================ @@ -5395,11 +5520,100 @@ static QualType GetImplicitObjectParameterType(ASTContext &Context, return Context.getLValueReferenceType(RawType); } +static TemplateDeductionResult CheckDeductionConsistency( + Sema &S, FunctionTemplateDecl *FTD, int ArgIdx, QualType P, QualType A, + ArrayRef<TemplateArgument> DeducedArgs, bool CheckConsistency) { + MultiLevelTemplateArgumentList MLTAL(FTD, DeducedArgs, + /*Final=*/true); + if (ArgIdx != -1) + if (auto *MD = dyn_cast<CXXMethodDecl>(FTD->getTemplatedDecl()); + MD && MD->isImplicitObjectMemberFunction()) + ArgIdx -= 1; + Sema::ArgumentPackSubstitutionIndexRAII PackIndex( + S, ArgIdx != -1 ? ::getPackIndexForParam(S, FTD, MLTAL, ArgIdx) : -1); + bool IsIncompleteSubstitution = false; + QualType InstP = S.SubstType(P, MLTAL, FTD->getLocation(), FTD->getDeclName(), + &IsIncompleteSubstitution); + if (InstP.isNull()) + return TemplateDeductionResult::SubstitutionFailure; + if (!CheckConsistency) + return TemplateDeductionResult::Success; + if (IsIncompleteSubstitution) + return TemplateDeductionResult::Incomplete; + + // [temp.deduct.call]/4 - Check we produced a consistent deduction. + // This handles just the cases that can appear when partial ordering. + if (auto *PA = dyn_cast<PackExpansionType>(A); + PA && !isa<PackExpansionType>(InstP)) + A = PA->getPattern(); + if (!S.Context.hasSameType( + S.Context.getUnqualifiedArrayType(InstP.getNonReferenceType()), + S.Context.getUnqualifiedArrayType(A.getNonReferenceType()))) + return TemplateDeductionResult::NonDeducedMismatch; + return TemplateDeductionResult::Success; +} + +template <class T> +static TemplateDeductionResult FinishTemplateArgumentDeduction( + Sema &S, FunctionTemplateDecl *FTD, + SmallVectorImpl<DeducedTemplateArgument> &Deduced, + TemplateDeductionInfo &Info, T &&CheckDeductionConsistency) { + // Unevaluated SFINAE context. + EnterExpressionEvaluationContext Unevaluated( + S, Sema::ExpressionEvaluationContext::Unevaluated); + Sema::SFINAETrap Trap(S); + + Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(FTD)); + + // C++ [temp.deduct.type]p2: + // [...] or if any template argument remains neither deduced nor + // explicitly specified, template argument deduction fails. + bool IsIncomplete = false; + SmallVector<TemplateArgument, 4> SugaredBuilder, CanonicalBuilder; + if (auto Result = ConvertDeducedTemplateArguments( + S, FTD, /*IsDeduced=*/true, Deduced, Info, SugaredBuilder, + CanonicalBuilder, /*CurrentInstantiationScope=*/nullptr, + /*NumAlreadyConverted=*/0, &IsIncomplete); + Result != TemplateDeductionResult::Success) + return Result; + + // Form the template argument list from the deduced template arguments. + TemplateArgumentList *SugaredDeducedArgumentList = + TemplateArgumentList::CreateCopy(S.Context, SugaredBuilder); + TemplateArgumentList *CanonicalDeducedArgumentList = + TemplateArgumentList::CreateCopy(S.Context, CanonicalBuilder); + + Info.reset(SugaredDeducedArgumentList, CanonicalDeducedArgumentList); + + // Substitute the deduced template arguments into the argument + // and verify that the instantiated argument is both valid + // and equivalent to the parameter. + LocalInstantiationScope InstScope(S); + + if (auto TDR = CheckDeductionConsistency(S, FTD, SugaredBuilder); + TDR != TemplateDeductionResult::Success) + return TDR; + + // C++20 [temp.deduct]p5 - Only check constraints when all parameters have + // been deduced. + if (!IsIncomplete) { ---------------- mizvekov wrote:
This would miss checking if the SFINAE trap captured any errors. Doing things in this order avoids having to check the trap twice. https://github.com/llvm/llvm-project/pull/100692 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits