Imported Upstream version 2.0.0.11992upstream/2.0.0.11992

12 files changed, 35 insertions, 780 deletions

diff --git a/src/mscorlib/src/System/Collections/ArrayList.cs b/src/mscorlib/src/System/Collections/ArrayList.cs
deleted file mode 100644
index cee7be726a..0000000000
--- a/src/mscorlib/src/System/Collections/ArrayList.cs
+++ /dev/null
@@ -1,626 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-/*============================================================
-**
-** 
-** 
-**
-**
-** Purpose: Implements a dynamically sized List as an array,
-**          and provides many convenience methods for treating
-**          an array as an IList.
-**
-** 
-===========================================================*/
-
-using System;
-using System.Runtime;
-using System.Security;
-using System.Diagnostics;
-using System.Runtime.CompilerServices;
-using System.Runtime.Serialization;
-using System.Diagnostics.CodeAnalysis;
-using System.Diagnostics.Contracts;
-
-namespace System.Collections
-{
-    // Implements a variable-size List that uses an array of objects to store the
-    // elements. A ArrayList has a capacity, which is the allocated length
-    // of the internal array. As elements are added to a ArrayList, the capacity
-    // of the ArrayList is automatically increased as required by reallocating the
-    // internal array.
-    // 
-    [FriendAccessAllowed]
-    [DebuggerTypeProxy(typeof(System.Collections.ArrayList.ArrayListDebugView))]
-    [DebuggerDisplay("Count = {Count}")]
-    [Serializable]
-    internal class ArrayList : IList, ICloneable
-    {
-        private Object[] _items;
-        [ContractPublicPropertyName("Count")]
-        private int _size;
-        private int _version;
-        [NonSerialized]
-        private Object _syncRoot;
-
-        private const int _defaultCapacity = 4;
-        private static readonly Object[] emptyArray = Array.Empty<Object>();
-
-        // Constructs a ArrayList. The list is initially empty and has a capacity
-        // of zero. Upon adding the first element to the list the capacity is
-        // increased to _defaultCapacity, and then increased in multiples of two as required.
-        public ArrayList()
-        {
-            _items = emptyArray;
-        }
-
-        // Constructs a ArrayList with a given initial capacity. The list is
-        // initially empty, but will have room for the given number of elements
-        // before any reallocations are required.
-        // 
-        public ArrayList(int capacity)
-        {
-            if (capacity < 0) throw new ArgumentOutOfRangeException(nameof(capacity), SR.Format(SR.ArgumentOutOfRange_MustBeNonNegNum, nameof(capacity)));
-            Contract.EndContractBlock();
-
-            if (capacity == 0)
-                _items = emptyArray;
-            else
-                _items = new Object[capacity];
-        }
-
-        // Constructs a ArrayList, copying the contents of the given collection. The
-        // size and capacity of the new list will both be equal to the size of the
-        // given collection.
-        // 
-        public ArrayList(ICollection c)
-        {
-            if (c == null)
-                throw new ArgumentNullException(nameof(c), SR.ArgumentNull_Collection);
-            Contract.EndContractBlock();
-
-            int count = c.Count;
-            if (count == 0)
-            {
-                _items = emptyArray;
-            }
-            else
-            {
-                _items = new Object[count];
-                AddRange(c);
-            }
-        }
-
-        // Gets and sets the capacity of this list.  The capacity is the size of
-        // the internal array used to hold items.  When set, the internal 
-        // array of the list is reallocated to the given capacity.
-        // 
-        public virtual int Capacity
-        {
-            get
-            {
-                Contract.Ensures(Contract.Result<int>() >= Count);
-                return _items.Length;
-            }
-            set
-            {
-                if (value < _size)
-                {
-                    throw new ArgumentOutOfRangeException(nameof(value), SR.ArgumentOutOfRange_SmallCapacity);
-                }
-                Contract.Ensures(Capacity >= 0);
-                Contract.EndContractBlock();
-                // We don't want to update the version number when we change the capacity.
-                // Some existing applications have dependency on this.
-                if (value != _items.Length)
-                {
-                    if (value > 0)
-                    {
-                        Object[] newItems = new Object[value];
-                        if (_size > 0)
-                        {
-                            Array.Copy(_items, 0, newItems, 0, _size);
-                        }
-                        _items = newItems;
-                    }
-                    else
-                    {
-                        _items = new Object[_defaultCapacity];
-                    }
-                }
-            }
-        }
-
-        // Read-only property describing how many elements are in the List.
-        public virtual int Count
-        {
-            get
-            {
-                Contract.Ensures(Contract.Result<int>() >= 0);
-                return _size;
-            }
-        }
-
-        public virtual bool IsFixedSize
-        {
-            get { return false; }
-        }
-
-
-        // Is this ArrayList read-only?
-        public virtual bool IsReadOnly
-        {
-            get { return false; }
-        }
-
-        // Is this ArrayList synchronized (thread-safe)?
-        public virtual bool IsSynchronized
-        {
-            get { return false; }
-        }
-
-        // Synchronization root for this object.
-        public virtual Object SyncRoot
-        {
-            get
-            {
-                if (_syncRoot == null)
-                {
-                    System.Threading.Interlocked.CompareExchange<Object>(ref _syncRoot, new Object(), null);
-                }
-                return _syncRoot;
-            }
-        }
-
-        // Sets or Gets the element at the given index.
-        // 
-        public virtual Object this[int index]
-        {
-            get
-            {
-                if (index < 0 || index >= _size) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_Index);
-                Contract.EndContractBlock();
-                return _items[index];
-            }
-            set
-            {
-                if (index < 0 || index >= _size) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_Index);
-                Contract.EndContractBlock();
-                _items[index] = value;
-                _version++;
-            }
-        }
-
-        // Adds the given object to the end of this list. The size of the list is
-        // increased by one. If required, the capacity of the list is doubled
-        // before adding the new element.
-        //
-        public virtual int Add(Object value)
-        {
-            Contract.Ensures(Contract.Result<int>() >= 0);
-            if (_size == _items.Length) EnsureCapacity(_size + 1);
-            _items[_size] = value;
-            _version++;
-            return _size++;
-        }
-
-        // Adds the elements of the given collection to the end of this list. If
-        // required, the capacity of the list is increased to twice the previous
-        // capacity or the new size, whichever is larger.
-        //
-        public virtual void AddRange(ICollection c)
-        {
-            InsertRange(_size, c);
-        }
-
-
-        // Clears the contents of ArrayList.
-        public virtual void Clear()
-        {
-            if (_size > 0)
-            {
-                Array.Clear(_items, 0, _size); // Don't need to doc this but we clear the elements so that the gc can reclaim the references.
-                _size = 0;
-            }
-            _version++;
-        }
-
-        // Clones this ArrayList, doing a shallow copy.  (A copy is made of all
-        // Object references in the ArrayList, but the Objects pointed to 
-        // are not cloned).
-        public virtual Object Clone()
-        {
-            Contract.Ensures(Contract.Result<Object>() != null);
-            ArrayList la = new ArrayList(_size);
-            la._size = _size;
-            la._version = _version;
-            Array.Copy(_items, 0, la._items, 0, _size);
-            return la;
-        }
-
-
-        // Contains returns true if the specified element is in the ArrayList.
-        // It does a linear, O(n) search.  Equality is determined by calling
-        // item.Equals().
-        //
-        public virtual bool Contains(Object item)
-        {
-            if (item == null)
-            {
-                for (int i = 0; i < _size; i++)
-                    if (_items[i] == null)
-                        return true;
-                return false;
-            }
-            else
-            {
-                for (int i = 0; i < _size; i++)
-                    if ((_items[i] != null) && (_items[i].Equals(item)))
-                        return true;
-                return false;
-            }
-        }
-
-        // Copies this ArrayList into array, which must be of a 
-        // compatible array type.  
-        //
-        public virtual void CopyTo(Array array, int arrayIndex)
-        {
-            if ((array != null) && (array.Rank != 1))
-                throw new ArgumentException(SR.Arg_RankMultiDimNotSupported);
-            Contract.EndContractBlock();
-            // Delegate rest of error checking to Array.Copy.
-            Array.Copy(_items, 0, array, arrayIndex, _size);
-        }
-
-        // Ensures that the capacity of this list is at least the given minimum
-        // value. If the currect capacity of the list is less than min, the
-        // capacity is increased to twice the current capacity or to min,
-        // whichever is larger.
-        private void EnsureCapacity(int min)
-        {
-            if (_items.Length < min)
-            {
-                int newCapacity = _items.Length == 0 ? _defaultCapacity : _items.Length * 2;
-                // Allow the list to grow to maximum possible capacity (~2G elements) before encountering overflow.
-                // Note that this check works even when _items.Length overflowed thanks to the (uint) cast
-                if ((uint)newCapacity > Array.MaxArrayLength) newCapacity = Array.MaxArrayLength;
-                if (newCapacity < min) newCapacity = min;
-                Capacity = newCapacity;
-            }
-        }
-
-        // Returns an enumerator for this list with the given
-        // permission for removal of elements. If modifications made to the list 
-        // while an enumeration is in progress, the MoveNext and 
-        // GetObject methods of the enumerator will throw an exception.
-        //
-        public virtual IEnumerator GetEnumerator()
-        {
-            Contract.Ensures(Contract.Result<IEnumerator>() != null);
-            return new ArrayListEnumeratorSimple(this);
-        }
-
-        // Returns the index of the first occurrence of a given value in a range of
-        // this list. The list is searched forwards from beginning to end.
-        // The elements of the list are compared to the given value using the
-        // Object.Equals method.
-        // 
-        // This method uses the Array.IndexOf method to perform the
-        // search.
-        // 
-        public virtual int IndexOf(Object value)
-        {
-            Contract.Ensures(Contract.Result<int>() < Count);
-            return Array.IndexOf((Array)_items, value, 0, _size);
-        }
-
-        // Inserts an element into this list at a given index. The size of the list
-        // is increased by one. If required, the capacity of the list is doubled
-        // before inserting the new element.
-        // 
-        public virtual void Insert(int index, Object value)
-        {
-            // Note that insertions at the end are legal.
-            if (index < 0 || index > _size) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_ArrayListInsert);
-            //Contract.Ensures(Count == Contract.OldValue(Count) + 1);
-            Contract.EndContractBlock();
-
-            if (_size == _items.Length) EnsureCapacity(_size + 1);
-            if (index < _size)
-            {
-                Array.Copy(_items, index, _items, index + 1, _size - index);
-            }
-            _items[index] = value;
-            _size++;
-            _version++;
-        }
-
-        // Inserts the elements of the given collection at a given index. If
-        // required, the capacity of the list is increased to twice the previous
-        // capacity or the new size, whichever is larger.  Ranges may be added
-        // to the end of the list by setting index to the ArrayList's size.
-        //
-        public virtual void InsertRange(int index, ICollection c)
-        {
-            if (c == null)
-                throw new ArgumentNullException(nameof(c), SR.ArgumentNull_Collection);
-            if (index < 0 || index > _size) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_Index);
-            //Contract.Ensures(Count == Contract.OldValue(Count) + c.Count);
-            Contract.EndContractBlock();
-
-            int count = c.Count;
-            if (count > 0)
-            {
-                EnsureCapacity(_size + count);
-                // shift existing items
-                if (index < _size)
-                {
-                    Array.Copy(_items, index, _items, index + count, _size - index);
-                }
-
-                Object[] itemsToInsert = new Object[count];
-                c.CopyTo(itemsToInsert, 0);
-                itemsToInsert.CopyTo(_items, index);
-                _size += count;
-                _version++;
-            }
-        }
-
-        // Returns a read-only IList wrapper for the given IList.
-        //
-        [FriendAccessAllowed]
-        public static IList ReadOnly(IList list)
-        {
-            if (list == null)
-                throw new ArgumentNullException(nameof(list));
-            Contract.Ensures(Contract.Result<IList>() != null);
-            Contract.EndContractBlock();
-            return new ReadOnlyList(list);
-        }
-
-        // Removes the element at the given index. The size of the list is
-        // decreased by one.
-        // 
-        public virtual void Remove(Object obj)
-        {
-            Contract.Ensures(Count >= 0);
-
-            int index = IndexOf(obj);
-            BCLDebug.Correctness(index >= 0 || !(obj is Int32), "You passed an Int32 to Remove that wasn't in the ArrayList." + Environment.NewLine + "Did you mean RemoveAt?  int: " + obj + "  Count: " + Count);
-            if (index >= 0)
-                RemoveAt(index);
-        }
-
-        // Removes the element at the given index. The size of the list is
-        // decreased by one.
-        // 
-        public virtual void RemoveAt(int index)
-        {
-            if (index < 0 || index >= _size) throw new ArgumentOutOfRangeException(nameof(index), SR.ArgumentOutOfRange_Index);
-            Contract.Ensures(Count >= 0);
-            //Contract.Ensures(Count == Contract.OldValue(Count) - 1);
-            Contract.EndContractBlock();
-
-            _size--;
-            if (index < _size)
-            {
-                Array.Copy(_items, index + 1, _items, index, _size - index);
-            }
-            _items[_size] = null;
-            _version++;
-        }
-
-        // ToArray returns a new array of a particular type containing the contents 
-        // of the ArrayList.  This requires copying the ArrayList and potentially
-        // downcasting all elements.  This copy may fail and is an O(n) operation.
-        // Internally, this implementation calls Array.Copy.
-        //
-        public virtual Array ToArray(Type type)
-        {
-            if (type == null)
-                throw new ArgumentNullException(nameof(type));
-            Contract.Ensures(Contract.Result<Array>() != null);
-            Contract.EndContractBlock();
-            Array array = Array.UnsafeCreateInstance(type, _size);
-            Array.Copy(_items, 0, array, 0, _size);
-            return array;
-        }
-
-        [Serializable]
-        private class ReadOnlyList : IList
-        {
-            private IList _list;
-
-            internal ReadOnlyList(IList l)
-            {
-                _list = l;
-            }
-
-            public virtual int Count
-            {
-                get { return _list.Count; }
-            }
-
-            public virtual bool IsReadOnly
-            {
-                get { return true; }
-            }
-
-            public virtual bool IsFixedSize
-            {
-                get { return true; }
-            }
-
-            public virtual bool IsSynchronized
-            {
-                get { return _list.IsSynchronized; }
-            }
-
-            public virtual Object this[int index]
-            {
-                get
-                {
-                    return _list[index];
-                }
-                set
-                {
-                    throw new NotSupportedException(SR.NotSupported_ReadOnlyCollection);
-                }
-            }
-
-            public virtual Object SyncRoot
-            {
-                get { return _list.SyncRoot; }
-            }
-
-            public virtual int Add(Object obj)
-            {
-                throw new NotSupportedException(SR.NotSupported_ReadOnlyCollection);
-            }
-
-            public virtual void Clear()
-            {
-                throw new NotSupportedException(SR.NotSupported_ReadOnlyCollection);
-            }
-
-            public virtual bool Contains(Object obj)
-            {
-                return _list.Contains(obj);
-            }
-
-            public virtual void CopyTo(Array array, int index)
-            {
-                _list.CopyTo(array, index);
-            }
-
-            public virtual IEnumerator GetEnumerator()
-            {
-                return _list.GetEnumerator();
-            }
-
-            public virtual int IndexOf(Object value)
-            {
-                return _list.IndexOf(value);
-            }
-
-            public virtual void Insert(int index, Object obj)
-            {
-                throw new NotSupportedException(SR.NotSupported_ReadOnlyCollection);
-            }
-
-            public virtual void Remove(Object value)
-            {
-                throw new NotSupportedException(SR.NotSupported_ReadOnlyCollection);
-            }
-
-            public virtual void RemoveAt(int index)
-            {
-                throw new NotSupportedException(SR.NotSupported_ReadOnlyCollection);
-            }
-        }
-
-        [Serializable]
-        private sealed class ArrayListEnumeratorSimple : IEnumerator, ICloneable
-        {
-            private ArrayList list;
-            private int index;
-            private int version;
-            private Object currentElement;
-            [NonSerialized]
-            private bool isArrayList;
-            // this object is used to indicate enumeration has not started or has terminated
-            private static Object dummyObject = new Object();
-
-            internal ArrayListEnumeratorSimple(ArrayList list)
-            {
-                this.list = list;
-                index = -1;
-                version = list._version;
-                isArrayList = (list.GetType() == typeof(ArrayList));
-                currentElement = dummyObject;
-            }
-
-            public Object Clone()
-            {
-                return MemberwiseClone();
-            }
-
-            public bool MoveNext()
-            {
-                if (version != list._version)
-                {
-                    throw new InvalidOperationException(SR.GetResourceString(ResId.InvalidOperation_EnumFailedVersion));
-                }
-
-                if (isArrayList)
-                {  // avoid calling virtual methods if we are operating on ArrayList to improve performance
-                    if (index < list._size - 1)
-                    {
-                        currentElement = list._items[++index];
-                        return true;
-                    }
-                    else
-                    {
-                        currentElement = dummyObject;
-                        index = list._size;
-                        return false;
-                    }
-                }
-                else
-                {
-                    if (index < list.Count - 1)
-                    {
-                        currentElement = list[++index];
-                        return true;
-                    }
-                    else
-                    {
-                        index = list.Count;
-                        currentElement = dummyObject;
-                        return false;
-                    }
-                }
-            }
-
-            public Object Current
-            {
-                get
-                {
-                    object temp = currentElement;
-                    if (dummyObject == temp)
-                    { // check if enumeration has not started or has terminated
-                        if (index == -1)
-                        {
-                            throw new InvalidOperationException(SR.GetResourceString(ResId.InvalidOperation_EnumNotStarted));
-                        }
-                        else
-                        {
-                            throw new InvalidOperationException(SR.GetResourceString(ResId.InvalidOperation_EnumEnded));
-                        }
-                    }
-
-                    return temp;
-                }
-            }
-
-            public void Reset()
-            {
-                if (version != list._version)
-                {
-                    throw new InvalidOperationException(SR.GetResourceString(ResId.InvalidOperation_EnumFailedVersion));
-                }
-
-                currentElement = dummyObject;
-                index = -1;
-            }
-        }
-
-        internal class ArrayListDebugView
-        {
-            private ArrayList arrayList;
-        }
-    }
-}
diff --git a/src/mscorlib/src/System/Collections/Comparer.cs b/src/mscorlib/src/System/Collections/Comparer.cs
index 7f4f9f0a07..76e19e77f1 100644
--- a/src/mscorlib/src/System/Collections/Comparer.cs
+++ b/src/mscorlib/src/System/Collections/Comparer.cs
@@ -20,7 +20,6 @@ using System.Diagnostics.Contracts;
 
