llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> 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. --- Full diff: https://github.com/llvm/llvm-project/pull/81449.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+2) - (modified) clang/lib/Sema/SemaTemplateDeduction.cpp (+5-2) - (modified) clang/test/CXX/over/over.match/over.match.best/p1-2a.cpp (+6-4) ``````````diff 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..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 @@ -97,13 +97,16 @@ 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(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 +125,6 @@ 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); } `````````` </details> https://github.com/llvm/llvm-project/pull/81449 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
