r290593 - DR1495: A partial specialization is ill-formed if it is not (strictly) more
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Tue Dec 27 12:11:05 PST 2016
Hi Eigen folks,
Clang (and GCC) recently implemented C++ DR 1495 (wg21.link/cwg1495), which
says that a class template partial specialization is ill-formed if it is
not more specialized than the primary template. (If we imagine the primary
template had a corresponding partial specialization, we require that the
partial specialization would always be chosen in any situation where both
match.)
This causes Clang to reject some code in Eigen:
https://bitbucket.org/eigen/eigen/src/e46c8246b284dea1690ac2
60dfe50851906138f0/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h?at=
default&fileviewer=file-view-default#TensorStorage.h-38
One way to fix this is:
-template<typename T, int Options_, typename FixedDimensions>
-class TensorStorage<T, FixedDimensions, Options_>
+template<typename T, typename FixedDimensions, int Options_>
+class TensorStorage
That is, define the primary template instead of defining a partial
specialization that doesn't actually specialize anything.
On 27 December 2016 at 10:41, Richard Smith <richard at metafoo.co.uk> wrote:
> On 27 Dec 2016 1:42 am, "Chandler Carruth via cfe-commits" <
> cfe-commits at lists.llvm.org> wrote:
>
> I suspect that this commit is responsible for a regression parsing widely
> used open source packages like Eigen.
>
> See the code in Eigen here:
> https://bitbucket.org/eigen/eigen/src/e46c8246b284dea1690ac2
> 60dfe50851906138f0/unsupported/Eigen/CXX11/src/Tensor/TensorStorage.h?at=
> default&fileviewer=file-view-default#TensorStorage.h-38
>
> I'm not claiming this code is correct, but I'm worried about how much code
> out there looks like this... Thoughts? Could we at least temporarily put
> this DR fix behind a flag or make it a warning?
>
>
> Sure, I'll downgrade it to an ExtWarn. We should also let the Eigen folks
> know.
>
> On Tue, Dec 27, 2016 at 12:07 AM Richard Smith via cfe-commits <
> cfe-commits at lists.llvm.org> wrote:
>
>> Author: rsmith
>> Date: Tue Dec 27 01:56:27 2016
>> New Revision: 290593
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=290593&view=rev
>> Log:
>> DR1495: A partial specialization is ill-formed if it is not (strictly)
>> more
>> specialized than the primary template. (Put another way, if we imagine
>> there
>> were a partial specialization matching the primary template, we should
>> never
>> select it if some other partial specialization also matches.)
>>
>> Modified:
>> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> cfe/trunk/include/clang/Sema/Sema.h
>> cfe/trunk/include/clang/Sema/TemplateDeduction.h
>> cfe/trunk/lib/Sema/SemaTemplate.cpp
>> cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp
>> cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp
>> cfe/trunk/test/CXX/drs/dr14xx.cpp
>> cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp
>> cfe/trunk/test/SemaTemplate/class-template-spec.cpp
>> cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp
>> cfe/trunk/www/cxx_dr_status.html
>>
>> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/
>> Basic/DiagnosticSemaKinds.td?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Dec 27
>> 01:56:27 2016
>> @@ -4043,6 +4043,10 @@ def err_partial_spec_args_match_primary_
>> "%select{class|variable}0 template partial specialization does not "
>> "specialize any template argument; to %select{declare|define}1 the "
>> "primary template, remove the template argument list">;
>> +def err_partial_spec_not_more_specialized_than_primary : Error<
>> + "%select{class|variable}0 template partial specialization is not "
>> + "more specialized than the primary template">;
>> +def note_partial_spec_not_more_specialized_than_primary : Note<"%0">;
>> def warn_partial_specs_not_deducible : Warning<
>> "%select{class|variable}0 template partial specialization contains "
>> "%select{a template parameter|template parameters}1 that cannot be "
>> @@ -4147,7 +4151,7 @@ def note_function_template_deduction_ins
>> "%1">;
>> def note_deduced_template_arg_substitution_here : Note<
>> "during template argument deduction for %select{class|variable}0
>> template "
>> - "partial specialization %1 %2">;
>> + "%select{partial specialization |}1%2 %3">;
>> def note_prior_template_arg_substitution : Note<
>> "while substituting prior template arguments into
>> %select{non-type|template}0"
>> " template parameter%1 %2">;
>>
>> Modified: cfe/trunk/include/clang/Sema/Sema.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/
>> Sema/Sema.h?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/include/clang/Sema/Sema.h (original)
>> +++ cfe/trunk/include/clang/Sema/Sema.h Tue Dec 27 01:56:27 2016
>> @@ -6697,10 +6697,16 @@ public:
>> ClassTemplatePartialSpecializationDecl
>> *PS2,
>> SourceLocation Loc);
>>
>> + bool isMoreSpecializedThanPrimary(ClassTemplatePartialSpecializationDecl
>> *T,
>> + sema::TemplateDeductionInfo &Info);
>> +
>> VarTemplatePartialSpecializationDecl *getMoreSpecializedPartialSpec
>> ialization(
>> VarTemplatePartialSpecializationDecl *PS1,
>> VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc);
>>
>> + bool isMoreSpecializedThanPrimary(VarTemplatePartialSpecializationDecl
>> *T,
>> + sema::TemplateDeductionInfo &Info);
>> +
>> void MarkUsedTemplateParameters(const TemplateArgumentList
>> &TemplateArgs,
>> bool OnlyDeduced,
>> unsigned Depth,
>> @@ -6752,7 +6758,7 @@ public:
>> /// template argument deduction for either a class template
>> /// partial specialization or a function template. The
>> /// Entity is either a {Class|Var}TemplatePartialSpecializationDecl
>> or
>> - /// a FunctionTemplateDecl.
>> + /// a TemplateDecl.
>> DeducedTemplateArgumentSubstitution,
>>
>> /// We are substituting prior template arguments into a new
>> @@ -6973,6 +6979,14 @@ public:
>> sema::TemplateDeductionInfo &DeductionInfo,
>> SourceRange InstantiationRange =
>> SourceRange());
>>
>> + /// \brief Note that we are instantiating as part of template
>> + /// argument deduction for a class template declaration.
>> + InstantiatingTemplate(Sema &SemaRef, SourceLocation
>> PointOfInstantiation,
>> + TemplateDecl *Template,
>> + ArrayRef<TemplateArgument> TemplateArgs,
>> + sema::TemplateDeductionInfo &DeductionInfo,
>> + SourceRange InstantiationRange =
>> SourceRange());
>> +
>> /// \brief Note that we are instantiating as part of template
>> /// argument deduction for a class template partial
>> /// specialization.
>>
>> Modified: cfe/trunk/include/clang/Sema/TemplateDeduction.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/
>> Sema/TemplateDeduction.h?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/include/clang/Sema/TemplateDeduction.h (original)
>> +++ cfe/trunk/include/clang/Sema/TemplateDeduction.h Tue Dec 27 01:56:27
>> 2016
>> @@ -79,6 +79,11 @@ public:
>> assert(HasSFINAEDiagnostic);
>> PD.first = SuppressedDiagnostics.front().first;
>> PD.second.swap(SuppressedDiagnostics.front().second);
>> + clearSFINAEDiagnostic();
>> + }
>> +
>> + /// \brief Discard any SFINAE diagnostics.
>> + void clearSFINAEDiagnostic() {
>> SuppressedDiagnostics.clear();
>> HasSFINAEDiagnostic = false;
>> }
>>
>> Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaT
>> emplate.cpp?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaTemplate.cpp Tue Dec 27 01:56:27 2016
>> @@ -2624,6 +2624,36 @@ makeTemplateArgumentListInfo(Sema &S, Te
>> return TemplateArgs;
>> }
>>
>> +template<typename PartialSpecDecl>
>> +static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl
>> *Partial) {
>> + if (Partial->getDeclContext()->isDependentContext())
>> + return;
>> +
>> + // FIXME: Get the TDK from deduction in order to provide better
>> diagnostics
>> + // for non-substitution-failure issues?
