Towards P0091R3: parsing support for class template argument deduction in typename-specifiers.
This reinstates r293455, reverted in r293455, with a fix for cv-qualifier
handling on dependent typename-specifiers.
llvm-svn: 293544
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index ce843a5..60daae0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -60,11 +60,6 @@
return DeclGroupPtrTy::make(DeclGroupRef(Ptr));
}
-static bool isTypeTemplate(NamedDecl *ND) {
- return isa<ClassTemplateDecl>(ND) || isa<TypeAliasTemplateDecl>(ND) ||
- isa<TemplateTemplateParmDecl>(ND);
-}
-
namespace {
class TypeNameValidatorCCC : public CorrectionCandidateCallback {
@@ -81,7 +76,7 @@
bool ValidateCandidate(const TypoCorrection &candidate) override {
if (NamedDecl *ND = candidate.getCorrectionDecl()) {
bool IsType = isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND);
- bool AllowedTemplate = AllowTemplates && isTypeTemplate(ND);
+ bool AllowedTemplate = AllowTemplates && getAsTypeTemplateDecl(ND);
return (IsType || AllowedTemplate) &&
(AllowInvalidDecl || !ND->isInvalidDecl());
}
@@ -405,7 +400,7 @@
for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
Res != ResEnd; ++Res) {
if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res) ||
- (AllowDeducedTemplate && isTypeTemplate(*Res))) {
+ (AllowDeducedTemplate && getAsTypeTemplateDecl(*Res))) {
if (!IIDecl ||
(*Res)->getLocation().getRawEncoding() <
IIDecl->getLocation().getRawEncoding())
@@ -458,9 +453,10 @@
(void)DiagnoseUseOfDecl(IDecl, NameLoc);
if (!HasTrailingDot)
T = Context.getObjCInterfaceType(IDecl);
- } else if (AllowDeducedTemplate && isTypeTemplate(IIDecl)) {
- T = Context.getDeducedTemplateSpecializationType(
- TemplateName(cast<TemplateDecl>(IIDecl)), QualType(), false);
+ } else if (AllowDeducedTemplate) {
+ if (auto *TD = getAsTypeTemplateDecl(IIDecl))
+ T = Context.getDeducedTemplateSpecializationType(TemplateName(TD),
+ QualType(), false);
}
if (T.isNull()) {
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 8f46ad0..d3b47f1 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -8792,8 +8792,18 @@
Context.getTypeDeclType(Type));
}
- // FIXME: Form a deduced template specialization type if we get a template
- // declaration here.
+ // C++ [dcl.type.simple]p2:
+ // A type-specifier of the form
+ // typename[opt] nested-name-specifier[opt] template-name
+ // is a placeholder for a deduced class type [...].
+ if (getLangOpts().CPlusPlus1z) {
+ if (auto *TD = getAsTypeTemplateDecl(Result.getFoundDecl())) {
+ return Context.getElaboratedType(
+ Keyword, QualifierLoc.getNestedNameSpecifier(),
+ Context.getDeducedTemplateSpecializationType(TemplateName(TD),
+ QualType(), false));
+ }
+ }
DiagID = diag::err_typename_nested_not_type;
Referenced = Result.getFoundDecl();
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index aff19ec..723a6c0 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1490,12 +1490,16 @@
/// a cast expression) or that the entity has no name (e.g., an
/// unnamed function parameter).
///
+/// \param AllowDeducedTST Whether a DeducedTemplateSpecializationType is
+/// acceptable as the top level type of the result.
+///
/// \returns If the instantiation succeeds, the instantiated
/// type. Otherwise, produces diagnostics and returns a NULL type.
TypeSourceInfo *Sema::SubstType(TypeSourceInfo *T,
const MultiLevelTemplateArgumentList &Args,
SourceLocation Loc,
- DeclarationName Entity) {
+ DeclarationName Entity,
+ bool AllowDeducedTST) {
assert(!ActiveTemplateInstantiations.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
@@ -1505,7 +1509,8 @@
return T;
TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
- return Instantiator.TransformType(T);
+ return AllowDeducedTST ? Instantiator.TransformTypeWithDeducedTST(T)
+ : Instantiator.TransformType(T);
}
TypeSourceInfo *Sema::SubstType(TypeLoc TL,
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 2310e99..46de4a1 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -657,10 +657,9 @@
ArrayRef<BindingDecl*> *Bindings) {
// Do substitution on the type of the declaration
- TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
- TemplateArgs,
- D->getTypeSpecStartLoc(),
- D->getDeclName());
+ TypeSourceInfo *DI = SemaRef.SubstType(
+ D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
+ D->getDeclName(), /*AllowDeducedTST*/true);
if (!DI)
return nullptr;
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index d27cd77..4ed5563 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -307,6 +307,17 @@
///
QualType TransformType(TypeLocBuilder &TLB, TypeLoc TL);
+ /// \brief Transform a type that is permitted to produce a
+ /// DeducedTemplateSpecializationType.
+ ///
+ /// This is used in the (relatively rare) contexts where it is acceptable
+ /// for transformation to produce a class template type with deduced
+ /// template arguments.
+ /// @{
+ QualType TransformTypeWithDeducedTST(QualType T);
+ TypeSourceInfo *TransformTypeWithDeducedTST(TypeSourceInfo *DI);
+ /// @}
+
/// \brief Transform the given statement.
///
/// By default, this routine transforms a statement by delegating to the
@@ -672,6 +683,16 @@
OMPClause *Transform ## Class(Class *S);
#include "clang/Basic/OpenMPKinds.def"
+ /// \brief Build a new qualified type given its unqualified type and type
+ /// qualifiers.
+ ///
+ /// By default, this routine adds type qualifiers only to types that can
+ /// have qualifiers, and silently suppresses those qualifiers that are not
+ /// permitted. Subclasses may override this routine to provide different
+ /// behavior.
+ QualType RebuildQualifiedType(QualType T, SourceLocation Loc,
+ Qualifiers Quals);
+
/// \brief Build a new pointer type given its pointee type.
///
/// By default, performs semantic analysis when building the pointer type.
@@ -898,7 +919,7 @@
/// By default, builds a new ParenType type from the inner type.
/// Subclasses may override this routine to provide different behavior.
QualType RebuildParenType(QualType InnerType) {
- return SemaRef.Context.getParenType(InnerType);
+ return SemaRef.BuildParenType(InnerType);
}
/// \brief Build a new qualified name type.
@@ -968,7 +989,8 @@
SourceLocation KeywordLoc,
NestedNameSpecifierLoc QualifierLoc,
const IdentifierInfo *Id,
- SourceLocation IdLoc) {
+ SourceLocation IdLoc,
+ bool DeducedTSTContext) {
CXXScopeSpec SS;
SS.Adopt(QualifierLoc);
@@ -980,9 +1002,25 @@
Id);
}
- if (Keyword == ETK_None || Keyword == ETK_Typename)
- return SemaRef.CheckTypenameType(Keyword, KeywordLoc, QualifierLoc,
- *Id, IdLoc);
+ if (Keyword == ETK_None || Keyword == ETK_Typename) {
+ QualType T = SemaRef.CheckTypenameType(Keyword, KeywordLoc, QualifierLoc,
+ *Id, IdLoc);
+ // If a dependent name resolves to a deduced template specialization type,
+ // check that we're in one of the syntactic contexts permitting it.
+ if (!DeducedTSTContext) {
+ if (auto *Deduced = dyn_cast_or_null<DeducedTemplateSpecializationType>(
+ T.isNull() ? nullptr : T->getContainedDeducedType())) {
+ SemaRef.Diag(IdLoc, diag::err_dependent_deduced_tst)
+ << (int)SemaRef.getTemplateNameKindForDiagnostics(
+ Deduced->getTemplateName())
+ << QualType(QualifierLoc.getNestedNameSpecifier()->getAsType(), 0);
+ if (auto *TD = Deduced->getTemplateName().getAsTemplateDecl())
+ SemaRef.Diag(TD->getLocation(), diag::note_template_decl_here);
+ return QualType();
+ }
+ }
+ return T;
+ }
TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForKeyword(Keyword);
@@ -3157,6 +3195,10 @@
TypeSourceInfo *TransformTSIInObjectScope(TypeLoc TL, QualType ObjectType,
NamedDecl *FirstQualifierInScope,
CXXScopeSpec &SS);
+
+ QualType TransformDependentNameType(TypeLocBuilder &TLB,
+ DependentNameTypeLoc TL,
+ bool DeducibleTSTContext);
};
template<typename Derived>
@@ -4048,11 +4090,57 @@
llvm_unreachable("unhandled type loc!");
}
-/// FIXME: By default, this routine adds type qualifiers only to types
-/// that can have qualifiers, and silently suppresses those qualifiers
-/// that are not permitted (e.g., qualifiers on reference or function
-/// types). This is the right thing for template instantiation, but
-/// probably not for other clients.
+template<typename Derived>
+QualType TreeTransform<Derived>::TransformTypeWithDeducedTST(QualType T) {
+ if (!isa<DependentNameType>(T))
+ return TransformType(T);
+
+ if (getDerived().AlreadyTransformed(T))
+ return T;
+ TypeSourceInfo *DI = getSema().Context.getTrivialTypeSourceInfo(T,
+ getDerived().getBaseLocation());
+ TypeSourceInfo *NewDI = getDerived().TransformTypeWithDeducedTST(DI);
+ return NewDI ? NewDI->getType() : QualType();
+}
+
+template<typename Derived>
+TypeSourceInfo *
+TreeTransform<Derived>::TransformTypeWithDeducedTST(TypeSourceInfo *DI) {
+ if (!isa<DependentNameType>(DI->getType()))
+ return TransformType(DI);
+
+ // Refine the base location to the type's location.
+ TemporaryBase Rebase(*this, DI->getTypeLoc().getBeginLoc(),
+ getDerived().getBaseEntity());
+ if (getDerived().AlreadyTransformed(DI->getType()))
+ return DI;
+
+ TypeLocBuilder TLB;
+
+ TypeLoc TL = DI->getTypeLoc();
+ TLB.reserve(TL.getFullDataSize());
+
+ Qualifiers Quals;
+ auto QTL = TL.getAs<QualifiedTypeLoc>();
+ if (QTL)
+ TL = QTL.getUnqualifiedLoc();
+
+ auto DNTL = TL.castAs<DependentNameTypeLoc>();
+
+ QualType Result = getDerived().TransformDependentNameType(
+ TLB, DNTL, /*DeducedTSTContext*/true);
+ if (Result.isNull())
+ return nullptr;
+
+ if (QTL) {
+ Result = getDerived().RebuildQualifiedType(
+ Result, QTL.getBeginLoc(), QTL.getType().getLocalQualifiers());
+ TLB.TypeWasModifiedSafely(Result);
+ }
+
+ return TLB.getTypeSourceInfo(SemaRef.Context, Result);
+}
+
template<typename Derived>
QualType
TreeTransform<Derived>::TransformQualifiedType(TypeLocBuilder &TLB,
@@ -4063,64 +4151,71 @@
if (Result.isNull())
return QualType();
- // Silently suppress qualifiers if the result type can't be qualified.
- // FIXME: this is the right thing for template instantiation, but
- // probably not for other clients.
- if (Result->isFunctionType() || Result->isReferenceType())
- return Result;
+ Result = getDerived().RebuildQualifiedType(Result, T.getBeginLoc(), Quals);
+
+ // RebuildQualifiedType might have updated the type, but not in a way
+ // that invalidates the TypeLoc. (There's no location information for
+ // qualifiers.)
+ TLB.TypeWasModifiedSafely(Result);
+
+ return Result;
+}
+
+template<typename Derived>
+QualType TreeTransform<Derived>::RebuildQualifiedType(QualType T,
+ SourceLocation Loc,
+ Qualifiers Quals) {
+ // C++ [dcl.fct]p7:
+ // [When] adding cv-qualifications on top of the function type [...] the
+ // cv-qualifiers are ignored.
+ // C++ [dcl.ref]p1:
+ // when the cv-qualifiers are introduced through the use of a typedef-name
+ // or decltype-specifier [...] the cv-qualifiers are ignored.
+ // Note that [dcl.ref]p1 lists all cases in which cv-qualifiers can be
+ // applied to a reference type.
+ // FIXME: This removes all qualifiers, not just cv-qualifiers!
+ if (T->isFunctionType() || T->isReferenceType())
+ return T;
// Suppress Objective-C lifetime qualifiers if they don't make sense for the
// resulting type.
if (Quals.hasObjCLifetime()) {
- if (!Result->isObjCLifetimeType() && !Result->isDependentType())
+ if (!T->isObjCLifetimeType() && !T->isDependentType())
Quals.removeObjCLifetime();
- else if (Result.getObjCLifetime()) {
+ else if (T.getObjCLifetime()) {
// Objective-C ARC:
// A lifetime qualifier applied to a substituted template parameter
// overrides the lifetime qualifier from the template argument.
const AutoType *AutoTy;
if (const SubstTemplateTypeParmType *SubstTypeParam
- = dyn_cast<SubstTemplateTypeParmType>(Result)) {
+ = dyn_cast<SubstTemplateTypeParmType>(T)) {
QualType Replacement = SubstTypeParam->getReplacementType();
Qualifiers Qs = Replacement.getQualifiers();
Qs.removeObjCLifetime();
- Replacement
- = SemaRef.Context.getQualifiedType(Replacement.getUnqualifiedType(),
- Qs);
- Result = SemaRef.Context.getSubstTemplateTypeParmType(
- SubstTypeParam->getReplacedParameter(),
- Replacement);
- TLB.TypeWasModifiedSafely(Result);
- } else if ((AutoTy = dyn_cast<AutoType>(Result)) && AutoTy->isDeduced()) {
+ Replacement = SemaRef.Context.getQualifiedType(
+ Replacement.getUnqualifiedType(), Qs);
+ T = SemaRef.Context.getSubstTemplateTypeParmType(
+ SubstTypeParam->getReplacedParameter(), Replacement);
+ } else if ((AutoTy = dyn_cast<AutoType>(T)) && AutoTy->isDeduced()) {
// 'auto' types behave the same way as template parameters.
QualType Deduced = AutoTy->getDeducedType();
Qualifiers Qs = Deduced.getQualifiers();
Qs.removeObjCLifetime();
- Deduced = SemaRef.Context.getQualifiedType(Deduced.getUnqualifiedType(),
- Qs);
- Result = SemaRef.Context.getAutoType(Deduced, AutoTy->getKeyword(),
- AutoTy->isDependentType());
- TLB.TypeWasModifiedSafely(Result);
+ Deduced =
+ SemaRef.Context.getQualifiedType(Deduced.getUnqualifiedType(), Qs);
+ T = SemaRef.Context.getAutoType(Deduced, AutoTy->getKeyword(),
+ AutoTy->isDependentType());
} else {
// Otherwise, complain about the addition of a qualifier to an
// already-qualified type.
- SourceRange R = T.getUnqualifiedLoc().getSourceRange();
- SemaRef.Diag(R.getBegin(), diag::err_attr_objc_ownership_redundant)
- << Result << R;
-
+ // FIXME: Why is this check not in Sema::BuildQualifiedType?
+ SemaRef.Diag(Loc, diag::err_attr_objc_ownership_redundant) << T;
Quals.removeObjCLifetime();
}
}
}
- if (!Quals.empty()) {
- Result = SemaRef.BuildQualifiedType(Result, T.getBeginLoc(), Quals);
- // BuildQualifiedType might not add qualifiers if they are invalid.
- if (Result.hasLocalQualifiers())
- TLB.push<QualifiedTypeLoc>(Result);
- // No location information to preserve.
- }
- return Result;
+ return SemaRef.BuildQualifiedType(T, Loc, Quals);
}
template<typename Derived>
@@ -5854,8 +5949,14 @@
}
template<typename Derived>
-QualType TreeTransform<Derived>::TransformDependentNameType(TypeLocBuilder &TLB,
- DependentNameTypeLoc TL) {
+QualType TreeTransform<Derived>::TransformDependentNameType(
+ TypeLocBuilder &TLB, DependentNameTypeLoc TL) {
+ return TransformDependentNameType(TLB, TL, false);
+}
+
+template<typename Derived>
+QualType TreeTransform<Derived>::TransformDependentNameType(
+ TypeLocBuilder &TLB, DependentNameTypeLoc TL, bool DeducedTSTContext) {
const DependentNameType *T = TL.getTypePtr();
NestedNameSpecifierLoc QualifierLoc
@@ -5868,7 +5969,8 @@
TL.getElaboratedKeywordLoc(),
QualifierLoc,
T->getIdentifier(),
- TL.getNameLoc());
+ TL.getNameLoc(),
+ DeducedTSTContext);
if (Result.isNull())
return QualType();
@@ -9474,7 +9576,8 @@
ExprResult
TreeTransform<Derived>::TransformCXXFunctionalCastExpr(
CXXFunctionalCastExpr *E) {
- TypeSourceInfo *Type = getDerived().TransformType(E->getTypeInfoAsWritten());
+ TypeSourceInfo *Type =
+ getDerived().TransformTypeWithDeducedTST(E->getTypeInfoAsWritten());
if (!Type)
return ExprError();
@@ -9663,8 +9766,8 @@
ExprResult
TreeTransform<Derived>::TransformCXXNewExpr(CXXNewExpr *E) {
// Transform the type that we're allocating
- TypeSourceInfo *AllocTypeInfo
- = getDerived().TransformType(E->getAllocatedTypeSourceInfo());
+ TypeSourceInfo *AllocTypeInfo =
+ getDerived().TransformTypeWithDeducedTST(E->getAllocatedTypeSourceInfo());
if (!AllocTypeInfo)
return ExprError();
@@ -10375,7 +10478,8 @@
ExprResult
TreeTransform<Derived>::TransformCXXTemporaryObjectExpr(
CXXTemporaryObjectExpr *E) {
- TypeSourceInfo *T = getDerived().TransformType(E->getTypeSourceInfo());
+ TypeSourceInfo *T =
+ getDerived().TransformTypeWithDeducedTST(E->getTypeSourceInfo());
if (!T)
return ExprError();
@@ -10672,7 +10776,8 @@
ExprResult
TreeTransform<Derived>::TransformCXXUnresolvedConstructExpr(
CXXUnresolvedConstructExpr *E) {
- TypeSourceInfo *T = getDerived().TransformType(E->getTypeSourceInfo());
+ TypeSourceInfo *T =
+ getDerived().TransformTypeWithDeducedTST(E->getTypeSourceInfo());
if (!T)
return ExprError();