PR12086, PR15117

Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).

This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.

llvm-svn: 183872

23 files changed, 291 insertions, 470 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index db4269bf163..ecd147aebe3 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1789,7 +1789,6 @@ InitListExpr::InitListExpr(ASTContext &C, SourceLocation lbraceloc,
     LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), AltForm(0, true)
 {
   sawArrayRangeDesignator(false);
-  setInitializesStdInitializerList(false);
   for (unsigned I = 0; I != initExprs.size(); ++I) {
     if (initExprs[I]->isTypeDependent())
       ExprBits.TypeDependent = true;
@@ -2836,6 +2835,7 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const {
   case DesignatedInitExprClass:
   case ParenListExprClass:
   case CXXPseudoDestructorExprClass:
+  case CXXStdInitializerListExprClass:
   case SubstNonTypeTemplateParmExprClass:
   case MaterializeTemporaryExprClass:
   case ShuffleVectorExprClass:
diff --git a/clang/lib/AST/ExprClassification.cpp b/clang/lib/AST/ExprClassification.cpp
index bcb6d4e809b..12510d68830 100644
--- a/clang/lib/AST/ExprClassification.cpp
+++ b/clang/lib/AST/ExprClassification.cpp
@@ -353,6 +353,7 @@ static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
   case Expr::CXXConstructExprClass:
   case Expr::CXXTemporaryObjectExprClass:
   case Expr::LambdaExprClass:
+  case Expr::CXXStdInitializerListExprClass:
     return Cl::CL_ClassTemporary;
 
   case Expr::VAArgExprClass:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index d94efc13413..21fb4599664 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -4576,6 +4576,7 @@ namespace {
     bool VisitCastExpr(const CastExpr *E);
     bool VisitInitListExpr(const InitListExpr *E);
     bool VisitCXXConstructExpr(const CXXConstructExpr *E);
+    bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E);
   };
 }
 
@@ -4691,10 +4692,6 @@ bool RecordExprEvaluator::VisitCastExpr(const CastExpr *E) {
 }
 
 bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
-  // Cannot constant-evaluate std::initializer_list inits.
-  if (E->initializesStdInitializerList())
-    return false;
-
   const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
   if (RD->isInvalidDecl()) return false;
   const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
@@ -4810,6 +4807,58 @@ bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
                                Result);
 }
 
+bool RecordExprEvaluator::VisitCXXStdInitializerListExpr(
+    const CXXStdInitializerListExpr *E) {
+  const ConstantArrayType *ArrayType =
+      Info.Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
+
+  LValue Array;
+  if (!EvaluateLValue(E->getSubExpr(), Array, Info))
+    return false;
+
+  // Get a pointer to the first element of the array.
+  Array.addArray(Info, E, ArrayType);
+
+  // FIXME: Perform the checks on the field types in SemaInit.
+  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
+  RecordDecl::field_iterator Field = Record->field_begin();
+  if (Field == Record->field_end())
+    return Error(E);
+
+  // Start pointer.
+  if (!Field->getType()->isPointerType() ||
+      !Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
+                            ArrayType->getElementType()))
+    return Error(E);
+
+  // FIXME: What if the initializer_list type has base classes, etc?
+  Result = APValue(APValue::UninitStruct(), 0, 2);
+  Array.moveInto(Result.getStructField(0));
+
+  if (++Field == Record->field_end())
+    return Error(E);
+
+  if (Field->getType()->isPointerType() &&
+      Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
+                           ArrayType->getElementType())) {
+    // End pointer.
+    if (!HandleLValueArrayAdjustment(Info, E, Array,
+                                     ArrayType->getElementType(),
+                                     ArrayType->getSize().getZExtValue()))
+      return false;
+    Array.moveInto(Result.getStructField(1));
+  } else if (Info.Ctx.hasSameType(Field->getType(), Info.Ctx.getSizeType()))
+    // Length.
+    Result.getStructField(1) = APValue(APSInt(ArrayType->getSize()));
+  else
+    return Error(E);
+
+  if (++Field != Record->field_end())
+    return Error(E);
+
+  return true;
+}
+
 static bool EvaluateRecord(const Expr *E, const LValue &This,
                            APValue &Result, EvalInfo &Info) {
   assert(E->isRValue() && E->getType()->isRecordType() &&
@@ -7762,6 +7811,7 @@ static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
   case Expr::UnresolvedLookupExprClass:
   case Expr::DependentScopeDeclRefExprClass:
   case Expr::CXXConstructExprClass:
+  case Expr::CXXStdInitializerListExprClass:
   case Expr::CXXBindTemporaryExprClass:
   case Expr::ExprWithCleanupsClass:
   case Expr::CXXTemporaryObjectExprClass:
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 3137f3c8fdc..20f699fafb4 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -2481,6 +2481,10 @@ recurse:
     mangleExpression(cast<CXXDefaultInitExpr>(E)->getExpr(), Arity);
     break;
 
+  case Expr::CXXStdInitializerListExprClass:
+    mangleExpression(cast<CXXStdInitializerListExpr>(E)->getSubExpr(), Arity);
+    break;
+
   case Expr::SubstNonTypeTemplateParmExprClass:
     mangleExpression(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(),
                      Arity);
diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
index 467413bfb20..d6358023907 100644
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -1534,6 +1534,10 @@ void StmtPrinter::VisitCXXConstructExpr(CXXConstructExpr *E) {
     OS << " }";
 }
 
+void StmtPrinter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
+  PrintExpr(E->getSubExpr());
+}
+
 void StmtPrinter::VisitExprWithCleanups(ExprWithCleanups *E) {
   // Just forward to the sub expression.
   PrintExpr(E->getSubExpr());
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index 4a3448c1e5f..391c1e60abe 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -758,6 +758,11 @@ void StmtProfiler::VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *S) {
   VisitExpr(S);
 }
 
