From 759a77031ebd91aa81735b216102d00c6ffbf94b Mon Sep 17 00:00:00 2001
From: Katy Coe <djkaty@start.no>
Date: Sun, 2 Feb 2020 04:45:43 +0100
Subject: [PATCH] Model: Substitute concrete parameter types into generic
 methods from MethodSpecs

---
 Il2CppInspector/Reflection/MethodBase.cs    | 10 +++++++++-
 Il2CppInspector/Reflection/ParameterInfo.cs | 12 +++++++++++-
 Il2CppTests/TestSources/GenericTypes.cs     |  1 -
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/Il2CppInspector/Reflection/MethodBase.cs b/Il2CppInspector/Reflection/MethodBase.cs
index 966c9c9..557350e 100644
--- a/Il2CppInspector/Reflection/MethodBase.cs
+++ b/Il2CppInspector/Reflection/MethodBase.cs
@@ -152,7 +152,14 @@ namespace Il2CppInspector.Reflection
             IsGenericMethod = true;
             genericArguments = model.ResolveGenericArguments(spec.methodIndexIndex);
 
-            // TODO: Substitute generic type arguments for concrete type arguments
+            // Substitute matching generic type parameters with concrete type arguments
+            foreach (var p in methodDef.DeclaredParameters) {
+                if (!p.ParameterType.IsGenericMethodParameter)
+                    DeclaredParameters.Add(p);
+                else
+                    DeclaredParameters.Add(new ParameterInfo(model, p, genericArguments[p.ParameterType.GenericParameterPosition]));
+            }
+
             // TODO: Populate VirtualAddress via Il2CppGenericMethodFunctionsDefinitions
         }
 
@@ -219,6 +226,7 @@ namespace Il2CppInspector.Reflection
         public string GetTypeParametersString(Scope usingScope) => !GetGenericArguments().Any()? "" :
             "<" + string.Join(", ", GetGenericArguments().Select(p => p.GetScopedCSharpName(usingScope))) + ">";
 
+        // TODO: The scope output for some System types does not match the real .NET output here
         public string GetFullTypeParametersString() => !GetGenericArguments().Any()? "" :
             "[" + string.Join(",", GetGenericArguments().Select(p => p.FullName ?? p.Name)) + "]";
 
diff --git a/Il2CppInspector/Reflection/ParameterInfo.cs b/Il2CppInspector/Reflection/ParameterInfo.cs
index 1c00750..9630c16 100644
--- a/Il2CppInspector/Reflection/ParameterInfo.cs
+++ b/Il2CppInspector/Reflection/ParameterInfo.cs
@@ -97,7 +97,17 @@ namespace Il2CppInspector.Reflection
 
         // Create a concrete type parameter from a generic type parameter
         public ParameterInfo(Il2CppModel model, ParameterInfo generic, TypeInfo concrete) {
-            // TODO: Implement generic parameter substitution
+
+            DeclaringMethod = generic.DeclaringMethod;
+            Name = generic.Name;
+            Position = generic.Position;
+            Attributes = generic.Attributes;
+
+            // TODO: Duplicate instances of 'concrete' may cause this search to fail. Replace with a straight lookup after eliminating GetTypeFromVirtualAddress
+            paramTypeReference = Array.IndexOf(model.TypesByReferenceIndex, concrete);
+
+            DefaultValue = generic.DefaultValue;
+            DefaultValueMetadataAddress = generic.DefaultValueMetadataAddress;
         }
 
         // ref will be handled as part of the type name
diff --git a/Il2CppTests/TestSources/GenericTypes.cs b/Il2CppTests/TestSources/GenericTypes.cs
index 5dfb56c..50b2283 100644
--- a/Il2CppTests/TestSources/GenericTypes.cs
+++ b/Il2CppTests/TestSources/GenericTypes.cs
@@ -6,7 +6,6 @@
 
 using System;
 using System.Collections.Generic;
-using Il2CppInspector;
 
 namespace Il2CppTests.TestSources
 {