https://github.com/a-tarasyuk updated https://github.com/llvm/llvm-project/pull/121419
>From 3f6b1d68978857035a972f49b1cfd9d9d0151be9 Mon Sep 17 00:00:00 2001 From: Oleksandr T <oleksandr.taras...@outlook.com> Date: Wed, 1 Jan 2025 01:47:17 +0200 Subject: [PATCH 1/5] [Clang] emit -Wignored-qualifiers diagnostic for cv-qualified base classes --- clang/docs/ReleaseNotes.rst | 1 + .../clang/Basic/DiagnosticSemaKinds.td | 4 ++++ clang/lib/Sema/SemaDeclCXX.cpp | 9 +++++++++ .../SemaCXX/warn-base-type-qualifiers.cpp | 20 +++++++++++++++++++ 4 files changed, 34 insertions(+) create mode 100644 clang/test/SemaCXX/warn-base-type-qualifiers.cpp diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index b7da12bcf65818..659f0ebd97fc46 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -733,6 +733,7 @@ Improvements to Clang's diagnostics scope.Unlock(); require(scope); // Warning! Requires mu1. } +- Clang now emits a ``-Wignored-qualifiers`` diagnostic when a base class includes cv-qualifiers (#GH55474). Improvements to Clang's time-trace ---------------------------------- diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 330ae045616aba..294cfa24975a73 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -487,6 +487,10 @@ def err_noreturn_non_function : Error< def warn_qual_return_type : Warning< "'%0' type qualifier%s1 on return type %plural{1:has|:have}1 no effect">, InGroup<IgnoredQualifiers>, DefaultIgnore; +def warn_qual_base_type : Warning< + "'%0' qualifier%s1 on base class type %2 have no effect">, + InGroup<IgnoredQualifiers>, DefaultIgnore; + def warn_deprecated_redundant_constexpr_static_def : Warning< "out-of-line definition of constexpr static data member is redundant " "in C++17 and is deprecated">, diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index c5a72cf812ebc9..b82ca1541ba249 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -2655,6 +2655,15 @@ CXXBaseSpecifier *Sema::CheckBaseSpecifier(CXXRecordDecl *Class, return nullptr; } + if (BaseType.hasQualifiers() && !isa<SubstTemplateTypeParmType>(BaseType)) { + auto Quals = + BaseType.getQualifiers().getAsString(Context.getPrintingPolicy()); + Diag(BaseLoc, diag::warn_qual_base_type) + << Quals << std::count(Quals.begin(), Quals.end(), ' ') + 1 + << BaseType; + Diag(BaseLoc, diag::note_base_class_specified_here) << BaseType; + } + // For the MS ABI, propagate DLL attributes to base class templates. if (Context.getTargetInfo().getCXXABI().isMicrosoft() || Context.getTargetInfo().getTriple().isPS()) { diff --git a/clang/test/SemaCXX/warn-base-type-qualifiers.cpp b/clang/test/SemaCXX/warn-base-type-qualifiers.cpp new file mode 100644 index 00000000000000..a5af7ec7415bf5 --- /dev/null +++ b/clang/test/SemaCXX/warn-base-type-qualifiers.cpp @@ -0,0 +1,20 @@ +// RUN: %clang_cc1 %s -std=c++11 -Wignored-qualifiers -verify + +class A { }; + +typedef const A A_Const; +class B : public A_Const { }; // expected-warning {{'const' qualifier on base class type 'A_Const' (aka 'const A') have no effect}} \ + // expected-note {{base class 'A_Const' (aka 'const A') specified here}} + +typedef const volatile A A_Const_Volatile; +class C : public A_Const_Volatile { }; // expected-warning {{'const volatile' qualifiers on base class type 'A_Const_Volatile' (aka 'const volatile A') have no effect}} \ + // expected-note {{base class 'A_Const_Volatile' (aka 'const volatile A') specified here}} + +struct D { + D(int); +}; +template <typename T> struct E : T { + using T::T; + E(int &) : E(0) {} +}; +E<const D> e(1); >From 397097340707dbefe5f4b07357523ff7ad515304 Mon Sep 17 00:00:00 2001 From: Oleksandr T <oleksandr.taras...@outlook.com> Date: Thu, 2 Jan 2025 17:06:05 +0200 Subject: [PATCH 2/5] use explicit variable type --- clang/lib/Sema/SemaDeclCXX.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index b82ca1541ba249..c4ec7fa4742bdf 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -2656,7 +2656,7 @@ CXXBaseSpecifier *Sema::CheckBaseSpecifier(CXXRecordDecl *Class, } if (BaseType.hasQualifiers() && !isa<SubstTemplateTypeParmType>(BaseType)) { - auto Quals = + std::string Quals = BaseType.getQualifiers().getAsString(Context.getPrintingPolicy()); Diag(BaseLoc, diag::warn_qual_base_type) << Quals << std::count(Quals.begin(), Quals.end(), ' ') + 1 >From 3129f7521984c68969f3dd0140d6001b25ab1a28 Mon Sep 17 00:00:00 2001 From: Oleksandr T <oleksandr.taras...@outlook.com> Date: Fri, 3 Jan 2025 00:47:47 +0200 Subject: [PATCH 3/5] eliminate template type constraint and add additional tests --- clang/lib/Sema/SemaDeclCXX.cpp | 2 +- .../SemaCXX/warn-base-type-qualifiers.cpp | 19 +++++++++++++++++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index c4ec7fa4742bdf..9a471f8d4c9678 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -2655,7 +2655,7 @@ CXXBaseSpecifier *Sema::CheckBaseSpecifier(CXXRecordDecl *Class, return nullptr; } - if (BaseType.hasQualifiers() && !isa<SubstTemplateTypeParmType>(BaseType)) { + if (BaseType.hasQualifiers()) { std::string Quals = BaseType.getQualifiers().getAsString(Context.getPrintingPolicy()); Diag(BaseLoc, diag::warn_qual_base_type) diff --git a/clang/test/SemaCXX/warn-base-type-qualifiers.cpp b/clang/test/SemaCXX/warn-base-type-qualifiers.cpp index a5af7ec7415bf5..b9fd577c574b99 100644 --- a/clang/test/SemaCXX/warn-base-type-qualifiers.cpp +++ b/clang/test/SemaCXX/warn-base-type-qualifiers.cpp @@ -1,5 +1,10 @@ // RUN: %clang_cc1 %s -std=c++11 -Wignored-qualifiers -verify +template <typename T> struct add_const { + using type = const T; +}; +template <typename T> using add_const_t = typename add_const<T>::type; + class A { }; typedef const A A_Const; @@ -13,8 +18,18 @@ class C : public A_Const_Volatile { }; // expected-warning {{'const volatile' qu struct D { D(int); }; -template <typename T> struct E : T { + +template <typename T> struct E : T { // expected-warning {{'const' qualifier on base class type 'const D' have no effect}} \ + // expected-note {{base class 'const D' specified here}} using T::T; E(int &) : E(0) {} }; -E<const D> e(1); +E<const D> e(1); // expected-note {{in instantiation of template class 'E<const D>' requested here}} + +template <typename T> +struct G : add_const<T>::type { // expected-warning {{'const' qualifier on base class type 'add_const<D>::type' (aka 'const D') have no effect}} \ + // expected-note {{base class 'add_const<D>::type' (aka 'const D') specified here}} + using T::T; + G(int &) : G(0) {} +}; +G<D> g(1); // expected-note {{in instantiation of template class 'G<D>' requested here}} >From 4da4f21c679ddd2daebff4d86d47e235a79d9876 Mon Sep 17 00:00:00 2001 From: Oleksandr T <oleksandr.taras...