https://github.com/mizvekov created https://github.com/llvm/llvm-project/pull/133113
This fixes a regression when interpreting a nested name specifier for deduction purposes in member pointers. This introduces a helper for fully translating a nested name specifier into a type. Other existing potential users will be deduplicated by using this helper in subsequent patches. This regression was introduced here: https://github.com/llvm/llvm-project/pull/130537 and was reported here: https://github.com/llvm/llvm-project/pull/132401#issuecomment-2751489581 No release notes, since this regression was never released. >From 1eb400c35c92e711d57c47a9f69334c4826fab59 Mon Sep 17 00:00:00 2001 From: Matheus Izvekov <mizve...@gmail.com> Date: Wed, 26 Mar 2025 12:26:40 -0300 Subject: [PATCH] [clang] fix deduction of member pointers with depednent named classes This fixes a regression when interpreting a nested name specifier for deduction purposes in member pointers. This introduces a helper for fully translating a nested name specifier into a type. Other existing potential users will be deduplicated by using this helper in subsequent patches. This regression was introduced here: https://github.com/llvm/llvm-project/pull/130537 and was reported here: https://github.com/llvm/llvm-project/pull/132401#issuecomment-2751489581 No release notes, since the regression was never released. --- clang/include/clang/AST/NestedNameSpecifier.h | 5 ++ clang/lib/AST/NestedNameSpecifier.cpp | 46 +++++++++++++++++++ clang/lib/Sema/SemaTemplateDeduction.cpp | 34 +++++++++----- clang/test/SemaCXX/member-pointer.cpp | 43 +++++++++++++++++ .../SemaTemplate/instantiation-backtrace.cpp | 6 +-- 5 files changed, 119 insertions(+), 15 deletions(-) diff --git a/clang/include/clang/AST/NestedNameSpecifier.h b/clang/include/clang/AST/NestedNameSpecifier.h index 051d632f1cdf9..273e73e7c1e95 100644 --- a/clang/include/clang/AST/NestedNameSpecifier.h +++ b/clang/include/clang/AST/NestedNameSpecifier.h @@ -201,6 +201,11 @@ class NestedNameSpecifier : public llvm::FoldingSetNode { return nullptr; } + /// Fully translate this nested name specifier to a type. + /// Unlike getAsType, this will convert this entire nested + /// name specifier chain into its equivalent type. + const Type *translateToType(const ASTContext &Context) const; + NestedNameSpecifierDependence getDependence() const; /// Whether this nested name specifier refers to a dependent diff --git a/clang/lib/AST/NestedNameSpecifier.cpp b/clang/lib/AST/NestedNameSpecifier.cpp index a256a87695afc..206e462a58a79 100644 --- a/clang/lib/AST/NestedNameSpecifier.cpp +++ b/clang/lib/AST/NestedNameSpecifier.cpp @@ -245,6 +245,52 @@ bool NestedNameSpecifier::containsErrors() const { return getDependence() & NestedNameSpecifierDependence::Error; } +const Type * +NestedNameSpecifier::translateToType(const ASTContext &Context) const { + NestedNameSpecifier *Prefix = getPrefix(); + switch (getKind()) { + case SpecifierKind::Identifier: + return Context + .getDependentNameType(ElaboratedTypeKeyword::None, Prefix, + getAsIdentifier()) + .getTypePtr(); + case SpecifierKind::TypeSpec: + case SpecifierKind::TypeSpecWithTemplate: { + const Type *T = getAsType(); + switch (T->getTypeClass()) { + case Type::DependentTemplateSpecialization: { + const auto *DT = cast<DependentTemplateSpecializationType>(T); + // FIXME: The type node can't represent the template keyword. + return Context + .getDependentTemplateSpecializationType(ElaboratedTypeKeyword::None, + Prefix, DT->getIdentifier(), + DT->template_arguments()) + .getTypePtr(); + } + case Type::Record: + case Type::TemplateSpecialization: + case Type::Using: + case Type::Enum: + case Type::Typedef: + case Type::UnresolvedUsing: + return Context + .getElaboratedType(ElaboratedTypeKeyword::None, Prefix, + QualType(T, 0)) + .getTypePtr(); + default: + assert(Prefix == nullptr && "unexpected type with elaboration"); + return T; + } + } + case SpecifierKind::Global: + case SpecifierKind::Namespace: + case SpecifierKind::NamespaceAlias: + case SpecifierKind::Super: + // These are not representable as types. + return nullptr; + } +} + /// Print this nested name specifier to the given output /// stream. void NestedNameSpecifier::print(raw_ostream &OS, const PrintingPolicy &Policy, diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index 410b5a2c83e8d..e4ef5e7f72737 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -2127,19 +2127,29 @@ static TemplateDeductionResult DeduceTemplateArgumentsByTypeMatch( /*DeducedFromArrayBound=*/false, HasDeducedAnyParam); Result != TemplateDeductionResult::Success) return Result; - const Type *QP = MPP->getQualifier()->getAsType(), - *QA = MPA->getQualifier()->getAsType(); - CXXRecordDecl *ClsP = MPP->getMostRecentCXXRecordDecl(), - *ClsA = MPA->getMostRecentCXXRecordDecl(); - // FIXME: Don't drop the rest of the prefixes here. - QualType P = !ClsP || declaresSameEntity(QP->getAsCXXRecordDecl(), ClsP) - ? QualType(QP, 0) - : S.Context.getTypeDeclType(ClsP); - QualType A = !ClsA || declaresSameEntity(QA->getAsCXXRecordDecl(), ClsA) - ? QualType(QA, 0) - : S.Context.getTypeDeclType(ClsA); + + QualType TP; + if (MPP->isSugared()) { + TP = S.Context.getTypeDeclType(MPP->getMostRecentCXXRecordDecl()); + } else { + NestedNameSpecifier *QP = MPP->getQualifier(); + if (QP->getKind() == clang::NestedNameSpecifier::Identifier) + // Skip translation if it's a non-deduced context anyway. + return TemplateDeductionResult::Success; + TP = QualType(QP->translateToType(S.Context), 0); + } + assert(!TP.isNull() && "member pointer with non-type class"); + + QualType TA; + if (MPA->isSugared()) { + TA = S.Context.getTypeDeclType(MPA->getMostRecentCXXRecordDecl()); + } else { + NestedNameSpecifier *QA = MPA->getQualifier(); + TA = QualType(QA->translateToType(S.Context), 0); + assert(!TA->isNullPtrType() && "member pointer with non-type class"); + } return DeduceTemplateArgumentsByTypeMatch( - S, TemplateParams, P, A, Info, Deduced, SubTDF, + S, TemplateParams, TP, TA, Info, Deduced, SubTDF, degradeCallPartialOrderingKind(POK), /*DeducedFromArrayBound=*/false, HasDeducedAnyParam); } diff --git a/clang/test/SemaCXX/member-pointer.cpp b/clang/test/SemaCXX/member-pointer.cpp index 3d9dd05755b8c..490e290e88058 100644 --- a/clang/test/SemaCXX/member-pointer.cpp +++ b/clang/test/SemaCXX/member-pointer.cpp @@ -355,3 +355,46 @@ namespace GH132401 { }; template struct CallableHelper<void (QIODevice::*)()>; } // namespace GH132401 + +namespace deduction1 { + template <typename> struct RunCallImpl; + + template <typename Derived> + struct RunCallImpl<int (Derived::Info::*)(Derived *)> {}; + + template <typename d> + void RunCall(d) { + RunCallImpl<d>(); + } + + struct Filter { + virtual void MakeCall(); + virtual ~Filter() = default; + }; + + template <typename Derived> + struct ImplementFilter : Filter { + void MakeCall() { RunCall(&Derived::Info::OnStuffHandler); } + }; + + struct FoobarFilter : ImplementFilter<FoobarFilter> { + struct Info { + int OnStuffHandler(FoobarFilter *); + }; + }; +} // namespace deduction1 + +namespace deduction2 { + template <typename> struct A; + template <typename T> + struct A<void (T::C::*)(int &, T *)> {}; + template <typename T> void e(T) { + A<T> f; + } + struct S { + struct C { + void h(int &, S *); + }; + void i() { e(&C::h); } + }; +} // namespace deduction2 diff --git a/clang/test/SemaTemplate/instantiation-backtrace.cpp b/clang/test/SemaTemplate/instantiation-backtrace.cpp index 39dfb0b32a2fb..6b51d0eba7979 100644 --- a/clang/test/SemaTemplate/instantiation-backtrace.cpp +++ b/clang/test/SemaTemplate/instantiation-backtrace.cpp @@ -22,7 +22,7 @@ void g() { (void)sizeof(B<X>); // expected-note{{in instantiation of template class 'B<X>' requested here}} } -template<typename T> +template<typename T> struct G : A<T>, // expected-error{{implicit instantiation of undefined template 'A<int>'}} A<T*> // expected-error{{implicit instantiation of undefined template 'A<int *>'}} { }; @@ -39,13 +39,13 @@ namespace PR13365 { template <class T1, class T2> typename ResultTy<T2>::error Deduce( void (T1::*member)(T2) ) {} // \ // expected-note {{instantiation of template class 'PR13365::ResultTy<int &>'}} \ - // expected-note {{substitution failure [with T1 = PR13365::Cls, T2 = int &]}} + // expected-note {{substitution failure [with T1 = Cls, T2 = int &]}} struct Cls { void method(int&); }; void test() { Deduce(&Cls::method); // expected-error {{no matching function}} \ - // expected-note {{substituting deduced template arguments into function template 'Deduce' [with T1 = PR13365::Cls, T2 = int &]}} + // expected-note {{substituting deduced template arguments into function template 'Deduce' [with T1 = Cls, T2 = int &]}} } } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
