[WIP] Implement reflection support for Symbolic Extended Existential types.

adrian-prantl · adrian-prantl · commit 7966da935c18 · 2025-06-23T17:19:06.000-07:00
diff --git a/include/swift/RemoteInspection/TypeRef.h b/include/swift/RemoteInspection/TypeRef.h
@@ -731,6 +731,71 @@ class ConstrainedExistentialTypeRef final : public TypeRef {
   }
 };
 
+class SymbolicExtendedExistentialTypeRef final : public TypeRef {
+  remote::RemoteAbsolutePointer Shape;
+  const ProtocolCompositionTypeRef *Protocol;
+  std::vector<TypeRefRequirement> Requirements;
+  std::vector<const TypeRef *> Arguments;
+  ExtendedExistentialTypeShapeFlags Flags;
+
+  static TypeRefID Profile(const remote::RemoteAbsolutePointer Shape,
+                           const ProtocolCompositionTypeRef *Protocol,
+                           llvm::ArrayRef<TypeRefRequirement> Requirements,
+                           llvm::ArrayRef<const TypeRef *> Arguments,
+                           ExtendedExistentialTypeShapeFlags Flags) {
+    TypeRefID ID;
+    ID.addString(Shape.getSymbol());
+    ID.addPointer(Protocol);
+      for (auto reqt : Requirements) {
+      ID.addPointer(reqt.getFirstType());
+      if (reqt.getKind() != RequirementKind::Layout)
+        ID.addPointer(reqt.getSecondType());
+      else
+        ID.addInteger(
+            unsigned(0)); // FIXME: Layout constraints aren't implemented yet
+      ID.addInteger(unsigned(reqt.getKind()));
+    }
+
+    for (auto &Arg : Arguments)
+      ID.addPointer(Arg);
+    return ID;
+  }
+
+public:
+  SymbolicExtendedExistentialTypeRef(
+      remote::RemoteAbsolutePointer Shape,
+      const ProtocolCompositionTypeRef *Protocol,
+      llvm::ArrayRef<TypeRefRequirement> Requirements,
+      llvm::ArrayRef<const TypeRef *> Args,
+      ExtendedExistentialTypeShapeFlags Flags)
+      : TypeRef(TypeRefKind::SymbolicExtendedExistential), Shape(Shape),
+        Protocol(Protocol), Requirements(Requirements), Arguments(Args),
+        Flags(Flags) {}
+
+  template <typename Allocator>
+  static const SymbolicExtendedExistentialTypeRef *
+  create(Allocator &A, remote::RemoteAbsolutePointer Shape,
+         const ProtocolCompositionTypeRef *Protocol,
+         llvm::ArrayRef<TypeRefRequirement> Requirements,
+         llvm::ArrayRef<const TypeRef *> Args,
+         ExtendedExistentialTypeShapeFlags Flags) {
+    FIND_OR_CREATE_TYPEREF(A, SymbolicExtendedExistentialTypeRef, Shape,
+                           Protocol, Requirements, Args, Flags);
+  }
+
+  //const remote::RemoteAbsolutePointer getShape() const { return Shape; }
+  const ProtocolCompositionTypeRef *getProtocol() const { return Protocol; }
+  llvm::ArrayRef<TypeRefRequirement> getRequirements() const {
+    return Requirements;
+  }
+  llvm::ArrayRef<const TypeRef *> getArguments() const { return Arguments; }
+  ExtendedExistentialTypeShapeFlags getFlags() const { return Flags; }
+
+  static bool classof(const TypeRef *TR) {
+    return TR->getKind() == TypeRefKind::SymbolicExtendedExistential;
+  }
+};
+
 class MetatypeTypeRef final : public TypeRef {
   const TypeRef *InstanceType;
   bool WasAbstract;
diff --git a/include/swift/RemoteInspection/TypeRefBuilder.h b/include/swift/RemoteInspection/TypeRefBuilder.h
@@ -1284,7 +1284,56 @@ class TypeRefBuilder {
   createSymbolicExtendedExistentialType(NodePointer shapeNode,
                                         llvm::ArrayRef<const TypeRef *> args) {
     // Can't handle this here.
-    return nullptr;
+    
+    remote::RemoteAddress shape(shapeNode->getIndex());
+    auto symbol = OpaquePointerSymbolResolver(shape);
+    if (!symbol)
+      return nullptr;
+    auto bytes = OpaqueByteReader(shape, 4);
+    if (!bytes)
+      return nullptr;
+    ExtendedExistentialTypeShapeFlags flags(*(const uint32_t *)bytes.get());
+
+    Demangler Dem;
+    auto *Node = Dem.demangleSymbol(symbol->getSymbol());
+    if (Node->getKind() != Node::Kind::Global || Node->getNumChildren() != 1)
+      return nullptr;
+    Node = Node->getChild(0);
+    if ((Node->getKind() == Node::Kind::Uniquable) &&
+        Node->getNumChildren() == 1)
+      Node = Node->getChild(0);
+    if (Node->getKind() != Node::Kind::ExtendedExistentialTypeShape ||
+        Node->getNumChildren() != 2)
+      return nullptr;
+    Node = Node->getChild(1);
+    if (Node->getKind() != Node::Kind::Type || Node->getNumChildren() != 1)
+      return nullptr;
+    Node = Node->getChild(0);
+    if (Node->getKind() != Node::Kind::ConstrainedExistential ||
+        Node->getNumChildren() != 2)
+      return nullptr;
+    auto ReqNode = Node->getChild(1);
+    Node = Node->getChild(0);
+    if (Node->getKind() != Node::Kind::Type || Node->getNumChildren() != 1)
+      return nullptr;
+    auto protocol = llvm::dyn_cast_or_null<ProtocolCompositionTypeRef>(
+        decodeMangledType(Node));
+    if (!protocol)
+      return nullptr;
+
+    if (!ReqNode ||
+        ReqNode->getKind() != Node::Kind::ConstrainedExistentialRequirementList)
+      return nullptr;
+
+    llvm::SmallVector<BuiltRequirement, 8> requirements;
+    llvm::SmallVector<BuiltInverseRequirement, 8> inverseRequirements;
+
+    decodeRequirement<BuiltType, BuiltRequirement, BuiltInverseRequirement,
+                      BuiltLayoutConstraint, TypeRefBuilder>(
+        ReqNode, requirements, inverseRequirements, *this);
+
+    return SymbolicExtendedExistentialTypeRef::create(
+        *this, *symbol, protocol, requirements, args, flags);
   }
 
   const ExistentialMetatypeTypeRef *createExistentialMetatypeType(
@@ -1312,6 +1361,7 @@ class TypeRefBuilder {
 
   const DependentMemberTypeRef *
   createDependentMemberType(const std::string &member, const TypeRef *base) {
+    return DependentMemberTypeRef::create(*this, member, base, "");
     // Should not have unresolved dependent member types here.
     return nullptr;
   }
@@ -1479,6 +1529,9 @@ class TypeRefBuilder {
   using PointerReader =
       std::function<std::optional<remote::RemoteAbsolutePointer>(
           remote::RemoteAddress, unsigned)>;
+  using PointerSymbolResolver =
+      std::function<std::optional<remote::RemoteAbsolutePointer>(
+          remote::RemoteAddress)>;
   using DynamicSymbolResolver =
       std::function<std::optional<remote::RemoteAbsolutePointer>(
           remote::RemoteAddress)>;
@@ -1511,6 +1564,7 @@ class TypeRefBuilder {
   ByteReader OpaqueByteReader;
   StringReader OpaqueStringReader;
   PointerReader OpaquePointerReader;
+  PointerSymbolResolver OpaquePointerSymbolResolver;
   DynamicSymbolResolver OpaqueDynamicSymbolResolver;
   IntVariableReader OpaqueIntVariableReader;
 
@@ -1549,6 +1603,11 @@ class TypeRefBuilder {
                 -> std::optional<remote::RemoteAbsolutePointer> {
               return reader.Reader->readPointer(address, size);
             }),
+        OpaquePointerSymbolResolver(
+            [&reader](remote::RemoteAddress address)
+                -> std::optional<remote::RemoteAbsolutePointer> {
+              return reader.Reader->resolvePointerAsSymbol(address);
+            }),
         OpaqueDynamicSymbolResolver(
             [&reader](remote::RemoteAddress address)
                 -> std::optional<remote::RemoteAbsolutePointer> {
diff --git a/include/swift/RemoteInspection/TypeRefs.def b/include/swift/RemoteInspection/TypeRefs.def
@@ -23,6 +23,7 @@ TYPEREF(Tuple, TypeRef)
 TYPEREF(Function, TypeRef)
 TYPEREF(ProtocolComposition, TypeRef)
 TYPEREF(ConstrainedExistential, TypeRef)
+TYPEREF(SymbolicExtendedExistential, TypeRef)
 TYPEREF(Metatype, TypeRef)
 TYPEREF(ExistentialMetatype, TypeRef)
 TYPEREF(GenericTypeParameter, TypeRef)
diff --git a/stdlib/public/RemoteInspection/TypeLowering.cpp b/stdlib/public/RemoteInspection/TypeLowering.cpp
@@ -1154,6 +1154,7 @@ class ExistentialTypeInfoBuilder {
   TypeConverter &TC;
   std::vector<const TypeRef *> Protocols;
   const TypeRef *Superclass = nullptr;
+  remote::RemoteAbsolutePointer Shape;
   ExistentialTypeRepresentation Representation;
   ReferenceCounting Refcounting;
   bool ObjC;
@@ -1258,6 +1259,10 @@ class ExistentialTypeInfoBuilder {
     }
   }
 
+  void examineShape() {
+    
+  }
+
 public:
   ExistentialTypeInfoBuilder(TypeConverter &TC)
     : TC(TC), Representation(ExistentialTypeRepresentation::Opaque),
@@ -1321,8 +1326,27 @@ class ExistentialTypeInfoBuilder {
     Representation = ExistentialTypeRepresentation::Class;
   }
 
+  void addShape(const ProtocolCompositionTypeRef *Protocol,
+                ExtendedExistentialTypeShapeFlags Flags) {
+    switch (Flags.getSpecialKind()) {
+      case ExtendedExistentialTypeShapeFlags::SpecialKind::Class:
+        Representation = ExistentialTypeRepresentation::Class;
+        break;
+      case ExtendedExistentialTypeShapeFlags::SpecialKind::Metatype:
+      case ExtendedExistentialTypeShapeFlags::SpecialKind::ExplicitLayout:
+      case ExtendedExistentialTypeShapeFlags::SpecialKind::None:
+        Representation = ExistentialTypeRepresentation::Opaque;
+        break;
+    }
+
+    if (Protocol)
+      for (auto *Protocol : Protocol->getProtocols())
+        addProtocol(Protocol);
+  }
+
   const TypeInfo *build(remote::TypeInfoProvider *ExternalTypeInfo) {
     examineProtocols();
+    examineShape();
 
     if (Invalid)
       return nullptr;
@@ -1780,6 +1804,11 @@ class HasFixedSize
     return true;
   }
 
+  bool visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    return true;
+  }
+
   bool
   visitSILBoxTypeRef(const SILBoxTypeRef *SB) {
     return true;
@@ -1923,6 +1952,11 @@ class HasSingletonMetatype
     return MetatypeRepresentation::Thin;
   }
 
+  MetatypeRepresentation visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    return MetatypeRepresentation::Thin;
+  }
+
   MetatypeRepresentation visitMetatypeTypeRef(const MetatypeTypeRef *M) {
     if (M->wasAbstract())
       return MetatypeRepresentation::Thick;
@@ -2520,6 +2554,13 @@ class LowerType
     return builder.buildMetatype(ExternalTypeInfo);
   }
 
+  const TypeInfo *visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    ExistentialTypeInfoBuilder builder(TC);
+    builder.addShape(SEET->getProtocol(), SEET->getFlags());
+    return builder.build(ExternalTypeInfo);
+  }
+
   const TypeInfo *
   visitGenericTypeParameterTypeRef(const GenericTypeParameterTypeRef *GTP) {
     DEBUG_LOG(fprintf(stderr, "Unresolved generic TypeRef: "); GTP->dump());
@@ -2736,7 +2777,7 @@ const RecordTypeInfo *TypeConverter::getClassInstanceTypeInfo(
   swift_unreachable("Unhandled FieldDescriptorKind in switch.");
 }
 
-} // namespace reflection
+    } // namespace reflection
 } // namespace swift
 
 #endif
diff --git a/stdlib/public/RemoteInspection/TypeRef.cpp b/stdlib/public/RemoteInspection/TypeRef.cpp
@@ -289,6 +289,16 @@ class PrintTypeRef : public TypeRefVisitor<PrintTypeRef, void> {
     stream << ")";
   }
 
+  void visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *CET) {
+    printHeader("symbolic_extended_existential_type");
+//    printRec(CET->getShape());
+    printRec(CET->getProtocol());
+    for (auto &arg : CET->getArguments())
+      printRec(arg);
+    stream << ")";
+  }
+
   void visitMetatypeTypeRef(const MetatypeTypeRef *M) {
     printHeader("metatype");
     if (M->wasAbstract())
@@ -513,6 +523,15 @@ struct TypeRefIsConcrete
     return visit(CET->getBase());
   }
 
+  bool visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    visit(SEET->getProtocol());
+    for (auto &Arg : SEET->getArguments())
+      if (!visit(Arg))
+        return false;
+    return true;
+  }
+
   bool visitMetatypeTypeRef(const MetatypeTypeRef *M) {
     return visit(M->getInstanceType());
   }
@@ -952,6 +971,19 @@ class DemanglingForTypeRef
     return node;
   }
 
+  Demangle::NodePointer visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    auto node = Dem.createNode(Node::Kind::ConstrainedExistential);
+    node->addChild(visit(SEET->getProtocol()), Dem);
+    auto constraintList =
+        Dem.createNode(Node::Kind::ConstrainedExistentialRequirementList);
+    for (auto req : SEET->getRequirements())
+      constraintList->addChild(visitTypeRefRequirement(req), Dem);
+    node->addChild(constraintList, Dem);
+    // FIXME: This is lossy. We're dropping the Arguments here.
+    return node;
+  }
+
   Demangle::NodePointer visitMetatypeTypeRef(const MetatypeTypeRef *M) {
     auto node = Dem.createNode(Node::Kind::Metatype);
     // FIXME: This is lossy. @objc_metatype is also abstract.
@@ -1354,6 +1386,11 @@ class ThickenMetatype
                                                  CET->getRequirements());
   }
 
+  const TypeRef *visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    return SEET;
+  }
+
   const TypeRef *visitMetatypeTypeRef(const MetatypeTypeRef *M) {
     return MetatypeTypeRef::create(Builder, visit(M->getInstanceType()),
                                    /*WasAbstract=*/true);
@@ -1641,6 +1678,12 @@ class TypeRefSubstitution
                                                  constraints);
   }
 
+  const TypeRef *visitSymbolicExtendedExistentialTypeRef(
+      const SymbolicExtendedExistentialTypeRef *SEET) {
+    assert(false);
+    return nullptr;
+  }
+
   const TypeRef *
   visitGenericTypeParameterTypeRef(const GenericTypeParameterTypeRef *GTP) {
     auto found = Substitutions.find({GTP->getDepth(), GTP->getIndex()});
