diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index f2ad84ea80b0da..4274848d154806 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -129,6 +129,10 @@ C++23 Feature Support C++20 Feature Support ^^^^^^^^^^^^^^^^^^^^^ +C++17 Feature Support +^^^^^^^^^^^^^^^^^^^^^ +- The implementation of the relaxed template template argument matching rules is + more complete and reliable, and should provide more accurate diagnostics. Resolutions to C++ Defect Reports ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -260,6 +264,10 @@ Improvements to Clang's diagnostics - Clang now diagnoses when the result of a [[nodiscard]] function is discarded after being cast in C. Fixes #GH104391. +- Clang now properly explains the reason a template template argument failed to + match a template template parameter, in terms of the C++17 relaxed matching rules + instead of the old ones. + - Don't emit duplicated dangling diagnostics. (#GH93386). - Improved diagnostic when trying to befriend a concept. (#GH45182). @@ -341,6 +349,8 @@ Bug Fixes to C++ Support - Correctly check constraints of explicit instantiations of member functions. (#GH46029) - When performing partial ordering of function templates, clang now checks that the deduction was consistent. Fixes (#GH18291). +- Fixes to several issues in partial ordering of template template parameters, which + were documented in the test suite. - Fixed an assertion failure about a constraint of a friend function template references to a value with greater template depth than the friend function template. (#GH98258) - Clang now rebuilds the template parameters of out-of-line declarations and specializations in the context diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index dcb49d8a67604a..2894142d8bbe58 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -5256,6 +5256,13 @@ def note_template_arg_refers_here_func : Note< def err_template_arg_template_params_mismatch : Error< "template template argument has different template parameters than its " "corresponding template template parameter">; +def note_template_arg_template_params_mismatch : Note< + "template template argument has different template parameters than its " + "corresponding template template parameter">; +def err_non_deduced_mismatch : Error< + "could not match %diff{$ against $|types}0,1">; +def err_inconsistent_deduction : Error< + "conflicting deduction %diff{$ against $|types}0,1 for parameter">; def err_template_arg_not_integral_or_enumeral : Error< "non-type template argument of type %0 must have an integral or enumeration" " type">; diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index 68c782a15c6f1b..f11d6bc6f865a8 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -12483,8 +12483,9 @@ class Sema final : public SemaBase { sema::TemplateDeductionInfo &Info); bool isTemplateTemplateParameterAtLeastAsSpecializedAs( - TemplateParameterList *PParam, TemplateDecl *AArg, - const DefaultArguments &DefaultArgs, SourceLocation Loc, bool IsDeduced); + TemplateParameterList *PParam, TemplateDecl *PArg, TemplateDecl *AArg, + const DefaultArguments &DefaultArgs, SourceLocation ArgLoc, + bool IsDeduced); /// Mark which template parameters are used in a given expression. /// @@ -12793,6 +12794,9 @@ class Sema final : public SemaBase { /// We are instantiating a type alias template declaration. TypeAliasTemplateInstantiation, + + /// We are performing partial ordering for template template parameters. + PartialOrderingTTP, } Kind; /// Was the enclosing context a non-instantiation SFINAE context? @@ -13014,6 +13018,12 @@ class Sema final : public SemaBase { TemplateDecl *Entity, BuildingDeductionGuidesTag, SourceRange InstantiationRange = SourceRange()); + struct PartialOrderingTTP {}; + /// \brief Note that we are partial ordering template template parameters. + InstantiatingTemplate(Sema &SemaRef, SourceLocation ArgLoc, + PartialOrderingTTP, TemplateDecl *PArg, + SourceRange InstantiationRange = SourceRange()); + /// Note that we have finished instantiating this template. void Clear(); diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp index 9f5d09e33ce244..cb9fbb8d02bd38 100644 --- a/clang/lib/Frontend/FrontendActions.cpp +++ b/clang/lib/Frontend/FrontendActions.cpp @@ -456,6 +456,8 @@ class DefaultTemplateInstCallback : public TemplateInstantiationCallback { return "BuildingDeductionGuides"; case CodeSynthesisContext::TypeAliasTemplateInstantiation: return "TypeAliasTemplateInstantiation"; + case CodeSynthesisContext::PartialOrderingTTP: + return "PartialOrderingTTP"; } return ""; } diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 513f83146fb59e..74fcd85843ad7d 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -5341,8 +5341,7 @@ bool Sema::CheckTemplateArgumentList( DefaultArgs && ParamIdx >= DefaultArgs.StartPos) { // All written arguments should have been consumed by this point. assert(ArgIdx == NumArgs && "bad default argument deduction"); - // FIXME: Don't ignore parameter packs. - if (ParamIdx == DefaultArgs.StartPos && !(*Param)->isParameterPack()) { + if (ParamIdx == DefaultArgs.StartPos) { assert(Param + DefaultArgs.Args.size() <= ParamEnd); // Default arguments from a DeducedTemplateName are already converted. for (const TemplateArgument &DefArg : DefaultArgs.Args) { @@ -5586,8 +5585,9 @@ bool Sema::CheckTemplateArgumentList( // pack expansions; they might be empty. This can happen even if // PartialTemplateArgs is false (the list of arguments is complete but // still dependent). - if (ArgIdx < NumArgs && CurrentInstantiationScope && - CurrentInstantiationScope->getPartiallySubstitutedPack()) { + if (PartialOrderingTTP || + (CurrentInstantiationScope && + CurrentInstantiationScope->getPartiallySubstitutedPack())) { while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion()) { const TemplateArgument &Arg = NewArgs[ArgIdx++].getArgument(); @@ -7185,64 +7185,46 @@ bool Sema::CheckTemplateTemplateArgument(TemplateTemplateParmDecl *Param, << Template; } + if (!getLangOpts().RelaxedTemplateTemplateArgs) + return !TemplateParameterListsAreEqual( + Template->getTemplateParameters(), Params, /*Complain=*/true, + TPL_TemplateTemplateArgumentMatch, Arg.getLocation()); + // C++1z [temp.arg.template]p3: (DR 150) // A template-argument matches a template template-parameter P when P // is at least as specialized as the template-argument A. - if (getLangOpts().RelaxedTemplateTemplateArgs) { - // Quick check for the common case: - // If P contains a parameter pack, then A [...] matches P if each of A's - // template parameters matches the corresponding template parameter in - // the template-parameter-list of P. - if (TemplateParameterListsAreEqual( - Template->getTemplateParameters(), Params, false, - TPL_TemplateTemplateArgumentMatch, Arg.getLocation()) && - // If the argument has no associated constraints, then the parameter is - // definitely at least as specialized as the argument. - // Otherwise - we need a more thorough check. - !Template->hasAssociatedConstraints()) - return false; - - if (isTemplateTemplateParameterAtLeastAsSpecializedAs( - Params, Template, DefaultArgs, Arg.getLocation(), IsDeduced)) { - // P2113 - // C++20[temp.func.order]p2 - // [...] If both deductions succeed, the partial ordering selects the - // more constrained template (if one exists) as determined below. - SmallVector ParamsAC, TemplateAC; - Params->getAssociatedConstraints(ParamsAC); - // C++2a[temp.arg.template]p3 - // [...] In this comparison, if P is unconstrained, the constraints on A - // are not considered. - if (ParamsAC.empty()) - return false; + if (!isTemplateTemplateParameterAtLeastAsSpecializedAs( + Params, Param, Template, DefaultArgs, Arg.getLocation(), IsDeduced)) + return true; + // P2113 + // C++20[temp.func.order]p2 + // [...] If both deductions succeed, the partial ordering selects the + // more constrained template (if one exists) as determined below. + SmallVector ParamsAC, TemplateAC; + Params->getAssociatedConstraints(ParamsAC); + // C++20[temp.arg.template]p3 + // [...] In this comparison, if P is unconstrained, the constraints on A + // are not considered. + if (ParamsAC.empty()) + return