From 02bb2beeef3d93360694de29573430f584caafe9 Mon Sep 17 00:00:00 2001 From: Amirreza Ashouri Date: Sun, 23 Jul 2023 10:40:48 +0200 Subject: [PATCH] [clang] Fix diagnostics for defaulted, implicitly deleted 'operator=='. https://godbolt.org/z/cMKE3o1aG According to the issue https://github.com/llvm/llvm-project/issues/63960 , compiler falsely complains that no viable `operator<=>` was found while we are actually looking for a `operator==`. This bug has been fixed through adding a check of the `OverloadedOperatorKind` type's object, `OO`, to see if it is `OO_EqualEqual` in addition to `OO_ExclaimEqual`. Reviewed By: #clang-language-wg, cor3ntin Differential Revision: https://reviews.llvm.org/D155714 --- clang/docs/ReleaseNotes.rst | 6 ++++-- clang/lib/Sema/SemaDeclCXX.cpp | 3 ++- .../CXX/class/class.compare/class.compare.default/p1.cpp | 2 +- .../CXX/class/class.compare/class.compare.default/p4.cpp | 2 +- .../class/class.compare/class.compare.secondary/p2.cpp | 8 ++++++++ clang/test/CXX/class/class.compare/class.eq/p2.cpp | 2 +- clang/test/CXX/class/class.compare/class.spaceship/p1.cpp | 4 ++-- 7 files changed, 19 insertions(+), 8 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 1944605f09a2..9298f24d6297 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -407,8 +407,10 @@ Improvements to Clang's diagnostics by making use of the syntactical structure of function calls. This avoids display of syntactically invalid codes in diagnostics. (`#57081: `_) -- Clang no longer emits inappropriate notes about the loss of ``__unaligned`` qualifier - on overload resolution, when the actual reason for the failure is loss of other qualifiers. +- The note emitted when an ``operator==`` was defaulted as deleted used to refer to + the lack of a data member's "three-way comparison operator". It now refers correctly + to the data member's ``operator==``. + (`#63960: `_) - Clang's notes about unconvertible types in overload resolution failure now covers the source range of parameter declaration of the candidate function declaration. diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index 30e8e380e659..40fbaa043c1b 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -8209,7 +8209,8 @@ private: if (Diagnose == ExplainDeleted) { S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function) - << FD << (OO == OO_ExclaimEqual) << Subobj.Kind << Subobj.Decl; + << FD << (OO == OO_EqualEqual || OO == OO_ExclaimEqual) + << Subobj.Kind << Subobj.Decl; // For a three-way comparison, list both the candidates for the // original operator and the candidates for the synthesized operator. diff --git a/clang/test/CXX/class/class.compare/class.compare.default/p1.cpp b/clang/test/CXX/class/class.compare/class.compare.default/p1.cpp index 9094d400fd54..b595825e1750 100644 --- a/clang/test/CXX/class/class.compare/class.compare.default/p1.cpp +++ b/clang/test/CXX/class/class.compare/class.compare.default/p1.cpp @@ -153,7 +153,7 @@ namespace P1946 { friend bool operator==(A &, A &); // expected-note {{would lose const qualifier}} }; struct B { - A a; // expected-note {{no viable three-way comparison}} + A a; // expected-note {{no viable 'operator=='}} friend bool operator==(B, B) = default; // ok friend bool operator==(const B&, const B&) = default; // expected-warning {{deleted}} expected-note{{replace 'default'}} }; diff --git a/clang/test/CXX/class/class.compare/class.compare.default/p4.cpp b/clang/test/CXX/class/class.compare/class.compare.default/p4.cpp index fab2abb7dee0..02cdd7f85aeb 100644 --- a/clang/test/CXX/class/class.compare/class.compare.default/p4.cpp +++ b/clang/test/CXX/class/class.compare/class.compare.default/p4.cpp @@ -100,7 +100,7 @@ namespace DeleteAfterFirstDecl { struct Q { struct X { friend std::strong_ordering operator<=>(const X&, const X&); - } x; // expected-note {{no