Give InitListChecker a verification-only mode, where it neither emits diagnostics nor

builds a semantic (structured) initializer list, just reports on whether it can match
the given list to the target type.
Use this mode for doing init list checking in the initial step of initialization, which
will eventually allow us to do overload resolution based on the outcome.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140457 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 320 insertions, 217 deletions

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 15bcb451e5..7c27e6fbae 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -169,6 +169,7 @@ namespace {
 class InitListChecker {
   Sema &SemaRef;
   bool hadError;
+  bool VerifyOnly; // no diagnostics, no structure building
   std::map<InitListExpr *, InitListExpr *> SyntacticToSemantic;
   InitListExpr *FullyStructuredList;
 
@@ -257,7 +258,7 @@ class InitListChecker {
                               bool TopLevelObject);
 public:
   InitListChecker(Sema &S, const InitializedEntity &Entity,
-                  InitListExpr *IL, QualType &T);
+                  InitListExpr *IL, QualType &T, bool VerifyOnly);
   bool HadError() { return hadError; }
 
   // @brief Retrieves the fully-structured initializer list used for
@@ -450,8 +451,9 @@ InitListChecker::FillInValueInitializations(const InitializedEntity &Entity,
 
 
 InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
-                                 InitListExpr *IL, QualType &T)
-  : SemaRef(S) {
+                                 InitListExpr *IL, QualType &T,
+                                 bool VerifyOnly)
+  : SemaRef(S), VerifyOnly(VerifyOnly) {
   hadError = false;
 
   unsigned newIndex = 0;
@@ -462,7 +464,7 @@ InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
                         FullyStructuredList, newStructuredIndex,
                         /*TopLevelObject=*/true);
 
-  if (!hadError) {
+  if (!hadError && !VerifyOnly) {
     bool RequiresSecondPass = false;
     FillInValueInitializations(Entity, FullyStructuredList, RequiresSecondPass);
     if (RequiresSecondPass && !hadError)
@@ -513,8 +515,9 @@ void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
     llvm_unreachable("CheckImplicitInitList(): Illegal type");
 
   if (maxElements == 0) {
-    SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(),
-                  diag::err_implicit_empty_initializer);
+    if (!VerifyOnly)
+      SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(),
+                   diag::err_implicit_empty_initializer);
     ++Index;
     hadError = true;
     return;
@@ -535,26 +538,29 @@ void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
                         StructuredSubobjectInitList,
                         StructuredSubobjectInitIndex);
   unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
-  StructuredSubobjectInitList->setType(T);
-
-  // Update the structured sub-object initializer so that it's ending
-  // range corresponds with the end of the last initializer it used.
-  if (EndIndex < ParentIList->getNumInits()) {
-    SourceLocation EndLoc
-      = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
-    StructuredSubobjectInitList->setRBraceLoc(EndLoc);
-  }
-
-  // Warn about missing braces.
-  if (T->isArrayType() || T->isRecordType()) {
-    SemaRef.Diag(StructuredSubobjectInitList->getLocStart(),
-                 diag::warn_missing_braces)
-    << StructuredSubobjectInitList->getSourceRange()
-    << FixItHint::CreateInsertion(StructuredSubobjectInitList->getLocStart(),
-                                  "{")
-    << FixItHint::CreateInsertion(SemaRef.PP.getLocForEndOfToken(
+  if (!VerifyOnly) {
+    StructuredSubobjectInitList->setType(T);
+
+    // Update the structured sub-object initializer so that it's ending
+    // range corresponds with the end of the last initializer it used.
+    if (EndIndex < ParentIList->getNumInits()) {
+      SourceLocation EndLoc
+        = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
+      StructuredSubobjectInitList->setRBraceLoc(EndLoc);
+    }
+
+    // Warn about missing braces.
+    if (T->isArrayType() || T->isRecordType()) {
+      SemaRef.Diag(StructuredSubobjectInitList->getLocStart(),
+                   diag::warn_missing_braces)
+        << StructuredSubobjectInitList->getSourceRange()
+        << FixItHint::CreateInsertion(
+              StructuredSubobjectInitList->getLocStart(), "{")
+        << FixItHint::CreateInsertion(
+              SemaRef.PP.getLocForEndOfToken(
                                       StructuredSubobjectInitList->getLocEnd()),
-                                  "}");
+              "}");
+    }
   }
 }
 
@@ -565,18 +571,31 @@ void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
                                             unsigned &StructuredIndex,
                                             bool TopLevelObject) {
   assert(IList->isExplicit() && "Illegal Implicit InitListExpr");
-  SyntacticToSemantic[IList] = StructuredList;
-  StructuredList->setSyntacticForm(IList);
+  if (!VerifyOnly) {
+    SyntacticToSemantic[IList] = StructuredList;
+    StructuredList->setSyntacticForm(IList);
+  }
   CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
                         Index, StructuredList, StructuredIndex, TopLevelObject);
-  QualType ExprTy = T.getNonLValueExprType(SemaRef.Context);
-  IList->setType(ExprTy);
-  StructuredList->setType(ExprTy);
+  if (!VerifyOnly) {
+    QualType ExprTy = T.getNonLValueExprType(SemaRef.Context);
+    IList->setType(ExprTy);
+    StructuredList->setType(ExprTy);
+  }
   if (hadError)
     return;
 
   if (Index < IList->getNumInits()) {
     // We have leftover initializers
+    if (VerifyOnly) {
+      if (SemaRef.getLangOptions().CPlusPlus ||
+          (SemaRef.getLangOptions().OpenCL &&
+           IList->getType()->isVectorType())) {
+        hadError = true;
+      }
+      return;
+    }
+
     if (StructuredIndex == 1 &&
         IsStringInit(StructuredList->getInit(0), T, SemaRef.Context)) {
       unsigned DK = diag::warn_excess_initializers_in_char_array_initializer;
@@ -613,7 +632,8 @@ void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
     }
   }
 
-  if (T->isScalarType() && IList->getNumInits() == 1 && !TopLevelObject)
+  if (!VerifyOnly && T->isScalarType() && IList->getNumInits() == 1 &&
+      !TopLevelObject)
     SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init)
       << IList->getSourceRange()
       << FixItHint::CreateRemoval(IList->getLocStart())
@@ -658,8 +678,9 @@ void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
   } else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
     // This type is invalid, issue a diagnostic.
     ++Index;
-    SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
-      << DeclType;
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
+        << DeclType;
     hadError = true;
   } else if (DeclType->isRecordType()) {
     // C++ [dcl.init]p14:
@@ -670,19 +691,22 @@ void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
     // we have an initializer list and a destination type that is not
     // an aggregate.
     // FIXME: In C++0x, this is yet another form of initialization.
-    SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
-      << DeclType << IList->getSourceRange();
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
+        << DeclType << IList->getSourceRange();
     hadError = true;
   } else if (DeclType->isReferenceType()) {
     CheckReferenceType(Entity, IList, DeclType, Index,
                        StructuredList, StructuredIndex);
   } else if (DeclType->isObjCObjectType()) {
-    SemaRef.Diag(IList->getLocStart(), diag::err_init_objc_class)
-      << DeclType;
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(), diag::err_init_objc_class)
+        << DeclType;
     hadError = true;
   } else {
-    SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
-      << DeclType;
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
+        << DeclType;
     hadError = true;
   }
 }
@@ -741,13 +765,15 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
     InitializationSequence Seq(SemaRef, Entity, Kind, &expr, 1);
 
     if (Seq) {
-      ExprResult Result =
-        Seq.Perform(SemaRef, Entity, Kind, MultiExprArg(&expr, 1));
-      if (Result.isInvalid())
-        hadError = true;
-
-      UpdateStructuredListElement(StructuredList, StructuredIndex,
-                                  Result.takeAs<Expr>());
+      if (!VerifyOnly) {
+        ExprResult Result =
+          Seq.Perform(SemaRef, Entity, Kind, MultiExprArg(&expr, 1));
+        if (Result.isInvalid())
+          hadError = true;
+
+        UpdateStructuredListElement(StructuredList, StructuredIndex,
+                                    Result.takeAs<Expr>());
+      }
       ++Index;
       return;
     }
@@ -764,7 +790,8 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
     //   that of the expression.
     ExprResult ExprRes = SemaRef.Owned(expr);
     if ((ElemType->isRecordType() || ElemType->isVectorType()) &&
-        SemaRef.CheckSingleAssignmentConstraints(ElemType, ExprRes)
+        SemaRef.CheckSingleAssignmentConstraints(ElemType, ExprRes,
+                                                 !VerifyOnly)
           == Sema::Compatible) {
       if (ExprRes.isInvalid())
         hadError = true;
@@ -794,11 +821,13 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
                           StructuredIndex);
     ++StructuredIndex;
   } else {
-    // We cannot initialize this element, so let
-    // PerformCopyInitialization produce the appropriate diagnostic.
-    SemaRef.PerformCopyInitialization(Entity, SourceLocation(),
-                                      SemaRef.Owned(expr),
-                                      /*TopLevelOfInitList=*/true);
+    if (!VerifyOnly) {
+      // We cannot initialize this element, so let
+      // PerformCopyInitialization produce the appropriate diagnostic.
+      SemaRef.PerformCopyInitialization(Entity, SourceLocation(),
+                                        SemaRef.Owned(expr),
+                                        /*TopLevelOfInitList=*/true);
+    }
     hadError = true;
     ++Index;
     ++StructuredIndex;
@@ -825,7 +854,7 @@ void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
 
   // This is an extension in C.  (The builtin _Complex type does not exist
   // in the C++ standard.)
-  if (!SemaRef.getLangOptions().CPlusPlus)
+  if (!SemaRef.getLangOptions().CPlusPlus && !VerifyOnly)
     SemaRef.Diag(IList->getLocStart(), diag::ext_complex_component_init)
       << IList->getSourceRange();
 
@@ -848,8 +877,10 @@ void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
                                       InitListExpr *StructuredList,
                                       unsigned &StructuredIndex) {
   if (Index >= IList->getNumInits()) {
-    SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer)
-      << IList->getSourceRange();
+    // FIXME: Allowed in C++11.
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer)
+        << IList->getSourceRange();
     hadError = true;
     ++Index;
     ++StructuredIndex;
@@ -858,23 +889,32 @@ void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
 
   Expr *expr = IList->getInit(Index);
   if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
-    SemaRef.Diag(SubIList->getLocStart(),
-                 diag::warn_many_braces_around_scalar_init)
-      << SubIList->getSourceRange();
+    if (!VerifyOnly)
+      SemaRef.Diag(SubIList->getLocStart(),
+                   diag::warn_many_braces_around_scalar_init)
+        << SubIList->getSourceRange();
 
     CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
                     StructuredIndex);
     return;
   } else if (isa<DesignatedInitExpr>(expr)) {
-    SemaRef.Diag(expr->getSourceRange().getBegin(),
-                 diag::err_designator_for_scalar_init)
-      << DeclType << expr->getSourceRange();
+    if (!VerifyOnly)
+      SemaRef.Diag(expr->getSourceRange().getBegin(),
+                   diag::err_designator_for_scalar_init)
+        << DeclType << expr->getSourceRange();
     hadError = true;
     ++Index;
     ++StructuredIndex;
     return;
   }
 
