Merge pull request swiftlang#75995 from slavapestov/open-existential-recursive-properties

Track recursive properties and outer substitutions for opened existential environments

Author: slavapestov

include/swift/AST/GenericEnvironment.h

@@ -58,21 +58,18 @@ class QueryInterfaceTypeSubstitutions {
 /// Extra data in a generic environment for an opaque type.
 struct OpaqueEnvironmentData {
   OpaqueTypeDecl *decl;
-  SubstitutionMap subMap;
 };
 
 /// Extra data in a generic environment for an opened existential.
 struct OpenedExistentialEnvironmentData {
   Type existential;
-  GenericSignature parentSig;
   UUID uuid;
 };
 
 /// Extra data in a generic environment for an opened pack element.
 struct OpenedElementEnvironmentData {
   UUID uuid;
   CanGenericTypeParamType shapeClass;
-  SubstitutionMap outerSubstitutions;
 };
 
 /// Describes the mapping between archetypes and interface types for the
@@ -86,6 +83,7 @@ struct OpenedElementEnvironmentData {
 class alignas(1 << DeclAlignInBits) GenericEnvironment final
     : private llvm::TrailingObjects<
         GenericEnvironment,
+        SubstitutionMap,
         OpaqueEnvironmentData,
         OpenedExistentialEnvironmentData,
         OpenedElementEnvironmentData,
@@ -114,6 +112,7 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   friend TrailingObjects;
   friend OpaqueTypeArchetypeType;
 
+  size_t numTrailingObjects(OverloadToken<SubstitutionMap>) const;
   size_t numTrailingObjects(OverloadToken<OpaqueEnvironmentData>) const;
   size_t numTrailingObjects(OverloadToken<OpenedExistentialEnvironmentData>) const;
   size_t numTrailingObjects(OverloadToken<OpenedElementEnvironmentData>) const;
@@ -147,8 +146,7 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
 
   /// Private constructor for opened existential environments.
   explicit GenericEnvironment(
-      GenericSignature signature,
-      Type existential, GenericSignature parentSig, UUID uuid);
+      GenericSignature signature, Type existential, SubstitutionMap subs, UUID uuid);
 
   /// Private constructor for opened element environments.
   explicit GenericEnvironment(GenericSignature signature,
@@ -185,20 +183,16 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   /// Retrieve the UUID for an opened existential environment.
   UUID getOpenedExistentialUUID() const;
 
-  /// Retrieve the parent signature for an opened existential environment.
-  GenericSignature getOpenedExistentialParentSignature() const;
-
   /// Retrieve the opaque type declaration for a generic environment describing
   /// opaque types.
   OpaqueTypeDecl *getOpaqueTypeDecl() const;
 
-  /// Retrieve the substitutions applied to an opaque type declaration to
-  /// create a generic environment.
-  SubstitutionMap getOpaqueSubstitutions() const;
-
-  /// Retrieve the substitutions for the outer generic parameters of an
-  /// opened pack element generic environment.
-  SubstitutionMap getPackElementContextSubstitutions() const;
+  /// Retrieve the outer substitutions for an opaque or local environment.
+  ///
+  /// Applying a substitution map to a local or opaque archetype outputs
+  /// an archetype with the same interface type, and composed outer
+  /// substitutions.
+  SubstitutionMap getOuterSubstitutions() const;
 
   /// Retrieve the shape equivalence class for an opened element environment.
   /// This is always a pack parameter.
@@ -238,10 +232,11 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   /// Create a new generic environment for an opened existential.
   ///
   /// \param existential The subject existential type
-  /// \param parentSig The signature of the context where this existential type is being opened
+  /// \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, GenericSignature parentSig, UUID uuid);
+  forOpenedExistential(Type existential, SubstitutionMap outerSubs, UUID uuid);
 
