AST: Fiddle with GenericEnvironment::forOpenedExistential() again

Author: slavapestov

include/swift/AST/GenericEnvironment.h

@@ -232,11 +232,21 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   /// Create a new generic environment for an opened existential.
   ///
   /// \param existential The subject existential type
+  /// \param uuid The unique identifier for this opened existential
+  static GenericEnvironment *
+  forOpenedExistential(Type existential, UUID uuid);
+
+  /// Create a new generic environment for an opened existential.
+  ///
+  /// \param signature The opened existential signature
+  /// \param existential The generalized existential type
   /// \param outerSubs The substitution map containing archetypes from the
   /// outer generic context
   /// \param uuid The unique identifier for this opened existential
   static GenericEnvironment *
-  forOpenedExistential(Type existential, SubstitutionMap outerSubs, UUID uuid);
+  forOpenedExistential(GenericSignature signature,
+                       Type existential, SubstitutionMap outerSubs,
+                       UUID uuid);
 
   /// Create a new generic environment for an opened element.
   ///

include/swift/SIL/SILCloner.h

@@ -387,7 +387,7 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
 
     auto substExistentialTy = getOpASTType(origExistentialTy);
     auto *newEnv = GenericEnvironment::forOpenedExistential(
-        substExistentialTy, subMap, UUID::fromTime());
+        substExistentialTy, UUID::fromTime());
 
     registerLocalArchetypeRemapping(origEnv, newEnv);
   }

lib/AST/ASTContext.cpp

@@ -5350,9 +5350,8 @@ CanOpenedArchetypeType OpenedArchetypeType::get(CanType existential,
   if (!knownID)
     knownID = UUID::fromTime();
 
-  auto *genericEnv =
-    GenericEnvironment::forOpenedExistential(
-      existential, SubstitutionMap(), *knownID);
+  auto *genericEnv = GenericEnvironment::forOpenedExistential(
+      existential, *knownID);
 
   // Map the interface type into that environment.
   auto result = genericEnv->mapTypeIntoContext(interfaceType)
@@ -5543,10 +5542,19 @@ GenericEnvironment *GenericEnvironment::forOpaqueType(
   return env;
 }
 
+/// Create a new generic environment for an opened archetype.
+GenericEnvironment *
+GenericEnvironment::forOpenedExistential(Type existential, UUID uuid) {
+  auto &ctx = existential->getASTContext();
+  auto signature = ctx.getOpenedExistentialSignature(existential, GenericSignature());
+  return forOpenedExistential(signature, existential, SubstitutionMap(), uuid);
+}
+
 /// Create a new generic environment for an opened archetype.
 GenericEnvironment *
 GenericEnvironment::forOpenedExistential(
-    Type existential, SubstitutionMap subs, UUID uuid) {
+    GenericSignature signature, Type existential,
+    SubstitutionMap subs, UUID uuid) {
   assert(existential->isExistentialType());
 
   // TODO: We could attempt to preserve type sugar in the substitution map.
@@ -5568,15 +5576,13 @@ GenericEnvironment::forOpenedExistential(
   if (found != environments.end()) {
     auto *existingEnv = found->second;
     assert(existingEnv->getOpenedExistentialType()->isEqual(existential));
+    assert(existingEnv->getGenericSignature().getPointer() == signature.getPointer());
     assert(existingEnv->getOuterSubstitutions() == subs);
     assert(existingEnv->getOpenedExistentialUUID() == uuid);
 
     return existingEnv;
   }
 
-  auto parentSig = subs.getGenericSignature().getCanonicalSignature();
-  auto signature = ctx.getOpenedExistentialSignature(existential, parentSig);
-
   // Allocate and construct the new environment.
   unsigned numGenericParams = signature.getGenericParams().size();
   size_t bytes = totalSizeToAlloc<SubstitutionMap,

lib/Sema/TypeCheckType.cpp

@@ -2863,7 +2863,7 @@ TypeResolver::resolveOpenedExistentialArchetype(
     // The opened existential type is formed by mapping the interface type
     // into a new opened generic environment.
     auto *env = GenericEnvironment::forOpenedExistential(
-        constraintType->getCanonicalType(), SubstitutionMap(),
+        constraintType->getCanonicalType(),
         openedAttr->getUUID());
     return env->mapTypeIntoContext(interfaceType);
   }

lib/Serialization/Deserialization.cpp

@@ -1660,7 +1660,10 @@ Expected<GenericEnvironment *> ModuleFile::getGenericEnvironmentChecked(
   switch (GenericEnvironmentKind(kind)) {
   case GenericEnvironmentKind::OpenedExistential:
     genericEnv = GenericEnvironment::forOpenedExistential(
-        existentialOrShapeTypeOrError.get(), contextSubsOrError.get(), UUID::fromTime());
+        genericSigOrError.get(),
+        existentialOrShapeTypeOrError.get(),
+        contextSubsOrError.get(),
+        UUID::fromTime());
     break;
 
   case GenericEnvironmentKind::OpenedElement:

lib/Serialization/ModuleFormat.h

@@ -58,7 +58,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 886; // SIL function thunk kind
+const uint16_t SWIFTMODULE_VERSION_MINOR = 887; // extravagant opened existentials
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///

lib/Serialization/Serialization.cpp

@@ -1667,7 +1667,7 @@ void Serializer::writeASTBlockEntity(const GenericEnvironment *genericEnv) {
   case GenericEnvironment::Kind::OpenedExistential: {
     auto kind = GenericEnvironmentKind::OpenedExistential;
     auto existentialTypeID = addTypeRef(genericEnv->getOpenedExistentialType());
-    auto parentSigID = addGenericSignatureRef(GenericSignature());
+    auto parentSigID = addGenericSignatureRef(genericEnv->getGenericSignature());
     auto contextSubs = genericEnv->getOuterSubstitutions();
     auto subsID = addSubstitutionMapRef(contextSubs);
 
@@ -1681,8 +1681,7 @@ void Serializer::writeASTBlockEntity(const GenericEnvironment *genericEnv) {
   case GenericEnvironment::Kind::OpenedElement: {
     auto kind = GenericEnvironmentKind::OpenedElement;
     auto shapeClassID = addTypeRef(genericEnv->getOpenedElementShapeClass());
-    auto parentSig = genericEnv->getGenericSignature();
-    auto parentSigID = addGenericSignatureRef(parentSig);
+    auto parentSigID = addGenericSignatureRef(genericEnv->getGenericSignature());
     auto contextSubs = genericEnv->getOuterSubstitutions();
     auto subsID = addSubstitutionMapRef(contextSubs);