Don't treat a non-deduced 'auto' type as being type-dependent. Instead, there
are now two distinct canonical 'AutoType's: one is the undeduced 'auto'
placeholder type, and the other is a deduced-but-dependent type. All
deduced-to-a-non-dependent-type cases are still non-canonical.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180789 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index de6a30a..49a470e 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -1597,7 +1597,8 @@
case Type::Auto: {
const AutoType *A = cast<AutoType>(T);
- assert(A->isDeduced() && "Cannot request the size of a dependent type");
+ assert(!A->getDeducedType().isNull() &&
+ "cannot request the size of an undeduced or dependent auto type");
return getTypeInfo(A->getDeducedType().getTypePtr());
}
@@ -3564,18 +3565,20 @@
/// getAutoType - We only unique auto types after they've been deduced.
QualType ASTContext::getAutoType(QualType DeducedType,
- bool IsDecltypeAuto) const {
+ bool IsDecltypeAuto,
+ bool IsDependent) const {
void *InsertPos = 0;
if (!DeducedType.isNull()) {
// Look in the folding set for an existing type.
llvm::FoldingSetNodeID ID;
- AutoType::Profile(ID, DeducedType, IsDecltypeAuto);
+ AutoType::Profile(ID, DeducedType, IsDecltypeAuto, IsDependent);
if (AutoType *AT = AutoTypes.FindNodeOrInsertPos(ID, InsertPos))
return QualType(AT, 0);
}
AutoType *AT = new (*this, TypeAlignment) AutoType(DeducedType,
- IsDecltypeAuto);
+ IsDecltypeAuto,
+ IsDependent);
Types.push_back(AT);
if (InsertPos)
AutoTypes.InsertNode(AT, InsertPos);
@@ -5387,6 +5390,11 @@
// FIXME. We should do a better job than gcc.
return;
+ case Type::Auto:
+ // We could see an undeduced auto type here during error recovery.
+ // Just ignore it.
+ return;
+
#define ABSTRACT_TYPE(KIND, BASE)
#define TYPE(KIND, BASE)
#define DEPENDENT_TYPE(KIND, BASE) \
@@ -7028,6 +7036,7 @@
#include "clang/AST/TypeNodes.def"
llvm_unreachable("Non-canonical and dependent types shouldn't get here");
+ case Type::Auto:
case Type::LValueReference:
case Type::RValueReference:
case Type::MemberPointer:
diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index 7922c33..fa16fac 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -2105,6 +2105,11 @@
assert(T->isInstantiationDependentType());
return CachedProperties(ExternalLinkage, false);
+ case Type::Auto:
+ // Give non-deduced 'auto' types external linkage. We should only see them
+ // here in error recovery.
+ return CachedProperties(ExternalLinkage, false);
+
case Type::Builtin:
// C++ [basic.link]p8:
// A type is said to have linkage if and only if:
@@ -2206,6 +2211,9 @@
case Type::Builtin:
return LinkageInfo::external();
+ case Type::Auto:
+ return LinkageInfo::external();
+
case Type::Record:
case Type::Enum:
return cast<TagType>(T)->getDecl()->getLinkageAndVisibility();
diff --git a/lib/AST/TypePrinter.cpp b/lib/AST/TypePrinter.cpp
index 07bcb74..0437076 100644
--- a/lib/AST/TypePrinter.cpp
+++ b/lib/AST/TypePrinter.cpp
@@ -776,7 +776,7 @@
void TypePrinter::printAutoBefore(const AutoType *T, raw_ostream &OS) {
// If the type has been deduced, do not print 'auto'.
- if (T->isDeduced()) {
+ if (!T->getDeducedType().isNull()) {
printBefore(T->getDeducedType(), OS);
} else {
OS << (T->isDecltypeAuto() ? "decltype(auto)" : "auto");
@@ -785,7 +785,7 @@
}
void TypePrinter::printAutoAfter(const AutoType *T, raw_ostream &OS) {
// If the type has been deduced, do not print 'auto'.
