CapersProject/Packages/com.singularitygroup.hotreload/Runtime/MethodCompatiblity.cs

111 lines
5.2 KiB
C#

#if ENABLE_MONO && (DEVELOPMENT_BUILD || UNITY_EDITOR)
using System;
using System.Reflection;
using SingularityGroup.HotReload.MonoMod.Utils;
namespace SingularityGroup.HotReload {
static class MethodCompatiblity {
internal static bool AreMethodsCompatible(MethodBase previousMethod, MethodBase patchMethod) {
var previousConstructor = previousMethod as ConstructorInfo;
var patchConstructor = patchMethod as ConstructorInfo;
if(previousConstructor != null && !ReferenceEquals(patchConstructor, null)) {
return AreConstructorsCompatible(previousConstructor, patchConstructor);
}
var previousMethodInfo = previousMethod as MethodInfo;
var patchMethodInfo = patchMethod as MethodInfo;
if(!ReferenceEquals(previousMethodInfo, null) && !ReferenceEquals(patchMethodInfo, null)) {
return AreMethodInfosCompatible(previousMethodInfo, patchMethodInfo);
}
return false;
}
static bool AreMethodBasesCompatible(MethodBase previousMethod, MethodBase patchMethod) {
if(previousMethod.Name != patchMethod.Name) {
return false;
}
//Declaring type of patch method is different from the target method but their full name (namespace + name) is equal
if(previousMethod.DeclaringType.FullName != patchMethod.DeclaringType.FullName) {
return false;
}
//Check in case type parameter overloads to distinguish between: void M<T>() { } <-> void M() { }
if(previousMethod.IsGenericMethodDefinition != patchMethod.IsGenericMethodDefinition) {
return false;
}
var prevParams = previousMethod.GetParameters();
var patchParams = patchMethod.GetParameters();
ArraySegment<ParameterInfo> patchParamsSegment;
bool patchMethodHasExplicitThis;
if(previousMethod.IsStatic || previousMethod.Name.Contains("<") && !patchMethod.IsStatic) {
patchMethodHasExplicitThis = false;
} else {
patchMethodHasExplicitThis = true;
}
if(LikelyHasExplicitThis(prevParams, patchParams, previousMethod)) {
patchMethodHasExplicitThis = true;
}
//Special edge case: User added static keyword to method. No explicit this will be generated in that case
if(!previousMethod.IsStatic && patchMethod.IsStatic && !LikelyHasExplicitThis(prevParams, patchParams, previousMethod)) {
patchMethodHasExplicitThis = false;
}
if(patchMethodHasExplicitThis) {
//Special case: patch method for an instance method is static and has an explicit this parameter.
//If the patch method doesn't have any parameters it is not compatible.
if(patchParams.Length == 0) {
return false;
}
//this parameter has to be the declaring type
if(!ParamTypeMatches(patchParams[0].ParameterType, previousMethod.DeclaringType)) {
return false;
}
//Ignore the this parameter and compare the remaining ones.
patchParamsSegment = new ArraySegment<ParameterInfo>(patchParams, 1, patchParams.Length - 1);
} else {
patchParamsSegment = new ArraySegment<ParameterInfo>(patchParams);
}
return CompareParameters(new ArraySegment<ParameterInfo>(prevParams), patchParamsSegment);
}
static bool LikelyHasExplicitThis(ParameterInfo[] prevParams, ParameterInfo[] patchParams, MethodBase previousMethod) {
if (patchParams.Length != prevParams.Length + 1) {
return false;
}
var patchT = patchParams[0].ParameterType;
if (!ParamTypeMatches(patchT, previousMethod.DeclaringType)) {
return false;
}
if (prevParams.Length >= 1 && prevParams[0].ParameterType == previousMethod.DeclaringType) {
return false;
}
return patchParams[0].Name == "this";
}
static bool ParamTypeMatches(Type patchT, Type originalT) {
return patchT == originalT || patchT.IsByRef && patchT.GetElementType() == originalT;
}
static bool CompareParameters(ArraySegment<ParameterInfo> x, ArraySegment<ParameterInfo> y) {
if(x.Count != y.Count) {
return false;
}
for (var i = 0; i < x.Count; i++) {
if(x.Array[i + x.Offset].ParameterType != y.Array[i + y.Offset].ParameterType) {
return false;
}
}
return true;
}
static bool AreConstructorsCompatible(ConstructorInfo x, ConstructorInfo y) {
return AreMethodBasesCompatible(x, y);
}
static bool AreMethodInfosCompatible(MethodInfo x, MethodInfo y) {
return AreMethodBasesCompatible(x, y) && x.ReturnType == y.ReturnType;
}
}
}
#endif