Fixing and synchronizing dumper

Author: kohanis

Harmony/Internal/Util/CecilEmitter.cs

@@ -1,6 +1,7 @@
 using HarmonyLib.Tools;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
+using Mono.Collections.Generic;
 using MonoMod.Cil;
 using MonoMod.Utils;
 using System;
@@ -19,7 +20,7 @@ namespace HarmonyLib.Internal.Util;
 /// <summary>
 /// Basic safe DLL emitter for dynamically generated <see cref="MethodDefinition"/>s.
 /// </summary>
-/// <remarks>Based on https://github.com/MonoMod/MonoMod.Common/blob/master/Utils/DMDGenerators/DMDCecilGenerator.cs</remarks>
+/// <remarks>Based on https://github.com/MonoMod/MonoMod/blob/reorganize/src/MonoMod.Utils/DMDGenerators/DMDCecilGenerator.cs</remarks>
 internal static class CecilEmitter
 {
 	private static readonly ConstructorInfo UnverifiableCodeAttributeConstructor =
@@ -49,26 +50,43 @@ public static void Dump(MethodDefinition md, IEnumerable<string> dumpPaths, Meth
 
 		MethodDefinition clone = null;
 
+		/* see below
 		var isVolatile = new TypeReference("System.Runtime.CompilerServices", "IsVolatile", module,
 			module.TypeSystem.CoreLibrary);
+		*/
 
-		Relinker relinker = (mtp, _) => mtp == md ? clone : module.ImportReference(mtp);
+		Relinker relinker = (mtp, _) =>
+		{
+			if (mtp == md)
+				return clone!;
+			if (mtp is MethodReference mr)
+			{
+				if (mr.FullName == md.FullName
+				    && mr.DeclaringType.FullName == md.DeclaringType.FullName
+				    && mr.DeclaringType.Scope.Name == md.DeclaringType.Scope.Name)
+					return clone!;
+			}
+			return module.ImportReference(mtp);
+		};
 
 		clone =
 			new MethodDefinition(original?.Name ?? "_" + md.Name.Replace(".", "_"), md.Attributes, module.TypeSystem.Void)
 			{
 				MethodReturnType = md.MethodReturnType,
-				Attributes = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Static,
+				Attributes = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Public | MethodAttributes.Static,
 				ImplAttributes = MethodImplAttributes.IL | MethodImplAttributes.Managed,
 				DeclaringType = td,
-				HasThis = false
+				HasThis = false,
+				NoInlining = true
 			};
+
 		td.Methods.Add(clone);
 
 		foreach (var param in md.Parameters)
 			clone.Parameters.Add(param.Clone().Relink(relinker, clone));
 
 		clone.ReturnType = md.ReturnType.Relink(relinker, clone);
+
 		var body = clone.Body = md.Body.Clone(clone);
 
 		foreach (var variable in clone.Body.Variables)
@@ -83,15 +101,25 @@ public static void Dump(MethodDefinition md, IEnumerable<string> dumpPaths, Meth
 			operand = operand switch
 			{
 				ParameterDefinition param  => clone.Parameters[param.Index],
-				ILLabel label => label.Target,
+				ILLabel label => LabelFix(label, body.Instructions, md.Body.Instructions),
 				IMetadataTokenProvider mtp => mtp.Relink(relinker, clone),
 				_                          => operand
 			};
 
-			if (instr.Previous?.OpCode == OpCodes.Volatile &&
-			    operand is FieldReference fref &&
-			    (fref.FieldType as RequiredModifierType)?.ModifierType != isVolatile)
-				fref.FieldType = new RequiredModifierType(isVolatile, fref.FieldType);
+			// System.Reflection doesn't contain any volatility info.
+			// System.Reflection.Emit presumably does something similar to this.
+			// Mono.Cecil thus isn't aware of the volatility as part of the imported field reference.
+			// The modifier is still necessary though.
+			// This is done here instead of the copier as Harmony and other users can't track modreqs
+
+			// This isn't actually a valid transformation though. A ldfld or stfld can have the volatile
+			// prefix, without having modreq(IsVolatile) on the field. Adding the modreq() causes the runtime
+			// to not be able to find the field.
+			/*if (instr.Previous?.OpCode == OpCodes.Volatile &&
+			   operand is FieldReference fref &&
+			   (fref.FieldType as RequiredModifierType)?.ModifierType != tr_IsVolatile) {
+			   fref.FieldType = new RequiredModifierType(tr_IsVolatile, fref.FieldType);
+			}*/
 
 			instr.Operand = operand;
 		}
@@ -129,4 +157,15 @@ private static string SanitizeTypeName(string typeName)
 			.Replace("<", "{")
 			.Replace(">", "}");
 	}
+
+	private static Instruction LabelFix(ILLabel label, Collection<Instruction> clone, Collection<Instruction> original)
+	{
+		var target = label.Target;
+		if (!clone.Contains(target))
+		{
+			var idx = original.IndexOf(label.Target);
+			if (idx != -1) return clone[idx];
+		}
+		return target;
+	}
 }