[Runtime/ABI] Replace emitTypeFieldAccessor with a single runtime method

include/swift/Demangling/TypeDecoder.h

@@ -124,7 +124,8 @@ class TypeDecoder {
     }
     case NodeKind::BoundGenericClass:
     case NodeKind::BoundGenericEnum:
-    case NodeKind::BoundGenericStructure: {
+    case NodeKind::BoundGenericStructure:
+    case NodeKind::BoundGenericOtherNominalType: {
       if (Node->getNumChildren() != 2)
         return BuiltType();
 

include/swift/Reflection/Records.h

@@ -19,6 +19,7 @@
 
 #include "swift/Basic/RelativePointer.h"
 #include "swift/Demangling/Demangle.h"
+#include "llvm/ADT/ArrayRef.h"
 
 const uint16_t SWIFT_REFLECTION_METADATA_VERSION = 3; // superclass field
 
@@ -204,6 +205,10 @@ class FieldDescriptor {
     return const_iterator { End, End };
   }
 
+  llvm::ArrayRef<FieldRecord> getFields() const {
+    return {getFieldRecordBuffer(), NumFields};
+  }
+
   bool hasMangledTypeName() const {
     return MangledTypeName;
   }

include/swift/Runtime/Metadata.h

@@ -37,11 +37,13 @@
 #include "swift/Basic/RelativePointer.h"
 #include "swift/Demangling/Demangle.h"
 #include "swift/Demangling/ManglingMacros.h"
+#include "swift/Reflection/Records.h"
 #include "swift/Runtime/Unreachable.h"
 #include "../../../stdlib/public/SwiftShims/HeapObject.h"
 #if SWIFT_OBJC_INTEROP
 #include <objc/runtime.h>
 #endif
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 
 namespace swift {
@@ -1287,16 +1289,6 @@ struct TargetClassMetadata : public TargetHeapMetadata<Runtime> {
     auto asWords = reinterpret_cast<const void * const*>(this);
     return reinterpret_cast<const StoredPointer *>(asWords + offset);
   }
-
-  /// Get a pointer to the field type vector, if present, or null.
-  const FieldType *getFieldTypes() const {
-    assert(isTypeMetadata());
-    auto *getter = getDescription()->GetFieldTypes.get();
-    if (!getter)
-      return nullptr;
-
-    return getter(this);
-  }
 
   uint32_t getSizeInWords() const {
     assert(isTypeMetadata());
@@ -1569,15 +1561,6 @@ struct TargetStructMetadata : public TargetValueMetadata<Runtime> {
     auto asWords = reinterpret_cast<const void * const*>(this);
     return reinterpret_cast<const StoredPointer *>(asWords + offset);
   }
-
-  /// Get a pointer to the field type vector, if present, or null.
-  const FieldType *getFieldTypes() const {
-    auto *getter = getDescription()->GetFieldTypes.get();
-    if (!getter)
-      return nullptr;
-
-    return getter(this);
-  }
 
   static bool classof(const TargetMetadata<Runtime> *metadata) {
     return metadata->getKind() == MetadataKind::Struct;
@@ -2531,6 +2514,12 @@ struct TargetContextDescriptor {
   /// context is not generic.
   const TargetGenericContext<Runtime> *getGenericContext() const;
 
+  unsigned getNumGenericParams() const {
+    auto *genericContext = getGenericContext();
+    return genericContext
+              ? genericContext->getGenericContextHeader().NumParams
+              : 0;
+  }
 private:
   TargetContextDescriptor(const TargetContextDescriptor &) = delete;
   TargetContextDescriptor(TargetContextDescriptor &&) = delete;
@@ -3165,15 +3154,11 @@ class TargetClassDescriptor final
   }
 
 public:
-  /// The field names. A doubly-null-terminated list of strings, whose
-  /// length and order is consistent with that of the field offset vector.
-  RelativeDirectPointer<const char, /*nullable*/ true> FieldNames;
-
-  /// The field type vector accessor. Returns a pointer to an array of
-  /// type metadata references whose order is consistent with that of the
-  /// field offset vector.
-  RelativeDirectPointer<const FieldType *
-    (const TargetMetadata<Runtime> *)> GetFieldTypes;
+  /// Indicates if the type represented by this descriptor
+  /// supports reflection (C and Obj-C enums currently don't).
+  /// FIXME: This is temporarily left as 32-bit integer to avoid
+  ///        changing layout of context descriptor.
+  uint32_t IsReflectable;
 
   /// True if metadata records for this type have a field offset vector for
   /// its stored properties.
@@ -3275,15 +3260,11 @@ class TargetStructDescriptor final
   /// vector.
   uint32_t FieldOffsetVectorOffset;
 
-  /// The field names. A doubly-null-terminated list of strings, whose
-  /// length and order is consistent with that of the field offset vector.
-  RelativeDirectPointer<const char, /*nullable*/ true> FieldNames;
-
-  /// The field type vector accessor. Returns a pointer to an array of
-  /// type metadata references whose order is consistent with that of the
-  /// field offset vector.
-  RelativeDirectPointer<const FieldType *
-    (const TargetMetadata<Runtime> *)> GetFieldTypes;
+  /// Indicates if the type represented by this descriptor
+  /// supports reflection (C and Obj-C enums currently don't).
+  /// FIXME: This is temporarily left as 32-bit integer to avoid
+  ///        changing layout of context descriptor.
+  uint32_t IsReflectable;
 
   /// True if metadata records for this type have a field offset vector for
   /// its stored properties.
@@ -3327,17 +3308,11 @@ class TargetEnumDescriptor final
   /// The number of empty cases in the enum.
   uint32_t NumEmptyCases;
 
-  /// The names of the cases. A doubly-null-terminated list of strings,
-  /// whose length is NumNonEmptyCases + NumEmptyCases. Cases are named in
-  /// tag order, non-empty cases first, followed by empty cases.
-  RelativeDirectPointer<const char, /*nullable*/ true> CaseNames;
-
-  /// The field type vector accessor. Returns a pointer to an array of
-  /// type metadata references whose order is consistent with that of the
-  /// CaseNames. Only types for payload cases are provided.
-  RelativeDirectPointer<
-    const FieldType * (const TargetMetadata<Runtime> *)>
-    GetCaseTypes;
+  /// Indicates if the type represented by this descriptor
+  /// supports reflection (C and Obj-C enums currently don't).
+  /// FIXME: This is temporarily left as 32-bit integer to avoid
+  ///        changing layout of context descriptor.
+  uint32_t IsReflectable;
 
   uint32_t getNumPayloadCases() const {
     return NumPayloadCasesAndPayloadSizeOffset & 0x00FFFFFFU;
@@ -3760,12 +3735,22 @@ SWIFT_RUNTIME_EXPORT
 void swift_registerTypeMetadataRecords(const TypeMetadataRecord *begin,
                                        const TypeMetadataRecord *end);
 
+/// Register a block of type field records for dynamic lookup.
+SWIFT_RUNTIME_EXPORT
+void swift_registerFieldDescriptors(const reflection::FieldDescriptor **records,
+                                    size_t size);
+
 /// Return the superclass, if any.  The result is nullptr for root
 /// classes and class protocol types.
 SWIFT_CC(swift)
 SWIFT_RUNTIME_STDLIB_INTERFACE
 const Metadata *_swift_class_getSuperclass(const Metadata *theClass);
 
+SWIFT_RUNTIME_STDLIB_INTERFACE
+void swift_getFieldAt(
+    const Metadata *type, unsigned index,
+    std::function<void(llvm::StringRef name, FieldType type)> callback);
+
 } // end namespace swift
 
 #pragma clang diagnostic pop

include/swift/Runtime/RuntimeFunctions.def

@@ -1198,6 +1198,11 @@ FUNCTION(RegisterTypeMetadataRecords,
          RETURNS(VoidTy),
          ARGS(TypeMetadataRecordPtrTy, TypeMetadataRecordPtrTy),
          ATTRS(NoUnwind))
+FUNCTION(RegisterFieldDescriptors,
+         swift_registerFieldDescriptors, DefaultCC,
+         RETURNS(VoidTy),
+         ARGS(FieldDescriptorPtrPtrTy, SizeTy),
+         ATTRS(NoUnwind))
 
 // void swift_beginAccess(void *pointer, ValueBuffer *scratch, size_t flags);
 FUNCTION(BeginAccess, swift_beginAccess, C_CC,

lib/Demangling/Demangler.cpp

@@ -65,7 +65,10 @@ static bool isAnyGeneric(Node::Kind kind) {
     case Node::Kind::Class:
     case Node::Kind::Enum:
     case Node::Kind::Protocol:
+    case Node::Kind::OtherNominalType:
     case Node::Kind::TypeAlias:
+    case Node::Kind::SymbolicReference:
+    case Node::Kind::UnresolvedSymbolicReference:
       return true;
     default:
       return false;
@@ -1237,11 +1240,35 @@ NodePointer Demangler::demangleBoundGenericType() {
 NodePointer Demangler::demangleBoundGenericArgs(NodePointer Nominal,
                                     const Vector<NodePointer> &TypeLists,
                                     size_t TypeListIdx) {
-  if (!Nominal || Nominal->getNumChildren() < 2)
+  // TODO: This would be a lot easier if we represented bound generic args
+  // flatly in the demangling tree, since that's how they're mangled and also
+  // how the runtime generally wants to consume them.
+
+  if (!Nominal)
     return nullptr;
 
   if (TypeListIdx >= TypeLists.size())
     return nullptr;
+
+  // Associate a symbolic reference with all remaining generic arguments.
+  if (Nominal->getKind() == Node::Kind::SymbolicReference
+      || Nominal->getKind() == Node::Kind::UnresolvedSymbolicReference) {
+    auto remainingTypeList = createNode(Node::Kind::TypeList);
+    for (unsigned i = TypeLists.size() - 1;
+         i >= TypeListIdx && i < TypeLists.size();
+         --i) {
+      auto list = TypeLists[i];
+      for (auto child : *list) {
+        remainingTypeList->addChild(child, *this);
+      }
+    }
+    return createWithChildren(Node::Kind::BoundGenericOtherNominalType,
+                              createType(Nominal), remainingTypeList);
+  }
+
+  if (Nominal->getNumChildren() < 2)
+    return nullptr;
+
   NodePointer args = TypeLists[TypeListIdx++];
 
