Merge pull request #204 from MonoMod/byreflike-sizeof

Properly support Extensions.GetManagedSize() for byreflike types
MonoMod · Dec 12, 2024 · 26a0a4d · 26a0a4d
2 parents c52e274 + 6e94f66
commit 26a0a4d
Showing 5 changed files with 56 additions and 4 deletions.
diff --git a/src/MonoMod.Core/MonoMod.Core.csproj b/src/MonoMod.Core/MonoMod.Core.csproj
@@ -12,7 +12,7 @@
     </Description>
     <PackageTags>RuntimeDetour;detour;detours;$(PackageTags)</PackageTags>
 
-    <VersionPrefix>1.2.1</VersionPrefix>
+    <VersionPrefix>1.2.2</VersionPrefix>
     <PackageValidationBaselineVersion>1.0.0</PackageValidationBaselineVersion>
 
     <MMIncludeTFMChecks>true</MMIncludeTFMChecks>

diff --git a/src/MonoMod.RuntimeDetour/MonoMod.RuntimeDetour.csproj b/src/MonoMod.RuntimeDetour/MonoMod.RuntimeDetour.csproj
@@ -13,7 +13,7 @@
 
     <MMIncludeTFMChecks>true</MMIncludeTFMChecks>
 
-    <VersionPrefix>25.2.1</VersionPrefix>
+    <VersionPrefix>25.2.2</VersionPrefix>
     <PackageValidationBaselineVersion>25.0.0</PackageValidationBaselineVersion>
   </PropertyGroup>
 

diff --git a/src/MonoMod.UnitTest/SizeofByRefLikeTest.cs b/src/MonoMod.UnitTest/SizeofByRefLikeTest.cs
@@ -0,0 +1,35 @@
+using MonoMod.Utils;
+using System;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace MonoMod.UnitTest
+{
+    public unsafe class SizeofByRefLikeTest : TestBase
+    {
+        public SizeofByRefLikeTest(ITestOutputHelper helper) : base(helper)
+        {
+        }
+
+        [Theory]
+        [InlineData(typeof(int))]
+        [InlineData(typeof(string))]
+        [InlineData(typeof(SizeofByRefLikeTest))]
+        [InlineData(typeof(ReadOnlySpan<char>))]
+        [InlineData(typeof(ReadOnlyMemory<char>))]
+        [InlineData(typeof(Span<byte>))]
+        [InlineData(typeof(void*))]
+        [InlineData(typeof(int*))]
+        [InlineData(typeof(int), true)]
+        [InlineData(typeof(string), true)]
+        [InlineData(typeof(object), true)]
+        public void SizeofDoesNotThrow(Type t, bool byref = false)
+        {
+            if (byref)
+            {
+                t = t.MakeByRefType();
+            }
+            _ = t.GetManagedSize();
+        }
+    }
+}
diff --git a/src/MonoMod.Utils/Extensions.Unsafe.cs b/src/MonoMod.Utils/Extensions.Unsafe.cs
@@ -26,7 +26,9 @@ public static partial class Extensions
         /// <param name="t">The type to get the size from.</param>
         /// <returns>The managed type size.</returns>
         public static int GetManagedSize(this Type t)
-            => _GetManagedSizeCache.GetOrAdd(Helpers.ThrowIfNull(t), ComputeManagedSize);
+            => Helpers.ThrowIfNull(t).IsByRef || t.IsPointer
+                ? IntPtr.Size
+                : _GetManagedSizeCache.GetOrAdd(Helpers.ThrowIfNull(t), ComputeManagedSize);
 
         private static int ComputeManagedSize(Type t)
         {
@@ -36,9 +38,24 @@ private static int ComputeManagedSize(Type t)
                 _GetManagedSizeHelper = szHelper = typeof(Unsafe).GetMethod(nameof(Unsafe.SizeOf))!;
             }
 
+            if (t.IsByRef || t.IsPointer || t.IsByRefLike())
+            {
+                // cannot instantiate a generic method on a byref, byreflike, or pointer type
+                return GenerateAndInvokeSizeofHelper(t);
+            }
+
             return szHelper.MakeGenericMethod(t).CreateDelegate<Func<int>>()();
         }
 
+        private static int GenerateAndInvokeSizeofHelper(Type t)
+        {
+            using var dmd = new DynamicMethodDefinition($"SizeOf<{t}>", typeof(int), []);
+            var il = dmd.GetILProcessor();
+            il.Emit(OpCodes.Sizeof, il.Import(t));
+            il.Emit(OpCodes.Ret);
+            return (int)dmd.Generate().Invoke(null, null)!;
+        }
+
         /// <summary>
         /// Get a type which matches what the method should receive via ldarg.0
         /// </summary>

diff --git a/src/MonoMod.Utils/MonoMod.Utils.csproj b/src/MonoMod.Utils/MonoMod.Utils.csproj
@@ -12,7 +12,7 @@
     <!-- Disable "Dispose objects before losing scope" because it utterly chokes on this project -->
     <NoWarn>$(NoWarn);CA2000</NoWarn>
 
-    <VersionPrefix>25.0.7</VersionPrefix>
+    <VersionPrefix>25.0.8</VersionPrefix>
     <PackageValidationBaselineVersion>25.0.0</PackageValidationBaselineVersion>
   </PropertyGroup>