   /// Create a new generic environment for an opened element.
   ///
@@ -251,7 +246,7 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   /// \param uuid The unique identifier for this opened element
   /// \param shapeClass The shape equivalence class for the originating packs
   /// \param outerSubs The substitution map containing archetypes from the
-  /// outer generic context.
+  /// outer generic context
   static GenericEnvironment *
   forOpenedElement(GenericSignature signature,
                    UUID uuid, CanGenericTypeParamType shapeClass,
@@ -271,9 +266,6 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   /// substitutions.
   Type maybeApplyOuterContextSubstitutions(Type type) const;
 
-  /// Compute the canonical interface type within this environment.
-  Type getCanonicalInterfaceType(Type interfaceType);
-
   /// Map an interface type to a contextual type.
   static Type mapTypeIntoContext(GenericEnvironment *genericEnv,
                                  Type type);

include/swift/AST/Types.h

@@ -6679,10 +6679,6 @@ class OpaqueTypeArchetypeType final : public ArchetypeType,
   /// Retrieve the set of substitutions applied to the opaque type.
   SubstitutionMap getSubstitutions() const;
 
-  /// Compute the canonical interface type within the environment of this
-  /// opaque type archetype.
-  CanType getCanonicalInterfaceType(Type interfaceType);
-
   static bool classof(const TypeBase *T) {
     return T->getKind() == TypeKind::OpaqueTypeArchetype;
   }
@@ -6870,8 +6866,10 @@ class OpenedArchetypeType final : public LocalArchetypeType,
 
 private:
   OpenedArchetypeType(GenericEnvironment *environment, Type interfaceType,
-                      ArrayRef<ProtocolDecl *> conformsTo, Type superclass,
-                      LayoutConstraint layout);
+                      ArrayRef<ProtocolDecl *> conformsTo,
+                      Type superclass,
+                      LayoutConstraint layout,
+                      RecursiveTypeProperties properties);
 };
 BEGIN_CAN_TYPE_WRAPPER(OpenedArchetypeType, LocalArchetypeType)
   CanOpenedArchetypeType getRoot() const {

include/swift/SIL/SILCloner.h

@@ -2870,7 +2870,7 @@ void SILCloner<ImplClass>::visitOpenPackElementInst(
 
   // Substitute the contextual substitutions.
   auto newContextSubs =
-    getOpSubstitutionMap(origEnv->getPackElementContextSubstitutions());
+    getOpSubstitutionMap(origEnv->getOuterSubstitutions());
 
   // The opened shape class is a parameter of the original signature,
   // which is unchanged.

lib/AST/ASTContext.cpp

@@ -520,6 +520,8 @@ struct ASTContext::Implementation {
                MetatypeRepresentation::Last_MetatypeRepresentation) + 1,
                "Use std::pair for MetatypeTypes and ExistentialMetatypeTypes.");
 
+    using OpenedExistentialKey = std::pair<SubstitutionMap, UUID>;
+
     llvm::DenseMap<Type, ErrorType *> ErrorTypesWithOriginal;
     llvm::FoldingSet<TypeAliasType> TypeAliasTypes;
     llvm::FoldingSet<TupleType> TupleTypes;
@@ -555,6 +557,8 @@ struct ASTContext::Implementation {
     llvm::FoldingSet<LayoutConstraintInfo> LayoutConstraints;
     llvm::DenseMap<std::pair<OpaqueTypeDecl *, SubstitutionMap>,
                    GenericEnvironment *> OpaqueArchetypeEnvironments;
+    llvm::DenseMap<OpenedExistentialKey, GenericEnvironment *>
+      OpenedExistentialEnvironments;
 