false; - Template->getAssociatedConstraints(TemplateAC); + Template->getAssociatedConstraints(TemplateAC); - bool IsParamAtLeastAsConstrained; - if (IsAtLeastAsConstrained(Param, ParamsAC, Template, TemplateAC, - IsParamAtLeastAsConstrained)) - return true; - if (!IsParamAtLeastAsConstrained) { - Diag(Arg.getLocation(), - diag::err_template_template_parameter_not_at_least_as_constrained) - << Template << Param << Arg.getSourceRange(); - Diag(Param->getLocation(), diag::note_entity_declared_at) << Param; - Diag(Template->getLocation(), diag::note_entity_declared_at) - << Template; - MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Param, ParamsAC, Template, - TemplateAC); - return true; - } - return false; - } - // FIXME: Produce better diagnostics for deduction failures. + bool IsParamAtLeastAsConstrained; + if (IsAtLeastAsConstrained(Param, ParamsAC, Template, TemplateAC, + IsParamAtLeastAsConstrained)) + return true; + if (!IsParamAtLeastAsConstrained) { + Diag(Arg.getLocation(), + diag::err_template_template_parameter_not_at_least_as_constrained) + << Template << Param << Arg.getSourceRange(); + Diag(Param->getLocation(), diag::note_entity_declared_at) << Param; + Diag(Template->getLocation(), diag::note_entity_declared_at) << Template; + MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Param, ParamsAC, Template, + TemplateAC); + return true; } - - return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), - Params, - true, - TPL_TemplateTemplateArgumentMatch, - Arg.getLocation()); + return false; } static Sema::SemaDiagnosticBuilder noteLocation(Sema &S, const NamedDecl &Decl, diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index 06986d8d2b2a51..b6381245983a9f 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -145,7 +145,9 @@ static TemplateDeductionResult DeduceTemplateArgumentsByTypeMatch( PartialOrderingKind POK, bool DeducedFromArrayBound, bool *HasDeducedAnyParam); -enum class PackFold { ParameterToArgument, ArgumentToParameter }; +/// What directions packs are allowed to match non-packs. +enum class PackFold { ParameterToArgument, ArgumentToParameter, Both }; + static TemplateDeductionResult DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, ArrayRef Ps, @@ -1703,7 +1705,21 @@ static TemplateDeductionResult DeduceTemplateArgumentsByTypeMatch( DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context, Deduced[Index], NewDeduced); if (Result.isNull()) { - Info.Param = cast(TemplateParams->getParam(Index)); + // We can also get inconsistencies when matching NTTP type. + switch (NamedDecl *Param = TemplateParams->getParam(Index); + Param->getKind()) { + case Decl::TemplateTypeParm: + Info.Param = cast(Param); + break; + case Decl::NonTypeTemplateParm: + Info.Param = cast(Param); + break; + case Decl::TemplateTemplateParm: + Info.Param = cast(Param); + break; + default: + llvm_unreachable("unexpected kind"); + } Info.FirstArg = Deduced[Index]; Info.SecondArg = NewDeduced; return TemplateDeductionResult::Inconsistent; @@ -2577,8 +2593,31 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, if (const NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(Info, P.getAsExpr())) { switch (A.getKind()) { + case TemplateArgument::Expression: { + const Expr *E = A.getAsExpr(); + // When checking NTTP, if either the parameter or the argument is + // dependent, as there would be otherwise nothing to deduce, we force + // the argument to the parameter type using this dependent implicit + // cast, in order to maintain invariants. Now we can deduce the + // resulting type from the original type, and deduce the original type + // against the parameter we are checking. + if (const auto *ICE = dyn_cast(E); + ICE && ICE->getCastKind() == clang::CK_Dependent) { + E = ICE->getSubExpr(); + if (auto Result = DeduceTemplateArgumentsByTypeMatch( + S, TemplateParams, ICE->getType(), E->getType(), Info, + Deduced, TDF_SkipNonDependent, + PartialOrdering ? PartialOrderingKind::NonCall + : PartialOrderingKind::None, + /*DeducedFromArrayBound=*/false, HasDeducedAnyParam); + Result != TemplateDeductionResult::Success) + return Result; + } + return DeduceNonTypeTemplateArgument( + S, TemplateParams, NTTP, DeducedTemplateArgument(A), E->getType(), + Info, PartialOrdering, Deduced, HasDeducedAnyParam); + } case TemplateArgument::Integral: - case TemplateArgument::Expression: case TemplateArgument::StructuralValue: return DeduceNonTypeTemplateArgument( S, TemplateParams, NTTP, DeducedTemplateArgument(A), @@ -2667,50 +2706,75 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, SmallVectorImpl &Deduced, bool NumberOfArgumentsMustMatch, bool PartialOrdering, PackFold PackFold, bool *HasDeducedAnyParam) { - if (PackFold == PackFold::ArgumentToParameter) - std::swap(Ps, As); + bool FoldPackParameter = PackFold == PackFold::ParameterToArgument || + PackFold == PackFold::Both, + FoldPackArgument = PackFold == PackFold::ArgumentToParameter || + PackFold == PackFold::Both; + // C++0x [temp.deduct.type]p9: // If the template argument list of P contains a pack expansion that is not // the last template argument, the entire template argument list is a // non-deduced context. - if (hasPackExpansionBeforeEnd(Ps)) + if (FoldPackParameter && hasPackExpansionBeforeEnd(Ps)) + return TemplateDeductionResult::Success; + + if (FoldPackArgument && hasPackExpansionBeforeEnd(As)) return TemplateDeductionResult::Success; // C++0x [temp.deduct.type]p9: // If P has a form that contains or , then each argument Pi of the // respective template argument list P is compared with the corresponding // argument Ai of the corresponding template argument list of A. - unsigned ArgIdx = 0, ParamIdx = 0; - for (; hasTemplateArgumentForDeduction(Ps, ParamIdx); ++ParamIdx) { - const TemplateArgument &P = Ps[ParamIdx]; - if (!P.isPackExpansion()) { + for (unsigned ArgIdx = 0, ParamIdx = 0; /**/; /**/) { + if (!hasTemplateArgumentForDeduction(Ps, ParamIdx)) + return !FoldPackParameter && hasTemplateArgumentForDeduction(As, ArgIdx) + ? TemplateDeductionResult::MiscellaneousDeductionFailure + : TemplateDeductionResult::Success; + + if (!Ps[ParamIdx].isPackExpansion()) { // The simple case: deduce template arguments by matching Pi and Ai. // Check whether we have enough arguments. if (!hasTemplateArgumentForDeduction(As, ArgIdx)) - return NumberOfArgumentsMustMatch + return !FoldPackArgument && NumberOfArgumentsMustMatch ? TemplateDeductionResult::MiscellaneousDeductionFailure : TemplateDeductionResult::Success; - // C++1z [temp.deduct.type]p9: - // During partial ordering, if Ai was originally a pack expansion [and] - // Pi is not a pack expansion, template argument deduction fails. - if (As[ArgIdx].isPackExpansion()) - return TemplateDeductionResult::MiscellaneousDeductionFailure; + if (As[ArgIdx].isPackExpansion()) { + // C++1z [temp.deduct.type]p9: + // During partial ordering, if Ai was originally a pack expansion + // [and] Pi is not a pack expansion, template argument deduction + // fails. + if (!FoldPackArgument) + return TemplateDeductionResult::MiscellaneousDeductionFailure; + + TemplateArgument Pattern = As[ArgIdx].getPackExpansionPattern(); + for (;;) { + // Deduce template parameters from the pattern. + if (auto Result = DeduceTemplateArguments( + S, TemplateParams, Ps[ParamIdx], Pattern, Info, + PartialOrdering, Deduced, HasDeducedAnyParam); + Result != TemplateDeductionResult::Success) + return Result; - // Perform deduction for this Pi/Ai pair. - TemplateArgument Pi = P, Ai = As[ArgIdx]; - if (PackFold == PackFold::ArgumentToParameter) - std::swap(Pi, Ai); - if (auto Result = DeduceTemplateArguments(S, TemplateParams, Pi, Ai, Info, - PartialOrdering, Deduced, - HasDeducedAnyParam); - Result != TemplateDeductionResult::Success) - return Result; + ++ParamIdx; + if (!hasTemplateArgumentForDeduction(Ps, ParamIdx)) + return TemplateDeductionResult::Success; + if (Ps[ParamIdx].isPackExpansion()) + break; + } + } else { + // Perform deduction for this Pi/Ai pair. + if (auto Result = DeduceTemplateArguments( + S, TemplateParams, Ps[ParamIdx], As[ArgIdx], Info, + PartialOrdering, Deduced, HasDeducedAnyParam); + Result != TemplateDeductionResult::Success) + return Result; - // Move to the next argument. - ++ArgIdx; - continue; + ++ArgIdx; + ++ParamIdx; + continue; + } } // The parameter is a pack expansion. @@ -2720,7 +2784,7 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, // each remaining argument in the template argument list of A. Each // comparison deduces template arguments for subsequent positions in the // template parameter packs expanded by Pi. - TemplateArgument Pattern = P.getPackExpansionPattern(); + TemplateArgument Pattern = Ps[ParamIdx].getPackExpansionPattern(); // Prepare to deduce the packs within the pattern. PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern); @@ -2731,13 +2795,12 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, for (; hasTemplateArgumentForDeduction(As, ArgIdx) && PackScope.hasNextElement(); ++ArgIdx) { - TemplateArgument Pi = Pattern, Ai = As[ArgIdx]; - if (PackFold == PackFold::ArgumentToParameter) - std::swap(Pi, Ai); + if (!FoldPackParameter && !As[ArgIdx].isPackExpansion()) + return TemplateDeductionResult::MiscellaneousDeductionFailure; // Deduce template arguments from the pattern. - if (auto Result = DeduceTemplateArguments(S, TemplateParams, Pi, Ai, Info, - PartialOrdering, Deduced, - HasDeducedAnyParam); + if (auto Result = DeduceTemplateArguments( + S, TemplateParams, Pattern, As[ArgIdx], Info, PartialOrdering, + Deduced, HasDeducedAnyParam); Result != TemplateDeductionResult::Success) return Result; @@ -2746,12 +2809,8 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, // Build argument packs for each of the parameter packs expanded by this // pack expansion. - if (auto Result = PackScope.finish(); - Result != TemplateDeductionResult::Success) - return Result; + return PackScope.finish(); } - - return TemplateDeductionResult::Success; } TemplateDeductionResult Sema::DeduceTemplateArguments( @@ -3330,7 +3389,6 @@ static TemplateDeductionResult FinishTemplateArgumentDeduction( // Unevaluated SFINAE context. EnterExpressionEvaluationContext Unevaluated( S, Sema::ExpressionEvaluationContext::Unevaluated); - Sema::SFINAETrap Trap(S); Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Template)); @@ -3348,20 +3406,36 @@ static TemplateDeductionResult FinishTemplateArgumentDeduction( // Check that we produced the correct argument list. TemplateParameterList *TemplateParams = Template->getTemplateParameters(); + auto isSame = [&](unsigned I, const TemplateArgument &P, + const TemplateArgument &A) { + if (isSameTemplateArg(S.Context, P, A, PartialOrdering, + /*PackExpansionMatchesPack=*/true)) + return true; + Info.Param = makeTemplateParameter(TemplateParams->getParam(I)); + Info.FirstArg = P; + Info.SecondArg = A; + return false; + }; for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) { - TemplateArgument InstArg = CanonicalBuilder[I]; - if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg, PartialOrdering, - /*PackExpansionMatchesPack=*/true)) { - Info.Param = makeTemplateParameter(TemplateParams->getParam(I)); - Info.FirstArg = TemplateArgs[I]; - Info.SecondArg = InstArg; - return TemplateDeductionResult::NonDeducedMismatch; + const TemplateArgument &P = TemplateArgs[I]; + if (P.isPackExpansion()) { + assert(I == TemplateArgs.size() - 1); + for (/**/; I != E; ++I) { + const TemplateArgument &A = CanonicalBuilder[I]; + if (A.getKind() == TemplateArgument::Pack) { + for (const TemplateArgument &Ai : A.getPackAsArray()) + if (!isSame(I, P, Ai)) + return TemplateDeductionResult::NonDeducedMismatch; + } else if (!isSame(I, P, A)) { + return TemplateDeductionResult::NonDeducedMismatch; + } + } + break; } + if (!isSame(I, P, CanonicalBuilder[I])) + return TemplateDeductionResult::NonDeducedMismatch; } - if (Trap.hasErrorOccurred()) - return TemplateDeductionResult::SubstitutionFailure; - if (!PartialOrdering) { if (auto Result = CheckDeducedArgumentConstraints( S, Template, SugaredBuilder, CanonicalBuilder, Info); @@ -3382,7 +3456,6 @@ static TemplateDeductionResult FinishTemplateArgumentDeduction( // Unevaluated SFINAE context. EnterExpressionEvaluationContext Unevaluated( S, Sema::ExpressionEvaluationContext::Unevaluated); - Sema::SFINAETrap