Represent C++ direct initializers as ParenListExprs before semantic analysis

instead of having a special-purpose function.

- ActOnCXXDirectInitializer, which was mostly duplication of
  AddInitializerToDecl (leading e.g. to PR10620, which Eli fixed a few days
  ago), is dropped completely.
- MultiInitializer, which was an ugly hack I added, is dropped again.
- We now have the infrastructure in place to distinguish between
  int x = {1};
  int x({1});
  int x{1};
-- VarDecl now has getInitStyle(), which indicates which of the above was used.
-- CXXConstructExpr now has a flag to indicate that it represents list-
   initialization, although this is not yet used.
- InstantiateInitializer was renamed to SubstInitializer and simplified.
- ActOnParenOrParenListExpr has been replaced by ActOnParenListExpr, which
  always produces a ParenListExpr. Placed that so far failed to convert that
  back to a ParenExpr containing comma operators have been fixed. I'm pretty
  sure I could have made a crashing test case before this.

The end result is a (I hope) considerably cleaner design of initializers.
More importantly, the fact that I can now distinguish between the various
initialization kinds means that I can get the tricky generalized initializer
test cases Johannes Schaub supplied to work. (This is not yet done.)

This commit passed self-host, with the resulting compiler passing the tests. I
hope it doesn't break more complicated code. It's a pretty big change, but one
that I feel is necessary.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150318 91177308-0d34-0410-b5e6-96231b3b80d8

18 files changed, 310 insertions, 540 deletions

diff --git a/lib/AST/DeclPrinter.cpp b/lib/AST/DeclPrinter.cpp
index 5a6686d164..32bdba1a0b 100644
--- a/lib/AST/DeclPrinter.cpp
+++ b/lib/AST/DeclPrinter.cpp
@@ -621,16 +621,20 @@ void DeclPrinter::VisitVarDecl(VarDecl *D) {
   Out << Name;
   Expr *Init = D->getInit();
   if (!Policy.SuppressInitializers && Init) {
-    if (D->hasCXXDirectInitializer())
-      Out << "(";
-    else {
-        CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init);
-        if (!CCE || CCE->getConstructor()->isCopyOrMoveConstructor())
-          Out << " = ";
+    bool ImplicitInit = false;
+    if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init))
+      ImplicitInit = D->getInitStyle() == VarDecl::CallInit &&
+          Construct->getNumArgs() == 0 && !Construct->isListInitialization();
+    if (!ImplicitInit) {
+      if (D->getInitStyle() == VarDecl::CallInit)
+        Out << "(";
+      else if (D->getInitStyle() == VarDecl::CInit) {
+        Out << " = ";
+      }
+      Init->printPretty(Out, Context, 0, Policy, Indentation);
+      if (D->getInitStyle() == VarDecl::CallInit)
+        Out << ")";
     }
-    Init->printPretty(Out, Context, 0, Policy, Indentation);
-    if (D->hasCXXDirectInitializer())
-      Out << ")";
   }
   prettyPrintAttributes(D);
 }
diff --git a/lib/AST/DumpXML.cpp b/lib/AST/DumpXML.cpp
index dcbc5180a0..b4038ddaf9 100644
--- a/lib/AST/DumpXML.cpp
+++ b/lib/AST/DumpXML.cpp
@@ -461,7 +461,13 @@ struct XMLDumper : public XMLDeclVisitor<XMLDumper>,
     if (D->getStorageClass() != SC_None)
       set("storage",
           VarDecl::getStorageClassSpecifierString(D->getStorageClass()));
-    setFlag("directinit", D->hasCXXDirectInitializer());
+    StringRef initStyle = "";
+    switch (D->getInitStyle()) {
+    case VarDecl::CInit: initStyle = "c"; break;
+    case VarDecl::CallInit: initStyle = "call"; break;
+    case VarDecl::ListInit: initStyle = "list"; break;
+    }
+    set("initstyle", initStyle);
     setFlag("nrvo", D->isNRVOVariable());
     // TODO: instantiation, etc.
   }
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 398e27ea97..5d22d144f4 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -3414,11 +3414,10 @@ void DesignatedInitExpr::ExpandDesignator(ASTContext &C, unsigned Idx,
 
 ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
                              Expr **exprs, unsigned nexprs,
-                             SourceLocation rparenloc, QualType T)
-  : Expr(ParenListExprClass, T, VK_RValue, OK_Ordinary,
+                             SourceLocation rparenloc)
+  : Expr(ParenListExprClass, QualType(), VK_RValue, OK_Ordinary,
          false, false, false, false),
     NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
-  assert(!T.isNull() && "ParenListExpr must have a valid type");
   Exprs = new (C) Stmt*[nexprs];
   for (unsigned i = 0; i != nexprs; ++i) {
     if (exprs[i]->isTypeDependent())
diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index 51dd57cfe3..a38488b877 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -653,7 +653,7 @@ CXXTemporaryObjectExpr::CXXTemporaryObjectExpr(ASTContext &C,
                      Type->getType().getNonReferenceType(), 
                      Type->getTypeLoc().getBeginLoc(),
                      Cons, false, Args, NumArgs,
-                     HadMultipleCandidates, ZeroInitialization,
+                     HadMultipleCandidates, /*FIXME*/false, ZeroInitialization,
                      CXXConstructExpr::CK_Complete, parenRange),
     Type(Type) {
 }
@@ -668,13 +668,15 @@ CXXConstructExpr *CXXConstructExpr::Create(ASTContext &C, QualType T,
                                            CXXConstructorDecl *D, bool Elidable,
                                            Expr **Args, unsigned NumArgs,
                                            bool HadMultipleCandidates,
+                                           bool ListInitialization,
                                            bool ZeroInitialization,
                                            ConstructionKind ConstructKind,
                                            SourceRange ParenRange) {
   return new (C) CXXConstructExpr(C, CXXConstructExprClass, T, Loc, D, 
                                   Elidable, Args, NumArgs,
-                                  HadMultipleCandidates, ZeroInitialization,
-                                  ConstructKind, ParenRange);
+                                  HadMultipleCandidates, ListInitialization,
+                                  ZeroInitialization, ConstructKind,
+                                  ParenRange);
 }
 
 CXXConstructExpr::CXXConstructExpr(ASTContext &C, StmtClass SC, QualType T,
@@ -682,6 +684,7 @@ CXXConstructExpr::CXXConstructExpr(ASTContext &C, StmtClass SC, QualType T,
                                    CXXConstructorDecl *D, bool elidable,
                                    Expr **args, unsigned numargs,
                                    bool HadMultipleCandidates,
+                                   bool ListInitialization,
                                    bool ZeroInitialization,
                                    ConstructionKind ConstructKind,
                                    SourceRange ParenRange)
@@ -691,6 +694,7 @@ CXXConstructExpr::CXXConstructExpr(ASTContext &C, StmtClass SC, QualType T,
          T->containsUnexpandedParameterPack()),
     Constructor(D), Loc(Loc), ParenRange(ParenRange),  NumArgs(numargs),
     Elidable(elidable), HadMultipleCandidates(HadMultipleCandidates),
+    ListInitialization(ListInitialization),
     ZeroInitialization(ZeroInitialization),
     ConstructKind(ConstructKind), Args(0)
 {
diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index dc68605555..94bad92180 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -2740,7 +2740,8 @@ CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
                              CXXConstExpr->getConstructor(),
                              CXXConstExpr->isElidable(),
                              &ConstructorArgs[0], ConstructorArgs.size(),
-                             CXXConstExpr->hadMultipleCandidates(), 
+                             CXXConstExpr->hadMultipleCandidates(),
+                             CXXConstExpr->isListInitialization(),
                              CXXConstExpr->requiresZeroInitialization(),
                              CXXConstExpr->getConstructionKind(), SourceRange());
   
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 0c8a647f65..914a5acd09 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -1344,10 +1344,11 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(Declarator &D,
         ExitScope();
       }
 
-      Actions.AddCXXDirectInitializerToDecl(ThisDecl, T.getOpenLocation(),
-                                            move_arg(Exprs),
-                                            T.getCloseLocation(),
-                                            TypeContainsAuto);
+      ExprResult Initializer = Actions.ActOnParenListExpr(T.getOpenLocation(),
+                                                          T.getCloseLocation(),
+                                                          move_arg(Exprs));
+      Actions.AddInitializerToDecl(ThisDecl, Initializer.take(),
+                                   /*DirectInit=*/true, TypeContainsAuto);
     }
   } else if (getLang().CPlusPlus0x && Tok.is(tok::l_brace)) {
     // Parse C++0x braced-init-list.
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index 3660b01816..b5e4a5f620 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -2006,8 +2006,8 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
 
