AST: Remove ProtocolDecl::hasInverseMarking()

Author: slavapestov

include/swift/AST/Decl.h

@@ -5254,10 +5254,6 @@ class ProtocolDecl final : public NominalTypeDecl {
   /// Determine whether this protocol inherits from the given ("super")
   /// protocol.
   bool inheritsFrom(const ProtocolDecl *Super) const;
-
-  /// Determine whether this protocol has ~<target>` stated on
-  /// itself, one of its inherited types or `Self` requirements.
-  InverseMarking::Mark hasInverseMarking(InvertibleProtocolKind target) const;
 
   SourceLoc getStartLoc() const { return ProtocolLoc; }
   SourceRange getSourceRange() const {

lib/AST/Decl.cpp

@@ -6688,8 +6688,7 @@ NominalTypeDecl::hasInverseMarking(InvertibleProtocolKind target) const {
   if (isa<BuiltinTupleDecl>(this))
     return InverseMarking::Mark(InverseMarking::Kind::Explicit);
 
-  if (auto P = dyn_cast<ProtocolDecl>(this))
-    return P->hasInverseMarking(target);
+  assert(!isa<ProtocolDecl>(this));
 
   // Search the inheritance clause first.
   if (auto inverse = findInverseInInheritance(getInherited(), target))
@@ -6698,41 +6697,6 @@ NominalTypeDecl::hasInverseMarking(InvertibleProtocolKind target) const {
   return InverseMarking::Mark();
 }
 
-InverseMarking::Mark
-ProtocolDecl::hasInverseMarking(InvertibleProtocolKind target) const {
-  auto &ctx = getASTContext();
-
-  // Legacy support stops here.
-  if (!ctx.LangOpts.hasFeature(Feature::NoncopyableGenerics))
-    return InverseMarking::Mark();
-
-  if (auto inverse = findInverseInInheritance(getInherited(), target))
-    return inverse;
-
-  auto *whereClause = getTrailingWhereClause();
-  if (!whereClause)
-    return InverseMarking::Mark();
-
-  for (const auto &reqRepr : whereClause->getRequirements()) {
-    if (reqRepr.isInvalid() ||
-        reqRepr.getKind() != RequirementReprKind::TypeConstraint)
-      continue;
-
-    auto *subjectRepr =
-        dyn_cast<UnqualifiedIdentTypeRepr>(reqRepr.getSubjectRepr());
-    auto *constraintRepr = reqRepr.getConstraintRepr();
-
-    if (!subjectRepr || !subjectRepr->getNameRef().isSimpleName(ctx.Id_Self))
-      continue;
-
-    if (constraintRepr->isInverseOf(target, getDeclContext()))
-      return InverseMarking::Mark(InverseMarking::Kind::Explicit,
-                                  constraintRepr->getLoc());
-  }
-
-  return InverseMarking::Mark();
-}
-
 bool ProtocolDecl::requiresClass() const {
   return evaluateOrDefault(getASTContext().evaluator,
     ProtocolRequiresClassRequest{const_cast<ProtocolDecl *>(this)}, false);