+void StmtProfiler::VisitCXXStdInitializerListExpr(
+    const CXXStdInitializerListExpr *S) {
+  VisitExpr(S);
+}
+
 void StmtProfiler::VisitCXXTypeidExpr(const CXXTypeidExpr *S) {
   VisitExpr(S);
   if (S->isTypeOperand())
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index b3a14772ad0..9d08d1c7f7a 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -433,52 +433,45 @@ static void EmitAggMemberInitializer(CodeGenFunction &CGF,
                                      unsigned Index) {
   if (Index == ArrayIndexes.size()) {
     LValue LV = LHS;
-    { // Scope for Cleanups.
-      CodeGenFunction::RunCleanupsScope Cleanups(CGF);
-
-      if (ArrayIndexVar) {
-        // If we have an array index variable, load it and use it as an offset.
-        // Then, increment the value.
-        llvm::Value *Dest = LHS.getAddress();
-        llvm::Value *ArrayIndex = CGF.Builder.CreateLoad(ArrayIndexVar);
-        Dest = CGF.Builder.CreateInBoundsGEP(Dest, ArrayIndex, "destaddress");
-        llvm::Value *Next = llvm::ConstantInt::get(ArrayIndex->getType(), 1);
-        Next = CGF.Builder.CreateAdd(ArrayIndex, Next, "inc");
-        CGF.Builder.CreateStore(Next, ArrayIndexVar);    
-
-        // Update the LValue.
-        LV.setAddress(Dest);
-        CharUnits Align = CGF.getContext().getTypeAlignInChars(T);
-        LV.setAlignment(std::min(Align, LV.getAlignment()));
-      }
 
-      switch (CGF.getEvaluationKind(T)) {
-      case TEK_Scalar:
-        CGF.EmitScalarInit(Init, /*decl*/ 0, LV, false);
-        break;
-      case TEK_Complex:
-        CGF.EmitComplexExprIntoLValue(Init, LV, /*isInit*/ true);
-        break;
-      case TEK_Aggregate: {
-        AggValueSlot Slot =
-          AggValueSlot::forLValue(LV,
-                                  AggValueSlot::IsDestructed,
-                                  AggValueSlot::DoesNotNeedGCBarriers,
-                                  AggValueSlot::IsNotAliased);
-
-        CGF.EmitAggExpr(Init, Slot);
-        break;
-      }
-      }
+    if (ArrayIndexVar) {
+      // If we have an array index variable, load it and use it as an offset.
+      // Then, increment the value.
+      llvm::Value *Dest = LHS.getAddress();
+      llvm::Value *ArrayIndex = CGF.Builder.CreateLoad(ArrayIndexVar);
+      Dest = CGF.Builder.CreateInBoundsGEP(Dest, ArrayIndex, "destaddress");
+      llvm::Value *Next = llvm::ConstantInt::get(ArrayIndex->getType(), 1);
+      Next = CGF.Builder.CreateAdd(ArrayIndex, Next, "inc");
+      CGF.Builder.CreateStore(Next, ArrayIndexVar);
+
+      // Update the LValue.
+      LV.setAddress(Dest);
+      CharUnits Align = CGF.getContext().getTypeAlignInChars(T);
+      LV.setAlignment(std::min(Align, LV.getAlignment()));
     }
 
-    // Now, outside of the initializer cleanup scope, destroy the backing array
-    // for a std::initializer_list member.
-    CGF.MaybeEmitStdInitializerListCleanup(LV.getAddress(), Init);
+    switch (CGF.getEvaluationKind(T)) {
+    case TEK_Scalar:
+      CGF.EmitScalarInit(Init, /*decl*/ 0, LV, false);
+      break;
+    case TEK_Complex:
+      CGF.EmitComplexExprIntoLValue(Init, LV, /*isInit*/ true);
+      break;
+    case TEK_Aggregate: {
+      AggValueSlot Slot =
+        AggValueSlot::forLValue(LV,
+                                AggValueSlot::IsDestructed,
+                                AggValueSlot::DoesNotNeedGCBarriers,
+                                AggValueSlot::IsNotAliased);
+
+      CGF.EmitAggExpr(Init, Slot);
+      break;
+    }
+    }
 
     return;
   }
-  
+
   const ConstantArrayType *Array = CGF.getContext().getAsConstantArrayType(T);
   assert(Array && "Array initialization without the array type?");
   llvm::Value *IndexVar
@@ -512,16 +505,12 @@ static void EmitAggMemberInitializer(CodeGenFunction &CGF,
 
   CGF.EmitBlock(ForBody);
   llvm::BasicBlock *ContinueBlock = CGF.createBasicBlock("for.inc");
-  
-  {
-    CodeGenFunction::RunCleanupsScope Cleanups(CGF);
-    
-    // Inside the loop body recurse to emit the inner loop or, eventually, the
-    // constructor call.
-    EmitAggMemberInitializer(CGF, LHS, Init, ArrayIndexVar,
-                             Array->getElementType(), ArrayIndexes, Index + 1);
-  }
-  
+
+  // Inside the loop body recurse to emit the inner loop or, eventually, the
+  // constructor call.
+  EmitAggMemberInitializer(CGF, LHS, Init, ArrayIndexVar,
+                           Array->getElementType(), ArrayIndexes, Index + 1);
+
   CGF.EmitBlock(ContinueBlock);
 
   // Emit the increment of the loop counter.
@@ -726,7 +715,7 @@ void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) {
   if (IsTryBody)
     EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true);
 
-  EHScopeStack::stable_iterator CleanupDepth = EHStack.stable_begin();
+  RunCleanupsScope RunCleanups(*this);
 
   // TODO: in restricted cases, we can emit the vbase initializers of
   // a complete ctor and then delegate to the base ctor.
@@ -745,7 +734,7 @@ void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) {
   // initializers, which includes (along the exceptional path) the
   // destructors for those members and bases that were fully
   // constructed.
-  PopCleanupBlocks(CleanupDepth);
+  RunCleanups.ForceCleanup();
 
   if (IsTryBody)
     ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true);
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 7fc79e08f0f..4d14014f9c9 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -1187,7 +1187,6 @@ void CodeGenFunction::EmitExprAsInit(const Expr *init,
                                          AggValueSlot::DoesNotNeedGCBarriers,
                                               AggValueSlot::IsNotAliased));
     }
-    MaybeEmitStdInitializerListCleanup(lvalue.getAddress(), init);
     return;
   }
   llvm_unreachable("bad evaluation kind");
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index d534ff440cf..f88da33fbf5 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -240,15 +240,6 @@ pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
     }
   }
 
-  if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E)) {
-    if (ILE->initializesStdInitializerList()) {
-      // FIXME: This is wrong if the temporary has static or thread storage
-      // duration.
-      CGF.EmitStdInitializerListCleanup(ReferenceTemporary, ILE);
-      return;
-    }
-  }
-
   CXXDestructorDecl *ReferenceTemporaryDtor = 0;
   if (const RecordType *RT =
           E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index f8b19d686b2..f3eb34567bd 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -91,7 +91,6 @@ public:
 
   void EmitMoveFromReturnSlot(const Expr *E, RValue Src);
 
-  void EmitStdInitializerList(llvm::Value *DestPtr, InitListExpr *InitList);
   void EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType,
                      QualType elementType, InitListExpr *E);
 
@@ -177,6 +176,7 @@ public:
   void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
   void VisitCXXConstructExpr(const CXXConstructExpr *E);
   void VisitLambdaExpr(LambdaExpr *E);
+  void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E);
   void VisitExprWithCleanups(ExprWithCleanups *E);
   void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
   void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
@@ -345,89 +345,70 @@ void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
                         std::min(dest.getAlignment(), src.getAlignment()));
 }
 
-static QualType GetStdInitializerListElementType(QualType T) {
-  // Just assume that this is really std::initializer_list.
-  ClassTemplateSpecializationDecl *specialization =
-      cast<ClassTemplateSpecializationDecl>(T->castAs<RecordType>()->getDecl());
-  return specialization->getTemplateArgs()[0].getAsType();
-}
-
-/// \brief Prepare cleanup for the temporary array.
-static void EmitStdInitializerListCleanup(CodeGenFunction &CGF,
-                                          QualType arrayType,
-                                          llvm::Value *addr,
-                                          const InitListExpr *initList) {
-  QualType::DestructionKind dtorKind = arrayType.isDestructedType();
-  if (!dtorKind)
-    return; // Type doesn't need destroying.
-  if (dtorKind != QualType::DK_cxx_destructor) {
-    CGF.ErrorUnsupported(initList, "ObjC ARC type in initializer_list");
-    return;
-  }
-
-  CodeGenFunction::Destroyer *destroyer = CGF.getDestroyer(dtorKind);
-  CGF.pushDestroy(NormalAndEHCleanup, addr, arrayType, destroyer,
-                  /*EHCleanup=*/true);
-}
-
 /// \brief Emit the initializer for a std::initializer_list initialized with a
 /// real initializer list.
-void AggExprEmitter::EmitStdInitializerList(llvm::Value *destPtr,
-                                            InitListExpr *initList) {
-  // We emit an array containing the elements, then have the init list point
-  // at the array.
-  ASTContext &ctx = CGF.getContext();
-  unsigned numInits = initList->getNumInits();
-  QualType element = GetStdInitializerListElementType(initList->getType());
-  llvm::APInt size(ctx.getTypeSize(ctx.getSizeType()), numInits);
-  QualType array = ctx.getConstantArrayType(element, size, ArrayType::Normal,0);
-  llvm::Type *LTy = CGF.ConvertTypeForMem(array);
-  llvm::AllocaInst *alloc = CGF.CreateTempAlloca(LTy);
-  alloc->setAlignment(ctx.getTypeAlignInChars(array).getQuantity());
-  alloc->setName(".initlist.");
-
-  EmitArrayInit(alloc, cast<llvm::ArrayType>(LTy), element, initList);
-
-  // FIXME: The diagnostics are somewhat out of place here.
-  RecordDecl *record = initList->getType()->castAs<RecordType>()->getDecl();
-  RecordDecl::field_iterator field = record->field_begin();
-  if (field == record->field_end()) {
-    CGF.ErrorUnsupported(initList, "weird std::initializer_list");
+void
+AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
+  // Emit an array containing the elements.  The array is externally destructed
+  // if the std::initializer_list object is.
+  ASTContext &Ctx = CGF.getContext();
+  LValue Array = CGF.EmitLValue(E->getSubExpr());
+  assert(Array.isSimple() && "initializer_list array not a simple lvalue");
+  llvm::Value *ArrayPtr = Array.getAddress();
+
+  const ConstantArrayType *ArrayType =
+      Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
+  assert(ArrayType && "std::initializer_list constructed from non-array");
+
+  // FIXME: Perform the checks on the field types in SemaInit.
+  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
+  RecordDecl::field_iterator Field = Record->field_begin();
+  if (Field == Record->field_end()) {
+    CGF.ErrorUnsupported(E, "weird std::initializer_list");
     return;
   }
 
-  QualType elementPtr = ctx.getPointerType(element.withConst());
-
   // Start pointer.
-  if (!ctx.hasSameType(field->getType(), elementPtr)) {
-    CGF.ErrorUnsupported(initList, "weird std::initializer_list");
+  if (!Field->getType()->isPointerType() ||
+      !Ctx.hasSameType(Field->getType()->getPointeeType(),
+                       ArrayType->getElementType())) {
+    CGF.ErrorUnsupported(E, "weird std::initializer_list");
     return;
   }
-  LValue DestLV = CGF.MakeNaturalAlignAddrLValue(destPtr, initList->getType());
-  LValue start = CGF.EmitLValueForFieldInitialization(DestLV, *field);
-  llvm::Value *arrayStart = Builder.CreateStructGEP(alloc, 0, "arraystart");
-  CGF.EmitStoreThroughLValue(RValue::get(arrayStart), start);
-  ++field;
-
-  if (field == record->field_end()) {
-    CGF.ErrorUnsupported(initList, "weird std::initializer_list");
+
+  AggValueSlot Dest = EnsureSlot(E->getType());
+  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(),
+                                     Dest.getAlignment());
+  LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
+  llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
+  llvm::Value *IdxStart[] = { Zero, Zero };
+  llvm::Value *ArrayStart =
+      Builder.CreateInBoundsGEP(ArrayPtr, IdxStart, "arraystart");
+  CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
+  ++Field;
+
+  if (Field == Record->field_end()) {
+    CGF.ErrorUnsupported(E, "weird std::initializer_list");
     return;
   }
-  LValue endOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *field);
-  if (ctx.hasSameType(field->getType(), elementPtr)) {
+
+  llvm::Value *Size = Builder.getInt(ArrayType->getSize());
+  LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
+  if (Field->getType()->isPointerType() &&
+      Ctx.hasSameType(Field->getType()->getPointeeType(),
+                      ArrayType->getElementType())) {
     // End pointer.
-    llvm::Value *arrayEnd = Builder.CreateStructGEP(alloc,numInits, "arrayend");
-    CGF.EmitStoreThroughLValue(RValue::get(arrayEnd), endOrLength);
-  } else if(ctx.hasSameType(field->getType(), ctx.getSizeType())) {
+    llvm::Value *IdxEnd[] = { Zero, Size };
+    llvm::Value *ArrayEnd =
+        Builder.CreateInBoundsGEP(ArrayPtr, IdxEnd, "arrayend");
+    CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
+  } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
     // Length.
-    CGF.EmitStoreThroughLValue(RValue::get(Builder.getInt(size)), endOrLength);
+    CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
   } else {
-    CGF.ErrorUnsupported(initList, "weird std::initializer_list");
+    CGF.ErrorUnsupported(E, "weird std::initializer_list");
     return;
   }
-
-  if (!Dest.isExternallyDestructed())
-    EmitStdInitializerListCleanup(CGF, array, alloc, initList);
 }
 
 /// \brief Emit initialization of an array from an initializer list.
@@ -490,15 +471,8 @@ void AggExprEmitter::EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType,
       if (endOfInit) Builder.CreateStore(element, endOfInit);
     }
 
-    // If these are nested std::initializer_list inits, do them directly,
-    // because they are conceptually the same "location".
-    InitListExpr *initList = dyn_cast<InitListExpr>(E->getInit(i));
-    if (initList && initList->initializesStdInitializerList()) {
-      EmitStdInitializerList(element, initList);
-    } else {
-      LValue elementLV = CGF.MakeAddrLValue(element, elementType);
-      EmitInitializationToLValue(E->getInit(i), elementLV);
-    }
+    LValue elementLV = CGF.MakeAddrLValue(element, elementType);
+    EmitInitializationToLValue(E->getInit(i), elementLV);
   }
 
   // Check whether there's a non-trivial array-fill expression.
@@ -1161,11 +1135,6 @@ void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
 
   AggValueSlot Dest = EnsureSlot(E->getType());
 
-  if (E->initializesStdInitializerList()) {
-    EmitStdInitializerList(Dest.getAddr(), E);
-    return;
-  }
-
   LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(),
                                      Dest.getAlignment());
 
@@ -1546,58 +1515,3 @@ void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
                        alignment.getQuantity(), isVolatile,
                        /*TBAATag=*/0, TBAAStructTag);
 }
-
-void CodeGenFunction::MaybeEmitStdInitializerListCleanup(llvm::Value *loc,
-                                                         const Expr *init) {
-  const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(init);
-  if (cleanups)
-    init = cleanups->getSubExpr();
-
-  if (isa<InitListExpr>(init) &&
-      cast<InitListExpr>(init)->initializesStdInitializerList()) {
-    // We initialized this std::initializer_list with an initializer list.
-    // A backing array was created. Push a cleanup for it.
-    EmitStdInitializerListCleanup(loc, cast<InitListExpr>(init));
-  }
-}
-
-static void EmitRecursiveStdInitializerListCleanup(CodeGenFunction &CGF,
-                                                   llvm::Value *arrayStart,
-                                                   const InitListExpr *init) {
-  // Check if there are any recursive cleanups to do, i.e. if we have
-  //   std::initializer_list<std::initializer_list<obj>> list = {{obj()}};
-  // then we need to destroy the inner array as well.
-  for (unsigned i = 0, e = init->getNumInits(); i != e; ++i) {
-    const InitListExpr *subInit = dyn_cast<InitListExpr>(init->getInit(i));
-    if (!subInit || !subInit->initializesStdInitializerList())
-      continue;
-
-    // This one needs to be destroyed. Get the address of the std::init_list.
-    llvm::Value *offset = llvm::ConstantInt::get(CGF.SizeTy, i);
-    llvm::Value *loc = CGF.Builder.CreateInBoundsGEP(arrayStart, offset,
-                                                 "std.initlist");
-    CGF.EmitStdInitializerListCleanup(loc, subInit);
-  }
-}
-
-void CodeGenFunction::EmitStdInitializerListCleanup(llvm::Value *loc,
-                                                    const InitListExpr *init) {
-  ASTContext &ctx = getContext();
-  QualType element = GetStdInitializerListElementType(init->getType());
-  unsigned numInits = init->getNumInits();
-  llvm::APInt size(ctx.getTypeSize(ctx.getSizeType()), numInits);
-  QualType array =ctx.getConstantArrayType(element, size, ArrayType::Normal, 0);
-  QualType arrayPtr = ctx.getPointerType(array);
-  llvm::Type *arrayPtrType = ConvertType(arrayPtr);
-
-  // lvalue is the location of a std::initializer_list, which as its first
-  // element has a pointer to the array we want to destroy.
-  llvm::Value *startPointer = Builder.CreateStructGEP(loc, 0, "startPointer");
-  llvm::Value *startAddress = Builder.CreateLoad(startPointer, "startAddress");
-
-  ::EmitRecursiveStdInitializerListCleanup(*this, startAddress, init);
-
-  llvm::Value *arrayAddress =
-      Builder.CreateBitCast(startAddress, arrayPtrType, "arrayAddress");
-  ::EmitStdInitializerListCleanup(*this, array, arrayAddress, init);
-}
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 83c8ace98cd..60a70f8e07f 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -838,8 +838,6 @@ static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
                               AggValueSlot::DoesNotNeedGCBarriers,
                               AggValueSlot::IsNotAliased);
     CGF.EmitAggExpr(Init, Slot);
-
-    CGF.MaybeEmitStdInitializerListCleanup(NewPtr, Init);
     return;
   }
   }
diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
index ca331cc92be..3e13e972801 100644
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -368,11 +368,6 @@ void ConstStructBuilder::ConvertStructToPacked() {
 }
                             
 bool ConstStructBuilder::Build(InitListExpr *ILE) {
-  if (ILE->initializesStdInitializerList()) {
-    //CGM.ErrorUnsupported(ILE, "global std::initializer_list");
-    return false;
-  }
-
   RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
   const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
 
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 7bbf788eb52..4619322e1e1 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1631,10 +1631,6 @@ public:
   llvm::Value *EmitDynamicCast(llvm::Value *V, const CXXDynamicCastExpr *DCE);
   llvm::Value* EmitCXXUuidofExpr(const CXXUuidofExpr *E);
 
-  void MaybeEmitStdInitializerListCleanup(llvm::Value *loc, const Expr *init);
-  void EmitStdInitializerListCleanup(llvm::Value *loc,
-                                     const InitListExpr *init);
-
   /// \brief Situations in which we might emit a check for the suitability of a
   ///        pointer or glvalue.
   enum TypeCheckKind {
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index d49fc0b0315..f6218cddfb5 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1628,125 +1628,6 @@ CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
       TheDataLayout.getTypeStoreSizeInBits(Ty));
 }
 
-llvm::Constant *
-CodeGenModule::MaybeEmitGlobalStdInitializerListInitializer(const VarDecl *D,
-                                                       const Expr *rawInit) {
-  ArrayRef<ExprWithCleanups::CleanupObject> cleanups;
-  if (const ExprWithCleanups *withCleanups =
-          dyn_cast<ExprWithCleanups>(rawInit)) {
-    cleanups = withCleanups->getObjects();
-    rawInit = withCleanups->getSubExpr();
-  }
-
-  const InitListExpr *init = dyn_cast<InitListExpr>(rawInit);
-  if (!init || !init->initializesStdInitializerList() ||
-      init->getNumInits() == 0)
-    return 0;
-
-  ASTContext &ctx = getContext();
-  unsigned numInits = init->getNumInits();
-  // FIXME: This check is here because we would otherwise silently miscompile
-  // nested global std::initializer_lists. Better would be to have a real
-  // implementation.
-  for (unsigned i = 0; i < numInits; ++i) {
-    const InitListExpr *inner = dyn_cast<InitListExpr>(init->getInit(i));
-    if (inner && inner->initializesStdInitializerList()) {
-      ErrorUnsupported(inner, "nested global std::initializer_list");
-      return 0;
-    }
-  }
-
-  // Synthesize a fake VarDecl for the array and initialize that.
-  QualType elementType = init->getInit(0)->getType();
-  llvm::APInt numElements(ctx.getTypeSize(ctx.getSizeType()), numInits);
-  QualType arrayType = ctx.getConstantArrayType(elementType, numElements,
-                                                ArrayType::Normal, 0);
-
-  IdentifierInfo *name = &ctx.Idents.get(D->getNameAsString() + "__initlist");
-  TypeSourceInfo *sourceInfo = ctx.getTrivialTypeSourceInfo(
-                                              arrayType, D->getLocation());
-  VarDecl *backingArray = VarDecl::Create(ctx, const_cast<DeclContext*>(
-                                                          D->getDeclContext()),
-                                          D->getLocStart(), D->getLocation(),
-                                          name, arrayType, sourceInfo,
-                                          SC_Static);
-  backingArray->setTSCSpec(D->getTSCSpec());
-
-  // Now clone the InitListExpr to initialize the array instead.
-  // Incredible hack: we want to use the existing InitListExpr here, so we need
-  // to tell it that it no longer initializes a std::initializer_list.
-  ArrayRef<Expr*> Inits(const_cast<InitListExpr*>(init)->getInits(),
-                        init->getNumInits());
-  Expr *arrayInit = new (ctx) InitListExpr(ctx, init->getLBraceLoc(), Inits,
-                                           init->getRBraceLoc());
-  arrayInit->setType(arrayType);
-
-  if (!cleanups.empty())
-    arrayInit = ExprWithCleanups::Create(ctx, arrayInit, cleanups);
-
-  backingArray->setInit(arrayInit);
-
-  // Emit the definition of the array.
-  EmitGlobalVarDefinition(backingArray);
-
-  // Inspect the initializer list to validate it and determine its type.
-  // FIXME: doing this every time is probably inefficient; caching would be nice
-  RecordDecl *record = init->getType()->castAs<RecordType>()->getDecl();
-  RecordDecl::field_iterator field = record->field_begin();
-  if (field == record->field_end()) {
-    ErrorUnsupported(D, "weird std::initializer_list");
-    return 0;
-  }
-  QualType elementPtr = ctx.getPointerType(elementType.withConst());
-  // Start pointer.
-  if (!ctx.hasSameType(field->getType(), elementPtr)) {
-    ErrorUnsupported(D, "weird std::initializer_list");
-    return 0;
-  }
-  ++field;
-  if (field == record->field_end()) {
-    ErrorUnsupported(D, "weird std::initializer_list");
-    return 0;
-  }
-  bool isStartEnd = false;
-  if (ctx.hasSameType(field->getType(), elementPtr)) {
-    // End pointer.
-    isStartEnd = true;
-  } else if(!ctx.hasSameType(field->getType(), ctx.getSizeType())) {
-    ErrorUnsupported(D, "weird std::initializer_list");
-    return 0;
-  }
-
-  // Now build an APValue representing the std::initializer_list.
-  APValue initListValue(APValue::UninitStruct(), 0, 2);
-  APValue &startField = initListValue.getStructField(0);
-  APValue::LValuePathEntry startOffsetPathEntry;
-  startOffsetPathEntry.ArrayIndex = 0;
-  startField = APValue(APValue::LValueBase(backingArray),
-                       CharUnits::fromQuantity(0),
-                       llvm::makeArrayRef(startOffsetPathEntry),
-                       /*IsOnePastTheEnd=*/false, 0);
-
-  if (isStartEnd) {
-    APValue &endField = initListValue.getStructField(1);
-    APValue::LValuePathEntry endOffsetPathEntry;
-    endOffsetPathEntry.ArrayIndex = numInits;
-    endField = APValue(APValue::LValueBase(backingArray),
-                       ctx.getTypeSizeInChars(elementType) * numInits,
-                       llvm::makeArrayRef(endOffsetPathEntry),
-                       /*IsOnePastTheEnd=*/true, 0);
-  } else {
-    APValue &sizeField = initListValue.getStructField(1);
-    sizeField = APValue(llvm::APSInt(numElements));
-  }
-
-  // Emit the constant for the initializer_list.
-  llvm::Constant *llvmInit =
-      EmitConstantValueForMemory(initListValue, D->getType());
-  assert(llvmInit && "failed to initialize as constant");
-  return llvmInit;
-}
-
 unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D,
                                                  unsigned AddrSpace) {
   if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) {
@@ -1817,18 +1698,10 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
     assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
     Init = EmitNullConstant(D->getType());
   } else {
-    // If this is a std::initializer_list, emit the special initializer.
-    Init = MaybeEmitGlobalStdInitializerListInitializer(D, InitExpr);
-    // An empty init list will perform zero-initialization, which happens
-    // to be exactly what we want.
-    // FIXME: It does so in a global constructor, which is *not* what we
-    // want.
+    initializedGlobalDecl = GlobalDecl(D);
+    Init = EmitConstantInit(*InitDecl);
 
     if (!Init) {
-      initializedGlobalDecl = GlobalDecl(D);
-      Init = EmitConstantInit(*InitDecl);
-    }
-    if (!Init) {
       QualType T = InitExpr->getType();
       if (D->getType()->isReferenceType())
         T = D->getType();
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index b2ff60deff2..ffb1243726e 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1020,8 +1020,6 @@ private:
 
   void EmitGlobalFunctionDefinition(GlobalDecl GD);
   void EmitGlobalVarDefinition(const VarDecl *D);
-  llvm::Constant *MaybeEmitGlobalStdInitializerListInitializer(const VarDecl *D,
-                                                              const Expr *init);
   void EmitAliasDefinition(GlobalDecl GD);
   void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);
   void EmitObjCIvarInitializations(ObjCImplementationDecl *D);
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 5d6eab0f173..be198ad3782 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2153,10 +2153,6 @@ Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc,
 
   ExprResult Init = InitExpr;
   if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
-    if (isa<InitListExpr>(InitExpr) && isStdInitializerList(FD->getType(), 0)) {
-      Diag(FD->getLocation(), diag::warn_dangling_std_initializer_list)
-        << /*at end of ctor*/1 << InitExpr->getSourceRange();
-    }
     InitializedEntity Entity = InitializedEntity::InitializeMember(FD);
     InitializationKind Kind = FD->getInClassInitStyle() == ICIS_ListInit
         ? InitializationKind::CreateDirectList(InitExpr->getLocStart())
@@ -2550,11 +2546,6 @@ Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
     if (isa<InitListExpr>(Init)) {
       InitList = true;
       Args = Init;
-
-      if (isStdInitializerList(Member->getType(), 0)) {
-        Diag(IdLoc, diag::warn_dangling_std_initializer_list)
-            << /*at end of ctor*/1 << InitRange;
-      }
     }
 
     // Initialize the member.
diff --git a/clang/lib/Sema/SemaExceptionSpec.cpp b/clang/lib/Sema/SemaExceptionSpec.cpp
index a121a75fa48..7ed32b89e3d 100644
--- a/clang/lib/Sema/SemaExceptionSpec.cpp
+++ b/clang/lib/Sema/SemaExceptionSpec.cpp
@@ -1006,6 +1006,7 @@ CanThrowResult Sema::canThrow(const Expr *E) {
   case Expr::CompoundLiteralExprClass:
   case Expr::CXXConstCastExprClass:
   case Expr::CXXReinterpretCastExprClass:
+  case Expr::CXXStdInitializerListExprClass:
   case Expr::DesignatedInitExprClass:
   case Expr::ExprWithCleanupsClass:
   case Expr::ExtVectorElementExprClass:
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index a4bccacb2da..18b3d8225e0 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -2937,6 +2937,12 @@ static void MaybeProduceObjCObject(Sema &S,
   }
 }
 
+static void TryListInitialization(Sema &S,
+                                  const InitializedEntity &Entity,
+                                  const InitializationKind &Kind,
+                                  InitListExpr *InitList,
+                                  InitializationSequence &Sequence);
+
 /// \brief When initializing from init list via constructor, handle
 /// initialization of an object of type std::initializer_list<T>.
 ///
@@ -2950,25 +2956,23 @@ static bool TryInitializerListConstruction(Sema &S,
   if (!S.isStdInitializerList(DestType, &E))
     return false;
 
-  // Check that each individual element can be copy-constructed. But since we
-  // have no place to store further information, we'll recalculate everything
-  // later.
-  InitializedEntity HiddenArray = InitializedEntity::InitializeTemporary(
-      S.Context.getConstantArrayType(E,
-          llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
-                      List->getNumInits()),
-          ArrayType::Normal, 0));
-  InitializedEntity Element = InitializedEntity::InitializeElement(S.Context,
-      0, HiddenArray);
-  for (unsigned i = 0, n = List->getNumInits(); i < n; ++i) {
-    Element.setElementIndex(i);
-    if (!S.CanPerformCopyInitialization(Element, List->getInit(i))) {
-      Sequence.SetFailed(
-          InitializationSequence::FK_InitListElementCopyFailure);
-      return true;
-    }
+  if (S.RequireCompleteType(List->getExprLoc(), E, 0)) {
+    Sequence.setIncompleteTypeFailure(E);
+    return true;
   }
-  Sequence.AddStdInitializerListConstructionStep(DestType);
+
+  // Try initializing a temporary array from the init list.
+  QualType ArrayType = S.Context.getConstantArrayType(
+      E.withConst(), llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
+                                 List->getNumInits()),
+      clang::ArrayType::Normal, 0);
+  InitializedEntity HiddenArray =
+      InitializedEntity::InitializeTemporary(ArrayType);
+  InitializationKind Kind =
+      InitializationKind::CreateDirectList(List->getExprLoc());
+  TryListInitialization(S, HiddenArray, Kind, List, Sequence);
+  if (Sequence)
+    Sequence.AddStdInitializerListConstructionStep(DestType);
   return true;
 }
 
@@ -3198,12 +3202,6 @@ static void TryValueInitialization(Sema &S,
                                    InitializationSequence &Sequence,
                                    InitListExpr *InitList = 0);
 
-static void TryListInitialization(Sema &S,
-                                  const InitializedEntity &Entity,
-                                  const InitializationKind &Kind,
-                                  InitListExpr *InitList,
-                                  InitializationSequence &Sequence);
-
 /// \brief Attempt list initialization of a reference.
 static void TryReferenceListInitialization(Sema &S,
                                            const InitializedEntity &Entity,
@@ -5135,7 +5133,7 @@ PerformConstructorInitialization(Sema &S,
     return ExprError();
 
   if (shouldBindAsTemporary(Entity))
-    CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>());
+    CurInit = S.MaybeBindToTemporary(CurInit.take());
 
   return CurInit;
 }
@@ -5277,19 +5275,18 @@ static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD) {
   if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
     Init = BTE->getSubExpr();
 
+  if (CXXStdInitializerListExpr *ILE =
+          dyn_cast<CXXStdInitializerListExpr>(Init))
+    return performReferenceExtension(ILE->getSubExpr(), ExtendingD);
+
   if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
-    if (ILE->initializesStdInitializerList() || ILE->getType()->isArrayType()) {
-      // FIXME: If this is an InitListExpr which creates a std::initializer_list
-      //        object, we also need to lifetime-extend the underlying array
-      //        itself. Fix the representation to explicitly materialize an
-      //        array temporary so we can model this properly.
+    if (ILE->getType()->isArrayType()) {
       for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
         performLifetimeExtension(ILE->getInit(I), ExtendingD);
       return;
     }
 
-    CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl();
-    if (RD) {
+    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
@@ -5319,6 +5316,39 @@ static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD) {
   }
 }
 
+static void warnOnLifetimeExtension(Sema &S, const InitializedEntity &Entity,
+                                    const Expr *Init, bool IsInitializerList,
+                                    const ValueDecl *ExtendingDecl) {
+  // Warn if a field lifetime-extends a temporary.
+  if (isa<FieldDecl>(ExtendingDecl)) {
+    if (IsInitializerList) {
+      S.Diag(Init->getExprLoc(), diag::warn_dangling_std_initializer_list)
+        << /*at end of constructor*/true;
+      return;
+    }
+
+    bool IsSubobjectMember = false;
+    for (const InitializedEntity *Ent = Entity.getParent(); Ent;
+         Ent = Ent->getParent()) {
+      if (Ent->getKind() != InitializedEntity::EK_Base) {
+        IsSubobjectMember = true;
+        break;
+      }
+    }
+    S.Diag(Init->getExprLoc(),
+           diag::warn_bind_ref_member_to_temporary)
+      << ExtendingDecl << Init->getSourceRange()
+      << IsSubobjectMember << IsInitializerList;
+    if (IsSubobjectMember)
+      S.Diag(ExtendingDecl->getLocation(),
+             diag::note_ref_subobject_of_member_declared_here);
+    else
+      S.Diag(ExtendingDecl->getLocation(),
+             diag::note_ref_or_ptr_member_declared_here)
+        << /*is pointer*/false;
+  }
+}
+
 ExprResult
 InitializationSequence::Perform(Sema &S,
                                 const InitializedEntity &Entity,
@@ -5570,29 +5600,7 @@ InitializationSequence::Perform(Sema &S,
           getDeclForTemporaryLifetimeExtension(Entity);
       if (ExtendingDecl) {
         performLifetimeExtension(CurInit.get(), ExtendingDecl);
-
-        // Warn if a field lifetime-extends a temporary.
-        if (isa<FieldDecl>(ExtendingDecl)) {
-          bool IsSubobjectMember = false;
-          for (const InitializedEntity *Ent = Entity.getParent(); Ent;
-               Ent = Ent->getParent()) {
-            if (Ent->getKind() != InitializedEntity::EK_Base) {
-              IsSubobjectMember = true;
-              break;
-            }
-          }
-          S.Diag(CurInit.get()->getExprLoc(),
-                 diag::warn_bind_ref_member_to_temporary)
-            << ExtendingDecl << CurInit.get()->getSourceRange()
-            << IsSubobjectMember;
-          if (IsSubobjectMember)
-            S.Diag(ExtendingDecl->getLocation(),
-                   diag::note_ref_subobject_of_member_declared_here);
-          else
-            S.Diag(ExtendingDecl->getLocation(),
-                   diag::note_ref_or_ptr_member_declared_here)
-              << /*IsPointer*/false;
-        }
+        warnOnLifetimeExtension(S, Entity, CurInit.get(), false, ExtendingDecl);
       }
 
       // Materialize the temporary into memory.
@@ -5763,16 +5771,10 @@ InitializationSequence::Perform(Sema &S,
 
     case SK_ListInitialization: {
       InitListExpr *InitList = cast<InitListExpr>(CurInit.get());
-      // Hack: We must pass *ResultType if available in order to set the type
-      // of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
-      // But in 'const X &x = {1, 2, 3};' we're supposed to initialize a
-      // temporary, not a reference, so we should pass Ty.
-      // Worst case: 'const int (&arref)[] = {1, 2, 3};'.
-      // Since this step is never used for a reference directly, we explicitly
-      // unwrap references here and rewrap them afterwards.
-      // We also need to create a InitializeTemporary entity for this.
-      QualType Ty = ResultType ? ResultType->getNonReferenceType() : Step->Type;
-      bool IsTemporary = Entity.getType()->isReferenceType();
+      // If we're not initializing the top-level entity, we need to create an
+      // InitializeTemporary entity for our target type.
+      QualType Ty = Step->Type;
+      bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty);
       InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty);
       InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity;
       InitListChecker PerformInitList(S, InitEntity,
@@ -5780,7 +5782,11 @@ InitializationSequence::Perform(Sema &S,
       if (PerformInitList.HadError())
         return ExprError();
 
-      if (ResultType) {
+      // Hack: We must update *ResultType if available in order to set the
+      // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
+      // Worst case: 'const int (&arref)[] = {1, 2, 3};'.
+      if (ResultType &&
+          ResultType->getNonReferenceType()->isIncompleteArrayType()) {
         if ((*ResultType)->isRValueReferenceType())
           Ty = S.Context.getRValueReferenceType(Ty);
         else if ((*ResultType)->isLValueReferenceType())
@@ -5973,56 +5979,35 @@ InitializationSequence::Perform(Sema &S,
       break;
 
     case SK_StdInitializerList: {
-      QualType Dest = Step->Type;
-      QualType E;
-      bool Success = S.isStdInitializerList(Dest.getNonReferenceType(), &E);
-      (void)Success;
-      assert(Success && "Destination type changed?");
-
-      // If the element type has a destructor, check it.
-      if (CXXRecordDecl *RD = E->getAsCXXRecordDecl()) {
-        if (!RD->hasIrrelevantDestructor()) {
-          if (CXXDestructorDecl *Destructor = S.LookupDestructor(RD)) {
-            S.MarkFunctionReferenced(Kind.getLocation(), Destructor);
-            S.CheckDestructorAccess(Kind.getLocation(), Destructor,
-                                    S.PDiag(diag::err_access_dtor_temp) << E);
-            if (S.DiagnoseUseOfDecl(Destructor, Kind.getLocation()))
-              return ExprError();
-          }
-        }
-      }
+      S.Diag(CurInit.get()->getExprLoc(),
+             diag::warn_cxx98_compat_initializer_list_init)
+        << CurInit.get()->getSourceRange();
 