>> + TemplateDeductionInfo Info(Partial->getLocation());
>> + if (S.isMoreSpecializedThanPrimary(Partial, Info))
>> + return;
>> +
>> + auto *Template = Partial->getSpecializedTemplate();
>> + S.Diag(Partial->getLocation(),
>> + diag::err_partial_spec_not_more_specialized_than_primary)
>> + << /*variable template*/isa<VarTemplateDecl>(Template);
>> +
>> + if (Info.hasSFINAEDiagnostic()) {
>> + PartialDiagnosticAt Diag = {SourceLocation(),
>> + PartialDiagnostic::NullDiagnostic()};
>> + Info.takeSFINAEDiagnostic(Diag);
>> + SmallString<128> SFINAEArgString;
>> + Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
>> + S.Diag(Diag.first,
>> + diag::note_partial_spec_not_more_specialized_than_primary)
>> + << SFINAEArgString;
>> + }
>> +
>> + S.Diag(Template->getLocation(), diag::note_template_decl_here);
>> +}
>> +
>> DeclResult Sema::ActOnVarTemplateSpecialization(
>> Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation
>> TemplateKWLoc,
>> TemplateParameterList *TemplateParams, StorageClass SC,
>> @@ -2749,6 +2779,11 @@ DeclResult Sema::ActOnVarTemplateSpecial
>> if (PrevPartial && PrevPartial->getInstantiatedFromMember())
>> PrevPartial->setMemberSpecialization();
>>
>> + // C++1z [temp.class.spec]p8: (DR1495)
>> + // - The specialization shall be more specialized than the primary
>> + // template (14.5.5.2).
>> + checkMoreSpecializedThanPrimary(*this, Partial);
>> +
>> // Check that all of the template parameters of the variable template
>> // partial specialization are deducible from the template
>> // arguments. If not, this variable template partial specialization
>> @@ -5041,7 +5076,7 @@ ExprResult Sema::CheckTemplateArgument(N
>>
>> if (CTAK == CTAK_Deduced &&
>> !Context.hasSameType(ParamType.getNonLValueExprType(Context),
>> - Arg->getType().getNonLValueExprType(Context)))
>> {
>> + Arg->getType())) {
>> // C++ [temp.deduct.type]p17: (DR1770)
>> // If P has a form that contains <i>, and if the type of i differs
>> from
>> // the type of the corresponding template parameter of the
>> template named
>> @@ -5055,7 +5090,7 @@ ExprResult Sema::CheckTemplateArgument(N
>> // itself, and so strip off references before comparing types. It's
>> // not clear how this is supposed to work for references.
>> Diag(StartLoc, diag::err_deduced_non_type_tem
>> plate_arg_type_mismatch)
>> - << Arg->getType().getUnqualifiedType()
>> + << Arg->getType()
>> << ParamType.getUnqualifiedType();
>> Diag(Param->getLocation(), diag::note_template_param_here);
>> return ExprError();
>> @@ -6501,6 +6536,9 @@ Sema::ActOnClassTemplateSpecialization(S
>> //
>> // -- The argument list of the specialization shall not be
>> identical
>> // to the implicit argument list of the primary template.
>> + //
>> + // This rule has since been removed, because it's redundant given
>> DR1495,
>> + // but we keep it because it produces better diagnostics and
>> recovery.
>> Diag(TemplateNameLoc, diag::err_partial_spec_args_ma
>> tch_primary_template)
>> << /*class template*/0 << (TUK == TUK_Definition)
>> << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
>> @@ -6543,6 +6581,11 @@ Sema::ActOnClassTemplateSpecialization(S
>> if (PrevPartial && PrevPartial->getInstantiatedFromMember())
>> PrevPartial->setMemberSpecialization();
>>
>> + // C++1z [temp.class.spec]p8: (DR1495)
>> + // - The specialization shall be more specialized than the primary
>> + // template (14.5.5.2).
>> + checkMoreSpecializedThanPrimary(*this, Partial);
>> +
>> // Check that all of the template parameters of the class template
>> // partial specialization are deducible from the template
>> // arguments. If not, this class template partial specialization
>>
>> Modified: cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaT
>> emplateDeduction.cpp?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp Tue Dec 27 01:56:27 2016
>> @@ -1972,8 +1972,14 @@ DeduceTemplateArguments(Sema &S,
>>
>> /// \brief Determine whether two template arguments are the same.