 namespace System.Collections
 {
-    [Serializable]
     internal sealed class Comparer : IComparer, ISerializable
     {
         private CompareInfo m_compareInfo;
@@ -44,21 +43,6 @@ namespace System.Collections
             m_compareInfo = culture.CompareInfo;
         }
 
-        private Comparer(SerializationInfo info, StreamingContext context)
-        {
-            m_compareInfo = null;
-            SerializationInfoEnumerator enumerator = info.GetEnumerator();
-            while (enumerator.MoveNext())
-            {
-                switch (enumerator.Name)
-                {
-                    case CompareInfoName:
-                        m_compareInfo = (CompareInfo)info.GetValue(CompareInfoName, typeof(CompareInfo));
-                        break;
-                }
-            }
-        }
-
         // Compares two Objects by calling CompareTo.  If a == 
         // b,0 is returned.  If a implements 
         // IComparable, a.CompareTo(b) is returned.  If a 
@@ -92,16 +76,7 @@ namespace System.Collections
 
         public void GetObjectData(SerializationInfo info, StreamingContext context)
         {
-            if (info == null)
-            {
-                throw new ArgumentNullException(nameof(info));
-            }
-            Contract.EndContractBlock();
-
-            if (m_compareInfo != null)
-            {
-                info.AddValue(CompareInfoName, m_compareInfo);
-            }
+            throw new PlatformNotSupportedException();
         }
     }
 }
diff --git a/src/mscorlib/src/System/Collections/CompatibleComparer.cs b/src/mscorlib/src/System/Collections/CompatibleComparer.cs
index 1c90707184..7dcaa4e103 100644
--- a/src/mscorlib/src/System/Collections/CompatibleComparer.cs
+++ b/src/mscorlib/src/System/Collections/CompatibleComparer.cs
@@ -8,7 +8,6 @@ using System.Diagnostics.Contracts;
 
