[CS] NFC: Remove OverloadChoiceKind::BaseType

This doesn't appear to be used any more.

Author: hamishknight

lib/Sema/CSApply.cpp

@@ -3132,9 +3132,6 @@ namespace {
                                              nameLoc.getBaseNameLoc(), toType));
       }
 
-      case OverloadChoiceKind::BaseType:
-        return base;
-
       case OverloadChoiceKind::KeyPathApplication:
         llvm_unreachable("should only happen in a subscript");
 

lib/Sema/CSRanking.cpp

@@ -143,7 +143,6 @@ static bool sameOverloadChoice(const OverloadChoice &x,
     return false;
 
   switch (x.getKind()) {
-  case OverloadChoiceKind::BaseType:
   case OverloadChoiceKind::KeyPathApplication:
     // FIXME: Compare base types after substitution?
     return true;
@@ -895,7 +894,6 @@ SolutionCompareResult ConstraintSystem::compareSolutions(
     case OverloadChoiceKind::TupleIndex:
       continue;
 
-    case OverloadChoiceKind::BaseType:
     case OverloadChoiceKind::KeyPathApplication:
       llvm_unreachable("Never considered different");
 

lib/Sema/CSSimplify.cpp

@@ -135,7 +135,6 @@ static bool areConservativelyCompatibleArgumentLabels(
     decl = choice.getDecl();
     break;
 
-  case OverloadChoiceKind::BaseType:
   // KeyPath application is not filtered in `performMemberLookup`.
   case OverloadChoiceKind::KeyPathApplication:
   case OverloadChoiceKind::DynamicMemberLookup:

lib/Sema/Constraint.cpp

@@ -405,9 +405,6 @@ void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm) const {
     case OverloadChoiceKind::KeyPathDynamicMemberLookup:
       Out << "dynamic member lookup '" << overload.getName() << "'";
       break;
-    case OverloadChoiceKind::BaseType:
-      Out << "base type";
-      break;
     case OverloadChoiceKind::TupleIndex:
       Out << "tuple index " << overload.getTupleIndex();
       break;

lib/Sema/ConstraintSystem.cpp

@@ -1549,7 +1549,6 @@ Type ConstraintSystem::getEffectiveOverloadType(const OverloadChoice &overload,
     // Declaration choices are handled below.
     break;
 
-  case OverloadChoiceKind::BaseType:
   case OverloadChoiceKind::DeclViaBridge:
   case OverloadChoiceKind::DeclViaDynamic:
   case OverloadChoiceKind::DeclViaUnwrappedOptional:
@@ -1918,7 +1917,6 @@ std::pair<Type, bool> ConstraintSystem::adjustTypeOfOverloadReference(
   case OverloadChoiceKind::DeclViaBridge:
   case OverloadChoiceKind::DeclViaUnwrappedOptional:
   case OverloadChoiceKind::TupleIndex:
-  case OverloadChoiceKind::BaseType:
   case OverloadChoiceKind::KeyPathApplication:
     return {refType, bindConstraintCreated};
   case OverloadChoiceKind::DeclViaDynamic: {
@@ -2020,7 +2018,6 @@ void ConstraintSystem::bindOverloadType(
   case OverloadChoiceKind::DeclViaBridge:
   case OverloadChoiceKind::DeclViaUnwrappedOptional:
   case OverloadChoiceKind::TupleIndex:
-  case OverloadChoiceKind::BaseType:
   case OverloadChoiceKind::KeyPathApplication:
   case OverloadChoiceKind::DeclViaDynamic:
     bindTypeOrIUO(openedType);
@@ -2272,10 +2269,6 @@ void ConstraintSystem::resolveOverload(ConstraintLocator *locator,
     break;
   }
 
-  case OverloadChoiceKind::BaseType:
-    refType = choice.getBaseType();
-    break;
-
   case OverloadChoiceKind::TupleIndex:
     if (auto lvalueTy = choice.getBaseType()->getAs<LValueType>()) {
       // When the base of a tuple lvalue, the member is always an lvalue.
@@ -2532,7 +2525,6 @@ DeclName OverloadChoice::getName() const {
     case OverloadChoiceKind::KeyPathDynamicMemberLookup:
       return DeclName(DynamicMember.getPointer());
 
-    case OverloadChoiceKind::BaseType:
     case OverloadChoiceKind::TupleIndex:
       llvm_unreachable("no name!");
   }
@@ -3246,7 +3238,6 @@ bool ConstraintSystem::diagnoseAmbiguity(ArrayRef<Solution> solutions) {
         // want them to noise up unrelated subscript diagnostics.
         break;
 
-      case OverloadChoiceKind::BaseType:
       case OverloadChoiceKind::TupleIndex:
         // FIXME: Actually diagnose something here.
         break;

lib/Sema/OverloadChoice.h

@@ -40,10 +40,6 @@ enum class OverloadChoiceKind : int {
   /// found via dynamic lookup and, therefore, might not actually be
   /// available at runtime.
   DeclViaDynamic,
-  /// The overload choice equates the member type with the
-  /// base type. Used for unresolved member expressions like ".none" that
-  /// refer to enum members with unit type.
-  BaseType,
   /// The overload choice selects a key path subscripting operation.
   KeyPathApplication,
   /// The member is looked up using @dynamicMemberLookup.

lib/Sema/TypeCheckConstraints.cpp

@@ -3175,10 +3175,6 @@ void Solution::dump(raw_ostream &out) const {
           << ovl.second.openedType->getString(PO) << "\n";
       break;
 
-    case OverloadChoiceKind::BaseType:
-      out << "base type " << choice.getBaseType()->getString(PO) << "\n";
-      break;
-
     case OverloadChoiceKind::KeyPathApplication:
       out << "key path application root "
           << choice.getBaseType()->getString(PO) << "\n";
@@ -3381,10 +3377,6 @@ void ConstraintSystem::print(raw_ostream &out) const {
             << resolved.openedType->getString(PO) << "\n";
         break;
 
-      case OverloadChoiceKind::BaseType:
-        out << "base type " << choice.getBaseType()->getString(PO) << "\n";
-        break;
-
       case OverloadChoiceKind::KeyPathApplication:
         out << "key path application root "
             << choice.getBaseType()->getString(PO) << "\n";