[NFC] TypeResolution: Nuke TypeResolutionStage::Contextual

Author: AnthonyLatsis

include/swift/AST/TypeResolutionStage.h

@@ -31,10 +31,6 @@ enum class TypeResolutionStage : uint8_t {
   /// Produces a complete interface type where all member references have been
   /// resolved.
   Interface,
-
-  /// Produces a contextual type involving archetypes within the context of
-  /// the type.
-  Contextual,
 };
 
 /// Display a type resolution stage.

lib/AST/TypeCheckRequests.cpp

@@ -58,10 +58,6 @@ void swift::simple_display(llvm::raw_ostream &out,
   case TypeResolutionStage::Interface:
     out << "interface";
     break;
-
-  case TypeResolutionStage::Contextual:
-    out << "contextual";
-    break;
   }
 }
 

lib/Sema/TypeCheckGeneric.cpp

@@ -965,9 +965,6 @@ RequirementRequest::evaluate(Evaluator &evaluator,
                                               /*unboundTyOpener*/ nullptr,
                                               /*placeholderHandler*/ nullptr);
     break;
-
-  case TypeResolutionStage::Contextual:
-    llvm_unreachable("No clients care about this. Use mapTypeIntoContext()");
   }
 
   auto &reqRepr = getRequirement();

lib/Sema/TypeCheckRequestFunctions.cpp

@@ -56,17 +56,6 @@ Type InheritedTypeRequest::evaluate(
                                      /*unboundTyOpener*/ nullptr,
                                      /*placeholderHandler*/ nullptr);
     break;
-
-  case TypeResolutionStage::Contextual: {
-    // Compute the contextual type by mapping the interface type into context.
-    auto result =
-      evaluator(InheritedTypeRequest{decl, index,
-                                     TypeResolutionStage::Interface});
-    if (!result)
-      return Type();
-
-    return dc->mapTypeIntoContext(*result);
-  }
   }
 
   const TypeLoc &typeLoc = getInheritedTypeLocAtIndex(decl, index);

lib/Sema/TypeCheckType.cpp

@@ -99,7 +99,7 @@ ASTContext &TypeResolution::getASTContext() const {
 
 GenericSignature TypeResolution::getGenericSignature() const {
   assert(
-      stage > TypeResolutionStage::Structural &&
+      stage == TypeResolutionStage::Interface &&
       "Structural resolution shouldn't require generic signature computation");
 
   if (genericEnv)
@@ -134,9 +134,6 @@ Type TypeResolution::resolveDependentMemberType(
   case TypeResolutionStage::Interface:
     // Handled below.
     break;
-
-  case TypeResolutionStage::Contextual:
-    llvm_unreachable("Use TypeResolution::resolveContextualType instead");
   }
 
   assert(stage == TypeResolutionStage::Interface);
@@ -233,9 +230,6 @@ Type TypeResolution::resolveSelfAssociatedType(Type baseTy,
   case TypeResolutionStage::Interface:
     // Handled below.
     break;
-
-  case TypeResolutionStage::Contextual:
-    llvm_unreachable("Use TypeResolution::resolveContextualType instead");
   }
 
   assert(stage == TypeResolutionStage::Interface);
@@ -274,17 +268,9 @@ bool TypeResolution::areSameType(Type type1, Type type2) const {
   if (type1->isEqual(type2))
     return true;
 
-  switch (stage) {
-  case TypeResolutionStage::Structural:
-  case TypeResolutionStage::Interface:
-    // If neither type has a type parameter, we're done.
-    if (!type1->hasTypeParameter() && !type2->hasTypeParameter())
-      return false;
-
-    break;
-
-  case TypeResolutionStage::Contextual:
-    llvm_unreachable("Use TypeResolution::resolveContextualType instead");
+  // If neither type has a type parameter, we're done.
+  if (!type1->hasTypeParameter() && !type2->hasTypeParameter()) {
+    return false;
   }
 
   if (stage == TypeResolutionStage::Interface) {
@@ -855,7 +841,7 @@ Type TypeResolution::applyUnboundGenericArguments(
   // generic signature.
   auto *module = getDeclContext()->getParentModule();
 
-  if (!skipRequirementsCheck && getStage() > TypeResolutionStage::Structural) {
+  if (!skipRequirementsCheck && getStage() == TypeResolutionStage::Interface) {
     // Check the generic arguments against the requirements of the declaration's
     // generic signature.
 

lib/Sema/TypeChecker.cpp

@@ -502,7 +502,7 @@ TypeChecker::getDeclTypeCheckingSemantics(ValueDecl *decl) {
 bool TypeChecker::isDifferentiable(Type type, bool tangentVectorEqualsSelf,
                                    DeclContext *dc,
                                    Optional<TypeResolutionStage> stage) {
-  if (stage && stage != TypeResolutionStage::Contextual)
+  if (stage)
     type = dc->mapTypeIntoContext(type);
   auto tanSpace = type->getAutoDiffTangentSpace(
       LookUpConformanceInModule(dc->getParentModule()));