Unity Roslyn Updater

A tool to update the Roslyn compiler and C# language versions for a Unity installation.

Installation

NOTE: This will modify your Unity installation folder, administrative privileges are required!

Interactive Mode

Launch the tool directly to interactively select a Unity editor version to patch.

Command Line (Advanced) Mode

Pass the Unity editor path to UnityRoslynUpdater.exe:

UnityRoslynUpdater.exe <path to Unity Editor folder>

For example: UnityRoslynUpdater.exe "C:\Program Files\Unity\Hub\Editor\2022.3.8f1\Editor"

Usage

After updating the Roslyn compiler, newer C# language versions are available but not enabled by default. To enable them, you must explicitly opt in for each assembly definition in your project.

Create a csc.rsp file in the same directory as your assembly definition (.asmdef) file with the following content (replace 14 with your desired language version):

-langversion:14

NOTE: Version 2.0.24 or later of the com.unity.ide.visualstudio package is required for the language version specified in csc.rsp to be reflected in the generated .csproj files.

Language Support

• Working
  • Feature works exactly as expected.
• PolySharp
  • Feature works when using PolySharp and/or manually implementing missing APIs.
• Not Supported
  • Requires runtime features or BCL changes that Unity does not have. Attempting to use the feature may result in compiler errors.
• Crash
  • Requires runtime features that Unity does not have. Attempting to use the feature may compile, but will result in crashes.

C# 14

Feature | Status -|- Extension members | Working Null-conditional assignment | Working nameof supports unbound generic types | Working More implicit conversions for Span<T> and ReadOnlySpan<T> | Working Modifiers on simple lambda parameters | Working field backed properties | Working partial events and constructors | Working

C# 13

Feature | Status -|- params collections | Working New lock type and semantics | Not Supported New escape sequence - \e | Working Method group natural type improvements | Working Implicit indexer access in object initializers | Working Enable ref locals and unsafe contexts in iterators and async methods | Working Enable ref struct types to implement interfaces | Not Supported Allow ref struct types as arguments for type parameters in generics | Not Supported Partial properties and indexers | Working Overload resolution priority | PolySharp field backed properties | Working

C# 12

Feature | Status -|- Primary constructors | Working Optional parameters in lambda expressions | Working Alias any type | Working Inline arrays | Not Supported Collection expressions | Working Interceptors | Not Supported

C# 11

Feature | Status -|- Raw string literals | Working static abstract/static virtual members in interfaces | Not Supported Checked user defined operators | Working Relaxed shift operators | Working Unsigned right-shift operator | Working Generic attributes | Crash UTF-8 string literals | Working Newlines in string interpolations | Working List patterns | Working File-local types | Working Required members | PolySharp Auto-default structs | Working Pattern match Span<char> or ReadOnlySpan<char> on a constant string | Working Extended nameof scope | Working Numeric IntPtr and UIntPtr | Working ref fields | Not Supported ref scoped variables | PolySharp Improved method group conversion to delegate | Working

C# 10

Feature | Status -|- Record structs | Working Improvements of structure types | Working Interpolated string handler | PolySharp Global using directives | Working File-scoped namespace declaration | Working¹ Extended property patterns | Working Lambda expression improvements | Working Constant interpolated strings | Working Record types can seal ToString | Working Assignment and declaration in same deconstruction | Working Improved definite assignment | Working Allow AsyncMethodBuilder attribute on methods | Not Supported² CallerArgumentExpression attribute | PolySharp Enhanced #line pragma | Working

1. Unity 2021 and earlier require UnityNamespacePatch to be installed.
2. AsyncMethodBuilderAttribute requires changes to its [AttributeUsage] attribute for this to work.