>> static bool isSameTemplateArg(ASTContext &Context,
>> - const TemplateArgument &X,
>> - const TemplateArgument &Y) {
>> + TemplateArgument X,
>> + const TemplateArgument &Y,
>> + bool PackExpansionMatchesPack = false) {
>> + // If we're checking deduced arguments (X) against original arguments
>> (Y),
>> + // we will have flattened packs to non-expansions in X.
>> + if (PackExpansionMatchesPack && X.isPackExpansion() &&
>> !Y.isPackExpansion())
>> + X = X.getPackExpansionPattern();
>> +
>> if (X.getKind() != Y.getKind())
>> return false;
>>
>> @@ -2016,7 +2022,7 @@ static bool isSameTemplateArg(ASTContext
>> XPEnd = X.pack_end(),
>> YP = Y.pack_begin();
>> XP != XPEnd; ++XP, ++YP)
>> - if (!isSameTemplateArg(Context, *XP, *YP))
>> + if (!isSameTemplateArg(Context, *XP, *YP,
>> PackExpansionMatchesPack))
>> return false;
>>
>> return true;
>> @@ -2400,6 +2406,48 @@ FinishTemplateArgumentDeduction(
>> return Sema::TDK_Success;
>> }
>>
>> +/// Complete template argument deduction for a class or variable
>> template,
>> +/// when partial ordering against a partial specialization.
>> +// FIXME: Factor out duplication with partial specialization version
>> above.
>> +Sema::TemplateDeductionResult FinishTemplateArgumentDeduction(
>> + Sema &S, TemplateDecl *Template, bool PartialOrdering,
>> + const TemplateArgumentList &TemplateArgs,
>> + SmallVectorImpl<DeducedTemplateArgument> &Deduced,
>> + TemplateDeductionInfo &Info) {
>> + // Unevaluated SFINAE context.
>> + EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated);
>> + Sema::SFINAETrap Trap(S);
>> +
>> + Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Te
>> mplate));
>> +
>> + // C++ [temp.deduct.type]p2:
>> + // [...] or if any template argument remains neither deduced nor
>> + // explicitly specified, template argument deduction fails.
>> + SmallVector<TemplateArgument, 4> Builder;
>> + if (auto Result = ConvertDeducedTemplateArguments(
>> + S, Template, /*IsDeduced*/PartialOrdering, Deduced, Info,
>> Builder))
>> + return Result;
>> +
>> + // Check that we produced the correct argument list.
>> + TemplateParameterList *TemplateParams = Template->getTemplateParameter
>> s();
>> + for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
>> + TemplateArgument InstArg = Builder[I];
>> + if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg,
>> + /*PackExpansionMatchesPack*/true)) {
>> + Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
>> + Info.FirstArg = TemplateArgs[I];
>> + Info.SecondArg = InstArg;
>> + return Sema::TDK_NonDeducedMismatch;
>> + }
>> + }
>> +
>> + if (Trap.hasErrorOccurred())
>> + return Sema::TDK_SubstitutionFailure;
>> +
>> + return Sema::TDK_Success;
>> +}
>> +
>> +
>> /// \brief Perform template argument deduction to determine whether
>> /// the given template arguments match the given class template
>> /// partial specialization per C++ [temp.class.spec.match].
>> @@ -4535,14 +4583,13 @@ UnresolvedSetIterator Sema::getMostSpeci
>> /// specialized than another, P2.
>> ///
>> /// \tparam PartialSpecializationDecl The kind of P2, which must be a
>> -/// {Class,Var}TemplatePartialSpecializationDecl.
>> +/// {Class,Var}Template{PartialSpecialization,}Decl.
>> /// \param T1 The injected-class-name of P1 (faked for a variable
>> template).
>> /// \param T2 The injected-class-name of P2 (faked for a variable
>> template).
>> -/// \param Loc The location at which the comparison is required.
>> template<typename PartialSpecializationDecl>
>> static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2,
>> PartialSpecializationDecl *P2,
>> - SourceLocation Loc) {
>> + TemplateDeductionInfo &Info) {
>> // C++ [temp.class.order]p1:
>> // For two class template partial specializations, the first is at
>> least as
>> // specialized as the second if, given the following rewrite to two
>> @@ -4568,7 +4615,6 @@ static bool isAtLeastAsSpecializedAs(Sem
>> // template partial specialization's template arguments, for
>> // example.
>> SmallVector<DeducedTemplateArgument, 4> Deduced;
>> - TemplateDeductionInfo Info(Loc);
>>
>> // Determine whether P1 is at least as specialized as P2.
>> Deduced.resize(P2->getTemplateParameters()->size());
>> @@ -4579,7 +4625,8 @@ static bool isAtLeastAsSpecializedAs(Sem
>>
>> SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(),
>> Deduced.end());
>> - Sema::InstantiatingTemplate Inst(S, Loc, P2, DeducedArgs, Info);
>> + Sema::InstantiatingTemplate Inst(S, Info.getLocation(), P2,
>> DeducedArgs,
>> + Info);
>> auto *TST1 = T1->castAs<TemplateSpecializationType>();
>> if (FinishTemplateArgumentDeduction(
>> S, P2, /*PartialOrdering=*/true,
>> @@ -4609,8 +4656,9 @@ Sema::getMoreSpecializedPartialSpecializ
>> QualType PT1 = PS1->getInjectedSpecializationType();
>> QualType PT2 = PS2->getInjectedSpecializationType();
>>
>> - bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Loc);
>> - bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Loc);
>> + TemplateDeductionInfo Info(Loc);
>> + bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info);
>> + bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info);
>>
>> if (Better1 == Better2)
>> return nullptr;
>> @@ -4618,6 +4666,20 @@ Sema::getMoreSpecializedPartialSpecializ
>> return Better1 ? PS1 : PS2;
>> }
>>
>> +bool Sema::isMoreSpecializedThanPrimary(
>> + ClassTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo
>> &Info) {
>> + ClassTemplateDecl *Primary = Spec->getSpecializedTemplate();
>> + QualType PrimaryT = Primary->getInjectedClassNameSpecialization();
>> + QualType PartialT = Spec->getInjectedSpecializationType();
>> + if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary,
>> Info))
>> + return false;
>> + if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) {
>> + Info.clearSFINAEDiagnostic();
>> + return false;
>> + }
>> + return true;
>> +}
>> +
>> VarTemplatePartialSpecializationDecl *
>> Sema::getMoreSpecializedPartialSpecialization(
>> VarTemplatePartialSpecializationDecl *PS1,
>> @@ -4634,8 +4696,9 @@ Sema::getMoreSpecializedPartialSpecializ
>> QualType PT2 = Context.getTemplateSpecializationType(
>> CanonTemplate, PS2->getTemplateArgs().asArray());
>>
>> - bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Loc);
>> - bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Loc);
>> + TemplateDeductionInfo Info(Loc);
>> + bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info);
>> + bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info);
>>
>> if (Better1 == Better2)
>> return nullptr;
>> @@ -4643,6 +4706,30 @@ Sema::getMoreSpecializedPartialSpecializ
>> return Better1 ? PS1 : PS2;
>> }
>>
>> +bool Sema::isMoreSpecializedThanPrimary(
>> + VarTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo
>> &Info) {
>> + TemplateDecl *Primary = Spec->getSpecializedTemplate();
>> + // FIXME: Cache the injected template arguments rather than recomputing
>> + // them for each partial specialization.
>> + SmallVector<TemplateArgument, 8> PrimaryArgs;
>> + Context.getInjectedTemplateArgs(Primary->getTemplateParameters(),
>> + PrimaryArgs);
>> +
>> + TemplateName CanonTemplate =
>> + Context.getCanonicalTemplateName(TemplateName(Primary));
>> + QualType PrimaryT = Context.getTemplateSpecializationType(
>> + CanonTemplate, PrimaryArgs);
>> + QualType PartialT = Context.getTemplateSpecializationType(
>> + CanonTemplate, Spec->getTemplateArgs().asArray());
>> + if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary,
>> Info))
>> + return false;
>> + if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) {
>> + Info.clearSFINAEDiagnostic();
>> + return false;
>> + }
>> + return true;
>> +}
>> +
>> static void
>> MarkUsedTemplateParameters(ASTContext &Ctx,
>> const TemplateArgument &TemplateArg,
>>
>> Modified: cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaT
>> emplateInstantiate.cpp?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp Tue Dec 27 01:56:27
>> 2016
>> @@ -279,6 +279,17 @@ Sema::InstantiatingTemplate::Instantiati
>>
>> Sema::InstantiatingTemplate::InstantiatingTemplate(
>> Sema &SemaRef, SourceLocation PointOfInstantiation,
>> + TemplateDecl *Template,
>> + ArrayRef<TemplateArgument> TemplateArgs,
>> + sema::TemplateDeductionInfo &DeductionInfo, SourceRange
>> InstantiationRange)
>> + : InstantiatingTemplate(
>> + SemaRef,
>> + ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitu
>> tion,
>> + PointOfInstantiation, InstantiationRange, Template, nullptr,
>> + TemplateArgs, &DeductionInfo) {}
>> +
>> +Sema::InstantiatingTemplate::InstantiatingTemplate(
>> + Sema &SemaRef, SourceLocation PointOfInstantiation,
>> ClassTemplatePartialSpecializationDecl *PartialSpec,
>> ArrayRef<TemplateArgument> TemplateArgs,
>> sema::TemplateDeductionInfo &DeductionInfo, SourceRange
>> InstantiationRange)
>> @@ -497,8 +508,12 @@ void Sema::PrintInstantiationStack() {
>> } else {
>> bool IsVar = isa<VarTemplateDecl>(Active->Entity) ||
>> isa<VarTemplateSpecializationDecl>(Active->Entity);
>> + bool IsTemplate = false;
>> TemplateParameterList *Params;
>> - if (auto *D = dyn_cast<ClassTemplatePartialSpecializationDecl>(
>> + if (auto *D = dyn_cast<TemplateDecl>(Active->Entity)) {
>> + IsTemplate = true;
>> + Params = D->getTemplateParameters();
>> + } else if (auto *D = dyn_cast<ClassTemplatePartialS
>> pecializationDecl>(
>> Active->Entity)) {
>> Params = D->getTemplateParameters();
>> } else if (auto *D = dyn_cast<VarTemplatePartialSpe
>> cializationDecl>(
>> @@ -510,7 +525,7 @@ void Sema::PrintInstantiationStack() {
>>
>> Diags.Report(Active->PointOfInstantiation,
>> diag::note_deduced_template_arg_substitution_here)
>> - << IsVar << cast<NamedDecl>(Active->Entity)
>> + << IsVar << IsTemplate << cast<NamedDecl>(Active->Entity)
>> << getTemplateArgumentBindingsText(Params,
>> Active->TemplateArgs,
>> Active->NumTemplateArgs)
>> << Active->InstantiationRange;
>>
>> Modified: cfe/trunk/test/CXX/drs/dr14xx.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/
>> dr14xx.cpp?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/test/CXX/drs/dr14xx.cpp (original)
>> +++ cfe/trunk/test/CXX/drs/dr14xx.cpp Tue Dec 27 01:56:27 2016
>> @@ -342,4 +342,32 @@ namespace dr1490 { // dr1490: 3.7 c++11
>> char s[4]{"abc"}; // Ok
>> std::initializer_list<char>{"abc"}; // expected-error {{expected
>> unqualified-id}}}
>> } // dr190
>> +
>> +namespace dr1495 { // dr1495: 4.0
>> + // Deduction succeeds in both directions.
>> + template<typename T, typename U> struct A {}; // expected-note
>> {{template is declared here}}
>> + template<typename T, typename U> struct A<U, T> {}; // expected-error
>> {{class template partial specialization is not more specialized}}
>> +
>> + // Primary template is more specialized.
>> + template<typename, typename...> struct B {}; // expected-note
>> {{template is declared here}}
>> + template<typename ...Ts> struct B<Ts...> {}; // expected-error {{not
>> more specialized}}
>> +
>> + // Deduction fails in both directions.
>> + template<int, typename, typename ...> struct C {}; // expected-note
>> {{template is declared here}}
>> + template<typename ...Ts> struct C<0, Ts...> {}; // expected-error
>> {{not more specialized}}
>> +
>> +#if __cplusplus >= 201402L
>> + // Deduction succeeds in both directions.
>> + template<typename T, typename U> int a; // expected-note {{template is
>> declared here}}
>> + template<typename T, typename U> int a<U, T>; // expected-error
>> {{variable template partial specialization is not more specialized}}
>> +
>> + // Primary template is more specialized.
>> + template<typename, typename...> int b; // expected-note {{template is
>> declared here}}
>> + template<typename ...Ts> int b<Ts...>; // expected-error {{not more
>> specialized}}
>> +
>> + // Deduction fails in both directions.
>> + template<int, typename, typename ...> int c; // expected-note
>> {{template is declared here}}
>> + template<typename ...Ts> int c<0, Ts...>; // expected-error {{not more
>> specialized}}
>> +#endif
>> +}
>> #endif
>>
>> Modified: cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expan
>> sion.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/
>> temp.decls/temp.variadic/fixed-expansion.cpp?rev=290593&r1=
>> 290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp
>> (original)
>> +++ cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/fixed-expansion.cpp
>> Tue Dec 27 01:56:27 2016
>> @@ -108,10 +108,10 @@ namespace PR9021b {
>>
>> namespace PartialSpecialization {
>> template<typename T, typename U, typename V = U>
>> - struct X0; // expected-note{{template is declared here}}
>> + struct X0; // expected-note 2{{template is declared here}}
>>
>> template<typename ...Ts>
>> - struct X0<Ts...> {
>> + struct X0<Ts...> { // expected-error {{class template partial
>> specialization is not more specialized than the primary template}}
>> };
>>
>> X0<int> x0i; // expected-error{{too few template arguments for class
>> template 'X0'}}
>>
>> Modified: cfe/trunk/test/SemaTemplate/class-template-spec.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTempl
>> ate/class-template-spec.cpp?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/test/SemaTemplate/class-template-spec.cpp (original)
>> +++ cfe/trunk/test/SemaTemplate/class-template-spec.cpp Tue Dec 27
>> 01:56:27 2016
>> @@ -167,10 +167,16 @@ namespace PR16519 {
>> // expected-warning at -2 {{variadic templates are a C++11 extension}}
>> #endif
>>
>> - template<typename T, T ...N, T ...Extra> struct
>> __make_integer_sequence_impl<integer_sequence<T, N...>, Extra...> {
>> + // Note that the following seemingly-equivalent template parameter
>> list is
>> + // not OK; it would result in a partial specialization that is not more
>> + // specialized than the primary template. (See NTTPTypeVsPartialOrder
>> below.)
>> + //
>> + // template<typename T, T ...N, T ...Extra>
>> + template<typename T, T ...N, typename integer_sequence<T,
>> N...>::value_type ...Extra>
>> #if __cplusplus <= 199711L
>> - // expected-warning at -2 2 {{variadic templates are a C++11 extension}}
>> + // expected-warning at -2 2{{variadic templates are a C++11 extension}}
>> #endif
>> + struct __make_integer_sequence_impl<integer_sequence<T, N...>,
>> Extra...> {
>> typedef integer_sequence<T, N..., sizeof...(N) + N..., Extra...>
>> type;
>> };
>>
>> @@ -193,6 +199,25 @@ namespace PR16519 {
>> #endif
>> }
>>
>> +namespace NTTPTypeVsPartialOrder {
>> + struct X { typedef int value_type; };
>> + template<typename T> struct Y { typedef T value_type; };
>> +
>> + template<typename T, typename T::value_type N> struct A; //
>> expected-note {{template}}
>> + template<int N> struct A<X, N> {};
>> + template<typename T, T N> struct A<Y<T>, N> {}; // expected-error
>> {{not more specialized}} expected-note {{'T' vs 'typename
>> Y<type-parameter-0-0>::value_type'}}
>> + A<X, 0> ax;
>> + A<Y<int>, 0> ay;
>> +
>> +
>> + template<int, typename T, typename T::value_type> struct B; //
>> expected-note {{template}}
>> + template<typename T, typename T::value_type N> struct B<0, T, N>; //
>> expected-note {{matches}}
>> + template<int N> struct B<0, X, N> {};
>> + template<typename T, T N> struct B<0, Y<T>, N> {}; // expected-error
>> {{not more specialized}} expected-note {{'T' vs 'typename
>> Y<type-parameter-0-0>::value_type'}} expected-note {{matches}}
>> + B<0, X, 0> bx;
>> + B<0, Y<int>, 0> by; // expected-error {{ambiguous}}
>> +}
>> +
>> namespace DefaultArgVsPartialSpec {
>> // Check that the diagnostic points at the partial specialization, not
>> just at
>> // the default argument.
>>
>> Modified: cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTempl
>> ate/temp_arg_nontype.cpp?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp (original)
>> +++ cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp Tue Dec 27 01:56:27
>> 2016
>> @@ -367,11 +367,11 @@ namespace PR17696 {
>>
>> namespace partial_order_different_types {
>> // These are unordered because the type of the final argument doesn't
>> match.
>> - // FIXME: The second partial specialization should actually be rejected
>> - // because it's not more specialized than the primary template.
>> - template<int, int, typename T, typename, T> struct A;
>> + template<int, int, typename T, typename, T> struct A; // expected-note
>> {{here}}
>> template<int N, typename T, typename U, T V> struct A<0, N, T, U, V>
>> {}; // expected-note {{matches}}
>> template<typename T, typename U, U V> struct A<0, 0, T, U, V> {}; //
>> expected-note {{matches}}
>> + // expected-error at -1 {{not more specialized than the primary}}
>> + // expected-note at -2 {{deduced non-type template argument does not
>> have the same type as the corresponding template parameter ('U' vs
>> 'type-parameter-0-0')}}
>> A<0, 0, int, int, 0> a; // expected-error {{ambiguous partial
>> specializations}}
>> }
>>
>> @@ -389,18 +389,22 @@ namespace partial_order_references {
>> int N;
>> A<0, 0, N> a;
>>
>> - // FIXME: These should all be rejected as they are not more
>> specialized than
>> - // the primary template (they can never be used due to the type
>> mismatch).
>> - template<int, int &R> struct B; // expected-note {{template}}
>> + template<int, int &R> struct B; // expected-note 2{{template}}
>> template<const int &R> struct B<0, R> {};
>> + // expected-error at -1 {{not more specialized than the primary}}
>> + // expected-note at -2 {{'const int' vs 'int &'}}
>> B<0, N> b; // expected-error {{undefined}}
>>
>> - template<int, const int &R> struct C; // expected-note {{template}}
>> + template<int, const int &R> struct C; // expected-note 2{{template}}
>> template<int &R> struct C<0, R> {};
>> + // expected-error at -1 {{not more specialized than the primary}}
>> + // expected-note at -2 {{'int' vs 'const int &'}}
>> C<0, N> c; // expected-error {{undefined}}
>>
>> - template<int, const int &R> struct D; // expected-note {{template}}
>> + template<int, const int &R> struct D; // expected-note 2{{template}}
>> template<int N> struct D<0, N> {};
>> + // expected-error at -1 {{not more specialized than the primary}}
>> + // expected-note at -2 {{'int' vs 'const int &'}}
>> extern const int K = 5;
>> D<0, K> d; // expected-error {{undefined}}
>> }
>>
>> Modified: cfe/trunk/www/cxx_dr_status.html
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_dr_sta
>> tus.html?rev=290593&r1=290592&r2=290593&view=diff
>> ============================================================
>> ==================
>> --- cfe/trunk/www/cxx_dr_status.html (original)
>> +++ cfe/trunk/www/cxx_dr_status.html Tue Dec 27 01:56:27 2016
>> @@ -4195,7 +4195,7 @@ and <I>POD class</I></td>
>> <td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defect
>> s.html#692">692</a></td>
>> <td>C++11</td>
>> <td>Partial ordering of variadic class template partial
>> specializations</td>
>> - <td class="none" align="center">Unknown</td>
>> + <td class="none" align="center">No</td>
>> </tr>
>> <tr id="693">
>> <td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defect
>> s.html#693">693</a></td>
>> @@ -8785,7 +8785,7 @@ and <I>POD class</I></td>
>> <td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defect
>> s.html#1495">1495</a></td>
>> <td>CD3</td>
>> <td>Partial specialization of variadic class template</td>
>> - <td class="none" align="center">Unknown</td>
>> + <td class="svn" align="center">SVN</td>
>> </tr>
>> <tr id="1496">
>> <td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defect
>> s.html#1496">1496</a></td>
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>
>
> _______________________________________________
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> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>
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