https://github.com/zyn0217 updated https://github.com/llvm/llvm-project/pull/81449
>From f4fb72075b8b3242656c10618eb5baa6a4204907 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Mon, 12 Feb 2024 15:47:59 +0800 Subject: [PATCH 1/2] [Clang][Sema] Don't consider top-level cv-qualifiers in template partial orderings This fixes a regression since https://github.com/llvm/llvm-project/commit/340eac01f7dad6c24cee35dd35f2484098dd6b1a, from which we compared function parameter types with cv-qualifiers taken into account. However, as per [dcl.fct]/p5: > After producing the list of parameter types, any top-level cv-qualifiers > modifying > a parameter type are deleted when forming the function type. Thus I think we should use hasSameUnqualifiedType for type comparison. This fixes https://github.com/llvm/llvm-project/issues/75404. --- clang/docs/ReleaseNotes.rst | 2 ++ clang/lib/Sema/SemaTemplateDeduction.cpp | 7 +++++-- clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp | 7 +++---- 3 files changed, 10 insertions(+), 6 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index ece6013f672621..88006b4fb782e9 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -225,6 +225,8 @@ Bug Fixes to C++ Support or non-constant more accurately. Previously, only a subset of the initializer elements were considered, misclassifying some initializers as constant. Fixes some of (`#80510 <https://github.com/llvm/llvm-project/issues/80510>`). +- Clang now ignores top-level cv-qualifiers on function parameters in template partial orderings. + (`#75404 <https://github.com/llvm/llvm-project/issues/75404>`_) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index a54ad27975890a..69c35db2945eb7 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -5599,9 +5599,12 @@ FunctionTemplateDecl *Sema::getMoreSpecializedTemplate( Sema::TPL_TemplateParamsEquivalent)) return nullptr; + // [dcl.fct]p5: + // Any top-level cv-qualifiers modifying a parameter type are deleted when + // forming the function type. for (unsigned i = 0; i < NumParams1; ++i) - if (!Context.hasSameType(FD1->getParamDecl(i)->getType(), - FD2->getParamDecl(i)->getType())) + if (!Context.hasSameUnqualifiedType(FD1->getParamDecl(i)->getType(), + FD2->getParamDecl(i)->getType())) return nullptr; // C++20 [temp.func.order]p6.3: diff --git a/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp b/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp index dae1ba760cc203..cec487575d8093 100644 --- a/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp +++ b/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp @@ -98,12 +98,12 @@ namespace non_template static_assert(is_same_v<decltype(bar<int>()), void>); // expected-error {{call to 'bar' is ambiguous}} template<typename T> - constexpr int goo(int a) requires AtLeast2<int> && true { // expected-note {{candidate function}} + constexpr int goo(T a) requires AtLeast2<T> && true { return 1; } template<typename T> - constexpr int goo(const int b) requires AtLeast2<int> { // expected-note {{candidate function}} + constexpr int goo(const T b) requires AtLeast2<T> { return 2; } @@ -122,7 +122,6 @@ namespace non_template return 2; } - // By temp.func.order-6.2.2, this is ambiguous because parameter a and b have different types. - static_assert(goo<int>(1) == 1); // expected-error {{call to 'goo' is ambiguous}} + static_assert(goo<int>(1) == 1); static_assert(doo<int>(2) == 1); } >From 1f66c477b8236bc798bd9823d8cd5b0f26888a1c Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Mon, 12 Feb 2024 16:18:44 +0800 Subject: [PATCH 2/2] comment --- clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp b/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp index cec487575d8093..db3e3e3bc85966 100644 --- a/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp +++ b/clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp @@ -97,6 +97,9 @@ namespace non_template static_assert(is_same_v<decltype(baz<int>()), int>); // expected-error {{call to 'baz' is ambiguous}} static_assert(is_same_v<decltype(bar<int>()), void>); // expected-error {{call to 'bar' is ambiguous}} + // Top-level cv-qualifiers are ignored in template partial ordering per [dcl.fct]/p5. + // After producing the list of parameter types, any top-level cv-qualifiers modifying + // a parameter type are deleted when forming the function type. template<typename T> constexpr int goo(T a) requires AtLeast2<T> && true { return 1; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits