https://github.com/cor3ntin updated https://github.com/llvm/llvm-project/pull/70176
>From 6fd05adec162b2d18b4b163cc0a0f6d6e6710139 Mon Sep 17 00:00:00 2001 From: Corentin Jabot <corentinja...@gmail.com> Date: Wed, 25 Oct 2023 10:08:24 +0200 Subject: [PATCH] [Clang] Diagnose defaulted assignment operator with incompatible object parameter. Per https://eel.is/c++draft/dcl.fct.def.default#2.2, the explicit object parameter of a defaulted special member function must be of the same type as the one of an equivalent implicitly defaulted function, ignoring references. Fixes #69233 --- .../clang/Basic/DiagnosticSemaKinds.td | 3 ++ clang/lib/Sema/SemaDeclCXX.cpp | 18 +++++++++++ clang/test/SemaCXX/cxx2b-deducing-this.cpp | 31 +++++++++++++++++++ 3 files changed, 52 insertions(+) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index a673ce726d6c220..6e138683334c2c3 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -9481,6 +9481,9 @@ def err_defaulted_special_member_return_type : Error< def err_defaulted_special_member_quals : Error< "an explicitly-defaulted %select{copy|move}0 assignment operator may not " "have 'const'%select{, 'constexpr'|}1 or 'volatile' qualifiers">; +def err_defaulted_special_member_explicit_object_mismatch : Error< + "the type of the explicit object parameter of an explicitly-defaulted " + "%select{copy|move}0 assignment operator should match the type of the class %1">; def err_defaulted_special_member_volatile_param : Error< "the parameter for an explicitly-defaulted %sub{select_special_member_kind}0 " "may not be volatile">; diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index a3f68d4ffc0f6ec..fb27168f7d2a700 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -7748,6 +7748,24 @@ bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD, HadError = true; } } + // [C++23][dcl.fct.def.default]/p2.2 + // if F2 has an implicit object parameter of type “reference to C”, + // F1 may be an explicit object member function whose explicit object + // parameter is of (possibly different) type “reference to C”, + // in which case the type of F1 would differ from the type of F2 + // in that the type of F1 has an additional parameter; + if (!Context.hasSameType( + ThisType.getNonReferenceType().getUnqualifiedType(), + Context.getRecordType(RD))) { + if (DeleteOnTypeMismatch) + ShouldDeleteForTypeMismatch = true; + else { + Diag(MD->getLocation(), + diag::err_defaulted_special_member_explicit_object_mismatch) + << (CSM == CXXMoveAssignment) << RD; + HadError = true; + } + } } // Check for parameter type matching. diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp index 535381e876da9c7..f9e73b41e2c330f 100644 --- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp +++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp @@ -585,3 +585,34 @@ class Server : public Thing { S name_; }; } + +namespace GH69233 { +struct Base {}; +struct S : Base { + int j; + S& operator=(this Base& self, const S&) = default; + // expected-warning@-1 {{explicitly defaulted copy assignment operator is implicitly deleted}} + // expected-note@-2 {{function is implicitly deleted because its declared type does not match the type of an implicit copy assignment operator}} + // expected-note@-3 {{explicitly defaulted function was implicitly deleted here}} +}; + +struct S2 { + S2& operator=(this int&& self, const S2&); + S2& operator=(this int&& self, S2&&); + operator int(); +}; + +S2& S2::operator=(this int&& self, const S2&) = default; +// expected-error@-1 {{the type of the explicit object parameter of an explicitly-defaulted copy assignment operator should match the type of the class 'S2'}} + +S2& S2::operator=(this int&& self, S2&&) = default; +// expected-error@-1 {{the type of the explicit object parameter of an explicitly-defaulted move assignment operator should match the type of the class 'S2'}} + +void test() { + S s; + s = s; // expected-error {{object of type 'S' cannot be assigned because its copy assignment operator is implicitly deleted}} + S2 s2; + s2 = s2; +} + +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
