Add methods for resolving il2cpp definitions to their contexts (#364)

Author: ds5678

Cpp2IL.Core.Tests/MemberResolutionTests.cs

@@ -0,0 +1,53 @@
+using System.Linq;
+
+namespace Cpp2IL.Core.Tests;
+
+public class MemberResolutionTests
+{
+    [SetUp]
+    public void Setup()
+    {
+        Cpp2IlApi.ResetInternalState();
+        TestGameLoader.LoadSimple2019Game();
+    }
+
+    [Test]
+    public void TestMethodResolving()
+    {
+        var appContext = Cpp2IlApi.CurrentAppContext;
+
+        var methodContext = appContext!.AllTypes.SelectMany(t => t.Methods).First(m => m.Definition is not null);
+
+        Assert.That(appContext.ResolveContextForMethod(methodContext.Definition), Is.EqualTo(methodContext));
+    }
+
+    [Test]
+    public void TestFieldResolving()
+    {
+        var appContext = Cpp2IlApi.CurrentAppContext;
+
+        var fieldContext = appContext!.AllTypes.SelectMany(t => t.Fields).First(f => f.BackingData?.Field is not null);
+
+        Assert.That(appContext.ResolveContextForField(fieldContext.BackingData!.Field), Is.EqualTo(fieldContext));
+    }
+
+    [Test]
+    public void TestEventResolving()
+    {
+        var appContext = Cpp2IlApi.CurrentAppContext;
+
+        var eventContext = appContext!.AllTypes.SelectMany(t => t.Events).First(e => e.Definition is not null);
+
+        Assert.That(appContext.ResolveContextForEvent(eventContext.Definition), Is.EqualTo(eventContext));
+    }
+
+    [Test]
+    public void TestPropertyResolving()
+    {
+        var appContext = Cpp2IlApi.CurrentAppContext;
+
+        var propertyContext = appContext!.AllTypes.SelectMany(t => t.Properties).First(p => p.Definition is not null);
+
+        Assert.That(appContext.ResolveContextForProperty(propertyContext.Definition), Is.EqualTo(propertyContext));
+    }
+}

Cpp2IL.Core/Model/Contexts/ApplicationAnalysisContext.cs

@@ -161,7 +161,32 @@ private void PopulateMethodsByAddressTable()
         return AssembliesByName[name];
     }
 
-    public TypeAnalysisContext? ResolveContextForType(Il2CppTypeDefinition typeDefinition) => GetAssemblyByName(typeDefinition.DeclaringAssembly!.Name!)?.GetTypeByDefinition(typeDefinition);
+    public TypeAnalysisContext? ResolveContextForType(Il2CppTypeDefinition? typeDefinition)
+    {
+        return typeDefinition is not null
+            ? GetAssemblyByName(typeDefinition.DeclaringAssembly!.Name!)?.GetTypeByDefinition(typeDefinition)
+            : null;
+    }
+
+    public MethodAnalysisContext? ResolveContextForMethod(Il2CppMethodDefinition? methodDefinition)
+    {
+        return ResolveContextForType(methodDefinition?.DeclaringType)?.Methods.FirstOrDefault(m => m.Definition == methodDefinition);
+    }
+
+    public FieldAnalysisContext? ResolveContextForField(Il2CppFieldDefinition? field)
+    {
+        return ResolveContextForType(field?.DeclaringType)?.Fields.FirstOrDefault(f => f.BackingData?.Field == field);
+    }
+
+    public EventAnalysisContext? ResolveContextForEvent(Il2CppEventDefinition? eventDefinition)
+    {
+        return ResolveContextForType(eventDefinition?.DeclaringType)?.Events.FirstOrDefault(e => e.Definition == eventDefinition);
+    }
+
+    public PropertyAnalysisContext? ResolveContextForProperty(Il2CppPropertyDefinition? propertyDefinition)
+    {
+        return ResolveContextForType(propertyDefinition?.DeclaringType)?.Properties.FirstOrDefault(p => p.Definition == propertyDefinition);
+    }
 
     public BaseKeyFunctionAddresses GetOrCreateKeyFunctionAddresses()
     {

Cpp2IL.Core/Model/Contexts/ConcreteGenericMethodAnalysisContext.cs

@@ -35,8 +35,8 @@ private ConcreteGenericMethodAnalysisContext(Cpp2IlMethodRef methodRef, Assembly
         DeclaringAsm = declaringAssembly;
         BaseMethodContext = ResolveBaseMethod(methodRef, declaringAssembly.GetTypeByDefinition(methodRef.DeclaringType)!);
 
-        var genericTypeParameters = ResolveTypeArray(methodRef.TypeGenericParams, declaringAssembly);
-        var genericMethodParameters = ResolveTypeArray(methodRef.MethodGenericParams, declaringAssembly);
+        var genericTypeParameters = ResolveTypeGenericParameters();
+        var genericMethodParameters = ResolveMethodGenericParameters();
 
         for (var i = 0; i < BaseMethodContext.Parameters.Count; i++)
         {
@@ -58,6 +58,10 @@ private ConcreteGenericMethodAnalysisContext(Cpp2IlMethodRef methodRef, Assembly
             rawMethodBody = AppContext.InstructionSet.GetRawBytesForMethod(this, false);
     }
 
+    public TypeAnalysisContext[] ResolveTypeGenericParameters() => ResolveTypeArray(MethodRef.TypeGenericParams, DeclaringAsm);
+
+    public TypeAnalysisContext[] ResolveMethodGenericParameters() => ResolveTypeArray(MethodRef.MethodGenericParams, DeclaringAsm);
+
     private static AssemblyAnalysisContext ResolveDeclaringAssembly(Cpp2IlMethodRef methodRef, ApplicationAnalysisContext context)
     {
         return context.GetAssemblyByName(methodRef.DeclaringType.DeclaringAssembly!.Name!)