   // Generic arguments for the outermost type come first.
@@ -1286,6 +1313,9 @@ NodePointer Demangler::demangleBoundGenericArgs(NodePointer Nominal,
     case Node::Kind::Enum:
       kind = Node::Kind::BoundGenericEnum;
       break;
+    case Node::Kind::OtherNominalType:
+      kind = Node::Kind::BoundGenericOtherNominalType;
+      break;
     default:
       return nullptr;
   }

lib/Demangling/Remangler.cpp

@@ -470,6 +470,7 @@ void Remangler::mangleGenericArgs(Node *node, char &Separator) {
       Separator = '_';
       break;
 
+    case Node::Kind::BoundGenericOtherNominalType:
     case Node::Kind::BoundGenericStructure:
     case Node::Kind::BoundGenericEnum:
     case Node::Kind::BoundGenericClass: {
@@ -1983,11 +1984,13 @@ bool Demangle::isSpecialized(Node *node) {
     case Node::Kind::BoundGenericStructure:
     case Node::Kind::BoundGenericEnum:
     case Node::Kind::BoundGenericClass:
+    case Node::Kind::BoundGenericOtherNominalType:
       return true;
 
     case Node::Kind::Structure:
     case Node::Kind::Enum:
     case Node::Kind::Class:
+    case Node::Kind::OtherNominalType:
       return isSpecialized(node->getChild(0));
 
     case Node::Kind::Extension:
@@ -2002,7 +2005,8 @@ NodePointer Demangle::getUnspecialized(Node *node, NodeFactory &Factory) {
   switch (node->getKind()) {
     case Node::Kind::Structure:
     case Node::Kind::Enum:
-    case Node::Kind::Class: {
+    case Node::Kind::Class:
+    case Node::Kind::OtherNominalType: {
       NodePointer result = Factory.createNode(node->getKind());
       NodePointer parentOrModule = node->getChild(0);
       if (isSpecialized(parentOrModule))
@@ -2015,7 +2019,8 @@ NodePointer Demangle::getUnspecialized(Node *node, NodeFactory &Factory) {
 
     case Node::Kind::BoundGenericStructure:
     case Node::Kind::BoundGenericEnum:
-    case Node::Kind::BoundGenericClass: {
+    case Node::Kind::BoundGenericClass:
+    case Node::Kind::BoundGenericOtherNominalType: {
       NodePointer unboundType = node->getChild(0);
       assert(unboundType->getKind() == Node::Kind::Type);
       NodePointer nominalType = unboundType->getChild(0);

lib/Demangling/TypeDecoder.cpp

@@ -24,6 +24,7 @@ NodePointer Demangle::stripGenericArgsFromContextNode(const NodePointer &node,
   case Demangle::Node::Kind::BoundGenericClass:
   case Demangle::Node::Kind::BoundGenericEnum:
   case Demangle::Node::Kind::BoundGenericStructure:
+  case Demangle::Node::Kind::BoundGenericOtherNominalType:
     // Bound generic types have a 'Type' node under them, whose child is
     // the non-generic reference. If we don't see that structure, do nothing.
     if (node->getNumChildren() < 2 ||
@@ -37,7 +38,8 @@ NodePointer Demangle::stripGenericArgsFromContextNode(const NodePointer &node,
 
   case Demangle::Node::Kind::Class:
   case Demangle::Node::Kind::Enum:
-  case Demangle::Node::Kind::Structure: {
+  case Demangle::Node::Kind::Structure:
+  case Demangle::Node::Kind::OtherNominalType: {
     if (node->getNumChildren() < 2)
       return node;
 

lib/IDE/TypeReconstruction.cpp

@@ -2105,6 +2105,7 @@ static void VisitNode(
   case Demangle::Node::Kind::BoundGenericClass:
   case Demangle::Node::Kind::BoundGenericStructure:
   case Demangle::Node::Kind::BoundGenericEnum:
+  case Demangle::Node::Kind::BoundGenericOtherNominalType:
     VisitNodeBoundGeneric(ast, node, result);
     break;
 
@@ -2115,6 +2116,7 @@ static void VisitNode(
   case Demangle::Node::Kind::Structure:
   case Demangle::Node::Kind::Class:
   case Demangle::Node::Kind::Enum:
+  case Demangle::Node::Kind::OtherNominalType:
   case Demangle::Node::Kind::Protocol:
     VisitNodeNominal(ast, node, result);
     break;