+  if (VerifyOnly) {
+    if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(expr)))
+      hadError = true;
+    ++Index;
+    return;
+  }
+
   ExprResult Result =
     SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(),
                                       SemaRef.Owned(expr),
@@ -904,47 +944,57 @@ void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
                                          unsigned &Index,
                                          InitListExpr *StructuredList,
                                          unsigned &StructuredIndex) {
-  if (Index < IList->getNumInits()) {
-    Expr *expr = IList->getInit(Index);
-    if (isa<InitListExpr>(expr)) {
-      SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
-        << DeclType << IList->getSourceRange();
-      hadError = true;
-      ++Index;
-      ++StructuredIndex;
-      return;
-    }
-
-    ExprResult Result =
-      SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(),
-                                        SemaRef.Owned(expr),
-                                        /*TopLevelOfInitList=*/true);
-
-    if (Result.isInvalid())
-      hadError = true;
-
-    expr = Result.takeAs<Expr>();
-    IList->setInit(Index, expr);
-
-    if (hadError)
-      ++StructuredIndex;
-    else
-      UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
-    ++Index;
-  } else {
+  if (Index >= IList->getNumInits()) {
     // FIXME: It would be wonderful if we could point at the actual member. In
     // general, it would be useful to pass location information down the stack,
     // so that we know the location (or decl) of the "current object" being
     // initialized.
-    SemaRef.Diag(IList->getLocStart(),
-                  diag::err_init_reference_member_uninitialized)
-      << DeclType
-      << IList->getSourceRange();
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(),
+                    diag::err_init_reference_member_uninitialized)
+        << DeclType
+        << IList->getSourceRange();
     hadError = true;
     ++Index;
     ++StructuredIndex;
     return;
   }
+
+  Expr *expr = IList->getInit(Index);
+  if (isa<InitListExpr>(expr)) {
+    // FIXME: Allowed in C++11.
+    if (!VerifyOnly)
+      SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
+        << DeclType << IList->getSourceRange();
+    hadError = true;
+    ++Index;
+    ++StructuredIndex;
+    return;
+  }
+
+  if (VerifyOnly) {
+    if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(expr)))
+      hadError = true;
+    ++Index;
+    return;
+  }
+
+  ExprResult Result =
+    SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(),
+                                      SemaRef.Owned(expr),
+                                      /*TopLevelOfInitList=*/true);
+
+  if (Result.isInvalid())
+    hadError = true;
+
+  expr = Result.takeAs<Expr>();
+  IList->setInit(Index, expr);
+
+  if (hadError)
+    ++StructuredIndex;
+  else
+    UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
+  ++Index;
 }
 
 void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
@@ -965,6 +1015,13 @@ void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
     // instead of breaking it apart (which is doomed to failure anyway).
     Expr *Init = IList->getInit(Index);
     if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
+      if (VerifyOnly) {
+        if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(Init)))
+          hadError = true;
+        ++Index;
+        return;
+      }
+
       ExprResult Result =
         SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(),
                                           SemaRef.Owned(Init),
@@ -984,7 +1041,8 @@ void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
       if (hadError)
         ++StructuredIndex;
       else
-        UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
+        UpdateStructuredListElement(StructuredList, StructuredIndex,
+                                    ResultExpr);
       ++Index;
       return;
     }
@@ -1037,11 +1095,11 @@ void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
   }
 
   // OpenCL requires all elements to be initialized.
-  if (numEltsInit != maxElements)
-    if (SemaRef.getLangOptions().OpenCL)
-      SemaRef.Diag(IList->getSourceRange().getBegin(),
-                   diag::err_vector_incorrect_num_initializers)
-        << (numEltsInit < maxElements) << maxElements << numEltsInit;
+  // FIXME: Shouldn't this set hadError to true then?
+  if (numEltsInit != maxElements && !VerifyOnly)
+    SemaRef.Diag(IList->getSourceRange().getBegin(),
+                 diag::err_vector_incorrect_num_initializers)
+      << (numEltsInit < maxElements) << maxElements << numEltsInit;
 }
 
 void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
@@ -1063,8 +1121,10 @@ void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
       // of the structured initializer list doesn't match exactly,
       // because doing so would involve allocating one character
       // constant for each string.
-      UpdateStructuredListElement(StructuredList, StructuredIndex, Str);
-      StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
+      if (!VerifyOnly) {
+        UpdateStructuredListElement(StructuredList, StructuredIndex, Str);
+        StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
+      }
       ++Index;
       return;
     }
@@ -1073,9 +1133,10 @@ void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
     // Check for VLAs; in standard C it would be possible to check this
     // earlier, but I don't know where clang accepts VLAs (gcc accepts
     // them in all sorts of strange places).
-    SemaRef.Diag(VAT->getSizeExpr()->getLocStart(),
-                  diag::err_variable_object_no_init)
-      << VAT->getSizeExpr()->getSourceRange();
+    if (!VerifyOnly)
+      SemaRef.Diag(VAT->getSizeExpr()->getLocStart(),
+                    diag::err_variable_object_no_init)
+        << VAT->getSizeExpr()->getSourceRange();
     hadError = true;
     ++Index;
     ++StructuredIndex;
@@ -1145,7 +1206,7 @@ void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
     if (!maxElementsKnown && elementIndex > maxElements)
       maxElements = elementIndex;
   }
-  if (!hadError && DeclType->isIncompleteArrayType()) {
+  if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
     // If this is an incomplete array type, the actual type needs to
     // be calculated here.
     llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
@@ -1188,12 +1249,14 @@ bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
     // Allow other cases.
     FlexArrayDiag = diag::ext_flexible_array_init;
   }
-  
-  SemaRef.Diag(InitExpr->getSourceRange().getBegin(),
-               FlexArrayDiag)
-    << InitExpr->getSourceRange().getBegin();
-  SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
-    << Field;
+
+  if (!VerifyOnly) {
+    SemaRef.Diag(InitExpr->getSourceRange().getBegin(),
+                 FlexArrayDiag)
+      << InitExpr->getSourceRange().getBegin();
+    SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
+      << Field;
+  }
 
   return FlexArrayDiag != diag::ext_flexible_array_init;
 }
@@ -1217,13 +1280,15 @@ void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity,
   }
 
   if (DeclType->isUnionType() && IList->getNumInits() == 0) {
-    // Value-initialize the first named member of the union.
-    RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
-    for (RecordDecl::field_iterator FieldEnd = RD->field_end();
-         Field != FieldEnd; ++Field) {
-      if (Field->getDeclName()) {
-        StructuredList->setInitializedFieldInUnion(*Field);
-        break;
+    if (!VerifyOnly) {
+      // Value-initialize the first named member of the union.
+      RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
+      for (RecordDecl::field_iterator FieldEnd = RD->field_end();
+           Field != FieldEnd; ++Field) {
+        if (Field->getDeclName()) {
+          StructuredList->setInitializedFieldInUnion(*Field);
+          break;
+        }
       }
     }
     return;
@@ -1283,13 +1348,18 @@ void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity,
     }
 
     // Make sure we can use this declaration.
-    if (SemaRef.DiagnoseUseOfDecl(*Field, 
-                                  IList->getInit(Index)->getLocStart())) {
+    bool InvalidUse;
+    if (VerifyOnly)
+      InvalidUse = !SemaRef.CanUseDecl(*Field);
+    else
+      InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field,
+                                          IList->getInit(Index)->getLocStart());
+    if (InvalidUse) {
       ++Index;
       ++Field;
       hadError = true;
       continue;
-    }        
+    }
 
     InitializedEntity MemberEntity =
       InitializedEntity::InitializeMember(*Field, &Entity);
@@ -1297,7 +1367,7 @@ void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity,
                         StructuredList, StructuredIndex);
     InitializedSomething = true;
 
-    if (DeclType->isUnionType()) {
+    if (DeclType->isUnionType() && !VerifyOnly) {
       // Initialize the first field within the union.
       StructuredList->setInitializedFieldInUnion(*Field);
     }
@@ -1306,8 +1376,9 @@ void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity,
   }
 
   // Emit warnings for missing struct field initializers.
-  if (InitializedSomething && CheckForMissingFields && Field != FieldEnd &&
-      !Field->getType()->isIncompleteArrayType() && !DeclType->isUnionType()) {
+  if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
+      Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
+      !DeclType->isUnionType()) {
     // It is possible we have one or more unnamed bitfields remaining.
     // Find first (if any) named field and emit warning.
     for (RecordDecl::field_iterator it = Field, end = RD->field_end();
@@ -1388,6 +1459,18 @@ static IndirectFieldDecl *FindIndirectFieldDesignator(FieldDecl *AnonField,
   return 0;
 }
 
+static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
+                                                   DesignatedInitExpr *DIE) {
+  unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
+  SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
+  for (unsigned I = 0; I < NumIndexExprs; ++I)
+    IndexExprs[I] = DIE->getSubExpr(I + 1);
+  return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators_begin(),
+                                    DIE->size(), IndexExprs.data(),
+                                    NumIndexExprs, DIE->getEqualOrColonLoc(),
+                                    DIE->usesGNUSyntax(), DIE->getInit());
+}
+
 /// @brief Check the well-formedness of a C99 designated initializer.
 ///
 /// Determines whether the designated initializer @p DIE, which
@@ -1426,14 +1509,14 @@ static IndirectFieldDecl *FindIndirectFieldDesignator(FieldDecl *AnonField,
 bool
 InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
                                             InitListExpr *IList,
-                                      DesignatedInitExpr *DIE,
-                                      unsigned DesigIdx,
-                                      QualType &CurrentObjectType,
-                                      RecordDecl::field_iterator *NextField,
-                                      llvm::APSInt *NextElementIndex,
-                                      unsigned &Index,
-                                      InitListExpr *StructuredList,
-                                      unsigned &StructuredIndex,
+                                            DesignatedInitExpr *DIE,
+                                            unsigned DesigIdx,
+                                            QualType &CurrentObjectType,
+                                          RecordDecl::field_iterator *NextField,
+                                            llvm::APSInt *NextElementIndex,
+                                            unsigned &Index,
+                                            InitListExpr *StructuredList,
+                                            unsigned &StructuredIndex,
                                             bool FinishSubobjectInit,
                                             bool TopLevelObject) {
   if (DesigIdx == DIE->size()) {
@@ -1458,19 +1541,21 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
     return hadError && !prevHadError;
   }
 
-  bool IsFirstDesignator = (DesigIdx == 0);
-  assert((IsFirstDesignator || StructuredList) &&
-         "Need a non-designated initializer list to start from");
-
   DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
-  // Determine the structural initializer list that corresponds to the
-  // current subobject.
-  StructuredList = IsFirstDesignator? SyntacticToSemantic[IList]
-    : getStructuredSubobjectInit(IList, Index, CurrentObjectType,
-                                 StructuredList, StructuredIndex,
-                                 SourceRange(D->getStartLocation(),
-                                             DIE->getSourceRange().getEnd()));
-  assert(StructuredList && "Expected a structured initializer list");
+  bool IsFirstDesignator = (DesigIdx == 0);
+  if (!VerifyOnly) {
+    assert((IsFirstDesignator || StructuredList) &&
+           "Need a non-designated initializer list to start from");
+
+    // Determine the structural initializer list that corresponds to the
+    // current subobject.
+    StructuredList = IsFirstDesignator? SyntacticToSemantic[IList]
+      : getStructuredSubobjectInit(IList, Index, CurrentObjectType,
+                                   StructuredList, StructuredIndex,
+                                   SourceRange(D->getStartLocation(),
+                                               DIE->getSourceRange().getEnd()));
+    assert(StructuredList && "Expected a structured initializer list");
+  }
 
   if (D->isFieldDesignator()) {
     // C99 6.7.8p7:
@@ -1487,8 +1572,9 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
       SourceLocation Loc = D->getDotLoc();
       if (Loc.isInvalid())
         Loc = D->getFieldLoc();
-      SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
-        << SemaRef.getLangOptions().CPlusPlus << CurrentObjectType;
+      if (!VerifyOnly)
+        SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
+          << SemaRef.getLangOptions().CPlusPlus << CurrentObjectType;
       ++Index;
       return true;
     }
@@ -1511,6 +1597,9 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
       if (!KnownField && Field->isAnonymousStructOrUnion()) {
         if (IndirectFieldDecl *IF =
             FindIndirectFieldDesignator(*Field, FieldName)) {
+          // In verify mode, don't modify the original.
+          if (VerifyOnly)
+            DIE = CloneDesignatedInitExpr(SemaRef, DIE);
           ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IF);
           D = DIE->getDesignator(DesigIdx);
           break;
@@ -1525,6 +1614,9 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
     }
 
     if (Field == FieldEnd) {
+      if (VerifyOnly)
+        return true; // No typo correction when just trying this out.
+
       // There was no normal field in the struct with the designated
       // name. Perform another lookup for this name, which may find
       // something that we can't designate (e.g., a member function),
@@ -1594,22 +1686,30 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
     // the initializer list.
     if (RT->getDecl()->isUnion()) {
       FieldIndex = 0;
-      StructuredList->setInitializedFieldInUnion(*Field);
+      if (!VerifyOnly)
+        StructuredList->setInitializedFieldInUnion(*Field);
     }
 
     // Make sure we can use this declaration.
-    if (SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc())) {
+    bool InvalidUse;
+    if (VerifyOnly)
+      InvalidUse = !SemaRef.CanUseDecl(*Field);
+    else
+      InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
+    if (InvalidUse) {
       ++Index;
       return true;
-    }        
+    }
 
-    // Update the designator with the field declaration.
-    D->setField(*Field);
+    if (!VerifyOnly) {
+      // Update the designator with the field declaration.
+      D->setField(*Field);
 
-    // Make sure that our non-designated initializer list has space
-    // for a subobject corresponding to this field.
-    if (FieldIndex >= StructuredList->getNumInits())
-      StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
+      // Make sure that our non-designated initializer list has space
+      // for a subobject corresponding to this field.
+      if (FieldIndex >= StructuredList->getNumInits())
+        StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
+    }
 
     // This designator names a flexible array member.
     if (Field->getType()->isIncompleteArrayType()) {
@@ -1617,25 +1717,29 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
       if ((DesigIdx + 1) != DIE->size()) {
         // We can't designate an object within the flexible array
         // member (because GCC doesn't allow it).
-        DesignatedInitExpr::Designator *NextD
-          = DIE->getDesignator(DesigIdx + 1);
-        SemaRef.Diag(NextD->getStartLocation(),
-                      diag::err_designator_into_flexible_array_member)
-          << SourceRange(NextD->getStartLocation(),
-                         DIE->getSourceRange().getEnd());
-        SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
-          << *Field;
+        if (!VerifyOnly) {
+          DesignatedInitExpr::Designator *NextD
+            = DIE->getDesignator(DesigIdx + 1);
+          SemaRef.Diag(NextD->getStartLocation(),
+                        diag::err_designator_into_flexible_array_member)
+            << SourceRange(NextD->getStartLocation(),
+                           DIE->getSourceRange().getEnd());
+          SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
+            << *Field;
+        }
         Invalid = true;
       }
 
       if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
           !isa<StringLiteral>(DIE->getInit())) {
         // The initializer is not an initializer list.
-        SemaRef.Diag(DIE->getInit()->getSourceRange().getBegin(),
-                      diag::err_flexible_array_init_needs_braces)
-          << DIE->getInit()->getSourceRange();
-        SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
-          << *Field;
+        if (!VerifyOnly) {
+          SemaRef.Diag(DIE->getInit()->getSourceRange().getBegin(),
+                        diag::err_flexible_array_init_needs_braces)
+            << DIE->getInit()->getSourceRange();
+          SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
+            << *Field;
+        }
         Invalid = true;
       }
 
@@ -1729,8 +1833,9 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
   //      [ constant-expression ... constant-expression ]
   const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
   if (!AT) {
-    SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
-      << CurrentObjectType;
+    if (!VerifyOnly)
+      SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
+        << CurrentObjectType;
     ++Index;
     return true;
   }
@@ -1756,7 +1861,7 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
     // elements with something that has a side effect, so codegen can emit an
     // "error unsupported" error instead of miscompiling the app.
     if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
-        DIE->getInit()->HasSideEffects(SemaRef.Context))
+        DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
       FullyStructuredList->sawArrayRangeDesignator();
   }
 
@@ -1769,10 +1874,11 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
       = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
     DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
     if (DesignatedEndIndex >= MaxElements) {
-      SemaRef.Diag(IndexExpr->getSourceRange().getBegin(),
-                    diag::err_array_designator_too_large)
-        << DesignatedEndIndex.toString(10) << MaxElements.toString(10)
-        << IndexExpr->getSourceRange();
+      if (VerifyOnly)
+        SemaRef.Diag(IndexExpr->getSourceRange().getBegin(),
+                      diag::err_array_designator_too_large)
+          << DesignatedEndIndex.toString(10) << MaxElements.toString(10)
+          << IndexExpr->getSourceRange();
       ++Index;
       return true;
     }
@@ -1791,7 +1897,8 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
 
   // Make sure that our non-designated initializer list has space
   // for a subobject corresponding to this array element.
-  if (DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
+  if (!VerifyOnly &&
+      DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
     StructuredList->resizeInits(SemaRef.Context,
                                 DesignatedEndIndex.getZExtValue() + 1);
 
@@ -1851,6 +1958,8 @@ InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
                                             InitListExpr *StructuredList,
                                             unsigned StructuredIndex,
                                             SourceRange InitRange) {
+  if (VerifyOnly)
+    return 0; // No structured list in verification-only mode.
   Expr *ExistingInit = 0;
   if (!StructuredList)
     ExistingInit = SyntacticToSemantic[IList];
@@ -2628,47 +2737,33 @@ static void TryListInitialization(Sema &S,
                                   const InitializationKind &Kind,
                                   InitListExpr *InitList,
                                   InitializationSequence &Sequence) {
-  // FIXME: We only perform rudimentary checking of list
-  // initializations at this point, then assume that any list
-  // initialization of an array, aggregate, or scalar will be
-  // well-formed. When we actually "perform" list initialization, we'll
-  // do all of the necessary checking.  C++0x initializer lists will
-  // force us to perform more checking here.
-
   QualType DestType = Entity.getType();
 
-  // C++ [dcl.init]p13:
-  //   If T is a scalar type, then a declaration of the form
-  //
-  //     T x = { a };
-  //
-  //   is equivalent to
-  //
-  //     T x = a;
-  if (DestType->isAnyComplexType()) {
-    // We allow more than 1 init for complex types in some cases, even though
-    // they are scalar.
-  } else if (DestType->isScalarType()) {
-    if (InitList->getNumInits() > 1 && S.getLangOptions().CPlusPlus) {
-      Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
-      return;
-    }
-
-    // Assume scalar initialization from a single value works.
-  } else if (DestType->isAggregateType()) {
-    // Assume aggregate initialization works.
-  } else if (DestType->isVectorType()) {
-    // Assume vector initialization works.
-  } else if (DestType->isReferenceType()) {
-    // FIXME: C++0x defines behavior for this.
+  // C++ doesn't allow scalar initialization with more than one argument.
+  // But C99 complex numbers are scalars and it makes sense there.
+  if (S.getLangOptions().CPlusPlus && DestType->isScalarType() &&
+      !DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
+    Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
+    return;
+  }
+  // FIXME: C++0x defines behavior for these two cases.
+  if (DestType->isReferenceType()) {
     Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
     return;
-  } else if (DestType->isRecordType()) {
-    // FIXME: C++0x defines behavior for this
+  }
+  if (DestType->isRecordType() && !DestType->isAggregateType()) {
     Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
+    return;
+  }
+
+  InitListChecker CheckInitList(S, Entity, InitList,
+          DestType, /*VerifyOnly=*/true);
+  if (CheckInitList.HadError()) {
+    Sequen