Eliminate extra dependencies

src/Microsoft.Diagnostics.Runtime/Microsoft.Diagnostics.Runtime.csproj

@@ -30,10 +30,4 @@
       <PackagePath></PackagePath>
     </Content>
   </ItemGroup>
-
-  <ItemGroup>
-    <PackageReference Include="System.Buffers" Version="4.5.0" />
-    <PackageReference Include="System.Memory" Version="4.5.3" />
-    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.6.0" />
-  </ItemGroup>
 </Project>

src/Microsoft.Diagnostics.Runtime/src/Utilities/PEFile/PEFile.cs

@@ -206,7 +206,7 @@ public FileVersionInfo GetFileVersionInfo()
 
             PEBuffer buff = AllocBuff();
             byte* bytes = versionNode.FetchData(0, versionNode.DataLength, buff);
-            FileVersionInfo ret = new FileVersionInfo(new Span<byte>(bytes, versionNode.DataLength));
+            FileVersionInfo ret = new FileVersionInfo(bytes, versionNode.DataLength);
 
             FreeBuff(buff);
             return ret;

src/Microsoft.Diagnostics.Runtime/src/Utilities/PEFile/ResourceNode.cs

@@ -26,8 +26,7 @@ public FileVersionInfo GetFileVersionInfo()
         {
             PEBuffer buff = _file.AllocBuff();
             byte* bytes = FetchData(0, DataLength, buff);
-
-            FileVersionInfo ret = new FileVersionInfo(new Span<byte>(bytes, DataLength));
+            FileVersionInfo ret = new FileVersionInfo(bytes, DataLength);
             _file.FreeBuff(buff);
             return ret;
         }

src/Microsoft.Diagnostics.Runtime/src/Utilities/PEImage/FileVersionInfo.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Text;
 
 namespace Microsoft.Diagnostics.Runtime.Utilities
 {
@@ -27,16 +28,33 @@ public sealed unsafe class FileVersionInfo
         /// </summary>
         public string? Comments { get; }
 
-        internal FileVersionInfo(Span<byte> data)
+        internal FileVersionInfo(byte[] data, int dataLen)
         {
-            data = data.Slice(DataOffset);
-            fixed (byte* ptr = data)
-            {
-                string dataAsString = new string((char*)ptr, 0, data.Length / 2);
+            FileVersion = "";
+            if (dataLen <= DataOffset)
+                return;
 
-                FileVersion = GetDataString(dataAsString, "FileVersion");
-                Comments = GetDataString(dataAsString, "Comments");
-            }
+            var dataAsString = Encoding.Unicode.GetString(data, DataOffset, dataLen - DataOffset);
+
+            FileVersion = GetDataString(dataAsString, "FileVersion");
+            Comments = GetDataString(dataAsString, "Comments");
+        }
+
+        [Obsolete]
+        internal FileVersionInfo(byte* data, int dataLen)
+        {
+            FileVersion = "";
+            if (dataLen <= 0x5c)
+                return;
+
+            // See http://msdn.microsoft.com/en-us/library/ms647001(v=VS.85).aspx
+            byte* stringInfoPtr = data + 0x5c; // Gets to first StringInfo
+
+            // TODO search for FileVersion string ... 
+            string dataAsString = new string((char*)stringInfoPtr, 0, (dataLen - 0x5c) / 2);
+
+            FileVersion = GetDataString(dataAsString, "FileVersion");
+            Comments = GetDataString(dataAsString, "Comments");
         }
 
         private static string? GetDataString(string dataAsString, string fileVersionKey)

src/Microsoft.Diagnostics.Runtime/src/Utilities/PEImage/PEImage.cs

@@ -1,8 +1,8 @@
 using Microsoft.Diagnostics.Runtime.Interop;
 using System;
-using System.Buffers;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.Data;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -220,27 +220,11 @@ public int Read(byte[] dest, int virtualAddress, int bytesRequested)
             return read;
         }
 
-        /// <summary>
-        /// Reads data out of PE image into a native buffer.
-        /// </summary>
-        /// <param name="virtualAddress">The address to read from.</param>
-        /// <param name="dest">The location to write the data.</param>
-        /// <returns>The number of bytes actually read from the image and written to dest.</returns>
-        public int Read(int virtualAddress, Span<byte> dest)
-        {
-            int offset = RvaToOffset(virtualAddress);
-            if (offset == -1)
-                return 0;
-
-            SeekTo(offset);
-            return Stream.Read(dest);
-        }
-
         /// <summary>
         /// Gets the File Version Information that is stored as a resource in the PE file.  (This is what the
         /// version tab a file's property page is populated with).
         /// </summary>
-        public FileVersionInfo? GetFileVersionInfo()
+        public unsafe FileVersionInfo? GetFileVersionInfo()
         {
             ResourceEntry? versionNode = Resources.Children.FirstOrDefault(r => r.Name == "Version");
             if (versionNode == null || versionNode.Children.Count != 1)
@@ -254,18 +238,11 @@ public int Read(int virtualAddress, Span<byte> dest)
             if (size <= FileVersionInfo.DataOffset)
                 return null;
 
-            byte[] buffer = ArrayPool<byte>.Shared.Rent(size);
-            try
-            {
-                int count = versionNode.GetData(buffer);
-                Span<byte> span = new Span<byte>(buffer, 0, count);
-                FileVersionInfo result = new FileVersionInfo(span);
-                return result;
-            }
-            finally
-            {
-                ArrayPool<byte>.Shared.Return(buffer);
-            }
+            byte[] bytes = versionNode.GetData();
+
+            FileVersionInfo ret = new FileVersionInfo(bytes, versionNode.Size);
+
+            return ret;
         }
 
         private ResourceEntry CreateResourceRoot()

src/Microsoft.Diagnostics.Runtime/src/Utilities/PEImage/ResourceEntry.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 
 namespace Microsoft.Diagnostics.Runtime.Utilities
@@ -98,36 +98,24 @@ public byte[] GetData()
             return result;
         }
 
-        /// <summary>
-        /// Get the data associated with this entry.
-        /// </summary>
-        /// <param name="span">The location to write the data</param>
-        /// <returns>The number of bytes actually read from the image and written to dest</returns>
-        public int GetData(Span<byte> span)
-        {
-            GetDataVaAndSize(out int va, out int size);
-            if (size == 0 || va == 0)
-                return 0;
-
-            return Image.Read(va, span);
-        }
-
         /// <summary>
         /// A convenience function to get structured data out of this entry.
         /// </summary>
         /// <typeparam name="T">A struct type to convert.</typeparam>
         /// <param name="offset">The offset into the data.</param>
         /// <returns>The struct that was read out of the data section.</returns>
-        public unsafe T GetData<T>(int offset = 0) where T : unmanaged
+        public T GetData<T>(int offset = 0) where T : struct
         {
-            int size = Unsafe.SizeOf<T>();
-            GetDataVaAndSize(out int va, out int sectionSize);
-            if (va == 0 || sectionSize < size + offset)
-                return default;
-
-            T output;
-            int read = Image.Read(va + offset, new Span<byte>(&output, size));
-            return read == size ? output : default;
+            byte[] data = GetData();
+            int size = Marshal.SizeOf(typeof(T));
+            if (size + offset > data.Length)
+                throw new IndexOutOfRangeException();
+
+            GCHandle hnd = GCHandle.Alloc(data, GCHandleType.Pinned);
+            T result = (T)Marshal.PtrToStructure(hnd.AddrOfPinnedObject(), typeof(T));
+            hnd.Free();
+
+            return result;
         }
 
         private ResourceEntry[] GetChildren()