Fixed ReversePatching, added GetOriginalInstructions

pardeike · Jan 25, 2020 · 8c2cf47 · 8c2cf47
1 parent a2c0eeb
commit 8c2cf47
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Showing 5 changed files with 32 additions and 23 deletions.
diff --git a/Harmony/Internal/MethodPatcher.cs b/Harmony/Internal/MethodPatcher.cs
@@ -1,10 +1,9 @@
+using MonoMod.RuntimeDetour;
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Reflection.Emit;
-using MonoMod.RuntimeDetour;
-using MonoMod.Utils;
 
 namespace HarmonyLib
 {
@@ -20,7 +19,7 @@ internal static class MethodPatcher
 		public static string PARAM_INDEX_PREFIX = "__";
 		public static string INSTANCE_FIELD_PREFIX = "___";
 
-		public static MethodInfo CreatePatchedMethod(MethodBase original, MethodBase source, string harmonyInstanceID, List<MethodInfo> prefixes, List<MethodInfo> postfixes, List<MethodInfo> transpilers, List<MethodInfo> finalizers)
+		internal static MethodInfo CreatePatchedMethod(MethodBase original, MethodBase source, string harmonyInstanceID, List<MethodInfo> prefixes, List<MethodInfo> postfixes, List<MethodInfo> transpilers, List<MethodInfo> finalizers)
 		{
 			try
 			{

diff --git a/Harmony/Internal/PatchFunctions.cs b/Harmony/Internal/PatchFunctions.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Reflection;
 using System.Reflection.Emit;
 
@@ -164,28 +165,24 @@ internal static MethodInfo ReversePatch(HarmonyMethod standin, MethodBase origin
 			if (standin.method == null)
 				throw new ArgumentNullException($"{nameof(standin)}.{nameof(standin.method)}");
 
-			var processor = instance.CreateProcessor(standin.method);
+			var transpilers = new List<MethodInfo>();
 			if (standin.reversePatchType == HarmonyReversePatchType.Snapshot)
 			{
 				var info = Harmony.GetPatchInfo(original);
-				foreach (var tr in info.Transpilers)
-				{
-					var transpiler = new HarmonyMethod(tr.GetMethod(original))
-					{
-						before = tr.before,
-						after = tr.after,
-
-						priority = tr.priority
-					};
-					_ = processor.AddTranspiler(transpiler);
-				}
+				transpilers.AddRange(GetSortedPatchMethods(original, info.Transpilers.ToArray()));
 			}
-			if (postTranspiler != null)
-			{
-				var transpiler = new HarmonyMethod(postTranspiler) { priority = int.MinValue };
-				_ = processor.AddTranspiler(transpiler);
-			}
-			return processor.Patch();
+			if (postTranspiler != null) transpilers.Add(postTranspiler);
+
+			var empty = new List<MethodInfo>();
+			var replacement = MethodPatcher.CreatePatchedMethod(standin.method, original, instance.Id, empty, empty, transpilers, empty);
+			if (replacement == null) throw new MissingMethodException($"Cannot create dynamic replacement for {standin.method.FullDescription()}");
+
+			var errorString = Memory.DetourMethod(standin.method, replacement);
+			if (errorString != null)
+				throw new FormatException($"Method {standin.method.FullDescription()} cannot be patched. Reason: {errorString}");
+
+			PatchTools.RememberObject(standin.method, replacement);
+			return replacement;
 		}
 	}
 }
diff --git a/Harmony/Public/PatchProcessor.cs b/Harmony/Public/PatchProcessor.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Reflection.Emit;
 
 namespace HarmonyLib
 {
@@ -236,5 +237,17 @@ public static Patches GetPatchInfo(MethodBase method)
 			});
 			return result;
 		}
+
+		/// <summary>Returns the methods unmodified list of CodeInstructions</summary>
+		/// <param name="original">The original method</param>
+		/// <param name="generator">The generator that now contains all local variables and labels contained in the result</param>
+		/// <returns>A list containing all the original CodeInstructions</returns>
+		public static List<CodeInstruction> GetOriginalInstructions(MethodBase original, out ILGenerator generator)
+		{
+			var patch = DynamicTools.CreateDynamicMethod(original, $"_Copy{Guid.NewGuid()}");
+			generator = patch.GetILGenerator();
+			var reader = MethodBodyReader.GetInstructions(generator, original);
+			return reader.Select(ins => ins.GetCodeInstruction()).ToList();
+		}
 	}
 }
diff --git a/HarmonyTests/ReversePatching/AttributeReversePatches.cs b/HarmonyTests/ReversePatching/AttributeReversePatches.cs
@@ -7,7 +7,7 @@ namespace HarmonyLibTests
 	[TestFixture]
 	public class AttributeReversePatches
 	{
-		//[Test]
+		[Test]
 		public void Test_ReversePatchingWithAttributes()
 		{
 			var test = new Class1Reverse();

diff --git a/HarmonyTests/ReversePatching/ReverseTranspiling.cs b/HarmonyTests/ReversePatching/ReverseTranspiling.cs
@@ -7,7 +7,7 @@ namespace HarmonyLibTests
 	[TestFixture]
 	public class ReverseTranspiling
 	{
-		//[Test]
+		[Test]
 		public void Test_ReverseTranspilerPatching()
 		{
 			var class0 = new Class0Reverse();