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i32 0, i32 0),
+// CHECK-STATIC-BE:            i32* bitcast (i8* getelementptr (i8* bitcast ([2 x i32]* @_ZGR6nested0 to i8*), i64 8) to i32*) }
 // CHECK-STATIC-BE:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i32 0, i32 0),
 // CHECK-STATIC-BE:            i32* bitcast (i8* getelementptr (i8* bitcast ([2 x i32]* @_ZGR6nested1 to i8*), i64 8) to i32*) }
 // CHECK-STATIC-BE:   {{.*}} { i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i32 0, i32 0),
 // CHECK-STATIC-BE:            i32* bitcast (i8* getelementptr (i8* bitcast ([2 x i32]* @_ZGR6nested2 to i8*), i64 8) to i32*) }
 // CHECK-STATIC-BE: ], align 8
-// CHECK-STATIC-BE: @nested = global {{.*}} { {{.*}} getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested3, i32 0, i32 0),
-// CHECK-STATIC-BE:                           {{.*}} bitcast ({{.*}}* getelementptr (i8* bitcast ([3 x {{.*}}]* @_ZGR6nested3 to i8*), i64 48) to {{.*}}*) }
+// CHECK-STATIC-BE: @nested = global {{.*}} { {{.*}} getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i32 0, i32 0),
+// CHECK-STATIC-BE:                           {{.*}} bitcast ({{.*}}* getelementptr (i8* bitcast ([3 x {{.*}}]* @_ZGR6nested to i8*), i64 48) to {{.*}}*) }
 
 // CHECK-DYNAMIC-BE: @nested = global
 // CHECK-DYNAMIC-BE: @_ZGR6nested = private global [3 x
+// CHECK-DYNAMIC-BE: @_ZGR6nested0 = private global [2 x i32] zeroinitializer
 // CHECK-DYNAMIC-BE: @_ZGR6nested1 = private global [2 x i32] zeroinitializer
 // CHECK-DYNAMIC-BE: @_ZGR6nested2 = private global [2 x i32] zeroinitializer
-// CHECK-DYNAMIC-BE: @_ZGR6nested3 = private global [2 x i32] zeroinitializer
-// CHECK-DYNAMIC-BE: store i32 1, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0)
+// CHECK-DYNAMIC-BE: store i32 1, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 0, i64 0)
+// CHECK-DYNAMIC-BE: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 0, i64 1)
+// CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 0, i64 0),
+// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0, i32 0), align 8
+// CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested0, i64 1, i64 0),
+// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0, i32 1), align 8
+// CHECK-DYNAMIC-BE: store i32 3, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0)
 // CHECK-DYNAMIC-BE: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 1)
 // CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 0, i64 0),
-// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0, i32 0), align 8
+// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 1, i32 0), align 8
 // CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested1, i64 1, i64 0),
-// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0, i32 1), align 8
-// CHECK-DYNAMIC-BE: store i32 3, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0)
+// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 1, i32 1), align 8
+// CHECK-DYNAMIC-BE: store i32 5, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0)
 // CHECK-DYNAMIC-BE: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 1)
 // CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 0, i64 0),
-// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 1, i32 0), align 8
-// CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 1, i64 0),
-// CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 1, i32 1), align 8
-// CHECK-DYNAMIC-BE: store i32 5, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 0, i64 0)
-// CHECK-DYNAMIC-BE: store i32 {{.*}}, i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 0, i64 1)
-// CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 0, i64 0),
 // CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 2, i32 0), align 8
-// CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested3, i64 1, i64 0),
+// CHECK-DYNAMIC-BE: store i32* getelementptr inbounds ([2 x i32]* @_ZGR6nested2, i64 1, i64 0),
 // CHECK-DYNAMIC-BE:       i32** getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 2, i32 1), align 8
 // CHECK-DYNAMIC-BE: store {{.*}}* getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 0, i64 0),
 // CHECK-DYNAMIC-BE:       {{.*}}** getelementptr inbounds ({{.*}}* @nested, i32 0, i32 0), align 8
 // CHECK-DYNAMIC-BE: store {{.*}}* getelementptr inbounds ([3 x {{.*}}]* @_ZGR6nested, i64 1, i64 0),
 // CHECK-DYNAMIC-BE:       {{.*}}** getelementptr inbounds ({{.*}}* @nested, i32 0, i32 1), align 8