public void TestGetRuntimeMethodForVirtual()
{
Type type = typeof(StubHelperTests);
MethodInfo methodInfo = type.GetMethod("TestGetRuntimeMethodForVirtual");
Assert.AreEqual(methodInfo, StubHelper.DevirtualizeMethod(type, methodInfo));
}
public static DynamicMethod GenerateStubForVirtualCall(MethodInfo method, TypeInfo constrainedType)
{
Type thisType = constrainedType.MakeByRefType();
MethodInfo actualMethod = StubHelper.DevirtualizeMethod(constrainedType, method);
List <Type> signatureParamTypes = new List <Type>();
signatureParamTypes.Add(thisType);
signatureParamTypes.AddRange(method.GetParameters().Select(p => p.ParameterType));
DynamicMethod stub = new DynamicMethod(
StubHelper.CreateStubNameFromMethod("stub_callvirt", method),
method.ReturnType,
signatureParamTypes.ToArray(),
StubHelper.GetOwningModule(),
true);
ILGenerator ilGenerator = stub.GetILGenerator();
if ((actualMethod.GetMethodBody() == null && !actualMethod.IsAbstract) || StubHelper.IsIntrinsic(actualMethod))
{
// Method has no body or is a compiler intrinsic,
// simply forward arguments to original or shim
for (int i = 0; i < signatureParamTypes.Count; i++)
{
ilGenerator.Emit(OpCodes.Ldarg, i);
}
ilGenerator.Emit(OpCodes.Call, actualMethod);
ilGenerator.Emit(OpCodes.Ret);
return(stub);
}
ilGenerator.DeclareLocal(typeof(IntPtr));
Label rewriteLabel = ilGenerator.DefineLabel();
Label returnLabel = ilGenerator.DefineLabel();
// Inject method info into instruction stream
ilGenerator.Emit(OpCodes.Ldtoken, actualMethod);
ilGenerator.Emit(OpCodes.Ldtoken, actualMethod.DeclaringType);
ilGenerator.Emit(OpCodes.Call, s_getMethodFromHandleMethod);
ilGenerator.Emit(OpCodes.Castclass, typeof(MethodInfo));
// Rewrite method
ilGenerator.MarkLabel(rewriteLabel);
ilGenerator.Emit(OpCodes.Ldc_I4_0);
ilGenerator.Emit(OpCodes.Call, s_createRewriterMethod);
ilGenerator.Emit(OpCodes.Call, s_rewriteMethod);
ilGenerator.Emit(OpCodes.Castclass, typeof(MethodInfo));
// Retrieve pointer to rewritten method
ilGenerator.Emit(OpCodes.Call, s_getMethodPointerMethod);
ilGenerator.Emit(OpCodes.Stloc_0);
// Setup stack and make indirect call
for (int i = 0; i < signatureParamTypes.Count; i++)
{
ilGenerator.Emit(OpCodes.Ldarg, i);
if (i == 0)
{
if (!constrainedType.IsValueType)
{
ilGenerator.Emit(OpCodes.Ldind_Ref);
signatureParamTypes[i] = constrainedType;
}
else
{
if (actualMethod.DeclaringType != constrainedType)
{
ilGenerator.Emit(OpCodes.Ldobj, constrainedType);
ilGenerator.Emit(OpCodes.Box, constrainedType);
signatureParamTypes[i] = actualMethod.DeclaringType;
}
}
}
}
ilGenerator.Emit(OpCodes.Ldloc_0);
ilGenerator.EmitCalli(OpCodes.Calli, CallingConventions.Standard, method.ReturnType, signatureParamTypes.ToArray(), null);
ilGenerator.MarkLabel(returnLabel);
ilGenerator.Emit(OpCodes.Ret);
return(stub);
}