[Runtime] Remove old-style mirrors in ReflectionLegacy.swift.

include/swift/Demangling/Demangle.h

@@ -24,6 +24,7 @@
 #include <cassert>
 #include <cstdint>
 #include "llvm/ADT/StringRef.h"
+#include "swift/Runtime/Config.h"
 
 namespace llvm {
   class raw_ostream;
@@ -553,4 +554,30 @@ llvm::StringRef makeSymbolicMangledNameStringRef(const char *base);
 } // end namespace Demangle
 } // end namespace swift
 
+// NB: This function is not used directly in the Swift codebase, but is
+// exported for Xcode support and is used by the sanitizers. Please coordinate
+// before changing.
+//
+/// Demangles a Swift symbol name.
+///
+/// \param mangledName is the symbol name that needs to be demangled.
+/// \param mangledNameLength is the length of the string that should be
+/// demangled.
+/// \param outputBuffer is the user provided buffer where the demangled name
+/// will be placed. If nullptr, a new buffer will be malloced. In that case,
+/// the user of this API is responsible for freeing the returned buffer.
+/// \param outputBufferSize is the size of the output buffer. If the demangled
+/// name does not fit into the outputBuffer, the output will be truncated and
+/// the size will be updated, indicating how large the buffer should be.
+/// \param flags can be used to select the demangling style. TODO: We should
+//// define what these will be.
+/// \returns the demangled name. Returns nullptr if the input String is not a
+/// Swift mangled name.
+SWIFT_RUNTIME_EXPORT
+char *swift_demangle(const char *mangledName,
+                     size_t mangledNameLength,
+                     char *outputBuffer,
+                     size_t *outputBufferSize,
+                     uint32_t flags);
+
 #endif // SWIFT_DEMANGLING_DEMANGLE_H

stdlib/public/core/CMakeLists.txt

@@ -89,7 +89,6 @@ set(SWIFTLIB_ESSENTIAL
   MutableCollection.swift
   NewtypeWrapper.swift.gyb
   NormalizedCodeUnitIterator.swift
-  ObjCMirrors.swift
   ObjectIdentifier.swift
   Optional.swift
   OptionSet.swift
@@ -101,7 +100,7 @@ set(SWIFTLIB_ESSENTIAL
   RandomAccessCollection.swift
   Range.swift
   RangeReplaceableCollection.swift
-  ReflectionLegacy.swift
+  ReflectionMirror.swift
   Repeat.swift
   REPL.swift
   Reverse.swift

stdlib/public/core/GroupInfo.json

@@ -123,9 +123,8 @@
     "Dump.swift",
     "Mirror.swift",
     "Mirrors.swift",
-    "ObjCMirrors.swift",
-    "ObjectIdentifier.swift",
-    "ReflectionLegacy.swift"
+    "ReflectionMirror.swift",
+    "ObjectIdentifier.swift"
   ],
   "Math": [
     "SetAlgebra.swift",

stdlib/public/core/Mirror.swift

@@ -121,9 +121,7 @@ public struct Mirror {
     if case let customized as CustomReflectable = subject {
       self = customized.customMirror
     } else {
-      self = Mirror(
-        legacy: _reflect(subject),
-        subjectType: type(of: subject))
+      self = Mirror(internalReflecting: subject)
     }
   }
 
@@ -164,29 +162,6 @@ public struct Mirror {
   @_versioned // FIXME(sil-serialize-all)
   internal static func _noSuperclassMirror() -> Mirror? { return nil }
 
-  /// Returns the legacy mirror representing the part of `subject`
-  /// corresponding to the superclass of `staticSubclass`.
-  @_inlineable // FIXME(sil-serialize-all)
-  @_versioned // FIXME(sil-serialize-all)
-  internal static func _legacyMirror(
-    _ subject: AnyObject, asClass targetSuperclass: AnyClass) -> _Mirror? {
-
-    // get a legacy mirror and the most-derived type
-    var cls: AnyClass = type(of: subject)
-    var clsMirror = _reflect(subject)
-
-    // Walk up the chain of mirrors/classes until we find staticSubclass
-    while let superclass: AnyClass = _getSuperclass(cls) {
-      guard let superclassMirror = clsMirror._superMirror() else { break }
-
-      if superclass == targetSuperclass { return superclassMirror }
-
-      clsMirror = superclassMirror
-      cls = superclass
-    }
-    return nil
-  }
-
   @_semantics("optimize.sil.specialize.generic.never")
   @inline(never)
   @_inlineable // FIXME(sil-serialize-all)
@@ -201,14 +176,19 @@ public struct Mirror {
       switch ancestorRepresentation {
       case .generated:
         return {
-          self._legacyMirror(_unsafeDowncastToAnyObject(fromAny: subject), asClass: superclass).map {
-            Mirror(legacy: $0, subjectType: superclass)
-          }
+          Mirror(internalReflecting: subject, subjectType: superclass)
         }
       case .customized(let makeAncestor):
         return {
-          Mirror(_unsafeDowncastToAnyObject(fromAny: subject), subjectClass: superclass,
-                 ancestor: makeAncestor())
+          let ancestor = makeAncestor()
+          if superclass == ancestor.subjectType
+            || ancestor._defaultDescendantRepresentation == .suppressed {
+            return ancestor
+          } else {
+            return Mirror(internalReflecting: subject,
+                          subjectType: superclass,
+                          customAncestor: ancestor)
+          }
         }
       case .suppressed:
         break
@@ -503,161 +483,6 @@ extension Mirror {
   }
 }
 
