Support changing C# nullable references context build option

Source/Tools/Flax.Build/Build/DotNet/Builder.DotNet.cs

@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using Flax.Build.Graph;
+using Flax.Build.NativeCpp;
 using Flax.Deploy;
 
 namespace Flax.Build
@@ -242,7 +243,9 @@ namespace Flax.Build
             args.Add("/filealign:512");
 #if USE_NETCORE
             args.Add("/langversion:11.0");
-            args.Add("-nowarn:8632"); // Nullable
+            args.Add(string.Format("/nullable:{0}", buildOptions.ScriptingAPI.CSharpNullableReferences.ToString().ToLowerInvariant()));
+            if (buildOptions.ScriptingAPI.CSharpNullableReferences == CSharpNullableReferences.Disable)
+                args.Add("-nowarn:8632"); // The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.
 #else
             args.Add("/langversion:7.3");
 #endif

Source/Tools/Flax.Build/Build/NativeCpp/BuildOptions.cs

@@ -23,6 +23,32 @@ namespace Flax.Build.NativeCpp
         GenerateProject = 1,
     }
 
+    /// <summary>
+    /// The nullable context type used with reference types (C#).
+    /// </summary>
+    public enum CSharpNullableReferences
+    {
+        /// <summary>
+        /// The code is nullable oblivious, nullable warnings and language analysis features are disabled.
+        /// </summary>
+        Disable,
+
+        /// <summary>
+        /// The compiler enables all null reference analysis and all language features.
+        /// </summary>
+        Enable,
+
+        /// <summary>
+        /// The compiler performs all null analysis and emits warnings when code might dereference null.
+        /// </summary>
+        Warnings,
+
+        /// <summary>
+        /// The compiler doesn't perform null analysis or emit warnings when code might dereference null.
+        /// </summary>
+        Annotations,
+    }
+
     /// <summary>
     /// The native C++ module build settings container.
     /// </summary>
@@ -188,6 +214,15 @@ namespace Flax.Build.NativeCpp
             /// </summary>
             public bool IgnoreMissingDocumentationWarnings;
 
+            /// <summary>
+            /// The nullable context used in C# project.
+            /// </summary>
+            public CSharpNullableReferences CSharpNullableReferences = CSharpNullableReferences.Disable;
+
+            public ScriptingAPIOptions()
+            {
+            }
+
             /// <summary>
             /// Adds the other options into this.
             /// </summary>

Source/Tools/Flax.Build/Projects/VisualStudio/CSSDKProjectGenerator.cs

@@ -88,7 +88,7 @@ namespace Flax.Build.Projects.VisualStudio
 
             csProjectFileContent.AppendLine("    <TargetFramework>net7.0</TargetFramework>");
             csProjectFileContent.AppendLine("    <ImplicitUsings>disable</ImplicitUsings>");
-            csProjectFileContent.AppendLine("    <Nullable>annotations</Nullable>");
+            csProjectFileContent.AppendLine(string.Format("    <Nullable>{0}</Nullable>", baseConfiguration.TargetBuildOptions.ScriptingAPI.CSharpNullableReferences.ToString().ToLowerInvariant()));
             csProjectFileContent.AppendLine("    <IsPackable>false</IsPackable>");
             csProjectFileContent.AppendLine("    <EnableDefaultItems>false</EnableDefaultItems>");
             csProjectFileContent.AppendLine("    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>");