 namespace System.Collections
 {
-    [Serializable]
     internal class CompatibleComparer : IEqualityComparer
     {
         private IComparer _comparer;
diff --git a/src/mscorlib/src/System/Collections/Concurrent/ConcurrentQueue.cs b/src/mscorlib/src/System/Collections/Concurrent/ConcurrentQueue.cs
index c6211dadd3..3540cca8cf 100644
--- a/src/mscorlib/src/System/Collections/Concurrent/ConcurrentQueue.cs
+++ b/src/mscorlib/src/System/Collections/Concurrent/ConcurrentQueue.cs
@@ -20,7 +20,6 @@ namespace System.Collections.Concurrent
     /// </remarks>
     [DebuggerDisplay("Count = {Count}")]
     [DebuggerTypeProxy(typeof(SystemCollectionsConcurrent_ProducerConsumerCollectionDebugView<>))]
-    [Serializable]
     internal class ConcurrentQueue<T> : IProducerConsumerCollection<T>, IReadOnlyCollection<T>
     {
         // This implementation provides an unbounded, multi-producer multi-consumer queue
diff --git a/src/mscorlib/src/System/Collections/EmptyReadOnlyDictionaryInternal.cs b/src/mscorlib/src/System/Collections/EmptyReadOnlyDictionaryInternal.cs
index 63e0d47c75..9841bdb4bb 100644
--- a/src/mscorlib/src/System/Collections/EmptyReadOnlyDictionaryInternal.cs
+++ b/src/mscorlib/src/System/Collections/EmptyReadOnlyDictionaryInternal.cs
@@ -18,7 +18,6 @@ using System.Diagnostics.Contracts;
 namespace System.Collections
 {
     ///    This is a simple implementation of IDictionary that is empty and readonly.
-    [Serializable]
     internal sealed class EmptyReadOnlyDictionaryInternal : IDictionary
     {
         // Note that this class must be agile with respect to AppDomains.  See its usage in
diff --git a/src/mscorlib/src/System/Collections/Generic/ArraySortHelper.cs b/src/mscorlib/src/System/Collections/Generic/ArraySortHelper.cs
index e313cda0fb..e4a4acf74e 100644
--- a/src/mscorlib/src/System/Collections/Generic/ArraySortHelper.cs
+++ b/src/mscorlib/src/System/Collections/Generic/ArraySortHelper.cs
@@ -368,7 +368,6 @@ namespace System.Collections.Generic
         }
     }
 
-    [Serializable()]
     internal class GenericArraySortHelper<T>
         : IArraySortHelper<T>
         where T : IComparable<T>
diff --git a/src/mscorlib/src/System/Collections/Generic/Comparer.cs b/src/mscorlib/src/System/Collections/Generic/Comparer.cs
index a9b4b3f0dd..e163faa80f 100644
--- a/src/mscorlib/src/System/Collections/Generic/Comparer.cs
+++ b/src/mscorlib/src/System/Collections/Generic/Comparer.cs
@@ -51,7 +51,6 @@ namespace System.Collections.Generic
     // reasons. Adding another base class (even one with no fields)
     // means another generic instantiation, which can be costly esp.
     // for value types.
-
     [Serializable]
     internal sealed class GenericComparer<T> : Comparer<T> where T : IComparable<T>
     {
@@ -112,7 +111,6 @@ namespace System.Collections.Generic
             GetType().GetHashCode();
     }
 
-    [Serializable]
     internal sealed class ComparisonComparer<T> : Comparer<T>
     {
         private readonly Comparison<T> _comparison;
@@ -133,7 +131,6 @@ namespace System.Collections.Generic
     // and have a SerializationInfo/StreamingContext ctor,
     // since we want to serialize as ObjectComparer for
     // back-compat reasons (see below).
-
     [Serializable]
     internal sealed class Int32EnumComparer<T> : Comparer<T>, ISerializable where T : struct
     {
diff --git a/src/mscorlib/src/System/Collections/Generic/Dictionary.cs b/src/mscorlib/src/System/Collections/Generic/Dictionary.cs
index e360eef897..cd33428ca1 100644
--- a/src/mscorlib/src/System/Collections/Generic/Dictionary.cs
+++ b/src/mscorlib/src/System/Collections/Generic/Dictionary.cs
@@ -17,29 +17,6 @@
 ** thread safety. If a reader writer lock is available, then that may be used
 ** with a Dictionary to get the same thread safety guarantee. 
 ** 
-** Reader writer locks don't exist in silverlight, so we do the following as a
-** result of removing non-generic collections from silverlight: 
-** 1. If the Hashtable was fully synchronized, then we replace it with a 
-**    Dictionary with full locks around reads/writes (same thread safety
-**    guarantee).
-** 2. Otherwise, the Hashtable has the default MR/SW thread safety behavior, 
-**    so we do one of the following on a case-by-case basis:
-**    a. If the race condition can be addressed by rearranging the code and using a temp
-**       variable (for example, it's only populated immediately after created)
-**       then we address the race condition this way and use Dictionary.
-**    b. If there's concern about degrading performance with the increased 
-**       locking, we ifdef with FEATURE_NONGENERIC_COLLECTIONS so we can at 
-**       least use Hashtable in the desktop build, but Dictionary with full 
-**       locks in silverlight builds. Note that this is heavier locking than 
-**       MR/SW, but this is the only option without rewriting (or adding back)
-**       the reader writer lock. 
-**    c. If there's no performance concern (e.g. debug-only code) we 
-**       consistently replace Hashtable with Dictionary plus full locks to 
-**       reduce complexity.
-**    d. Most of serialization is dead code in silverlight. Instead of updating
-**       those Hashtable occurences in serialization, we carved out references 
-**       to serialization such that this code doesn't need to build in 
-**       silverlight. 
 ===========================================================*/
 
 namespace System.Collections.Generic
@@ -706,22 +683,6 @@ namespace System.Collections.Generic
             value = default(TValue);
             return false;
         }
-
-        // Method similar to TryGetValue that returns the value instead of putting it in an out param.
-        public TValue GetValueOrDefault(TKey key) => GetValueOrDefault(key, default(TValue));
-
-        // Method similar to TryGetValue that returns the value instead of putting it in an out param. If the entry
-        // doesn't exist, returns the defaultValue instead.
-        public TValue GetValueOrDefault(TKey key, TValue defaultValue)
-        {
-            int i = FindEntry(key);
-            if (i >= 0)
-            {
-                return entries[i].value;
-            }
-            return defaultValue;
-        }
-
         public bool TryAdd(TKey key, TValue value) => TryInsert(key, value, InsertionBehavior.None);
 
         bool ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly
@@ -947,7 +908,6 @@ namespace System.Collections.Generic
             }
         }
 
-        [Serializable]
         public struct Enumerator : IEnumerator<KeyValuePair<TKey, TValue>>,
             IDictionaryEnumerator
         {
@@ -1076,7 +1036,6 @@ namespace System.Collections.Generic
 
         [DebuggerTypeProxy(typeof(Mscorlib_DictionaryKeyCollectionDebugView<,>))]
         [DebuggerDisplay("Count = {Count}")]
-        [Serializable]
         public sealed class KeyCollection : ICollection<TKey>, ICollection, IReadOnlyCollection<TKey>
         {
             private Dictionary<TKey, TValue> dictionary;
@@ -1227,7 +1186,6 @@ namespace System.Collections.Generic
                 get { return ((ICollection)dictionary).SyncRoot; }
             }
 
-            [Serializable]
             public struct Enumerator : IEnumerator<TKey>, System.Collections.IEnumerator
             {
                 private Dictionary<TKey, TValue> dictionary;
@@ -1306,7 +1264,6 @@ namespace System.Collections.Generic
 
         [DebuggerTypeProxy(typeof(Mscorlib_DictionaryValueCollectionDebugView<,>))]
         [DebuggerDisplay("Count = {Count}")]
-        [Serializable]
         public sealed class ValueCollection : ICollection<TValue>, ICollection, IReadOnlyCollection<TValue>
         {
             private Dictionary<TKey, TValue> dictionary;
@@ -1455,7 +1412,6 @@ namespace System.Collections.Generic
                 get { return ((ICollection)dictionary).SyncRoot; }
             }
 
-            [Serializable]
             public struct Enumerator : IEnumerator<TValue>, System.Collections.IEnumerator
             {
                 private Dictionary<TKey, TValue> dictionary;
diff --git a/src/mscorlib/src/System/Collections/Generic/EqualityComparer.cs b/src/mscorlib/src/System/Collections/Generic/EqualityComparer.cs
index 0cd1bc1c12..d6b213c9d7 100644
--- a/src/mscorlib/src/System/Collections/Generic/EqualityComparer.cs
+++ b/src/mscorlib/src/System/Collections/Generic/EqualityComparer.cs
@@ -10,6 +10,7 @@ using System.Security;
 using System.Globalization;
 using System.Runtime;
 using System.Runtime.CompilerServices;
+using System.Runtime.Serialization;
 using System.Diagnostics.Contracts;
 
 namespace System.Collections.Generic
@@ -352,7 +353,7 @@ namespace System.Collections.Generic
     }
 
     [Serializable]
-    internal class EnumEqualityComparer<T> : EqualityComparer<T> where T : struct
+    internal class EnumEqualityComparer<T> : EqualityComparer<T>, ISerializable where T : struct
     {
         [Pure]
         public override bool Equals(T x, T y)
@@ -371,6 +372,9 @@ namespace System.Collections.Generic
 
         public EnumEqualityComparer() { }
 
+        // This is used by the serialization engine.
+        protected EnumEqualityComparer(SerializationInfo information, StreamingContext context) { }
+
         // Equals method for the comparer itself.
         public override bool Equals(Object obj) =>
             obj != null && GetType() == obj.GetType();
@@ -401,6 +405,14 @@ namespace System.Collections.Generic
             }
             return -1;
         }
+
+        public void GetObjectData(SerializationInfo info, StreamingContext context)
+        {
+            // For back-compat we need to serialize the comparers for enums with underlying types other than int as ObjectEqualityComparer 
+            if (Type.GetTypeCode(Enum.GetUnderlyingType(typeof(T))) != TypeCode.Int32) {
+                info.SetType(typeof(ObjectEqualityComparer<T>));
+            }
+        }
     }
 
     [Serializable]
@@ -408,6 +420,9 @@ namespace System.Collections.Generic
     {
         public SByteEnumEqualityComparer() { }
 
+        // This is used by the serialization engine.
+        public SByteEnumEqualityComparer(SerializationInfo information, StreamingContext context) { }
+
         [Pure]
         public override int GetHashCode(T obj)
         {
@@ -417,10 +432,13 @@ namespace System.Collections.Generic
     }
 
     [Serializable]
-    internal sealed class ShortEnumEqualityComparer<T> : EnumEqualityComparer<T> where T : struct
+    internal sealed class ShortEnumEqualityComparer<T> : EnumEqualityComparer<T>, ISerializable where T : struct
     {
         public ShortEnumEqualityComparer() { }
 
+        // This is used by the serialization engine.
+        public ShortEnumEqualityComparer(SerializationInfo information, StreamingContext context) { }
+
         [Pure]
         public override int GetHashCode(T obj)
         {
@@ -430,7 +448,7 @@ namespace System.Collections.Generic
     }
 
     [Serializable]
-    internal sealed class LongEnumEqualityComparer<T> : EqualityComparer<T> where T : struct
+    internal sealed class LongEnumEqualityComparer<T> : EqualityComparer<T>, ISerializable where T : struct
     {
         [Pure]
         public override bool Equals(T x, T y)
@@ -479,5 +497,15 @@ namespace System.Collections.Generic
             }
             return -1;
         }
+
+        // This is used by the serialization engine.
+        public LongEnumEqualityComparer(SerializationInfo information, StreamingContext context) { }
+
+        public void GetObjectData(SerializationInfo info, StreamingContext context)
+        {
+            // The LongEnumEqualityComparer does not exist on 4.0 so we need to serialize this comparer as ObjectEqualityComparer
+            // to allow for roundtrip between 4.0 and 4.5.
+            info.SetType(typeof(ObjectEqualityComparer<T>));
+        }
     }
 }
diff --git a/src/mscorlib/src/System/Collections/Generic/List.cs b/src/mscorlib/src/System/Collections/Generic/List.cs
index 4e480885ef..94e794cfd2 100644
--- a/src/mscorlib/src/System/Collections/Generic/List.cs
+++ b/src/mscorlib/src/System/Collections/Generic/List.cs
@@ -1254,7 +1254,6 @@ namespace System.Collections.Generic
             }
         }
 
-        [Serializable]
         public struct Enumerator : IEnumerator<T>, System.Collections.IEnumerator
         {
             private List<T> list;
diff --git a/src/mscorlib/src/System/Collections/Hashtable.cs b/src/mscorlib/src/System/Collections/Hashtable.cs
index e2fd57ea4d..0c89632828 100644
--- a/src/mscorlib/src/System/Collections/Hashtable.cs
+++ b/src/mscorlib/src/System/Collections/Hashtable.cs
@@ -66,7 +66,6 @@ namespace System.Collections
     // 
     [DebuggerTypeProxy(typeof(System.Collections.Hashtable.HashtableDebugView))]
     [DebuggerDisplay("Count = {Count}")]
-    [Serializable]
     internal class Hashtable : IDictionary, ISerializable, IDeserializationCallback, ICloneable
     {
         /*
@@ -919,58 +918,7 @@ namespace System.Collections
 
         public virtual void GetObjectData(SerializationInfo info, StreamingContext context)
         {
-            if (info == null)
-            {
-                throw new ArgumentNullException(nameof(info));
-            }
-            Contract.EndContractBlock();
-            // This is imperfect - it only works well if all other writes are
-            // also using our synchronized wrapper.  But it's still a good idea.
-            lock (SyncRoot)
-            {
-                // This method hasn't been fully tweaked to be safe for a concurrent writer.
-                int oldVersion = version;
-                info.AddValue(LoadFactorName, loadFactor);
-                info.AddValue(VersionName, version);
-
-                //
-                // We need to maintain serialization compatibility with Everett and RTM.
-                // If the comparer is null or a compatible comparer, serialize Hashtable
-                // in a format that can be deserialized on Everett and RTM.            
-                //
-#pragma warning disable 618
-                IEqualityComparer keyComparerForSerilization = _keycomparer;
-
-                if (keyComparerForSerilization == null)
-                {
-                    info.AddValue(ComparerName, null, typeof(IComparer));
-                    info.AddValue(HashCodeProviderName, null, typeof(IHashCodeProvider));
-                }
-                else if (keyComparerForSerilization is CompatibleComparer)
-                {
-                    CompatibleComparer c = keyComparerForSerilization as CompatibleComparer;
-                    info.AddValue(ComparerName, c.Comparer, typeof(IComparer));
-                    info.AddValue(HashCodeProviderName, c.HashCodeProvider, typeof(IHashCodeProvider));
-                }
-                else
-                {
-                    info.AddValue(KeyComparerName, keyComparerForSerilization, typeof(IEqualityComparer));
-                }
-#pragma warning restore 618
-
-                info.AddValue(HashSizeName, buckets.Length); //This is the length of the bucket array.
-                Object[] serKeys = new Object[count];
-                Object[] serValues = new Object[count];
-                CopyKeys(serKeys, 0);
-                CopyValues(serValues, 0);
-                info.AddValue(KeysName, serKeys, typeof(Object[]));
-                info.AddValue(ValuesName, serValues, typeof(Object[]));
-
-                // Explicitly check to see if anyone changed the Hashtable while we 
-                // were serializing it.  That's a race condition in their code.
-                if (version != oldVersion)
-                    throw new InvalidOperationException(SR.GetResourceString(ResId.InvalidOperation_EnumFailedVersion));
-            }
+            throw new PlatformNotSupportedException();
         }
 
         //
@@ -1073,7 +1021,6 @@ namespace System.Collections
 
         // Implements a Collection for the keys of a hashtable. An instance of this
         // class is created by the GetKeys method of a hashtable.
-        [Serializable]
         private class KeyCollection : ICollection
         {
             private Hashtable _hashtable;
@@ -1120,7 +1067,6 @@ namespace System.Collections
 
         // Implements a Collection for the values of a hashtable. An instance of
         // this class is created by the GetValues method of a hashtable.
-        [Serializable]
         private class ValueCollection : ICollection
         {
             private Hashtable _hashtable;
@@ -1166,7 +1112,6 @@ namespace System.Collections
         }
 
         // Synchronized wrapper for hashtable
-        [Serializable]
         private class SyncHashtable : Hashtable, IEnumerable
         {
             protected Hashtable _table;
@@ -1189,17 +1134,7 @@ namespace System.Collections
             ==============================================================================*/
             public override void GetObjectData(SerializationInfo info, StreamingContext context)
             {
-                if (info == null)
-                {
-                    throw new ArgumentNullException(nameof(info));
-                }
-                Contract.EndContractBlock();
-                // Our serialization code hasn't been fully tweaked to be safe 
-                // for a concurrent writer.
-                lock (_table.SyncRoot)
-                {
-                    info.AddValue("ParentTable", _table, typeof(Hashtable));
-                }
+                throw new PlatformNotSupportedException();
             }
 
             public override int Count
@@ -1339,7 +1274,7 @@ namespace System.Collections
             ==============================================================================*/
             public override void OnDeserialization(Object sender)
             {
-                return;
+                throw new PlatformNotSupportedException();
             }
         }
 
@@ -1347,7 +1282,6 @@ namespace System.Collections
         // Implements an enumerator for a hashtable. The enumerator uses the
         // internal version number of the hashtabke to ensure that no modifications
         // are made to the hashtable while an enumeration is in progress.
-        [Serializable]
         private class HashtableEnumerator : IDictionaryEnumerator, ICloneable
         {
             private Hashtable hashtable;
diff --git a/src/mscorlib/src/System/Collections/ObjectModel/ReadOnlyDictionary.cs b/src/mscorlib/src/System/Collections/ObjectModel/ReadOnlyDictionary.cs
index ebf86cdc58..3fd0cf8c6c 100644
--- a/src/mscorlib/src/System/Collections/ObjectModel/ReadOnlyDictionary.cs
+++ b/src/mscorlib/src/System/Collections/ObjectModel/ReadOnlyDictionary.cs
@@ -19,7 +19,6 @@ using System.Diagnostics.Contracts;
 
 namespace System.Collections.ObjectModel
 {
-    [Serializable]
     [DebuggerTypeProxy(typeof(Mscorlib_DictionaryDebugView<,>))]
     [DebuggerDisplay("Count = {Count}")]
     internal class ReadOnlyDictionary<TKey, TValue> : IDictionary<TKey, TValue>, IDictionary, IReadOnlyDictionary<TKey, TValue>
@@ -365,7 +364,6 @@ namespace System.Collections.ObjectModel
             }
         }
 
-        [Serializable]
         private struct DictionaryEnumerator : IDictionaryEnumerator
         {
             private readonly IDictionary<TKey, TValue> m_dictionary;
@@ -432,7 +430,6 @@ namespace System.Collections.ObjectModel
 
         [DebuggerTypeProxy(typeof(Mscorlib_CollectionDebugView<>))]
         [DebuggerDisplay("Count = {Count}")]
-        [Serializable]
         public sealed class KeyCollection : ICollection<TKey>, ICollection, IReadOnlyCollection<TKey>
         {
             private readonly ICollection<TKey> m_collection;
@@ -543,7 +540,6 @@ namespace System.Collections.ObjectModel
 
         [DebuggerTypeProxy(typeof(Mscorlib_CollectionDebugView<>))]
         [DebuggerDisplay("Count = {Count}")]
-        [Serializable]
         public sealed class ValueCollection : ICollection<TValue>, ICollection, IReadOnlyCollection<TValue>
         {
             private readonly ICollection<TValue> m_collection;