Add UnsafeAccessorAttribute polyfill

src/PolySharp.SourceGenerators/EmbeddedResources/RuntimeSupported/System.Runtime.CompilerServices.UnsafeAccessorAttribute.cs

@@ -0,0 +1,80 @@
+// <auto-generated/>
+#pragma warning disable
+#nullable enable annotations
+
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>
+    /// Provides access to an inaccessible member of a specific type.
+    /// </summary>
+    /// <remarks>
+    /// This attribute may be applied to an <code>extern static</code> method.
+    /// The implementation of the <code>extern static</code> method annotated with
+    /// this attribute will be provided by the runtime based on the information in
+    /// the attribute and the signature of the method that the attribute is applied to.
+    /// The runtime will try to find the matching method or field and forward the call
+    /// to it. If the matching method or field is not found, the body of the <code>extern</code>
+    /// method will throw <see cref="global::System.MissingFieldException" /> or <see cref="global::System.MissingMethodException" />.
+    /// Only the specific type defined will be examined for inaccessible members. The type hierarchy
+    /// is not walked looking for a match.
+    ///
+    /// For <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorKind.Method"/>,
+    /// <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorKind.StaticMethod"/>,
+    /// <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorKind.Field"/>,
+    /// and <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorKind.StaticField"/>, the type of
+    /// the first argument of the annotated <code>extern</code> method identifies the owning type.
+    /// The value of the first argument is treated as <code>this</code> pointer for instance fields and methods.
+    /// The first argument must be passed as <code>ref</code> for instance fields and methods on structs.
+    /// The value of the first argument is not used by the implementation for <code>static</code> fields and methods.
+    ///
+    /// Return type is considered for the signature match. modreqs and modopts are initially not considered for
+    /// the signature match. However, if an ambiguity exists ignoring modreqs and modopts, a precise match
+    /// is attempted. If an ambiguity still exists <see cref="global::System.Reflection.AmbiguousMatchException" /> is thrown.
+    ///
+    /// By default, the attributed method's name dictates the name of the method/field. This can cause confusion
+    /// in some cases since language abstractions, like C# local functions, generate mangled IL names. The
+    /// solution to this is to use the <code>nameof</code> mechanism and define the <see cref="Name"/> property.
+    ///
+    /// <code>
+    /// public void Method(Class c)
+    /// {
+    ///     PrivateMethod(c);
+    ///
+    ///     [UnsafeAccessor(UnsafeAccessorKind.Method, Name = nameof(PrivateMethod))]
+    ///     extern static void PrivateMethod(Class c);
+    /// }
+    /// </code>
+    /// </remarks>
+    [global::System.AttributeUsage(global::System.AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.Conditional("MULTI_TARGETING_SUPPORT_ATTRIBUTES")]
+    internal sealed class UnsafeAccessorAttribute : global::System.Attribute
+    {
+        /// <summary>
+        /// Instantiates an <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorAttribute"/>
+        /// providing access to a member of kind <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorKind"/>.
+        /// </summary>
+        /// <param name="kind">The kind of the target to which access is provided.</param>
+        public UnsafeAccessorAttribute(global::System.Runtime.CompilerServices.UnsafeAccessorKind kind)
+        {
+            Kind = kind;
+        }
+
+        /// <summary>
+        /// Gets the kind of member to which access is provided.
+        /// </summary>
+        public global::System.Runtime.CompilerServices.UnsafeAccessorKind Kind { get; }
+
+        /// <summary>
+        /// Gets or sets the name of the member to which access is provided.
+        /// </summary>
+        /// <remarks>
+        /// The name defaults to the annotated method name if not specified.
+        /// The name must be unset/<code>null</code> for <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorKind.Constructor"/>.
+        /// </remarks>
+        public string? Name { get; set; }
+    }
+}

src/PolySharp.SourceGenerators/EmbeddedResources/RuntimeSupported/System.Runtime.CompilerServices.UnsafeAccessorKind.cs

@@ -0,0 +1,40 @@
+// <auto-generated/>
+#pragma warning disable
+#nullable enable annotations
+
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>
+    /// Specifies the kind of target to which an <see cref="global::System.Runtime.CompilerServices.UnsafeAccessorAttribute" /> is providing access.
+    /// </summary>
+    internal enum UnsafeAccessorKind
+    {
+        /// <summary>
+        /// Provide access to a constructor.
+        /// </summary>
+        Constructor,
+
+        /// <summary>
+        /// Provide access to a method.
+        /// </summary>
+        Method,
+
+        /// <summary>
+        /// Provide access to a static method.
+        /// </summary>
+        StaticMethod,
+
+        /// <summary>
+        /// Provide access to a field.
+        /// </summary>
+        Field,
+
+        /// <summary>
+        /// Provide access to a static field.
+        /// </summary>
+        StaticField
+    }
+}