viable three-way comparison}} + } x; // expected-note {{no viable 'operator=='}} // expected-error@+1 {{defaulting the corresponding implicit 'operator==' for this defaulted 'operator<=>' would delete it after its first declaration}} friend std::strong_ordering operator<=>(const Q&, const Q&) = default; }; diff --git a/clang/test/CXX/class/class.compare/class.compare.secondary/p2.cpp b/clang/test/CXX/class/class.compare/class.compare.secondary/p2.cpp index 07d43f15aac1..e53738632e80 100644 --- a/clang/test/CXX/class/class.compare/class.compare.secondary/p2.cpp +++ b/clang/test/CXX/class/class.compare/class.compare.secondary/p2.cpp @@ -5,6 +5,14 @@ struct A { // expected-note@-1 {{defaulted 'operator!=' is implicitly deleted because there is no viable 'operator==' for 'A'}} }; +struct A2 { + struct E {}; + E e; + bool operator==(const A2&) const = default; // expected-warning {{explicitly defaulted equality comparison operator is implicitly deleted}} expected-note{{replace 'default'}} + // expected-note@-2 {{defaulted 'operator==' is implicitly deleted because there is no viable 'operator==' for member 'e'}} +}; + + struct Q {}; bool operator!=(Q, Q); // expected-note {{defaulted 'operator!=' is implicitly deleted because this non-rewritten comparison function would be the best match for the comparison}} struct B { diff --git a/clang/test/CXX/class/class.compare/class.eq/p2.cpp b/clang/test/CXX/class/class.compare/class.eq/p2.cpp index 7cb07b784bc2..7ff827e208aa 100644 --- a/clang/test/CXX/class/class.compare/class.eq/p2.cpp +++ b/clang/test/CXX/class/class.compare/class.eq/p2.cpp @@ -37,7 +37,7 @@ struct H3 { template struct X { X(); bool operator==(const X&) const = default; // #x expected-note 4{{deleted here}} - T t; // expected-note 3{{because there is no viable three-way comparison function for member 't'}} + T t; // expected-note 3{{because there is no viable 'operator==' for member 't'}} // expected-note@-1 {{because it would invoke a deleted comparison function for member 't'}} }; diff --git a/clang/test/CXX/class/class.compare/class.spaceship/p1.cpp b/clang/test/CXX/class/class.compare/class.spaceship/p1.cpp index cd5c8b155a9f..7e801f459ab2 100644 --- a/clang/test/CXX/class/class.compare/class.spaceship/p1.cpp +++ b/clang/test/CXX/class/class.compare/class.spaceship/p1.cpp @@ -80,7 +80,7 @@ namespace Deletedness { // expected-note@#base {{deleted comparison function for base class 'C'}} // expected-note@#base {{no viable three-way comparison function for base class 'D1'}} // expected-note@#base {{three-way comparison cannot be synthesized because there is no viable function for '<' comparison}} - // expected-note@#base {{no viable three-way comparison function for base class 'D2'}} + // expected-note@#base {{no viable 'operator==' for base class 'D2'}} // expected-note@#base {{three-way comparison cannot be synthesized because there is no viable function for '==' comparison}} // expected-note@#base {{deleted comparison function for base class 'E'}} // expected-note@#base {{implied comparison for base class 'F' is ambiguous}} @@ -112,7 +112,7 @@ namespace Deletedness { // expected-note@#arr {{deleted comparison function for member 'arr'}} // expected-note@#arr {{no viable three-way comparison function for member 'arr'}} // expected-note@#arr {{three-way comparison cannot be synthesized because there is no viable function for '<' comparison}} - // expected-note@#arr {{no viable three-way comparison function for member 'arr'}} + // expected-note@#arr {{no viable 'operator==' for member 'arr'}} // expected-note@#arr {{three-way comparison cannot be synthesized because there is no viable function for '==' comparison}} // expected-note@#arr {{deleted comparison function for member 'arr'}} // expected-note@#arr {{implied comparison for member 'arr' is ambiguous}}