     if (!ParseExpressionList(ArgExprs, CommaLocs)) {
       ExprType = SimpleExpr;
-      Result = Actions.ActOnParenOrParenListExpr(OpenLoc, Tok.getLocation(),
-                                                 move_arg(ArgExprs));
+      Result = Actions.ActOnParenListExpr(OpenLoc, Tok.getLocation(),
+                                          move_arg(ArgExprs));
     }
   } else {
     InMessageExpressionRAIIObject InMessage(*this, false);
diff --git a/lib/Sema/CMakeLists.txt b/lib/Sema/CMakeLists.txt
index dece5bd998..c576d765b2 100644
--- a/lib/Sema/CMakeLists.txt
+++ b/lib/Sema/CMakeLists.txt
@@ -8,7 +8,6 @@ add_clang_library(clangSema
   DelayedDiagnostic.cpp
   IdentifierResolver.cpp
   JumpDiagnostics.cpp
-  MultiInitializer.cpp
   Scope.cpp
   Sema.cpp
   SemaAccess.cpp
diff --git a/lib/Sema/MultiInitializer.cpp b/lib/Sema/MultiInitializer.cpp
deleted file mode 100644
index d8944efba3..0000000000
--- a/lib/Sema/MultiInitializer.cpp
+++ /dev/null
@@ -1,93 +0,0 @@
-//===--- MultiInitializer.cpp - Initializer expression group ----*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the MultiInitializer class, which can represent a list
-// initializer or a parentheses-wrapped group of expressions in a C++ member
-// initializer.
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/Sema/MultiInitializer.h"
-#include "clang/Sema/Initialization.h"
-#include "clang/Sema/Sema.h"
-#include "clang/AST/Expr.h"
-
-using namespace clang;
-
-InitListExpr *MultiInitializer::getInitList() const {
-  return cast<InitListExpr>(InitListOrExpressions.get<Expr*>());
-}
-
-SourceLocation MultiInitializer::getStartLoc() const {
-  return isInitializerList() ? getInitList()->getLBraceLoc() : LParenLoc;
-}
-
-SourceLocation MultiInitializer::getEndLoc() const {
-  return isInitializerList() ? getInitList()->getRBraceLoc() : RParenLoc;
-}
-
-MultiInitializer::iterator MultiInitializer::begin() const {
-  return isInitializerList() ? getInitList()->getInits() : getExpressions();
-}
-
-MultiInitializer::iterator MultiInitializer::end() const {
-  if (isInitializerList()) {
-    InitListExpr *ILE = getInitList();
-    return ILE->getInits() + ILE->getNumInits();
-  }
-  return getExpressions() + NumInitializers;
-}
-
-bool MultiInitializer::isTypeDependent() const {
-  if (isInitializerList())
-    return getInitList()->isTypeDependent();
-  for (iterator I = begin(), E = end(); I != E; ++I) {
-    if ((*I)->isTypeDependent())
-      return true;
-  }
-  return false;
-}
-
-bool MultiInitializer::DiagnoseUnexpandedParameterPack(Sema &SemaRef) const {
-  if (isInitializerList())
-    return SemaRef.DiagnoseUnexpandedParameterPack(getInitList(),
-                                                   Sema::UPPC_Initializer);
-  for (iterator I = begin(), E = end(); I != E; ++I) {
-    if (SemaRef.DiagnoseUnexpandedParameterPack(*I, Sema::UPPC_Initializer))
-      return true;
-  }
-  return false;
-}
-
-Expr *MultiInitializer::CreateInitExpr(ASTContext &Ctx, QualType T) const {
-  if (isInitializerList())
-    return InitListOrExpressions.get<Expr*>();
-
-  return new (Ctx) ParenListExpr(Ctx, LParenLoc, getExpressions(),
-                                 NumInitializers, RParenLoc, T);
-}
-
-ExprResult MultiInitializer::PerformInit(Sema &SemaRef,
-                                         InitializedEntity Entity,
-                                         InitializationKind Kind) const {
-  Expr *Single;
-  Expr **Args;
-  unsigned NumArgs;
-  if (isInitializerList()) {
-    Single = InitListOrExpressions.get<Expr*>();
-    Args = &Single;
-    NumArgs = 1;
-  } else {
-    Args = getExpressions();
-    NumArgs = NumInitializers;
-  }
-  InitializationSequence InitSeq(SemaRef, Entity, Kind, Args, NumArgs);
-  return InitSeq.Perform(SemaRef, Entity, Kind,
-                         MultiExprArg(SemaRef, Args, NumArgs), 0);
-}
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 6ba3228b08..feffaf13fa 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2139,9 +2139,8 @@ void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
 /// emitting diagnostics as appropriate.
 ///
 /// Declarations using the auto type specifier (C++ [decl.spec.auto]) call back
-/// to here in AddInitializerToDecl and AddCXXDirectInitializerToDecl. We can't
-/// check them before the initializer is attached.
-///
+/// to here in AddInitializerToDecl. We can't check them before the initializer
+/// is attached.
 void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old) {
   if (New->isInvalidDecl() || Old->isInvalidDecl())
     return;
@@ -5983,17 +5982,6 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
   if (RealDecl == 0 || RealDecl->isInvalidDecl())
     return;
 
