/// <summary>
/// Rewrites a target method using the given CilWorker.
/// </summary>
/// <param name="method">The target method.</param>
/// <param name="IL">The CilWorker that will be used to rewrite the target method.</param>
/// <param name="oldInstructions">The original instructions from the target method body.</param>
public void Rewrite(MethodDefinition method, CilWorker IL, IEnumerable<Instruction> oldInstructions)
{
if (!ShouldRewrite(method))
return;
var declaringType = method.DeclaringType;
var body = IL.GetBody();
body.InitLocals = true;
var module = declaringType.Module;
// Interfaces and Enums cannot be modified
if (declaringType.IsInterface || declaringType.IsEnum)
return;
ImportReferences(module);
AddLocals(method);
if (!_modifiedTypes.Contains(declaringType))
{
AddAdditionalMembers(declaringType);
_modifiedTypes.Add(declaringType);
}
RewriteMethodBody(method, IL, oldInstructions);
}
/// <summary>
/// Saves the ref arguments of a given method using the
/// <paramref name="arguments"/> from the <paramref name="invocationInfo"/>
/// object.
/// </summary>
/// <param name="IL">The <see cref="CilWorker"/> that will emit the method body.</param>
/// <param name="parameters">The parameters of the target method.</param>
/// <param name="invocationInfo">The local variable that contains the <see cref="IInvocationInfo"/> instance.</param>
/// <param name="arguments">The local variable that will store the arguments from the <see cref="IInvocationInfo"/> instance.</param>
private static void SaveRefArguments(CilWorker IL, IEnumerable<ParameterDefinition> parameters,
VariableDefinition invocationInfo, VariableDefinition arguments)
{
var body = IL.GetBody();
var targetMethod = body.Method;
var declaringType = targetMethod.DeclaringType;
var module = declaringType.Module;
// Save the arguments returned from the handler method
var getArguments = module.ImportMethod<IInvocationInfo>("get_Arguments");
IL.Emit(OpCodes.Ldloc, invocationInfo);
IL.Emit(OpCodes.Callvirt, getArguments);
IL.Emit(OpCodes.Stloc, arguments);
var index = 0;
foreach (var param in parameters)
{
if (!param.IsByRef())
{
index++;
continue;
}
// Load the destination address
IL.Emit(OpCodes.Ldarg, index + 1);
// Load the argument value
IL.Emit(OpCodes.Ldloc, arguments);
IL.Emit(OpCodes.Ldc_I4, index++);
IL.Emit(OpCodes.Ldelem_Ref);
// Determine the actual parameter type
var referenceType = param.ParameterType as ReferenceType;
if (referenceType == null)
continue;
var actualParameterType = referenceType.ElementType;
IL.Emit(OpCodes.Unbox_Any, actualParameterType);
IL.Stind(param.ParameterType);
}
}
/// <summary>
/// Causes the <see cref="CilWorker"/> to make the method throw a
/// <see cref="NotImplementedException"/> if the method cannot be found.
/// </summary>
/// <param name="IL">The <see cref="CilWorker"/> responsible for emitting the method body.</param>
protected virtual void ImplementNotFound(CilWorker IL)
{
var body = IL.GetBody();
var declaringType = body.Method.DeclaringType;
var module = declaringType.Module;
// throw new NotImplementedException();
var notImplementedConstructor = module.ImportConstructor<NotImplementedException>();
IL.Emit(OpCodes.Newobj, notImplementedConstructor);
IL.Emit(OpCodes.Throw);
}
/// <summary>
/// Causes the <see cref="CilWorker"/> to make the method throw a
/// <see cref="NotImplementedException"/> if the method cannot be found.
/// </summary>
/// <param name="IL">The <see cref="CilWorker"/> responsible for emitting the method body.</param>
protected virtual void ImplementNotFound(CilWorker IL)
{
MethodBody body = IL.GetBody();
TypeDefinition declaringType = body.Method.DeclaringType;
ModuleDefinition module = declaringType.Module;
// throw new NotImplementedException();
MethodReference notImplementedConstructor = module.ImportConstructor<NotImplementedException>();
IL.Emit(OpCodes.Newobj, notImplementedConstructor);
IL.Emit(OpCodes.Throw);
}