     /// The set of function types.
     llvm::FoldingSet<FunctionType> FunctionTypes;
@@ -618,7 +622,6 @@ struct ASTContext::Implementation {
   llvm::DenseMap<BuiltinIntegerWidth, BuiltinIntegerType*> IntegerTypes;
   llvm::FoldingSet<BuiltinVectorType> BuiltinVectorTypes;
   llvm::FoldingSet<DeclName::CompoundDeclName> CompoundNames;
-  llvm::DenseMap<UUID, GenericEnvironment *> OpenedExistentialEnvironments;
   llvm::DenseMap<UUID, GenericEnvironment *> OpenedElementEnvironments;
   llvm::FoldingSet<IndexSubset> IndexSubsets;
   llvm::FoldingSet<AutoDiffDerivativeFunctionIdentifier>
@@ -863,7 +866,6 @@ void ASTContext::Implementation::dump(llvm::raw_ostream &os) const {
   SIZE_AND_BYTES(SILBlockStorageTypes);
   SIZE_AND_BYTES(SILMoveOnlyWrappedTypes);
   SIZE_AND_BYTES(IntegerTypes);
-  SIZE_AND_BYTES(OpenedExistentialEnvironments);
   SIZE_AND_BYTES(OpenedElementEnvironments);
   SIZE_AND_BYTES(ForeignRepresentableCache);
   SIZE(SearchPathsSet);
@@ -3125,7 +3127,6 @@ size_t ASTContext::getTotalMemory() const {
     // getImpl().BuiltinVectorTypes ?
     // getImpl().GenericSignatures ?
     // getImpl().CompoundNames ?
-    getImpl().OpenedExistentialEnvironments.getMemorySize() +
     getImpl().Permanent.getTotalMemory();
 
     Size += getSolverMemory();
@@ -3162,7 +3163,9 @@ size_t ASTContext::Implementation::Arena::getTotalMemory() const {
     llvm::capacity_in_bytes(StructTypes) +
     llvm::capacity_in_bytes(ClassTypes) +
     llvm::capacity_in_bytes(ProtocolTypes) +
-    llvm::capacity_in_bytes(DynamicSelfTypes);
+    llvm::capacity_in_bytes(DynamicSelfTypes) +
+    OpaqueArchetypeEnvironments.getMemorySize() +
+    OpenedExistentialEnvironments.getMemorySize();
     // FunctionTypes ?
     // UnboundGenericTypes ?
     // BoundGenericTypes ?
@@ -3209,6 +3212,7 @@ void ASTContext::Implementation::Arena::dump(llvm::raw_ostream &os) const {
     SIZE(ParameterizedProtocolTypes);
     SIZE(LayoutConstraints);
     SIZE_AND_BYTES(OpaqueArchetypeEnvironments);
+    SIZE_AND_BYTES(OpenedExistentialEnvironments);
     SIZE(FunctionTypes);
     SIZE(NormalConformances);
     SIZE(SelfConformances);
@@ -5295,7 +5299,7 @@ OpaqueTypeArchetypeType *OpaqueTypeArchetypeType::getNew(
     ArrayRef<ProtocolDecl *> conformsTo, Type superclass,
     LayoutConstraint layout) {
   auto properties = getOpaqueTypeArchetypeProperties(
-      environment->getOpaqueSubstitutions());
+      environment->getOuterSubstitutions());
   auto arena = getArena(properties);
   auto size = OpaqueTypeArchetypeType::totalSizeToAlloc<
       ProtocolDecl *, Type, LayoutConstraint>(
@@ -5313,26 +5317,39 @@ Type OpaqueTypeArchetypeType::get(
   return env->getOrCreateArchetypeFromInterfaceType(interfaceType);
 }
 
+/// Compute the recursive type properties of an opaque type archetype.
+static RecursiveTypeProperties getOpenedArchetypeProperties(SubstitutionMap subs) {
+  // An opaque type isn't contextually dependent like other archetypes, so
+  // by itself, it doesn't impose the "Has Archetype" recursive property,
+  // but the substituted types might. A disjoint "Has Opaque Archetype" tracks
+  // the presence of opaque archetypes.
+  RecursiveTypeProperties properties =
+    RecursiveTypeProperties::HasOpenedExistential;
+  for (auto type : subs.getReplacementTypes()) {
+    properties |= type->getRecursiveProperties();
+  }
+  return properties;
+}
+
 CanTypeWrapper<OpenedArchetypeType> OpenedArchetypeType::getNew(
     GenericEnvironment *environment, Type interfaceType,
     ArrayRef<ProtocolDecl *> conformsTo, Type superclass,
     LayoutConstraint layout) {
-  // FIXME: It'd be great if all of our callers could submit interface types.
-  // But the constraint solver submits archetypes when e.g. trying to issue
-  // checks against members of existential types.
-  //  assert((!superclass || !superclass->hasArchetype())
-  //         && "superclass must be interface type");
-  auto arena = AllocationArena::Permanent;
-  ASTContext &ctx = interfaceType->getASTContext();
-  void *mem = ctx.Allocate(
-    OpenedArchetypeType::totalSizeToAlloc<ProtocolDecl *,Type,LayoutConstraint>(
+  auto properties = getOpenedArchetypeProperties(
+      environment->getOuterSubstitutions());
+  auto arena = getArena(properties);
+  auto size = OpenedArchetypeType::totalSizeToAlloc<
+      ProtocolDecl *, Type, LayoutConstraint>(
       conformsTo.size(),
       superclass ? 1 : 0,
-      layout ? 1 : 0),
-      alignof(OpenedArchetypeType), arena);
+      layout ? 1 : 0);
+
+  ASTContext &ctx = interfaceType->getASTContext();
+  void *mem = ctx.Allocate(size, alignof(OpenedArchetypeType), arena);
 
   return CanOpenedArchetypeType(::new (mem) OpenedArchetypeType(
-      environment, interfaceType, conformsTo, superclass, layout));
+      environment, interfaceType, conformsTo, superclass, layout,
+      properties));
 }
 
 CanTypeWrapper<OpenedArchetypeType>
@@ -5353,7 +5370,7 @@ CanOpenedArchetypeType OpenedArchetypeType::get(CanType existential,
 
   auto *genericEnv =
     GenericEnvironment::forOpenedExistential(
-      existential, GenericSignature(), *knownID);
+      existential, SubstitutionMap(), *knownID);
 
   // Map the interface type into that environment.
   auto result = genericEnv->mapTypeIntoContext(interfaceType)
@@ -5508,10 +5525,11 @@ GenericEnvironment *GenericEnvironment::forPrimary(GenericSignature signature) {
 
   // Allocate and construct the new environment.
   unsigned numGenericParams = signature.getGenericParams().size();
-  size_t bytes = totalSizeToAlloc<OpaqueEnvironmentData,
+  size_t bytes = totalSizeToAlloc<SubstitutionMap,
+                                  OpaqueEnvironmentData,
                                   OpenedExistentialEnvironmentData,
                                   OpenedElementEnvironmentData, Type>(
-      0, 0, 0, numGenericParams);
+      0, 0, 0, 0, numGenericParams);
   void *mem = ctx.Allocate(bytes, alignof(GenericEnvironment));
   return new (mem) GenericEnvironment(signature);
 }
@@ -5537,10 +5555,11 @@ GenericEnvironment *GenericEnvironment::forOpaqueType(
     // Allocate and construct the new environment.
     auto signature = opaque->getOpaqueInterfaceGenericSignature();
     unsigned numGenericParams = signature.getGenericParams().size();
-    size_t bytes = totalSizeToAlloc<OpaqueEnvironmentData,
+    size_t bytes = totalSizeToAlloc<SubstitutionMap,
+                                  OpaqueEnvironmentData,
                                     OpenedExistentialEnvironmentData,
                                     OpenedElementEnvironmentData, Type>(
-        1, 0, 0, numGenericParams);
+        1, 1, 0, 0, numGenericParams);
     void *mem = ctx.Allocate(bytes, alignof(GenericEnvironment), arena);
     env = new (mem) GenericEnvironment(signature, opaque, subs);
 
@@ -5553,46 +5572,49 @@ GenericEnvironment *GenericEnvironment::forOpaqueType(
 /// Create a new generic environment for an opened archetype.
 GenericEnvironment *
 GenericEnvironment::forOpenedExistential(
-    Type existential, GenericSignature parentSig, UUID uuid) {
+    Type existential, SubstitutionMap subs, UUID uuid) {
   assert(existential->isExistentialType());
-  // FIXME: Opened archetypes can't be transformed because the
-  // the identity of the archetype has to be preserved. This
-  // means that simplifying an opened archetype in the constraint
-  // system to replace type variables with fixed types is not
-  // yet supported. For now, assert that an opened archetype never
-  // contains type variables to catch cases where type variables
-  // would be applied to the type-checked AST.
-  assert(!existential->hasTypeVariable() &&
-         "opened existentials containing type variables cannot be simplified");
+
+  // TODO: We could attempt to preserve type sugar in the substitution map.
+  // Currently archetypes are assumed to be always canonical in many places,
+  // though, so doing so would require fixing those places.
+  subs = subs.getCanonical();
 
   auto &ctx = existential->getASTContext();
 
-  auto &openedExistentialEnvironments =
-      ctx.getImpl().OpenedExistentialEnvironments;
-  auto found = openedExistentialEnvironments.find(uuid);
+  auto properties = getOpenedArchetypeProperties(subs);
+  auto arena = getArena(properties);
+
+  auto key = std::make_pair(subs, uuid);
+
+  auto &environments =
+      ctx.getImpl().getArena(arena).OpenedExistentialEnvironments;
+  auto found = environments.find(key);
 
-  if (found != openedExistentialEnvironments.end()) {
+  if (found != environments.end()) {
     auto *existingEnv = found->second;
     assert(existingEnv->getOpenedExistentialType()->isEqual(existential));
-    assert(existingEnv->getOpenedExistentialParentSignature().getPointer() == parentSig.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<OpaqueEnvironmentData,
+  size_t bytes = totalSizeToAlloc<SubstitutionMap,
+                                  OpaqueEnvironmentData,
                                   OpenedExistentialEnvironmentData,
                                   OpenedElementEnvironmentData, Type>(
-      0, 1, 0, numGenericParams);
+      1, 0, 1, 0, numGenericParams);
   void *mem = ctx.Allocate(bytes, alignof(GenericEnvironment));
   auto *genericEnv =
-      new (mem) GenericEnvironment(signature, existential, parentSig, uuid);
+      new (mem) GenericEnvironment(signature, existential, subs, uuid);
 
-  openedExistentialEnvironments[uuid] = genericEnv;
+  environments[key] = genericEnv;
 
   return genericEnv;
 }
@@ -5621,11 +5643,12 @@ GenericEnvironment::forOpenedElement(GenericSignature signature,
   // Allocate and construct the new environment.
   unsigned numGenericParams = signature.getGenericParams().size();
   unsigned numOpenedParams = signature.getInnermostGenericParams().size();
-  size_t bytes = totalSizeToAlloc<OpaqueEnvironmentData,
+  size_t bytes = totalSizeToAlloc<SubstitutionMap,
+                                  OpaqueEnvironmentData,
                                   OpenedExistentialEnvironmentData,
                                   OpenedElementEnvironmentData,
                                   Type>(
-      0, 0, 1, numGenericParams + numOpenedParams);
+      1, 0, 0, 1, numGenericParams + numOpenedParams);
   void *mem = ctx.Allocate(bytes, alignof(GenericEnvironment));
   auto *genericEnv = new (mem) GenericEnvironment(signature,
                                                   uuid, shapeClass,

lib/AST/ASTPrinter.cpp

@@ -6955,7 +6955,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
     // the generic signature of the contextual substitution map in the
     // opened element environment.
     auto env = T->getGenericEnvironment();
-    auto subs = env->getPackElementContextSubstitutions();
+    auto subs = env->getOuterSubstitutions();
     auto sig = subs.getGenericSignature();
     auto params = sig.getGenericParams();