-//===--- Legacy _Mirror Support -------------------------------------------===//
-extension Mirror.DisplayStyle {
-  /// Construct from a legacy `_MirrorDisposition`
-  @_inlineable // FIXME(sil-serialize-all)
-  @_versioned // FIXME(sil-serialize-all)
-  internal init?(legacy: _MirrorDisposition) {
-    switch legacy {
-    case .`struct`: self = .`struct`
-    case .`class`: self = .`class`
-    case .`enum`: self = .`enum`
-    case .tuple: self = .tuple
-    case .aggregate: return nil
-    case .indexContainer: self = .collection
-    case .keyContainer: self = .dictionary
-    case .membershipContainer: self = .`set`
-    case .container: preconditionFailure("unused!")
-    case .optional: self = .optional
-    case .objCObject: self = .`class`
-    }
-  }
-}
-
-@_inlineable // FIXME(sil-serialize-all)
-@_versioned // FIXME(sil-serialize-all)
-internal func _isClassSuperMirror(_ t: Any.Type) -> Bool {
-#if  _runtime(_ObjC)
-  return t == _ClassSuperMirror.self || t == _ObjCSuperMirror.self
-#else
-  return t == _ClassSuperMirror.self
-#endif
-}
-
-extension _Mirror {
-  @_inlineable // FIXME(sil-serialize-all)
-  @_versioned // FIXME(sil-serialize-all)
-  internal func _superMirror() -> _Mirror? {
-    if self.count > 0 {
-      let childMirror = self[0].1
-      if _isClassSuperMirror(type(of: childMirror)) {
-        return childMirror
-      }
-    }
-    return nil
-  }
-}
-
-/// When constructed using the legacy reflection infrastructure, the
-/// resulting `Mirror`'s `children` collection will always be
-/// upgradable to `AnyRandomAccessCollection` even if it doesn't
-/// exhibit appropriate performance. To avoid this pitfall, convert
-/// mirrors to use the new style, which only present forward
-/// traversal in general.
-internal extension Mirror {
-  /// An adapter that represents a legacy `_Mirror`'s children as
-  /// a `Collection` with integer `Index`.  Note that the performance
-  /// characteristics of the underlying `_Mirror` may not be
-  /// appropriate for random access!  To avoid this pitfall, convert
-  /// mirrors to use the new style, which only present forward
-  /// traversal in general.
-  @_fixed_layout // FIXME(sil-serialize-all)
-  @_versioned // FIXME(sil-serialize-all)
-  internal struct LegacyChildren : RandomAccessCollection {
-    internal typealias Indices = Range<Int>
-
-    @_inlineable // FIXME(sil-serialize-all)
-    @_versioned // FIXME(sil-serialize-all)
-    internal init(_ oldMirror: _Mirror) {
-      self._oldMirror = oldMirror
-    }
-
-    @_inlineable // FIXME(sil-serialize-all)
-    @_versioned // FIXME(sil-serialize-all)
-    internal var startIndex: Int {
-      return _oldMirror._superMirror() == nil ? 0 : 1
-    }
-
-    @_inlineable // FIXME(sil-serialize-all)
-    @_versioned // FIXME(sil-serialize-all)
-    internal var endIndex: Int { return _oldMirror.count }
-
-    @_inlineable // FIXME(sil-serialize-all)
-    @_versioned // FIXME(sil-serialize-all)
-    internal subscript(position: Int) -> Child {
-      let (label, childMirror) = _oldMirror[position]
-      return (label: label, value: childMirror.value)
-    }
-
-    @_versioned // FIXME(sil-serialize-all)
-    internal let _oldMirror: _Mirror
-  }
-
-  /// Initialize for a view of `subject` as `subjectClass`.
-  ///
-  /// - parameter ancestor: A Mirror for a (non-strict) ancestor of
-  ///   `subjectClass`, to be injected into the resulting hierarchy.
-  ///
-  /// - parameter legacy: Either `nil`, or a legacy mirror for `subject`
-  ///    as `subjectClass`.
-  @_inlineable // FIXME(sil-serialize-all)
-  @_versioned // FIXME(sil-serialize-all)
-  internal init(
-    _ subject: AnyObject,
-    subjectClass: AnyClass,
-    ancestor: Mirror,
-    legacy legacyMirror: _Mirror? = nil
-  ) {
-    if ancestor.subjectType == subjectClass
-      || ancestor._defaultDescendantRepresentation == .suppressed {
-      self = ancestor
-    }
-    else {
-      let legacyMirror = legacyMirror ?? Mirror._legacyMirror(
-        subject, asClass: subjectClass)!
-
-      self = Mirror(
-        legacy: legacyMirror,
-        subjectType: subjectClass,
-        makeSuperclassMirror: {
-          _getSuperclass(subjectClass).map {
-            Mirror(
-              subject,
-              subjectClass: $0,
-              ancestor: ancestor,
-              legacy: legacyMirror._superMirror())
-          }
-        })
-    }
-  }
-
-  @_inlineable // FIXME(sil-serialize-all)
-  @_versioned // FIXME(sil-serialize-all)
-  internal init(
-    legacy legacyMirror: _Mirror,
-    subjectType: Any.Type,
-    makeSuperclassMirror: (() -> Mirror?)? = nil
-  ) {
-    if let makeSuperclassMirror = makeSuperclassMirror {
-      self._makeSuperclassMirror = makeSuperclassMirror
-    }
-    else if let subjectSuperclass = _getSuperclass(subjectType) {
-      self._makeSuperclassMirror = {
-        legacyMirror._superMirror().map {
-          Mirror(legacy: $0, subjectType: subjectSuperclass) }
-      }
-    }
-    else {
-      self._makeSuperclassMirror = Mirror._noSuperclassMirror
-    }
-    self.subjectType = subjectType
-    self.children = Children(LegacyChildren(legacyMirror))
-    self.displayStyle = DisplayStyle(legacy: legacyMirror.disposition)
-    self._defaultDescendantRepresentation = .generated
-  }
-}
-
 //===--- QuickLooks -------------------------------------------------------===//
 
 /// The sum of types that can be used as a Quick Look representation.
@@ -769,7 +594,7 @@ extension PlaygroundQuickLook {
       self = customized._defaultCustomPlaygroundQuickLook
     }
     else {
-      if let q = _reflect(subject).quickLookObject {
+      if let q = Mirror.quickLookObject(subject) {
         self = q
       }
       else {