diff --git a/Harmony/Internal/PatchTools.cs b/Harmony/Internal/PatchTools.cs
index 3905e29b..65355073 100644
--- a/Harmony/Internal/PatchTools.cs
+++ b/Harmony/Internal/PatchTools.cs
@@ -65,13 +65,13 @@ internal static MethodBase GetOriginalMethod(this HarmonyMethod attr)
case MethodType.Getter:
if (attr.methodName is null)
- return AccessTools.DeclaredIndexer(attr.declaringType, attr.argumentTypes).GetGetMethod(true);
- return AccessTools.DeclaredProperty(attr.declaringType, attr.methodName).GetGetMethod(true);
+ return AccessTools.DeclaredIndexer(attr.declaringType, attr.argumentTypes)?.GetGetMethod(true);
+ return AccessTools.DeclaredProperty(attr.declaringType, attr.methodName)?.GetGetMethod(true);
case MethodType.Setter:
if (attr.methodName is null)
- return AccessTools.DeclaredIndexer(attr.declaringType, attr.argumentTypes).GetSetMethod(true);
- return AccessTools.DeclaredProperty(attr.declaringType, attr.methodName).GetSetMethod(true);
+ return AccessTools.DeclaredIndexer(attr.declaringType, attr.argumentTypes)?.GetSetMethod(true);
+ return AccessTools.DeclaredProperty(attr.declaringType, attr.methodName)?.GetSetMethod(true);
case MethodType.Constructor:
return AccessTools.DeclaredConstructor(attr.GetDeclaringType(), attr.argumentTypes);
diff --git a/Harmony/Public/Attributes.cs b/Harmony/Public/Attributes.cs
index 80eb0103..7fe50292 100644
--- a/Harmony/Public/Attributes.cs
+++ b/Harmony/Public/Attributes.cs
@@ -777,4 +777,18 @@ public HarmonyArgument(int index, string name)
NewName = name;
}
}
+
+ /// Attribute used for optionally patching members that might not exist.
+ /// Harmony patches with this attribute will not throw an exception and abort the patching process if the target member is not found (a warning is logged instead).
+ ///
+ [AttributeUsage(AttributeTargets.Method)]
+ public class HarmonyOptional : HarmonyAttribute
+ {
+ /// Default constructor
+ ///
+ public HarmonyOptional()
+ {
+ info.optional = true;
+ }
+ }
}
diff --git a/Harmony/Public/HarmonyMethod.cs b/Harmony/Public/HarmonyMethod.cs
index dd741713..28f8c4b2 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;
+
+ /// Whether to not throw/abort when trying to patch members that do not exist (skip instead).
+ ///
+ public bool? optional;
/// Default constructor
///
diff --git a/Harmony/Public/PatchClassProcessor.cs b/Harmony/Public/PatchClassProcessor.cs
index d05e55e2..6baac2c6 100644
--- a/Harmony/Public/PatchClassProcessor.cs
+++ b/Harmony/Public/PatchClassProcessor.cs
@@ -59,7 +59,7 @@ 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();
@@ -128,6 +128,18 @@ void ReversePatch(ref MethodBase lastOriginal)
var annotatedOriginal = patchMethod.info.GetOriginalMethod();
if (annotatedOriginal is object)
lastOriginal = annotatedOriginal;
+
+ if (lastOriginal is null)
+ {
+ if (patchMethod.info.optional == true)
+ {
+ 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();
@@ -171,7 +183,15 @@ List PatchWithAttributes(ref MethodBase lastOriginal)
{
lastOriginal = patchMethod.info.GetOriginalMethod();
if (lastOriginal is null)
+ {
+ if (patchMethod.info.optional == true)
+ {
+ 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);
diff --git a/HarmonyTests/Patching/Assets/Specials.cs b/HarmonyTests/Patching/Assets/Specials.cs
index e8e821f2..3947bcd2 100644
--- a/HarmonyTests/Patching/Assets/Specials.cs
+++ b/HarmonyTests/Patching/Assets/Specials.cs
@@ -127,6 +127,48 @@ 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();
+
+ [HarmonyPrefix]
+ [HarmonyOptional]
+ [HarmonyPatch(typeof(OptionalPatch), "missing_method1")]
+ [HarmonyPatch(typeof(OptionalPatch), nameof(Thrower), MethodType.Normal)]
+ [HarmonyPatch(typeof(OptionalPatch), "missing_method2")]
+ public static bool Test6() => false;
+
+ private void NotEnumerator() => throw new InvalidOperationException();
+ public static void Thrower() => throw new InvalidOperationException();
+ }
+
+ public static class OptionalPatchNone
+ {
+ [HarmonyPrefix]
+ [HarmonyPatch(typeof(OptionalPatch), "missing_method1")]
+ [HarmonyPatch(typeof(OptionalPatchNone), nameof(Thrower), MethodType.Normal)]
+ [HarmonyPatch(typeof(OptionalPatch), "missing_method2")]
+ public static bool Test6() => false;
+
+ public static void Thrower() => 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..c6e09168 100644
--- a/HarmonyTests/Patching/Specials.cs
+++ b/HarmonyTests/Patching/Specials.cs
@@ -42,6 +42,21 @@ public void Test_HttpWebRequestGetResponse()
}
*/
+ [Test]
+ public void Test_Optional_Patch()
+ {
+ var instance = new Harmony("special-case-optional-patch");
+ Assert.NotNull(instance);
+
+ Assert.Throws(OptionalPatch.Thrower);
+ Assert.DoesNotThrow(() => instance.PatchAll(typeof(OptionalPatch)));
+ Assert.DoesNotThrow(OptionalPatch.Thrower);
+
+ Assert.Throws(OptionalPatchNone.Thrower);
+ Assert.Throws(() => instance.PatchAll(typeof(OptionalPatchNone)));
+ Assert.Throws(OptionalPatchNone.Thrower);
+ }
+
[Test]
public void Test_Wrap_Patch()
{
@@ -185,7 +200,7 @@ 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);
}