Prepare for nullability annotation in BizHawk.Common

attributes: https://docs.microsoft.com/en-us/dotnet/csharp/nullable-attributes

BizHawk.Common/AWEMemoryStream.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.IO;
 using System.Collections.Generic;

BizHawk.Common/BinaryQuickSerializer.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;

BizHawk.Common/Bit.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System.Diagnostics;
 
 namespace BizHawk.Common

BizHawk.Common/BitReverse.cs

@@ -1,4 +1,6 @@
-namespace BizHawk.Common
+#nullable disable
+
+namespace BizHawk.Common
 {
 	public static class BitReverse
 	{

BizHawk.Common/BizHawk.Common.csproj

@@ -1,9 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk">
 	<Import Project="../Common.abs.props" />
+	<Import Project="../CommonNullable.abs.props" />
 	<PropertyGroup>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
 		<OutputPath>../output/dll</OutputPath>
-		<TargetFramework>netstandard2.0</TargetFramework>
+		<TargetFrameworks>netstandard2.0;netcoreapp3.1</TargetFrameworks>
 	</PropertyGroup>
 	<ItemGroup>
 		<PackageReference Include="System.ComponentModel.Annotations" Version="4.7.0" PrivateAssets="All" />

BizHawk.Common/Buffer.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Runtime.InteropServices;
 

BizHawk.Common/CRC32.cs

@@ -1,4 +1,6 @@
-namespace BizHawk.Common
+#nullable disable
+
+namespace BizHawk.Common
 {
 	// we could get a little list of crcs from here and make it clear which crc this class was for, and expose others
 	// http://www.ross.net/crc/download/crc_v3.txt

BizHawk.Common/Colors.cs

@@ -1,4 +1,6 @@
-namespace BizHawk.Common
+#nullable disable
+
+namespace BizHawk.Common
 {
 	public static class Colors
 	{

BizHawk.Common/CustomCollections.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;

BizHawk.Common/DeepEquality.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;

BizHawk.Common/DescribableEnumConverter.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.ComponentModel.DataAnnotations;

BizHawk.Common/Extensions/BufferExtensions.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Globalization;
 using System.IO;
 using System.Text;

BizHawk.Common/Extensions/CollectionExtensions.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 
 namespace BizHawk.Common.CollectionExtensions

BizHawk.Common/Extensions/IOExtensions.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.IO;
 using System.Text;
 

BizHawk.Common/Extensions/NumberExtensions.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Linq;
 
 namespace BizHawk.Common.NumberExtensions

BizHawk.Common/Extensions/ReflectionExtensions.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Linq;
 using System.Collections.Generic;
 using System.ComponentModel;

BizHawk.Common/Extensions/StringExtensions.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

BizHawk.Common/HawkFile.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;

BizHawk.Common/IImportResolver.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;

BizHawk.Common/IMonitor.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 
 namespace BizHawk.Common
 {

BizHawk.Common/Log.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.IO;
 

BizHawk.Common/OSTailoredCode.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Diagnostics;
 using System.Runtime.InteropServices;

BizHawk.Common/QuickCollections.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 
 namespace BizHawk.Common

BizHawk.Common/Ranges.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;

BizHawk.Common/Serializer.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;

BizHawk.Common/SettingsUtil.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.Reflection;
 using System.Reflection.Emit;

BizHawk.Common/SimpleTime.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Diagnostics;
 
 namespace BizHawk.Common

BizHawk.Common/SwitcherStream.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.IO;
 

BizHawk.Common/TempFileManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Linq;
 using System.Collections.Generic;

BizHawk.Common/UndoHistory.cs

@@ -1,4 +1,6 @@
-using System.Collections.Generic;
+#nullable disable
+
+using System.Collections.Generic;
 using System.Linq;
 
 namespace BizHawk.Common

BizHawk.Common/Util.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Compression;

BizHawk.Common/Win32/AVIWriterImports.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Runtime.InteropServices;
 

BizHawk.Common/Win32/MotWHack.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace BizHawk.Common
 {
 	/// <remarks>This code (and an import for <see cref="Win32Imports.DeleteFileW"/>) is duplicated in each executable project because it needs to be used before loading assemblies.</remarks>

BizHawk.Common/Win32/ProcessorFeatureImports.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System.Runtime.InteropServices;
 
 namespace BizHawk.Common

BizHawk.Common/Win32/ShellLinkImports.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Runtime.InteropServices;
 using System.Text;

BizHawk.Common/Win32/ThreadHacks.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Runtime.InteropServices;
 

BizHawk.Common/Win32/Win32Imports.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable disable
+
+using System;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Text;

CommonNullable.abs.props

@@ -0,0 +1,9 @@
+<Project>
+	<PropertyGroup>
+		<Nullable>enable</Nullable>
+	</PropertyGroup>
+	<ItemGroup>
+		<!--<PackageReference Include="Nullable" Version="1.2.0" PrivateAssets="all" IncludeAssets="runtime; build; native; contentfiles; analyzers" />-->
+		<PackageReference Include="Nullable" Version="1.2.0" PrivateAssets="all" />
+	</ItemGroup>
+</Project>

Version/VersionInfo.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System.IO;
 
 internal static class VersionInfo