-  // Check for self-references within variable initializers.
-  if (VarDecl *vd = dyn_cast<VarDecl>(RealDecl)) {
-    // Variables declared within a function/method body are handled
-    // by a dataflow analysis.
-    if (!vd->hasLocalStorage() && !vd->isStaticLocal())
-      CheckSelfReference(RealDecl, Init);    
-  }
-  else {
-    CheckSelfReference(RealDecl, Init);
-  }
-
   if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) {
     // With declarators parsed the way they are, the parser cannot
     // distinguish between a normal initializer and a pure-specifier.
@@ -6018,12 +6006,44 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
     return;
   }
 
+  // Check for self-references within variable initializers.
+  // Variables declared within a function/method body are handled
+  // by a dataflow analysis.
+  if (!VDecl->hasLocalStorage() && !VDecl->isStaticLocal())
+    CheckSelfReference(RealDecl, Init);
+
+  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
+
   // C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
   if (TypeMayContainAuto && VDecl->getType()->getContainedAutoType()) {
+    Expr *DeduceInit = Init;
+    // Initializer could be a C++ direct-initializer. Deduction only works if it
+    // contains exactly one expression.
+    if (CXXDirectInit) {
+      if (CXXDirectInit->getNumExprs() == 0) {
+        // It isn't possible to write this directly, but it is possible to
+        // end up in this situation with "auto x(some_pack...);"
+        Diag(CXXDirectInit->getSourceRange().getBegin(),
+             diag::err_auto_var_init_no_expression)
+          << VDecl->getDeclName() << VDecl->getType()
+          << VDecl->getSourceRange();
+        RealDecl->setInvalidDecl();
+        return;
+      } else if (CXXDirectInit->getNumExprs() > 1) {
+        Diag(CXXDirectInit->getExpr(1)->getSourceRange().getBegin(),
+             diag::err_auto_var_init_multiple_expressions)
+          << VDecl->getDeclName() << VDecl->getType()
+          << VDecl->getSourceRange();
+        RealDecl->setInvalidDecl();
+        return;
+      } else {
+        DeduceInit = CXXDirectInit->getExpr(0);
+      }
+    }
     TypeSourceInfo *DeducedType = 0;
-    if (DeduceAutoType(VDecl->getTypeSourceInfo(), Init, DeducedType) ==
+    if (DeduceAutoType(VDecl->getTypeSourceInfo(), DeduceInit, DeducedType) ==
             DAR_Failed)
-      DiagnoseAutoDeductionFailure(VDecl, Init);
+      DiagnoseAutoDeductionFailure(VDecl, DeduceInit);
     if (!DeducedType) {
       RealDecl->setInvalidDecl();
       return;
@@ -6048,25 +6068,26 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
     return;
   }
 
+  if (!VDecl->getType()->isDependentType()) {
+    // A definition must end up with a complete type, which means it must be
+    // complete with the restriction that an array type might be completed by
+    // the initializer; note that later code assumes this restriction.
+    QualType BaseDeclType = VDecl->getType();
+    if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType))
+      BaseDeclType = Array->getElementType();
+    if (RequireCompleteType(VDecl->getLocation(), BaseDeclType,
+                            diag::err_typecheck_decl_incomplete_type)) {
+      RealDecl->setInvalidDecl();
+      return;
+    }
 
-  // A definition must end up with a complete type, which means it must be
-  // complete with the restriction that an array type might be completed by the
-  // initializer; note that later code assumes this restriction.
-  QualType BaseDeclType = VDecl->getType();
-  if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType))
-    BaseDeclType = Array->getElementType();
-  if (RequireCompleteType(VDecl->getLocation(), BaseDeclType,
-                          diag::err_typecheck_decl_incomplete_type)) {
-    RealDecl->setInvalidDecl();
-    return;
+    // The variable can not have an abstract class type.
+    if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(),
+                               diag::err_abstract_type_in_decl,
+                               AbstractVariableType))
+      VDecl->setInvalidDecl();
   }
 
-  // The variable can not have an abstract class type.
-  if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(),
-                             diag::err_abstract_type_in_decl,
-                             AbstractVariableType))
-    VDecl->setInvalidDecl();
-
   const VarDecl *Def;
   if ((Def = VDecl->getDefinition()) && Def != VDecl) {
     Diag(VDecl->getLocation(), diag::err_redefinition)
@@ -6128,9 +6149,15 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
                    : InitializationKind::CreateCopy(VDecl->getLocation(),
                                                     Init->getLocStart());
 
-    InitializationSequence InitSeq(*this, Entity, Kind, &Init, 1);
+    Expr **Args = &Init;
+    unsigned NumArgs = 1;
+    if (CXXDirectInit) {
+      Args = CXXDirectInit->getExprs();
+      NumArgs = CXXDirectInit->getNumExprs();
+    }
+    InitializationSequence InitSeq(*this, Entity, Kind, Args, NumArgs);
     ExprResult Result = InitSeq.Perform(*this, Entity, Kind,
-                                              MultiExprArg(*this, &Init, 1),
+                                              MultiExprArg(*this, Args,NumArgs),
                                               &DclT);
     if (Result.isInvalid()) {
       VDecl->setInvalidDecl();
@@ -6266,6 +6293,28 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
       CheckForConstantInitializer(Init, DclT);
   }
 
+  // We will represent direct-initialization similarly to copy-initialization:
+  //    int x(1);  -as-> int x = 1;
+  //    ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
+  //
+  // Clients that want to distinguish between the two forms, can check for
+  // direct initializer using VarDecl::getInitStyle().
+  // A major benefit is that clients that don't particularly care about which
+  // exactly form was it (like the CodeGen) can handle both cases without
+  // special case code.
+
+  // C++ 8.5p11:
+  // The form of initialization (using parentheses or '=') is generally
+  // insignificant, but does matter when the entity being initialized has a
+  // class type.
+  if (CXXDirectInit) {
+    assert(DirectInit && "Call-style initializer must be direct init.");
+    VDecl->setInitStyle(VarDecl::CallInit);
+  } else if (DirectInit) {
+    // This must be list-initialization. No other way is direct-initialization.
+    VDecl->setInitStyle(VarDecl::ListInit);
+  }
+
   CheckCompleteVariableDeclaration(VDecl);
 }
 
@@ -6496,8 +6545,11 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl,
                                       MultiExprArg(*this, 0, 0));
     if (Init.isInvalid())
       Var->setInvalidDecl();
-    else if (Init.get())
+    else if (Init.get()) {
       Var->setInit(MaybeCreateExprWithCleanups(Init.get()));
+      // This is important for template substitution.
+      Var->setInitStyle(VarDecl::CallInit);
+    }
 
     CheckCompleteVariableDeclaration(Var);
   }
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index a6d7d63b3a..72a8de2b71 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -1768,7 +1768,7 @@ Sema::ActOnMemInitializer(Decl *ConstructorD,
                           Expr *InitList,
                           SourceLocation EllipsisLoc) {
   return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
-                             DS, IdLoc, MultiInitializer(InitList), 
+                             DS, IdLoc, InitList,
                              EllipsisLoc);
 }
 
@@ -1785,10 +1785,10 @@ Sema::ActOnMemInitializer(Decl *ConstructorD,
                           Expr **Args, unsigned NumArgs,
                           SourceLocation RParenLoc,
                           SourceLocation EllipsisLoc) {
+  Expr *List = new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
+                                           RParenLoc);
   return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
-                             DS, IdLoc, MultiInitializer(LParenLoc, Args, 
-                                                         NumArgs, RParenLoc),
-                             EllipsisLoc);
+                             DS, IdLoc, List, EllipsisLoc);
 }
 
 namespace {
@@ -1825,7 +1825,7 @@ Sema::BuildMemInitializer(Decl *ConstructorD,
                           ParsedType TemplateTypeTy,
                           const DeclSpec &DS,
                           SourceLocation IdLoc,
-                          const MultiInitializer &Args,
+                          Expr *Init,
                           SourceLocation EllipsisLoc) {
   if (!ConstructorD)
     return true;
@@ -1864,9 +1864,10 @@ Sema::BuildMemInitializer(Decl *ConstructorD,
           (Member = dyn_cast<IndirectFieldDecl>(*Result.first))) {
         if (EllipsisLoc.isValid())
           Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
-            << MemberOrBase << SourceRange(IdLoc, Args.getEndLoc());
+            << MemberOrBase
+            << SourceRange(IdLoc, Init->getSourceRange().getEnd());
 
