Merge pull request swiftlang#63535 from Azoy/reflection-fixes

[Reflection] Some bug fixes and other improvements

Author: Azoy

stdlib/public/Reflection/Package.swift

@@ -29,17 +29,19 @@ public struct Case {
 
   @inlinable
   public init?(from instance: Any) {
-    guard Type(instance).isEnum else {
+    let instanceTy = type(of: instance)
+
+    guard Type(instanceTy).isEnum else {
       return nil
     }
 
     var container = unsafeBitCast(instance, to: AnyExistentialContainer.self)
 
     let tag = container.projectValue {
-      Metadata(type(of: instance)).enum.enumVWT.getEnumTag($0)
+      Metadata(instanceTy).enum.enumVWT.getEnumTag($0)
     }
 
-    self.parent = Metadata(type(of: instance)).enum
+    self.parent = Metadata(instanceTy).enum
     self.tag = Int(truncatingIfNeeded: tag)
   }
 }

stdlib/public/Reflection/README.md

@@ -42,8 +42,7 @@ extension Field {
   @inlinable
   public var name: String {
     guard parent.kind != .tuple else {
-      //return TupleMetadata(parent.ptr).elements[index].
-      return "hello"
+      return parent.tuple.elements[index].label
     }
 
     return parent.type.descriptor.fields[index].name

stdlib/public/Reflection/Sources/Reflection/Case.swift

@@ -51,7 +51,7 @@ extension GenericArguments: RandomAccessCollection {
 
     let start = argumentPointer.unsafelyUnwrapped
     let address = start + position * MemoryLayout<Type>.size
-    return address.loadUnaligned(as: Type.self)
+    return address.unprotectedLoad(as: Type.self)
   }
 }
 

stdlib/public/Reflection/Sources/Reflection/Field.swift

@@ -96,7 +96,7 @@ extension Case {
     var value = pair.buffer
 
     if isIndirect {
-      let owner = value.loadUnaligned(as: HeapObject.self)
+      let owner = value.unprotectedLoad(as: HeapObject.self)
       value = swift_projectBox(owner)
     }
 

stdlib/public/Reflection/Sources/Reflection/GenericArguments.swift

@@ -80,7 +80,7 @@ extension ClassDescriptor {
     // 'TargetStoredClassMetadataBounds', by the time we access this it will
     // have already been initialized way before for us. Thus, it is safe to
     // access this value non-atomically.
-    return storedBounds.load(as: Int.self)
+    return storedBounds.unprotectedLoad(as: Int.self)
   }
 
   @inlinable

stdlib/public/Reflection/Sources/Reflection/KeyPath.swift

@@ -119,7 +119,7 @@ extension GenericSignature.RequirementDescriptor {
   @available(SwiftStdlib 5.9, *)
   @inlinable
   public var layoutKind: GenericSignature.LayoutKind {
-    address(for: \.requirement).loadUnaligned(
+    address(for: \.requirement).unprotectedLoad(
       as: GenericSignature.LayoutKind.self
     )
   }
@@ -140,7 +140,7 @@ extension GenericSignature.RequirementDescriptor {
   ) -> Any.Type? {
     _getTypeByMangledNameInContext(
       UnsafePointer(parameter.ptr._rawValue),
-      UInt(parameter.length),
+      UInt(truncatingIfNeeded: parameter.length),
       genericContext: context.ptr,
       genericArguments: argPtr
     )
@@ -269,7 +269,7 @@ extension GenericSignature.RequirementDescriptor {
 func getGenericSignature(at address: UnsafeRawPointer) -> GenericSignature {
   var address = address
 
-  let header = address.loadUnaligned(as: GenericSignature.Header.self)
+  let header = address.unprotectedLoad(as: GenericSignature.Header.self)
   address += MemoryLayout<GenericSignature.Header>.size
 
   let parameters = BufferView<GenericSignature.ParameterDescriptor>(

stdlib/public/Reflection/Sources/_Runtime/ContextDescriptor/ClassDescriptor.swift

@@ -67,15 +67,14 @@ extension AnyExistentialContainer {
       }
     }
 
-    let alignMask = UInt(metadata.vwt.flags.alignmentMask)
+    let alignMask = UInt(truncatingIfNeeded:metadata.vwt.flags.alignmentMask)
     let heapObjSize = UInt(MemoryLayout<Int>.size * 2)
     let byteOffset = (heapObjSize + alignMask) & ~alignMask
 
     return try withUnsafeMutablePointer(to: &self) {
-      let raw = UnsafeMutableRawPointer($0)
-      let heap = raw.loadUnaligned(as: UnsafeMutableRawPointer.self)
+      let heap = $0.raw.unprotectedLoad(as: UnsafeMutableRawPointer.self)
 
-      return try body(heap + Int(byteOffset))
+      return try body(heap + Int(truncatingIfNeeded: byteOffset))
     }
   }
 }

stdlib/public/Reflection/Sources/_Runtime/ContextDescriptor/GenericSignature.swift

@@ -85,7 +85,7 @@ extension TupleMetadata.Elements.Element {
     // string
     address -= MemoryLayout<Int>.size
 
-    guard let cString = address.loadUnaligned(
+    guard let cString = address.unprotectedLoad(
       as: UnsafePointer<CChar>?.self
     ) else {
       return ""