private static string GetMethodSignature(MethodInfo method, InterceptMethodAttribute attribute)
{
var returnType = method.ReturnType;
var parameters = method.GetParameters().Select(p => p.ParameterType).ToArray();
var requiredParameterTypes = new[] { typeof(int), typeof(int), typeof(long) };
var lastParameterTypes = parameters.Skip(parameters.Length - requiredParameterTypes.Length);
if (attribute.MethodReplacementAction == MethodReplacementActionType.ReplaceTargetMethod)
{
if (!lastParameterTypes.SequenceEqual(requiredParameterTypes))
{
throw new Exception(
$"Method {method.DeclaringType.FullName}.{method.Name}() does not meet parameter requirements. " +
"Wrapper methods must have at least 3 parameters and the last 3 must be of types Int32 (opCode), Int32 (mdToken), and Int64 (moduleVersionPtr).");
}
}
else if (attribute.MethodReplacementAction == MethodReplacementActionType.InsertFirst)
{
if (attribute.CallerAssembly == null || attribute.CallerType == null || attribute.CallerMethod == null)
{
throw new Exception(
$"Method {method.DeclaringType.FullName}.{method.Name}() does not meet InterceptMethodAttribute requirements. " +
"Currently, InsertFirst methods must have CallerAssembly, CallerType, and CallerMethod defined. " +
$"Current values: CallerAssembly=\"{attribute.CallerAssembly}\", CallerType=\"{attribute.CallerType}\", CallerMethod=\"{attribute.CallerMethod}\"");
}
else if (parameters.Any())
{
throw new Exception(
$"Method {method.DeclaringType.FullName}.{method.Name}() does not meet parameter requirements. " +
"Currently, InsertFirst methods must have zero parameters.");
}
else if (returnType != typeof(void))
{
throw new Exception(
$"Method {method.DeclaringType.FullName}.{method.Name}() does not meet return type requirements. " +
"Currently, InsertFirst methods must have a void return type.");
}
}
var signatureHelper = SignatureHelper.GetMethodSigHelper(method.CallingConvention, returnType);
signatureHelper.AddArguments(parameters, requiredCustomModifiers: null, optionalCustomModifiers: null);
var signatureBytes = signatureHelper.GetSignature();
if (method.IsGenericMethod)
{
// if method is generic, fix first byte (calling convention)
// and insert a second byte with generic parameter count
const byte IMAGE_CEE_CS_CALLCONV_GENERIC = 0x10;
var genericArguments = method.GetGenericArguments();
var newSignatureBytes = new byte[signatureBytes.Length + 1];
newSignatureBytes[0] = (byte)(signatureBytes[0] | IMAGE_CEE_CS_CALLCONV_GENERIC);
newSignatureBytes[1] = (byte)genericArguments.Length;
Array.Copy(signatureBytes, 1, newSignatureBytes, 2, signatureBytes.Length - 1);
signatureBytes = newSignatureBytes;
}
return(string.Join(" ", signatureBytes.Select(b => b.ToString("X2"))));
}
public void AllMethodsHaveProperlyFormedTargetSignatureTypes(MethodInfo wrapperMethod, InterceptMethodAttribute attribute)
{
Assert.True(
attribute.TargetSignatureTypes != null,
$"{wrapperMethod.DeclaringType.Name}.{wrapperMethod.Name}: {nameof(attribute.TargetSignatureTypes)} definition missing.");
// add 1 for return type, subtract 3 for extra parameters (opcode, mdToken, moduleVersionPtr)
// 1 - 3 = -2
var expectedParameterCount = wrapperMethod.GetParameters().Length - 2;
if (!StaticInstrumentations.Contains(wrapperMethod))
{
// Subtract the instance (this) parameter
expectedParameterCount--;
}
var typeSigLength = attribute.TargetSignatureTypes.Length;
Assert.True(
expectedParameterCount == typeSigLength,
$"{wrapperMethod.DeclaringType.Name}.{wrapperMethod.Name}: {nameof(attribute.TargetSignatureTypes)} has {typeSigLength} items, expected {expectedParameterCount}.");
Assert.False(
attribute.TargetSignatureTypes.Any(string.IsNullOrWhiteSpace),
$"{wrapperMethod.DeclaringType.Name}.{wrapperMethod.Name}: {nameof(attribute.TargetSignatureTypes)} has null or empty arguments.");
}