@outlook.com> Date: Tue, 14 Jan 2025 00:07:27 +0200 Subject: [PATCH 4/5] remove cv-qualifiers from inherited classes in tuple declaration --- libcxx/include/tuple | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libcxx/include/tuple b/libcxx/include/tuple index b2478746f5e26a..955583e7dc57e7 100644 --- a/libcxx/include/tuple +++ b/libcxx/include/tuple @@ -257,6 +257,7 @@ template <class... Types> # include <__type_traits/maybe_const.h> # include <__type_traits/nat.h> # include <__type_traits/negation.h> +# include <__type_traits/remove_cv.h> # include <__type_traits/remove_cvref.h> # include <__type_traits/remove_reference.h> # include <__type_traits/unwrap_ref.h> @@ -535,7 +536,7 @@ __memberwise_forward_assign(_Dest& __dest, _Source&& __source, __tuple_types<_Up template <class... _Tp> class _LIBCPP_TEMPLATE_VIS tuple { - typedef __tuple_impl<typename __make_tuple_indices<sizeof...(_Tp)>::type, _Tp...> _BaseT; + typedef __tuple_impl<typename __make_tuple_indices<sizeof...(_Tp)>::type, __remove_cv_t<_Tp>...> _BaseT; _BaseT __base_; >From 0c90ff82622cb9c3ceacd5183567a850c3eb813b Mon Sep 17 00:00:00 2001 From: Oleksandr T <oleksandr.taras...@outlook.com> Date: Tue, 14 Jan 2025 14:41:52 +0200 Subject: [PATCH 5/5] update tuple declaration --- libcxx/include/tuple | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/libcxx/include/tuple b/libcxx/include/tuple index 90257e9bae0acf..1c575cb4a6f5d5 100644 --- a/libcxx/include/tuple +++ b/libcxx/include/tuple @@ -391,7 +391,9 @@ public: }; template <size_t _Ip, class _Hp> -class __tuple_leaf<_Ip, _Hp, true> : private _Hp { +class __tuple_leaf<_Ip, _Hp, true> : private __remove_cv_t<_Hp> { + typedef __remove_cv_t<_Hp> _BaseT; + public: _LIBCPP_CONSTEXPR_SINCE_CXX14 __tuple_leaf& operator=(const __tuple_leaf&) = delete; @@ -402,29 +404,29 @@ public: template <class _Alloc> _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a) - : _Hp(allocator_arg_t(), __a) {} + : _BaseT(allocator_arg_t(), __a) {} template <class _Alloc> - _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a) : _Hp(__a) {} + _LIBCPP_HIDE_FROM_ABI constexpr __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a) : _BaseT(__a) {} template <class _Tp, __enable_if_t< _And< _IsNotSame<__remove_cvref_t<_Tp>, __tuple_leaf>, is_constructible<_Hp, _Tp> >::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __tuple_leaf(_Tp&& __t) noexcept(is_nothrow_constructible<_Hp, _Tp>::value) - : _Hp(std::forward<_Tp>(__t)) {} + : _BaseT(std::forward<_Tp>(__t)) {} template <class _Tp, class _Alloc> _LIBCPP_HIDE_FROM_ABI constexpr explicit __tuple_leaf(integral_constant<int, 0>, const _Alloc&, _Tp&& __t) - : _Hp(std::forward<_Tp>(__t)) {} + : _BaseT(std::forward<_Tp>(__t)) {} template <class _Tp, class _Alloc> _LIBCPP_HIDE_FROM_ABI constexpr explicit __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a, _Tp&& __t) - : _Hp(allocator_arg_t(), __a, std::forward<_Tp>(__t)) {} + : _BaseT(allocator_arg_t(), __a, std::forward<_Tp>(__t)) {} template <class _Tp, class _Alloc> _LIBCPP_HIDE_FROM_ABI constexpr explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t) - : _Hp(std::forward<_Tp>(__t), __a) {} + : _BaseT(std::forward<_Tp>(__t), __a) {} __tuple_leaf(__tuple_leaf const&) = default; __tuple_leaf(__tuple_leaf&&) = default; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits