AST: PackConformance::getAssociatedType() => getTypeWitness()

Author: slavapestov

include/swift/AST/PackConformance.h

@@ -74,7 +74,8 @@ class alignas(1 << DeclAlignInBits) PackConformance final
 
   PackConformance *getCanonicalConformance() const;
 
-  PackType *getAssociatedType(Type assocType) const;
+  PackType *getTypeWitness(AssociatedTypeDecl *assocType,
+                           SubstOptions options=std::nullopt) const;
 
   PackConformance *
   getAssociatedConformance(Type assocType, ProtocolDecl *protocol) const;

lib/AST/PackConformance.cpp

@@ -97,7 +97,9 @@ PackConformance *PackConformance::getCanonicalConformance() const {
 /// Project the corresponding associated type from each pack element
 /// of the conforming type, collecting the results into a new pack type
 /// that has the same pack expansion structure as the conforming type.
-PackType *PackConformance::getAssociatedType(Type assocType) const {
+PackType *PackConformance::getTypeWitness(
+    AssociatedTypeDecl *assocType,
+    SubstOptions options) const {
   SmallVector<Type, 4> packElements;
 
   auto conformances = getPatternConformances();
@@ -110,8 +112,8 @@ PackType *PackConformance::getAssociatedType(Type assocType) const {
     // conformance.
     if (auto *packExpansion = packElement->getAs<PackExpansionType>()) {
       auto assocTypePattern =
-        conformances[i].getAssociatedType(packExpansion->getPatternType(),
-                                          assocType);
+        conformances[i].getTypeWitness(packExpansion->getPatternType(),
+                                       assocType, options);
 
       packElements.push_back(PackExpansionType::get(
           assocTypePattern, packExpansion->getCountType()));
@@ -120,7 +122,7 @@ PackType *PackConformance::getAssociatedType(Type assocType) const {
     // the associated type witness from the pattern conformance.
     } else {
       auto assocTypeScalar =
-        conformances[i].getAssociatedType(packElement, assocType);
+        conformances[i].getTypeWitness(packElement, assocType, options);
       packElements.push_back(assocTypeScalar);
     }
   }

lib/AST/ProtocolConformanceRef.cpp

@@ -199,7 +199,7 @@ Type ProtocolConformanceRef::getTypeWitness(Type conformingType,
   if (isPack()) {
     auto *pack = getPack();
     ASSERT(conformingType->isEqual(pack->getType()));
-    return pack->getAssociatedType(assocType->getDeclaredInterfaceType());
+    return pack->getTypeWitness(assocType);
   }
 
   auto failed = [&]() {

lib/AST/TypeSubstitution.cpp

@@ -576,10 +576,8 @@ Type TypeSubstituter::transformDependentMemberType(DependentMemberType *dependen
 
   // Retrieve the type witness.
   if (conformance.isPack()) {
-    auto *packConformance = conformance.getPack();
-
-    witnessTy = packConformance->getAssociatedType(
-        assocType->getDeclaredInterfaceType());
+    witnessTy = conformance.getPack()->getTypeWitness(assocType,
+                                                      IFS.getOptions());
   } else if (conformance.isConcrete()) {
     auto witness =
         conformance.getConcrete()->getTypeWitnessAndDecl(assocType,