Trap(S); Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(TD)); @@ -3391,20 +3464,13 @@ static TemplateDeductionResult FinishTemplateArgumentDeduction( // explicitly specified, template argument deduction fails. SmallVector SugaredBuilder, CanonicalBuilder; if (auto Result = ConvertDeducedTemplateArguments( - S, TD, /*IsPartialOrdering=*/false, Deduced, Info, SugaredBuilder, + S, TD, /*IsDeduced=*/false, Deduced, Info, SugaredBuilder, CanonicalBuilder); Result != TemplateDeductionResult::Success) return Result; - if (Trap.hasErrorOccurred()) - return TemplateDeductionResult::SubstitutionFailure; - - if (auto Result = CheckDeducedArgumentConstraints(S, TD, SugaredBuilder, - CanonicalBuilder, Info); - Result != TemplateDeductionResult::Success) - return Result; - - return TemplateDeductionResult::Success; + return ::CheckDeducedArgumentConstraints(S, TD, SugaredBuilder, + CanonicalBuilder, Info); } /// Perform template argument deduction to determine whether the given template @@ -3451,16 +3517,20 @@ DeduceTemplateArguments(Sema &S, T *Partial, if (Inst.isInvalid()) return TemplateDeductionResult::InstantiationDepth; - if (Trap.hasErrorOccurred()) - return TemplateDeductionResult::SubstitutionFailure; - TemplateDeductionResult Result; S.runWithSufficientStackSpace(Info.getLocation(), [&] { Result = ::FinishTemplateArgumentDeduction(S, Partial, /*IsPartialOrdering=*/false, TemplateArgs, Deduced, Info); }); - return Result; + + if (Result != TemplateDeductionResult::Success) + return Result; + + if (Trap.hasErrorOccurred()) + return TemplateDeductionResult::SubstitutionFailure; + + return TemplateDeductionResult::Success; } TemplateDeductionResult @@ -3516,14 +3586,18 @@ Sema::DeduceTemplateArgumentsFromType(TemplateDecl *TD, QualType FromType, if (Inst.isInvalid()) return TemplateDeductionResult::InstantiationDepth; - if (Trap.hasErrorOccurred()) - return TemplateDeductionResult::SubstitutionFailure; - TemplateDeductionResult Result; runWithSufficientStackSpace(Info.getLocation(), [&] { Result = ::FinishTemplateArgumentDeduction(*this, TD, Deduced, Info); }); - return Result; + + if (Result != TemplateDeductionResult::Success) + return Result; + + if (Trap.hasErrorOccurred()) + return TemplateDeductionResult::SubstitutionFailure; + + return TemplateDeductionResult::Success; } /// Determine whether the given type T is a simple-template-id type. @@ -6162,14 +6236,23 @@ static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2, return false; const auto *TST1 = cast(T1); - bool AtLeastAsSpecialized; + + Sema::SFINAETrap Trap(S); + + TemplateDeductionResult Result; S.runWithSufficientStackSpace(Info.getLocation(), [&] { - AtLeastAsSpecialized = - FinishTemplateArgumentDeduction( - S, P2, /*IsPartialOrdering=*/true, TST1->template_arguments(), - Deduced, Info) == TemplateDeductionResult::Success; + Result = ::FinishTemplateArgumentDeduction( + S, P2, /*IsPartialOrdering=*/true, TST1->template_arguments(), Deduced, + Info); }); - return AtLeastAsSpecialized; + + if (Result != TemplateDeductionResult::Success) + return false; + + if (Trap.hasErrorOccurred()) + return false; + + return true; } namespace { @@ -6407,8 +6490,9 @@ bool Sema::isMoreSpecializedThanPrimary( } bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( - TemplateParameterList *P, TemplateDecl *AArg, - const DefaultArguments &DefaultArgs, SourceLocation Loc, bool IsDeduced) { + TemplateParameterList *P, TemplateDecl *PArg, TemplateDecl *AArg, + const DefaultArguments &DefaultArgs, SourceLocation ArgLoc, + bool IsDeduced) { // C++1z [temp.arg.template]p4: (DR 150) // A template template-parameter P is at least as specialized as a // template template-argument A if, given the following rewrite to two @@ -6420,6 +6504,12 @@ bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( // TemplateParameterList *A = AArg->getTemplateParameters(); + Sema::InstantiatingTemplate Inst( + *this, ArgLoc, Sema::InstantiatingTemplate::PartialOrderingTTP(), PArg, + SourceRange(P->getTemplateLoc(), P->getRAngleLoc())); + if (Inst.isInvalid()) + return false; + // Given an invented class template X with the template parameter list of // A (including default arguments): // - Each function template has a single function parameter whose type is @@ -6434,8 +6524,6 @@ bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( // templates. SmallVector PArgs; { - SFINAETrap Trap(*this); - Context.getInjectedTemplateArgs(P, PArgs); TemplateArgumentListInfo PArgList(P->getLAngleLoc(), P->getRAngleLoc()); @@ -6455,18 +6543,17 @@ bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( // C++1z [temp.arg.template]p3: // If the rewrite produces an invalid type, then P is not at least as // specialized as A. - SmallVector SugaredPArgs; - if (CheckTemplateArgumentList(AArg, Loc, PArgList, DefaultArgs, false, - SugaredPArgs, PArgs, + SmallVector CanonicalPArgs; + if (CheckTemplateArgumentList(AArg, ArgLoc, PArgList, DefaultArgs, false, + PArgs, CanonicalPArgs, /*UpdateArgsWithConversions=*/true, /*ConstraintsNotSatisfied=*/nullptr, - /*PartialOrderTTP=*/true) || - Trap.hasErrorOccurred()) + /*PartialOrderingTTP=*/true)) return false; } // Determine whether P1 is at least as specialized as P2. - TemplateDeductionInfo Info(Loc, A->getDepth()); + TemplateDeductionInfo Info(ArgLoc, A->getDepth()); SmallVector Deduced; Deduced.resize(A->size()); @@ -6481,29 +6568,89 @@ bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( // be inverted between Ps and As. On non-deduced context, matching needs to // happen both ways, according to [temp.arg.template]p3, but this is // currently implemented as a special case elsewhere. - if (::DeduceTemplateArguments(*this, A, AArgs, PArgs, Info, Deduced, - /*NumberOfArgumentsMustMatch=*/false, - /*PartialOrdering=*/true, - IsDeduced ? PackFold::ArgumentToParameter - : PackFold::ParameterToArgument, - /*HasDeducedAnyParam=*/nullptr) != - TemplateDeductionResult::Success) + switch (TemplateDeductionResult Result = ::DeduceTemplateArguments( + *this, A, AArgs, PArgs, Info, Deduced, + /*NumberOfArgumentsMustMatch=*/false, /*PartialOrdering=*/true, + IsDeduced ? PackFold::ArgumentToParameter : PackFold::Both, + /*HasDeducedAnyParam=*/nullptr)) { + case clang::TemplateDeductionResult::Success: + break; + + case TemplateDeductionResult::MiscellaneousDeductionFailure: + Diag(AArg->getLocation(), diag::err_template_param_list_different_arity) + << (A->size() > P->size()) << /*isTemplateTemplateParameter=*/true + << SourceRange(A->getTemplateLoc(), P->getRAngleLoc()); + return false; + case TemplateDeductionResult::NonDeducedMismatch: + Diag(AArg->getLocation(), diag::err_non_deduced_mismatch) + << Info.FirstArg << Info.SecondArg; return false; + case TemplateDeductionResult::Inconsistent: + Diag(getAsNamedDecl(Info.Param)->getLocation(), + diag::err_inconsistent_deduction) + << Info.FirstArg << Info.SecondArg; + return false; + case TemplateDeductionResult::AlreadyDiagnosed: + return false; + + // None of these should happen for a plain deduction. + case TemplateDeductionResult::Invalid: + case TemplateDeductionResult::InstantiationDepth: + case TemplateDeductionResult::Incomplete: + case TemplateDeductionResult::IncompletePack: + case TemplateDeductionResult::Underqualified: + case TemplateDeductionResult::SubstitutionFailure: + case TemplateDeductionResult::DeducedMismatch: + case TemplateDeductionResult::DeducedMismatchNested: + case TemplateDeductionResult::TooManyArguments: + case TemplateDeductionResult::TooFewArguments: + case TemplateDeductionResult::InvalidExplicitArguments: + case TemplateDeductionResult::NonDependentConversionFailure: + case TemplateDeductionResult::ConstraintsNotSatisfied: + case TemplateDeductionResult::CUDATargetMismatch: + llvm_unreachable("Unexpected Result"); + } SmallVector DeducedArgs(Deduced.begin(), Deduced.end()); - Sema::InstantiatingTemplate Inst(*this, Info.getLocation(), AArg, DeducedArgs, - Info); - if (Inst.isInvalid()) - return false; - bool AtLeastAsSpecialized; + TemplateDeductionResult TDK; runWithSufficientStackSpace(Info.getLocation(), [&] { - AtLeastAsSpecialized = - ::FinishTemplateArgumentDeduction( - *this, AArg, /*IsPartialOrdering=*/true, PArgs, Deduced, Info) == - TemplateDeductionResult::Success; + TDK = ::FinishTemplateArgumentDeduction( + *this, AArg, /*IsPartialOrdering=*/true, PArgs, Deduced, Info); }); - return AtLeastAsSpecialized; + switch (TDK) { + case TemplateDeductionResult::Success: + return true; + + // It doesn't seem possible to get a non-deduced mismatch when partial + // ordering TTPs. + case TemplateDeductionResult::NonDeducedMismatch: + llvm_unreachable("Unexpected NonDeducedMismatch"); + + // Substitution failures should have already been diagnosed. + case TemplateDeductionResult::AlreadyDiagnosed: + case TemplateDeductionResult::SubstitutionFailure: + case TemplateDeductionResult::InstantiationDepth: + return false; + + // None of these should happen when just converting deduced arguments. + case TemplateDeductionResult::Invalid: + case TemplateDeductionResult::Incomplete: + case TemplateDeductionResult::IncompletePack: + case TemplateDeductionResult::Inconsistent: + case TemplateDeductionResult::Underqualified: + case TemplateDeductionResult::DeducedMismatch: + case TemplateDeductionResult::DeducedMismatchNested: + case TemplateDeductionResult::TooManyArguments: + case TemplateDeductionResult::TooFewArguments: + case TemplateDeductionResult::InvalidExplicitArguments: + case TemplateDeductionResult::NonDependentConversionFailure: + case TemplateDeductionResult::ConstraintsNotSatisfied: + case TemplateDeductionResult::MiscellaneousDeductionFailure: + case TemplateDeductionResult::CUDATargetMismatch: + llvm_unreachable("Unexpected Result"); + } + llvm_unreachable("Unexpected TDK"); } namespace { diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp index c42cc250bb904a..4779dc327dbb0f 100644 --- a/clang/lib/Sema/SemaTemplateInstantiate.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp @@ -572,6 +572,7 @@ bool Sema::CodeSynthesisContext::isInstantiationRecord() const { case LambdaExpressionSubstitution: case BuildingDeductionGuides: case TypeAliasTemplateInstantiation: + case PartialOrderingTTP: return false; // This function should never be called when Kind's value is Memoization. @@ -804,6 +805,11 @@ Sema::InstantiatingTemplate::InstantiatingTemplate( SemaRef, CodeSynthesisContext::BuildingDeductionGuides, PointOfInstantiation, InstantiationRange, Entity) {} +Sema::InstantiatingTemplate::InstantiatingTemplate( + Sema &SemaRef, SourceLocation ArgLoc, PartialOrderingTTP, + TemplateDecl *PArg, SourceRange InstantiationRange) + : InstantiatingTemplate(SemaRef, CodeSynthesisContext::PartialOrderingTTP, + ArgLoc, InstantiationRange, PArg) {} void Sema::pushCodeSynthesisContext(CodeSynthesisContext Ctx) { Ctx.SavedInNonInstantiationSFINAEContext = InNonInstantiationSFINAEContext; @@ -1243,6 +1249,14 @@ void Sema::PrintInstantiationStack() { << cast(Active->Entity) << Active->InstantiationRange; break; + case CodeSynthesisContext::PartialOrderingTTP: + Diags.Report(Active->PointOfInstantiation, + diag::note_template_arg_template_params_mismatch); + if (SourceLocation ParamLoc = Active->Entity->getLocation(); + ParamLoc.isValid()) + Diags.Report(ParamLoc, diag::note_template_prev_declaration) + << /*isTemplateTemplateParam=*/true << Active->InstantiationRange; + break; } } } @@ -1285,6 +1299,7 @@ std::optional Sema::isSFINAEContext() const { case CodeSynthesisContext::PriorTemplateArgumentSubstitution: case CodeSynthesisContext::DefaultTemplateArgumentChecking: case CodeSynthesisContext::RewritingOperatorAsSpaceship: + case CodeSynthesisContext::PartialOrderingTTP: // A default template argument instantiation and substitution into // template parameters with arguments for prior parameters may or may // not be a SFINAE context; look further up the stack. diff --git a/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp b/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp index 19793fe8263726..1bbbd1d3429ddd 100644 --- a/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp +++ b/clang/test/CXX/temp/temp.arg/temp.arg.template/p3-0x.cpp @@ -2,13 +2,13 @@ template struct eval; // expected-note 3{{template is declared here}} -template