From fcbb26407b5b87a2d6cc47ff0c8b4cc9e834a47a Mon Sep 17 00:00:00 2001
From: Ahson Khan <ahkha@microsoft.com>
Date: Wed, 8 Nov 2017 14:29:51 -0800
Subject: [PATCH] Adding placeholder Span debugger proxy (dotnet/coreclr#14749)

* Adding placeholder Span debugger proxy.

* Remove unnecessary unsafe keyword.

Signed-off-by: dotnet-bot-corefx-mirror <dotnet-bot@microsoft.com>
---
 .../System.Private.CoreLib.Shared.projitems   |  1 +
 src/Common/src/CoreLib/System/ReadOnlySpan.cs |  1 +
 src/Common/src/CoreLib/System/Span.cs         |  1 +
 .../src/CoreLib/System/SpanDebugView.cs       | 28 +++++++++++++++++++
 4 files changed, 31 insertions(+)
 create mode 100644 src/Common/src/CoreLib/System/SpanDebugView.cs

diff --git a/src/Common/src/CoreLib/System.Private.CoreLib.Shared.projitems b/src/Common/src/CoreLib/System.Private.CoreLib.Shared.projitems
index 5b7629f24548..68234374044d 100644
--- a/src/Common/src/CoreLib/System.Private.CoreLib.Shared.projitems
+++ b/src/Common/src/CoreLib/System.Private.CoreLib.Shared.projitems
@@ -441,6 +441,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\SerializableAttribute.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Single.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Span.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\SpanDebugView.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Span.NonGeneric.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\String.Searching.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\StringSpanHelpers.cs" />
diff --git a/src/Common/src/CoreLib/System/ReadOnlySpan.cs b/src/Common/src/CoreLib/System/ReadOnlySpan.cs
index c5f301a6f27e..a0a0cf9c055f 100644
--- a/src/Common/src/CoreLib/System/ReadOnlySpan.cs
+++ b/src/Common/src/CoreLib/System/ReadOnlySpan.cs
@@ -15,6 +15,7 @@ namespace System
     /// ReadOnlySpan represents a contiguous region of arbitrary memory. Unlike arrays, it can point to either managed
     /// or native memory, or to memory allocated on the stack. It is type- and memory-safe.
     /// </summary>
+    [DebuggerTypeProxy(typeof(SpanDebugView<>))]
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     [NonVersionable]
     public readonly ref struct ReadOnlySpan<T>
diff --git a/src/Common/src/CoreLib/System/Span.cs b/src/Common/src/CoreLib/System/Span.cs
index 261b15c07878..f885c63850f1 100644
--- a/src/Common/src/CoreLib/System/Span.cs
+++ b/src/Common/src/CoreLib/System/Span.cs
@@ -21,6 +21,7 @@ namespace System
     /// Span represents a contiguous region of arbitrary memory. Unlike arrays, it can point to either managed
     /// or native memory, or to memory allocated on the stack. It is type- and memory-safe.
     /// </summary>
+    [DebuggerTypeProxy(typeof(SpanDebugView<>))]
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     [NonVersionable]
     public readonly ref struct Span<T>
diff --git a/src/Common/src/CoreLib/System/SpanDebugView.cs b/src/Common/src/CoreLib/System/SpanDebugView.cs
new file mode 100644
index 000000000000..caa12ef9ed9d
--- /dev/null
+++ b/src/Common/src/CoreLib/System/SpanDebugView.cs
@@ -0,0 +1,28 @@
+// 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.
+
+using System.Diagnostics;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+
+namespace System
+{
+    internal sealed class SpanDebugView<T>
+    {
+        private readonly T[] _array;
+
+        public SpanDebugView(Span<T> span)
+        {
+           _array = span.ToArray();
+        }
+
+        public SpanDebugView(ReadOnlySpan<T> span)
+        {
+            _array = span.ToArray();
+        }
+
+        [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
+        public T[] Items => _array;
+    }
+}