-        return BuildMemberInitializer(Member, Args, IdLoc);
+        return BuildMemberInitializer(Member, Init, IdLoc);
       }
     }
   }
@@ -1927,7 +1928,7 @@ Sema::BuildMemInitializer(Decl *ConstructorD,
           Diag(Member->getLocation(), diag::note_previous_decl)
             << CorrectedQuotedStr;
 
-          return BuildMemberInitializer(Member, Args, IdLoc);
+          return BuildMemberInitializer(Member, Init, IdLoc);
         } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
           const CXXBaseSpecifier *DirectBaseSpec;
           const CXXBaseSpecifier *VirtualBaseSpec;
@@ -1955,7 +1956,7 @@ Sema::BuildMemInitializer(Decl *ConstructorD,
 
       if (!TyD && BaseType.isNull()) {
         Diag(IdLoc, diag::err_mem_init_not_member_or_class)
-          << MemberOrBase << SourceRange(IdLoc, Args.getEndLoc());
+          << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
         return true;
       }
     }
@@ -1975,7 +1976,7 @@ Sema::BuildMemInitializer(Decl *ConstructorD,
   if (!TInfo)
     TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
 
-  return BuildBaseInitializer(BaseType, TInfo, Args, ClassDecl, EllipsisLoc);
+  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
 }
 
 /// Checks a member initializer expression for cases where reference (or
@@ -2102,15 +2103,14 @@ static bool InitExprContainsUninitializedFields(const Stmt *S,
 }
 
 MemInitResult
-Sema::BuildMemberInitializer(ValueDecl *Member,
-                             const MultiInitializer &Args,
+Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
                              SourceLocation IdLoc) {
   FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
   IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
   assert((DirectMember || IndirectMember) &&
          "Member must be a FieldDecl or IndirectFieldDecl");
 
-  if (Args.DiagnoseUnexpandedParameterPack(*this))
+  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
     return true;
 
   if (Member->isInvalidDecl())
@@ -2120,13 +2120,19 @@ Sema::BuildMemberInitializer(ValueDecl *Member,
   //   foo(foo)
   // where foo is not also a parameter to the constructor.
   // TODO: implement -Wuninitialized and fold this into that framework.
-  for (MultiInitializer::iterator I = Args.begin(), E = Args.end();
-       I != E; ++I) {
+  Expr **Args;
+  unsigned NumArgs;
+  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
+    Args = ParenList->getExprs();
+    NumArgs = ParenList->getNumExprs();
+  } else {
+    InitListExpr *InitList = cast<InitListExpr>(Init);
+    Args = InitList->getInits();
+    NumArgs = InitList->getNumInits();
+  }
+  for (unsigned i = 0; i < NumArgs; ++i) {
     SourceLocation L;
-    Expr *Arg = *I;
-    if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Arg))
-      Arg = DIE->getInit();
-    if (InitExprContainsUninitializedFields(Arg, Member, &L)) {
+    if (InitExprContainsUninitializedFields(Args[i], Member, &L)) {
       // FIXME: Return true in the case when other fields are used before being
       // uninitialized. For example, let this field be the i'th field. When
       // initializing the i'th field, throw a warning if any of the >= i'th
@@ -2137,14 +2143,11 @@ Sema::BuildMemberInitializer(ValueDecl *Member,
     }
   }
 
-  bool HasDependentArg = Args.isTypeDependent();
+  SourceRange InitRange = Init->getSourceRange();
 
-  Expr *Init;
-  if (Member->getType()->isDependentType() || HasDependentArg) {
+  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
     // Can't check initialization for a member of dependent type or when
     // any of the arguments are type-dependent expressions.
-    Init = Args.CreateInitExpr(Context,Member->getType().getNonReferenceType());
-
     DiscardCleanupsInEvaluationContext();
   } else {
     // Initialize the member.
@@ -2152,14 +2155,22 @@ Sema::BuildMemberInitializer(ValueDecl *Member,
       DirectMember ? InitializedEntity::InitializeMember(DirectMember, 0)
                    : InitializedEntity::InitializeMember(IndirectMember, 0);
     InitializationKind Kind =
-      InitializationKind::CreateDirect(IdLoc, Args.getStartLoc(),
-                                       Args.getEndLoc());
+      InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
+                                       InitRange.getEnd());
 
-    ExprResult MemberInit = Args.PerformInit(*this, MemberEntity, Kind);
+    if (isa<InitListExpr>(Init)) {
+      Args = &Init;
+      NumArgs = 1;
+    }
+    InitializationSequence InitSeq(*this, MemberEntity, Kind, Args, NumArgs);
+    ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind,
+                                            MultiExprArg(*this, Args, NumArgs),
+                                            0);
     if (MemberInit.isInvalid())
       return true;
 
-    CheckImplicitConversions(MemberInit.get(), Args.getStartLoc());
+    CheckImplicitConversions(MemberInit.get(),
+                             InitRange.getBegin());
 
     // C++0x [class.base.init]p7:
     //   The initialization of each base and member constitutes a
@@ -2170,14 +2181,13 @@ Sema::BuildMemberInitializer(ValueDecl *Member,
 
     // If we are in a dependent context, template instantiation will
     // perform this type-checking again. Just save the arguments that we
-    // received in a ParenListExpr.
+    // received.
     // FIXME: This isn't quite ideal, since our ASTs don't capture all
     // of the information that we have about the member
     // initializer. However, deconstructing the ASTs is a dicey process,
     // and this approach is far more likely to get the corner cases right.
     if (CurContext->isDependentContext()) {
-      Init = Args.CreateInitExpr(Context,
-                                 Member->getType().getNonReferenceType());
+      // The existing Init will do fine.
     } else {
       Init = MemberInit.get();
       CheckForDanglingReferenceOrPointer(*this, Member, Init, IdLoc);
@@ -2185,19 +2195,18 @@ Sema::BuildMemberInitializer(ValueDecl *Member,
   }
 
   if (DirectMember) {
-    return new (Context) CXXCtorInitializer(Context, DirectMember,
-                                                    IdLoc, Args.getStartLoc(),
-                                                    Init, Args.getEndLoc());
+    return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
+                                            InitRange.getBegin(), Init,
+                                            InitRange.getEnd());
   } else {
-    return new (Context) CXXCtorInitializer(Context, IndirectMember,
-                                                    IdLoc, Args.getStartLoc(),
-                                                    Init, Args.getEndLoc());
+    return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
+                                            InitRange.getBegin(), Init,
+                                            InitRange.getEnd());
   }
 }
 
 MemInitResult
-Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo,
-                                 const MultiInitializer &Args,
+Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
                                  CXXRecordDecl *ClassDecl) {
   SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
   if (!LangOpts.CPlusPlus0x)
@@ -2205,21 +2214,31 @@ Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo,
       << TInfo->getTypeLoc().getLocalSourceRange();
   Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
 
+  SourceRange InitRange = Init->getSourceRange();
   // Initialize the object.
   InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
                                      QualType(ClassDecl->getTypeForDecl(), 0));
   InitializationKind Kind =
-    InitializationKind::CreateDirect(NameLoc, Args.getStartLoc(),
-                                     Args.getEndLoc());
-
-  ExprResult DelegationInit = Args.PerformInit(*this, DelegationEntity, Kind);
+    InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
+                                     InitRange.getEnd());
+
+  Expr **Args = &Init;
+  unsigned NumArgs = 1;
+  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
+    Args = ParenList->getExprs();
+    NumArgs = ParenList->getNumExprs();
+  }
+  InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args, NumArgs);
+  ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
+                                              MultiExprArg(*this, Args,NumArgs),
+                                              0);
   if (DelegationInit.isInvalid())
     return true;
 
   assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
          "Delegating constructor with no target?");
 
-  CheckImplicitConversions(DelegationInit.get(), Args.getStartLoc());
+  CheckImplicitConversions(DelegationInit.get(), InitRange.getBegin());
 
   // C++0x [class.base.init]p7:
   //   The initialization of each base and member constitutes a
@@ -2228,18 +2247,15 @@ Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo,
   if (DelegationInit.isInvalid())