-      InitListExpr *ILE = cast<InitListExpr>(CurInit.take());
-      S.Diag(ILE->getExprLoc(), diag::warn_cxx98_compat_initializer_list_init)
-        << ILE->getSourceRange();
-      unsigned NumInits = ILE->getNumInits();
-      SmallVector<Expr*, 16> Converted(NumInits);
-      InitializedEntity HiddenArray = InitializedEntity::InitializeTemporary(
-          S.Context.getConstantArrayType(E,
-              llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
-                          NumInits),
-              ArrayType::Normal, 0));
-      InitializedEntity Element =InitializedEntity::InitializeElement(S.Context,
-          0, HiddenArray);
-      for (unsigned i = 0; i < NumInits; ++i) {
-        Element.setElementIndex(i);
-        ExprResult Init = S.Owned(ILE->getInit(i));
-        ExprResult Res = S.PerformCopyInitialization(
-                             Element, Init.get()->getExprLoc(), Init,
-                             /*TopLevelOfInitList=*/ true);
-        if (Res.isInvalid())
-          return ExprError();
-        Converted[i] = Res.take();
+      // 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);
+        warnOnLifetimeExtension(S, Entity, CurInit.get(), true, ExtendingDecl);
       }
-      InitListExpr *Semantic = new (S.Context)
-          InitListExpr(S.Context, ILE->getLBraceLoc(),
-                       Converted, ILE->getRBraceLoc());
-      Semantic->setSyntacticForm(ILE);
-      Semantic->setType(Dest);
-      Semantic->setInitializesStdInitializerList();
-      CurInit = S.Owned(Semantic);
+
+      // Materialize the temporary into memory.
+      MaterializeTemporaryExpr *MTE = new (S.Context)
+          MaterializeTemporaryExpr(CurInit.get()->getType(), CurInit.get(),
+                                   /*lvalue reference*/ false, ExtendingDecl);
+
+      // 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))
+        CurInit = S.MaybeBindToTemporary(CurInit.take());
       break;
     }
+
     case SK_OCLSamplerInit: {
       assert(Step->Type->isSamplerT() && 
              "Sampler initialization on non sampler type.");
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index fe49153d991..da1e41c2afb 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -2639,6 +2639,10 @@ ExprResult TreeTransform<Derived>::TransformInitializer(Expr *Init,
   if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
     Init = ICE->getSubExprAsWritten();
 
+  if (CXXStdInitializerListExpr *ILE =
+          dyn_cast<CXXStdInitializerListExpr>(Init))
+    return TransformInitializer(ILE->getSubExpr(), CXXDirectInit);
+
   // If this is not a direct-initializer, we only need to reconstruct
   // InitListExprs. Other forms of copy-initialization will be a no-op if
   // the initializer is already the right type.
@@ -8549,6 +8553,13 @@ TreeTransform<Derived>::TransformMaterializeTemporaryExpr(
 
 template<typename Derived>
 ExprResult
+TreeTransform<Derived>::TransformCXXStdInitializerListExpr(
+    CXXStdInitializerListExpr *E) {
+  return getDerived().TransformExpr(E->getSubExpr());
+}
+
+template<typename Derived>
+ExprResult
 TreeTransform<Derived>::TransformObjCStringLiteral(ObjCStringLiteral *E) {
   return SemaRef.MaybeBindToTemporary(E);
 }
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 9e0157d7afb..2f5dee8282d 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -723,7 +723,6 @@ void ASTStmtReader::VisitInitListExpr(InitListExpr *E) {
   } else
     E->ArrayFillerOrUnionFieldInit = ReadDeclAs<FieldDecl>(Record, Idx);
   E->sawArrayRangeDesignator(Record[Idx++]);
-  E->setInitializesStdInitializerList(Record[Idx++]);
   unsigned NumInits = Record[Idx++];
   E->reserveInits(Reader.getContext(), NumInits);
   if (isArrayFiller) {
@@ -1227,6 +1226,12 @@ void ASTStmtReader::VisitLambdaExpr(LambdaExpr *E) {
   }
 }
 
+void
+ASTStmtReader::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
+  VisitExpr(E);
+  E->SubExpr = Reader.ReadSubExpr();
+}
+
 void ASTStmtReader::VisitCXXNamedCastExpr(CXXNamedCastExpr *E) {
   VisitExplicitCastExpr(E);
   SourceRange R = ReadSourceRange(Record, Idx);
@@ -2161,6 +2166,10 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = new (Context) UserDefinedLiteral(Context, Empty);
       break;
 
+    case EXPR_CXX_STD_INITIALIZER_LIST:
+      S = new (Context) CXXStdInitializerListExpr(Empty);
+      break;
+
     case EXPR_CXX_BOOL_LITERAL:
       S = new (Context) CXXBoolLiteralExpr(Empty);
       break;
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index ba6243a51af..ece297f3e53 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -735,6 +735,7 @@ static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
   RECORD(EXPR_CXX_CONST_CAST);
   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
   RECORD(EXPR_USER_DEFINED_LITERAL);
+  RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
   RECORD(EXPR_CXX_BOOL_LITERAL);
   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
   RECORD(EXPR_CXX_TYPEID_EXPR);
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 5a8baa9d88a..4b01a218f56 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -683,7 +683,6 @@ void ASTStmtWriter::VisitInitListExpr(InitListExpr *E) {
   else
     Writer.AddDeclRef(E->getInitializedFieldInUnion(), Record);
   Record.push_back(E->hadArrayRangeDesignator());
-  Record.push_back(E->initializesStdInitializerList());
   Record.push_back(E->getNumInits());
   if (isArrayFiller) {
     // ArrayFiller may have filled "holes" due to designated initializer.
@@ -1187,6 +1186,12 @@ void ASTStmtWriter::VisitLambdaExpr(LambdaExpr *E) {
   Code = serialization::EXPR_LAMBDA;
 }
 
+void ASTStmtWriter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
+  VisitExpr(E);
+  Writer.AddStmt(E->getSubExpr());
+  Code = serialization::EXPR_CXX_STD_INITIALIZER_LIST;
+}
+
 void ASTStmtWriter::VisitCXXNamedCastExpr(CXXNamedCastExpr *E) {
   VisitExplicitCastExpr(E);
   Writer.AddSourceRange(SourceRange(E->getOperatorLoc(), E->getRParenLoc()),
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index a07b72e36f2..db32003e7bf 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -607,6 +607,7 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::CXXDefaultInitExprClass:
     case Stmt::CXXDependentScopeMemberExprClass:
     case Stmt::CXXPseudoDestructorExprClass:
+    case Stmt::CXXStdInitializerListExprClass:
     case Stmt::CXXTryStmtClass:
     case Stmt::CXXTypeidExprClass:
     case Stmt::CXXUuidofExprClass: