From baa51ffea1bf25f4900bbe4b85ea8efbc6f103a6 Mon Sep 17 00:00:00 2001
From: ManlyMarco <39247311+ManlyMarco@users.noreply.github.com>
Date: Tue, 23 Jan 2024 11:46:45 +0100
Subject: [PATCH] Add HarmonyOptional attribute
---
Harmony/Public/Attributes.cs | 27 +++++++++++++++++++
Harmony/Public/HarmonyMethod.cs | 4 +++
Harmony/Public/PatchClassProcessor.cs | 28 ++++++++++++++++++-
HarmonyTests/Patching/Assets/Specials.cs | 34 ++++++++++++++++++++++++
HarmonyTests/Patching/Specials.cs | 13 ++++++++-
5 files changed, 104 insertions(+), 2 deletions(-)
diff --git a/Harmony/Public/Attributes.cs b/Harmony/Public/Attributes.cs
index 80eb0103..ac37b59d 100644
--- a/Harmony/Public/Attributes.cs
+++ b/Harmony/Public/Attributes.cs
@@ -777,4 +777,31 @@ public HarmonyArgument(int index, string name)
NewName = name;
}
}
+
+ /// Flags used for optionally patching members that might not exist.
+ ///
+ [Flags]
+ public enum OptionalFlags
+ {
+ /// Default behavior (throw and abort patching if there are no matches).
+ ///
+ None = 0,
+
+ /// Do not throw an exception and abort the patching process if no matches are found (a warning is logged instead).
+ ///
+ AllowNoMatches = 1 << 1,
+ }
+
+ /// Attribute used for optionally patching members that might not exist.
+ ///
+ [AttributeUsage(AttributeTargets.Method)]
+ public class HarmonyOptional : HarmonyAttribute
+ {
+ /// Default constructor
+ ///
+ public HarmonyOptional(OptionalFlags flags = OptionalFlags.AllowNoMatches)
+ {
+ info.optionalFlags = flags;
+ }
+ }
}
diff --git a/Harmony/Public/HarmonyMethod.cs b/Harmony/Public/HarmonyMethod.cs
index dd741713..c72c9a55 100644
--- a/Harmony/Public/HarmonyMethod.cs
+++ b/Harmony/Public/HarmonyMethod.cs
@@ -66,6 +66,10 @@ public class HarmonyMethod
/// Whether to wrap the patch itself into a try/catch.
///
public bool? wrapTryCatch;
+
+ /// Flags used for optionally patching members that might not exist.
+ ///
+ public OptionalFlags? optionalFlags;
/// Default constructor
///
diff --git a/Harmony/Public/PatchClassProcessor.cs b/Harmony/Public/PatchClassProcessor.cs
index e5817b11..5460b67a 100644
--- a/Harmony/Public/PatchClassProcessor.cs
+++ b/Harmony/Public/PatchClassProcessor.cs
@@ -5,6 +5,7 @@
using System.Text;
using HarmonyLib.Public.Patching;
using HarmonyLib.Tools;
+using MonoMod.Utils;
namespace HarmonyLib
{
@@ -59,7 +60,7 @@ public PatchClassProcessor(Harmony instance, Type type, bool allowUnannotatedTyp
containerAttributes = HarmonyMethod.Merge(harmonyAttributes);
if (containerAttributes.methodType is null) // MethodType default is Normal
containerAttributes.methodType = MethodType.Normal;
-
+
this.Category = containerAttributes.category;
auxilaryMethods = new Dictionary();
@@ -128,8 +129,18 @@ void ReversePatch(ref MethodBase lastOriginal)
var annotatedOriginal = patchMethod.info.GetOriginalMethod();
if (annotatedOriginal is object)
lastOriginal = annotatedOriginal;
+
if (lastOriginal is null)
+ {
+ if (IsPatchOptional(patchMethod))
+ {
+ Logger.Log(Logger.LogChannel.Warn, () => $"Skipping optional reverse patch {patchMethod.info.method.FullDescription()} - target method not found");
+ continue;
+ }
+
throw new ArgumentException($"Undefined target method for reverse patch method {patchMethod.info.method.FullDescription()}");
+ }
+
var reversePatcher = instance.CreateReversePatcher(lastOriginal, patchMethod.info);
lock (PatchProcessor.locker)
_ = reversePatcher.Patch();
@@ -173,7 +184,15 @@ List PatchWithAttributes(ref MethodBase lastOriginal)
{
lastOriginal = patchMethod.info.GetOriginalMethod();
if (lastOriginal is null)
+ {
+ if (IsPatchOptional(patchMethod))
+ {
+ Logger.Log(Logger.LogChannel.Warn, () => $"Skipping optional patch {patchMethod.info.method.FullDescription()} - target method not found");
+ continue;
+ }
+
throw new ArgumentException($"Undefined target method for patch method {patchMethod.info.method.FullDescription()}");
+ }
var job = jobs.GetJob(lastOriginal);
job.AddPatch(patchMethod);
@@ -186,6 +205,13 @@ List PatchWithAttributes(ref MethodBase lastOriginal)
return jobs.GetReplacements();
}
+ static bool IsPatchOptional(AttributePatch patchMethod)
+ {
+ var optionalFlags = patchMethod.info.optionalFlags;
+ var isOptional = optionalFlags != null && optionalFlags.Value.Has(OptionalFlags.AllowNoMatches);
+ return isOptional;
+ }
+
void ProcessPatchJob(PatchJobs.Job job)
{
MethodInfo replacement = default;
diff --git a/HarmonyTests/Patching/Assets/Specials.cs b/HarmonyTests/Patching/Assets/Specials.cs
index e8e821f2..4eb1a0a6 100644
--- a/HarmonyTests/Patching/Assets/Specials.cs
+++ b/HarmonyTests/Patching/Assets/Specials.cs
@@ -127,6 +127,40 @@ public static void ReplaceGetValue(ref bool __result)
}
}
+ public class OptionalPatch
+ {
+ [HarmonyPrefix, HarmonyOptional, HarmonyPatch(typeof(OptionalPatch), "missing_method")]
+ public static void Test0() => throw new InvalidOperationException();
+
+ [HarmonyReversePatch, HarmonyOptional, HarmonyPatch(typeof(OptionalPatch), "missing_method")]
+ public static void Test1() => throw new InvalidOperationException();
+
+ [HarmonyPostfix, HarmonyOptional, HarmonyPatch(typeof(OptionalPatch), MethodType.Constructor, typeof(string))]
+ public static void Test2() => throw new InvalidOperationException();
+
+ [HarmonyTranspiler, HarmonyOptional, HarmonyPatch(typeof(OptionalPatch), "missing_method", MethodType.Getter)]
+ public static void Test3() => throw new InvalidOperationException();
+
+ [HarmonyPostfix, HarmonyOptional, HarmonyPatch(typeof(OptionalPatch), nameof(NotEnumerator), MethodType.Enumerator)]
+ public static void Test4() => throw new InvalidOperationException();
+
+ [HarmonyPostfix, HarmonyOptional, HarmonyPatch(typeof(OptionalPatch), nameof(NotEnumerator), MethodType.Async)]
+ public static void Test5() => throw new InvalidOperationException();
+
+ private void NotEnumerator() => throw new InvalidOperationException();
+ }
+
+ public static class OptionalPatchNone
+ {
+ [HarmonyPrefix]
+ [HarmonyOptional(OptionalFlags.None)]
+ [HarmonyPatch(typeof(OptionalPatch), "missing_method")]
+ public static void Prefix()
+ {
+ throw new InvalidOperationException();
+ }
+ }
+
public static class SafeWrapPatch
{
public static bool called = false;
diff --git a/HarmonyTests/Patching/Specials.cs b/HarmonyTests/Patching/Specials.cs
index 7800c3ad..917657d5 100644
--- a/HarmonyTests/Patching/Specials.cs
+++ b/HarmonyTests/Patching/Specials.cs
@@ -42,6 +42,17 @@ public void Test_HttpWebRequestGetResponse()
}
*/
+ [Test]
+ public void Test_Optional_Patch()
+ {
+ var instance = new Harmony("special-case-optional-patch");
+ Assert.NotNull(instance);
+
+ Assert.DoesNotThrow(() => instance.PatchAll(typeof(OptionalPatch)));
+
+ Assert.Throws(() => instance.PatchAll(typeof(OptionalPatchNone)));
+ }
+
[Test]
public void Test_Wrap_Patch()
{
@@ -185,7 +196,7 @@ public void Test_Enumerator_Patch()
Assert.AreEqual("MoveNext", EnumeratorPatch.patchTarget.Name);
var testObject = new EnumeratorCode();
- Assert.AreEqual(new []{ 1, 2, 3, 4, 5 }, testObject.NumberEnumerator().ToArray());
+ Assert.AreEqual(new[] { 1, 2, 3, 4, 5 }, testObject.NumberEnumerator().ToArray());
Assert.AreEqual(6, EnumeratorPatch.runTimes);
}