- if (T->isDeduced())
+ if (!T->getDeducedType().isNull())
printAfter(T->getDeducedType(), OS);
}
diff --git a/lib/CodeGen/CGRTTI.cpp b/lib/CodeGen/CGRTTI.cpp
index 869843c..40dc6bf 100644
--- a/lib/CodeGen/CGRTTI.cpp
+++ b/lib/CodeGen/CGRTTI.cpp
@@ -412,6 +412,9 @@
case Type::RValueReference:
llvm_unreachable("References shouldn't get here");
+ case Type::Auto:
+ llvm_unreachable("Undeduced auto type shouldn't get here");
+
case Type::Builtin:
// GCC treats vector and complex types as fundamental types.
case Type::Vector:
@@ -619,6 +622,9 @@
case Type::RValueReference:
llvm_unreachable("References shouldn't get here");
+ case Type::Auto:
+ llvm_unreachable("Undeduced auto type shouldn't get here");
+
case Type::ConstantArray:
case Type::IncompleteArray:
case Type::VariableArray:
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index a12e7dc..0daae58 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -91,6 +91,9 @@
#include "clang/AST/TypeNodes.def"
llvm_unreachable("non-canonical or dependent type in IR-generation");
+ case Type::Auto:
+ llvm_unreachable("undeduced auto type in IR-generation");
+
// Various scalar types.
case Type::Builtin:
case Type::Pointer:
diff --git a/lib/CodeGen/CodeGenTypes.cpp b/lib/CodeGen/CodeGenTypes.cpp
index 6f6e52c..4240216 100644
--- a/lib/CodeGen/CodeGenTypes.cpp
+++ b/lib/CodeGen/CodeGenTypes.cpp
@@ -392,6 +392,8 @@
}
break;
}
+ case Type::Auto:
+ llvm_unreachable("Unexpected undeduced auto type!");
case Type::Complex: {
llvm::Type *EltTy = ConvertType(cast<ComplexType>(Ty)->getElementType());
ResultType = llvm::StructType::get(EltTy, EltTy, NULL);
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index ab8be57..181deb6 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -1456,6 +1456,8 @@
if (!InitExpr.isInvalid())
Actions.AddInitializerToDecl(DeclOut, InitExpr.take(), !CopyInitialization,
DS.containsPlaceholderType());
+ else
+ Actions.ActOnInitializerError(DeclOut);
// FIXME: Build a reference to this declaration? Convert it to bool?
// (This is currently handled by Sema).
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 9a3499d..1e5e5bb 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2798,8 +2798,7 @@
QualType MergedT;
if (getLangOpts().CPlusPlus) {
- AutoType *AT = New->getType()->getContainedAutoType();
- if (AT && !AT->isDeduced()) {
+ if (New->getType()->isUndeducedType()) {
// We don't know what the new type is until the initializer is attached.
return;
} else if (Context.hasSameType(New->getType(), Old->getType())) {
@@ -5142,27 +5141,18 @@
return ND->isExternC();
}
-/// \brief Perform semantic checking on a newly-created variable
-/// declaration.
-///
-/// This routine performs all of the type-checking required for a
-/// variable declaration once it has been built. It is used both to
-/// check variables after they have been parsed and their declarators
-/// have been translated into a declaration, and to check variables
-/// that have been instantiated from a template.
-///
-/// Sets NewVD->isInvalidDecl() if an error was encountered.
-///
-/// Returns true if the variable declaration is a redeclaration.
-bool Sema::CheckVariableDeclaration(VarDecl *NewVD,
- LookupResult &Previous) {
+void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
// If the decl is already known invalid, don't check it.
if (NewVD->isInvalidDecl())
- return false;
+ return;
TypeSourceInfo *TInfo = NewVD->getTypeSourceInfo();
QualType T = TInfo->getType();
+ // Defer checking an 'auto' type until its initializer is attached.
+ if (T->isUndeducedType())
+ return;
+
if (T->isObjCObjectType()) {
Diag(NewVD->getLocation(), diag::err_statically_allocated_object)
<< FixItHint::CreateInsertion(NewVD->getLocation(), "*");
@@ -5177,7 +5167,7 @@
if (NewVD->hasLocalStorage() && T.getAddressSpace() != 0) {
Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl);
NewVD->setInvalidDecl();
- return false;
+ return;
}
// OpenCL v1.2 s6.5 - All program scope variables must be declared in the
@@ -5187,7 +5177,7 @@
&& !T->isSamplerT()){
Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space);
NewVD->setInvalidDecl();
- return false;
+ return;
}
// OpenCL v1.2 s6.8 -- The static qualifier is valid only in program
@@ -5196,7 +5186,7 @@
&& NewVD->isStaticLocal()) {
Diag(NewVD->getLocation(), diag::err_static_function_scope);
NewVD->setInvalidDecl();
- return false;
+ return;
}
if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
@@ -5237,7 +5227,7 @@
Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage)
<< SizeRange;
NewVD->setInvalidDecl();
- return false;
+ return;
}
if (FixedTInfo == 0) {
@@ -5246,7 +5236,7 @@
else
Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage);
NewVD->setInvalidDecl();
- return false;
+ return;
}
Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size);
@@ -5254,6 +5244,54 @@
NewVD->setTypeSourceInfo(FixedTInfo);
}
+ if (T->isVoidType() && NewVD->isThisDeclarationADefinition()) {
+ Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
+ << T;
+ NewVD->setInvalidDecl();
+ return;
+ }
+
+ if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
+ Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
+ NewVD->setInvalidDecl();
+ return;
+ }
+
+ if (isVM && NewVD->hasAttr<BlocksAttr>()) {
+ Diag(NewVD->getLocation(), diag::err_block_on_vm);
+ NewVD->setInvalidDecl();
+ return;
+ }
+
+ if (NewVD->isConstexpr() && !T->isDependentType() &&
+ RequireLiteralType(NewVD->getLocation(), T,
+ diag::err_constexpr_var_non_literal)) {
+ // Can't perform this check until the type is deduced.
+ NewVD->setInvalidDecl();
+ return;
+ }
+}
+
+/// \brief Perform semantic checking on a newly-created variable
+/// declaration.
+///
+/// This routine performs all of the type-checking required for a
+/// variable declaration once it has been built. It is used both to
+/// check variables after they have been parsed and their declarators
+/// have been translated into a declaration, and to check variables
+/// that have been instantiated from a template.
+///
+/// Sets NewVD->isInvalidDecl() if an error was encountered.
+///
+/// Returns true if the variable declaration is a redeclaration.
+bool Sema::CheckVariableDeclaration(VarDecl *NewVD,
+ LookupResult &Previous) {
+ CheckVariableDeclarationType(NewVD);
+
+ // If the decl is already known invalid, don't check it.
+ if (NewVD->isInvalidDecl())
+ return false;
+
// If we did not find anything by this name, look for a non-visible
// extern "C" declaration with the same name.
//
@@ -5292,32 +5330,6 @@
// Filter out any non-conflicting previous declarations.
filterNonConflictingPreviousDecls(Context, NewVD, Previous);
- if (T->isVoidType() && NewVD->isThisDeclarationADefinition()) {
- Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
- << T;
- NewVD->setInvalidDecl();
- return false;
- }
-
- if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
- Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
- NewVD->setInvalidDecl();
- return false;
- }
-
- if (isVM && NewVD->hasAttr<BlocksAttr>()) {
- Diag(NewVD->getLocation(), diag::err_block_on_vm);
- NewVD->setInvalidDecl();
- return false;
- }
-
- if (NewVD->isConstexpr() && !T->isDependentType() &&
- RequireLiteralType(NewVD->getLocation(), T,
- diag::err_constexpr_var_non_literal)) {
- NewVD->setInvalidDecl();
- return false;
- }
-
if (!Previous.empty()) {
MergeVarDecl(NewVD, Previous, PreviousWasHidden);
return true;
@@ -7284,10 +7296,7 @@
ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
// C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
- AutoType *Auto = 0;
- if (TypeMayContainAuto &&
- (Auto = VDecl->getType()->getContainedAutoType()) &&
- !Auto->isDeduced()) {
+ if (TypeMayContainAuto && VDecl->getType()->isUndeducedType()) {
Expr *DeduceInit = Init;
// Initializer could be a C++ direct-initializer. Deduction only works if it
// contains exactly one expression.
@@ -7357,6 +7366,11 @@
// the previously declared type.
if (VarDecl *Old = VDecl->getPreviousDecl())
MergeVarDeclTypes(VDecl, Old, /*OldWasHidden*/ false);
+
+ // Check the deduced type is valid for a variable declaration.
+ CheckVariableDeclarationType(VDecl);
+ if (VDecl->isInvalidDecl())
+ return;
}
if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) {
@@ -8190,8 +8204,8 @@
// Don't reissue diagnostics when instantiating a template.
if (AT && D->isInvalidDecl())
break;
- if (AT && AT->isDeduced()) {
- QualType U = AT->getDeducedType();
+ QualType U = AT ? AT->getDeducedType() : QualType();
+ if (!U.isNull()) {
CanQualType UCanon = Context.getCanonicalType(U);
if (Deduced.isNull()) {
Deduced = U;
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index c05d29d..df09b4b 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -1118,9 +1118,7 @@
HaveCompleteInit = true;
// C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
- AutoType *AT = 0;
- if (TypeMayContainAuto &&
- (AT = AllocType->getContainedAutoType()) && !AT->isDeduced()) {
+ if (TypeMayContainAuto && AllocType->isUndeducedType()) {
if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
<< AllocType << TypeRange);
@@ -2279,6 +2277,9 @@
ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar,
SourceLocation StmtLoc,
bool ConvertToBoolean) {
+ if (ConditionVar->isInvalidDecl())
+ return ExprError();
+
QualType T = ConditionVar->getType();
// C++ [stmt.select]p2:
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index eab2d81..85a7449 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -2087,6 +2087,10 @@
case Type::Complex:
break;
+ // Non-deduced auto types only get here for error cases.
+ case Type::Auto:
+ break;
+
// If T is an Objective-C object or interface type, or a pointer to an
// object or interface type, the associated namespace is the global
// namespace.
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 4fc1818..63c2a7d 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -1923,7 +1923,15 @@
StmtResult BeginEndDecl = BeginEnd;
ExprResult NotEqExpr = Cond, IncrExpr = Inc;
- if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) {
+ if (RangeVarType->isDependentType()) {
+ // The range is implicitly used as a placeholder when it is dependent.
+ RangeVar->setUsed();
+
+ // Deduce any 'auto's in the loop variable as 'DependentTy'. We'll fill
+ // them in properly when we instantiate the loop.
+ if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check)
+ LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy));
+ } else if (!BeginEndDecl.get()) {
SourceLocation RangeLoc = RangeVar->getLocation();
const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
@@ -2110,9 +2118,6 @@
if (LoopVar->isInvalidDecl())
NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
}
- } else {
- // The range is implicitly used as a placeholder when it is dependent.
- RangeVar->setUsed();
}
// Don't bother to actually allocate the result if we're just trying to
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index a681371..ea5b145 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -3584,8 +3584,12 @@
NewTL.setNameLoc(TL.getNameLoc());
return Result;
} else {
- QualType Result = RebuildAutoType(Replacement,
- TL.getTypePtr()->isDecltypeAuto());
+ bool Dependent =
+ !Replacement.isNull() && Replacement->isDependentType();
+ QualType Result =
+ SemaRef.Context.getAutoType(Dependent ? QualType() : Replacement,
+ TL.getTypePtr()->isDecltypeAuto(),
+ Dependent);
AutoTypeLoc NewTL = TLB.push<AutoTypeLoc>(Result);
NewTL.setNameLoc(TL.getNameLoc());
return Result;
@@ -3597,41 +3601,6 @@
return E;
}
};
-
- /// Determine whether the specified type (which contains an 'auto' type
- /// specifier) is dependent. This is not trivial, because the 'auto' specifier
- /// itself claims to be type-dependent.
- bool isDependentAutoType(QualType Ty) {
- while (1) {
- QualType Pointee = Ty->getPointeeType();
- if (!Pointee.isNull()) {
- Ty = Pointee;
- } else if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()){
- if (MPT->getClass()->isDependentType())
- return true;
- Ty = MPT->getPointeeType();
- } else if (const FunctionProtoType *FPT = Ty->getAs<FunctionProtoType>()){
- for (FunctionProtoType::arg_type_iterator I = FPT->arg_type_begin(),
- E = FPT->arg_type_end();
- I != E; ++I)
- if ((*I)->isDependentType())
- return true;
- Ty = FPT->getResultType();
- } else if (Ty->isDependentSizedArrayType()) {
- return true;
- } else if (const ArrayType *AT = Ty->getAsArrayTypeUnsafe()) {
- Ty = AT->getElementType();
- } else if (Ty->getAs<DependentSizedExtVectorType>()) {
- return true;
- } else if (const VectorType *VT = Ty->getAs<VectorType>()) {
- Ty = VT->getElementType();
- } else {
- break;
- }
- }
- assert(Ty->getAs<AutoType>() && "didn't find 'auto' in auto type");
- return false;
- }
}
/// \brief Deduce the type for an auto type-specifier (C++0x [dcl.spec.auto]p6)
@@ -3654,8 +3623,9 @@
Init = result.take();
}
- if (Init->isTypeDependent() || isDependentAutoType(Type->getType())) {
- Result = Type;
+ if (Init->isTypeDependent() || Type->getType()->isDependentType()) {
+ Result =
+ SubstituteAutoTransform(*this, Context.DependentTy).TransformType(Type);
return DAR_Succeeded;
}
@@ -3749,6 +3719,10 @@
return DAR_Succeeded;
}
+QualType Sema::SubstAutoType(QualType Type, QualType Deduced) {
+ return SubstituteAutoTransform(*this, Deduced).TransformType(Type);
+}
+
void Sema::DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init) {
if (isa<InitListExpr>(Init))
Diag(VDecl->getLocation(),
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 8bf5143..7ed1687 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -2569,11 +2569,11 @@
if (const AutoType *AT = T->getContainedAutoType()) {
// We've already diagnosed this for decltype(auto).
- if (!AT->isDecltypeAuto()) {
+ if (!AT->isDecltypeAuto())
S.Diag(DeclType.Loc, diag::err_illegal_decl_array_of_auto)
<< getPrintableNameForEntity(Name) << T;
- D.setInvalidType(true);
- }
+ T = QualType();
+ break;
}
T = S.BuildArrayType(T, ASM, ArraySize, ATI.TypeQuals,
@@ -3831,7 +3831,7 @@
QualType &type) {
bool NonObjCPointer = false;
- if (!type->isDependentType()) {
+ if (!type->isDependentType() && !type->isUndeducedType()) {
if (const PointerType *ptr = type->getAs<PointerType>()) {
QualType pointee = ptr->getPointeeType();
if (pointee->isObjCRetainableType() || pointee->isPointerType())
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index c0bc34f..925860a 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -764,6 +764,9 @@
///
/// By default, builds a new AutoType with the given deduced type.
QualType RebuildAutoType(QualType Deduced, bool IsDecltypeAuto) {
+ // Note, IsDependent is always false here: we implicitly convert an 'auto'
+ // which has been deduced to a dependent type into an undeduced 'auto', so
+ // that we'll retry deduction after the transformation.
return SemaRef.Context.getAutoType(Deduced, IsDecltypeAuto);
}
@@ -4500,7 +4503,8 @@
}
QualType Result = TL.getType();
- if (getDerived().AlwaysRebuild() || NewDeduced != OldDeduced) {
+ if (getDerived().AlwaysRebuild() || NewDeduced != OldDeduced ||
+ T->isDependentType()) {
Result = getDerived().RebuildAutoType(NewDeduced, T->isDecltypeAuto());
if (Result.isNull())
return QualType();
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 9406c74..a5fd2e3 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -4641,7 +4641,8 @@
case TYPE_AUTO: {
QualType Deduced = readType(*Loc.F, Record, Idx);
bool IsDecltypeAuto = Record[Idx++];
- return Context.getAutoType(Deduced, IsDecltypeAuto);
+ bool IsDependent = Deduced.isNull() ? Record[Idx++] : false;
+ return Context.getAutoType(Deduced, IsDecltypeAuto, IsDependent);
}
case TYPE_RECORD: {
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 9d9d619..2d691b1 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -246,6 +246,8 @@
void ASTTypeWriter::VisitAutoType(const AutoType *T) {
Writer.AddTypeRef(T->getDeducedType(), Record);
Record.push_back(T->isDecltypeAuto());
+ if (T->getDeducedType().isNull())
+ Record.push_back(T->isDependentType());
Code = TYPE_AUTO;
}