AST: Simplify ProtocolConformanceRef::getTypeWitnessByName()

Author: slavapestov

include/swift/AST/ProtocolConformanceRef.h

@@ -138,8 +138,7 @@ class ProtocolConformanceRef {
   static Type
   getTypeWitnessByName(Type type,
                        ProtocolConformanceRef conformance,
-                       Identifier name,
-                       LazyResolver *resolver);
+                       Identifier name);
 
   /// Determine whether this conformance is canonical.
   bool isCanonical() const;

lib/AST/ASTContext.cpp

@@ -4225,13 +4225,8 @@ Type ASTContext::getBridgedToObjC(const DeclContext *dc, Type type,
       *bridgedValueType = type;
 
     // Find the Objective-C class type we bridge to.
-    if (conformance->isConcrete()) {
-      return ProtocolConformanceRef::getTypeWitnessByName(
-               type, *conformance, Id_ObjectiveCType,
-               getLazyResolver());
-    } else {
-      return type->castTo<ArchetypeType>()->getNestedType(Id_ObjectiveCType);
-    }
+    return ProtocolConformanceRef::getTypeWitnessByName(
+        type, *conformance, Id_ObjectiveCType);
   }
 
   // Do we conform to Error?

lib/AST/ProtocolConformance.cpp

@@ -144,13 +144,13 @@ ProtocolConformanceRef::subst(Type origType,
 Type
 ProtocolConformanceRef::getTypeWitnessByName(Type type,
                                              ProtocolConformanceRef conformance,
-                                             Identifier name,
-                                             LazyResolver *resolver) {
+                                             Identifier name) {
   assert(!conformance.isInvalid());
 
   // Find the named requirement.
+  ProtocolDecl *proto = conformance.getRequirement();
   AssociatedTypeDecl *assocType = nullptr;
-  auto members = conformance.getRequirement()->lookupDirect(name);
+  auto members = proto->lookupDirect(name);
   for (auto member : members) {
     assocType = dyn_cast<AssociatedTypeDecl>(member);
     if (assocType)
@@ -161,21 +161,8 @@ ProtocolConformanceRef::getTypeWitnessByName(Type type,
   if (!assocType)
     return nullptr;
 
-  if (conformance.isAbstract()) {
-    // For an archetype, retrieve the nested type with the appropriate
-    // name. There are no conformance tables.
-    if (auto archetype = type->getAs<ArchetypeType>()) {
-      return archetype->getNestedType(name);
-    }
-
-    return DependentMemberType::get(type, assocType);
-  }
-
-  auto concrete = conformance.getConcrete();
-  if (!concrete->hasTypeWitness(assocType, resolver)) {
-    return nullptr;
-  }
-  return concrete->getTypeWitness(assocType, resolver);
+  return assocType->getDeclaredInterfaceType().subst(
+    SubstitutionMap::getProtocolSubstitutions(proto, type, conformance));
 }
 
 void *ProtocolConformance::operator new(size_t bytes, ASTContext &context,

lib/PrintAsObjC/PrintAsObjC.cpp

@@ -1380,8 +1380,7 @@ class ObjCPrinter : private DeclVisitor<ObjCPrinter>,
     Type objcType = ProtocolConformanceRef::getTypeWitnessByName(
                       nominal->getDeclaredType(),
                       ProtocolConformanceRef(conformance),
-                      ctx.Id_ObjectiveCType,
-                      nullptr);
+                      ctx.Id_ObjectiveCType);
     if (!objcType) return nullptr;
 
     // Dig out the Objective-C class.

lib/SIL/Bridging.cpp

@@ -225,8 +225,7 @@ Type TypeConverter::getLoweredCBridgedType(AbstractionPattern pattern,
     Type bridgedTy =
       ProtocolConformanceRef::getTypeWitnessByName(
         t, ProtocolConformanceRef(conformance),
-        M.getASTContext().Id_ObjectiveCType,
-        M.getASTContext().getLazyResolver());
+        M.getASTContext().Id_ObjectiveCType);
     assert(bridgedTy && "Missing _ObjectiveCType witness?");
     if (purpose == BridgedTypePurpose::ForResult && clangTy)
       bridgedTy = OptionalType::get(bridgedTy);

lib/Sema/CSDiag.cpp

@@ -1741,7 +1741,7 @@ static Type isRawRepresentable(Type fromType, const ConstraintSystem &CS) {
     return Type();
 
   Type rawTy = ProtocolConformanceRef::getTypeWitnessByName(
-      fromType, *conformance, CS.getASTContext().Id_RawValue, &CS.TC);
+      fromType, *conformance, CS.getASTContext().Id_RawValue);
   return rawTy;
 }
 
@@ -2120,8 +2120,8 @@ bool FailureDiagnosis::diagnoseContextualConversionError(
         Type errorCodeType = CS.getType(expr);
         Type errorType =
           ProtocolConformanceRef::getTypeWitnessByName(errorCodeType, *conformance,
-                                                       TC.Context.Id_ErrorType,
-                                                       &TC)->getCanonicalType();
+                                                       TC.Context.Id_ErrorType)
+                                                         ->getCanonicalType();
         if (errorType) {
           auto diag = diagnose(expr->getLoc(), diag::cannot_throw_error_code,
                                errorCodeType, errorType);
@@ -6255,7 +6255,7 @@ bool FailureDiagnosis::visitArrayExpr(ArrayExpr *E) {
     Type contextualElementType =
         ProtocolConformanceRef::getTypeWitnessByName(
             contextualType, *Conformance,
-            CS.getASTContext().Id_ArrayLiteralElement, &CS.TC)
+            CS.getASTContext().Id_ArrayLiteralElement)
             ->getDesugaredType();
 
     // Type check each of the subexpressions in place, passing down the contextual
@@ -6344,12 +6344,12 @@ bool FailureDiagnosis::visitDictionaryExpr(DictionaryExpr *E) {
 
     contextualKeyType =
         ProtocolConformanceRef::getTypeWitnessByName(
-            contextualType, *Conformance, CS.getASTContext().Id_Key, &CS.TC)
+            contextualType, *Conformance, CS.getASTContext().Id_Key)
             ->getDesugaredType();
 
     contextualValueType =
         ProtocolConformanceRef::getTypeWitnessByName(
-            contextualType, *Conformance, CS.getASTContext().Id_Value, &CS.TC)
+            contextualType, *Conformance, CS.getASTContext().Id_Value)
             ->getDesugaredType();
 
     assert(contextualKeyType && contextualValueType &&

lib/Sema/TypeCheckProtocol.cpp

@@ -4326,7 +4326,7 @@ void TypeChecker::useBridgedNSErrorConformances(DeclContext *dc, Type type) {
     // protocol, also use the RawRepresentable and _ErrorCodeProtocol
     // conformances on the Code associated type witness.
     if (auto codeType = ProtocolConformanceRef::getTypeWitnessByName(
-                          type, *conformance, Context.Id_Code, this)) {
+                          type, *conformance, Context.Id_Code)) {
       (void)conformsToProtocol(codeType, errorCodeProto, dc,
                                ConformanceCheckFlags::Used);
       (void)conformsToProtocol(codeType, rawProto, dc,
@@ -4341,7 +4341,7 @@ void TypeChecker::useBridgedNSErrorConformances(DeclContext *dc, Type type) {
                       ConformanceCheckFlags::Used));
   if (conformance && conformance->isConcrete()) {
     if (Type errorType = ProtocolConformanceRef::getTypeWitnessByName(
-          type, *conformance, Context.Id_ErrorType, this)) {
+          type, *conformance, Context.Id_ErrorType)) {
       (void)conformsToProtocol(errorType, bridgedStoredNSError, dc,
                                ConformanceCheckFlags::Used);
     }
@@ -5663,8 +5663,7 @@ Type TypeChecker::getWitnessType(Type type, ProtocolDecl *protocol,
                                  ProtocolConformanceRef conformance,
                                  Identifier name,
                                  Diag<> brokenProtocolDiag) {
-  Type ty = ProtocolConformanceRef::getTypeWitnessByName(type, conformance,
-                                                         name, this);
+  Type ty = ProtocolConformanceRef::getTypeWitnessByName(type, conformance, name);
   if (!ty &&
       !(conformance.isConcrete() && conformance.getConcrete()->isInvalid()))
     diagnose(protocol->getLoc(), brokenProtocolDiag);