[c++20] Implement P1185R2 (as modified by P2002R0).
For each defaulted operator<=> in a class that doesn't explicitly
declare any operator==, also inject a matching implicit defaulted
operator==.
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 1451fe4..6db8eb3 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -203,6 +203,7 @@
case DefaultTemplateArgumentChecking:
case DeclaringSpecialMember:
+ case DeclaringImplicitEqualityComparison:
case DefiningSynthesizedFunction:
case ExceptionSpecEvaluation:
case ConstraintSubstitution:
@@ -671,6 +672,11 @@
<< cast<CXXRecordDecl>(Active->Entity) << Active->SpecialMember;
break;
+ case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
+ Diags.Report(Active->Entity->getLocation(),
+ diag::note_in_declaration_of_implicit_equality_comparison);
+ break;
+
case CodeSynthesisContext::DefiningSynthesizedFunction: {
// FIXME: For synthesized functions that are not defaulted,
// produce a note.
@@ -772,6 +778,7 @@
return Active->DeductionInfo;
case CodeSynthesisContext::DeclaringSpecialMember:
+ case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
case CodeSynthesisContext::DefiningSynthesizedFunction:
case CodeSynthesisContext::RewritingOperatorAsSpaceship:
// This happens in a context unrelated to template instantiation, so