private MethodBuilder CreateMethodOverride(MethodBuilder delegateMethod)
{
MethodAttributes attrs =
_methodToOverride.Attributes & ~MethodAttributes.NewSlot & ~MethodAttributes.Abstract;
MethodBuilder methodBuilder = _typeBuilder.DefineMethod(_methodToOverride.Name, attrs);
var paramMapper = new MethodOverrideParameterMapper(_methodToOverride);
paramMapper.SetupParameters(methodBuilder, _targetTypeParameterMapper);
methodBuilder.SetReturnType(paramMapper.GetParameterType(_methodToOverride.ReturnType));
methodBuilder.SetParameters(_methodParameters.Select(pi => paramMapper.GetParameterType(pi.ParameterType)).ToArray());
int paramNum = 1;
foreach (ParameterInfo pi in _methodParameters)
{
methodBuilder.DefineParameter(paramNum++, pi.Attributes, pi.Name);
}
ILGenerator il = methodBuilder.GetILGenerator();
LocalBuilder methodReturn = il.DeclareLocal(typeof(IMethodReturn));
LocalBuilder ex = il.DeclareLocal(typeof(Exception));
LocalBuilder parameterArray = il.DeclareLocal(typeof(object[]));
LocalBuilder inputs = il.DeclareLocal(typeof(VirtualMethodInvocation));
// Create instance of VirtualMethodInvocation
il.Emit(OpCodes.Ldarg_0); // target object
// If we have a generic method, we want to make sure we're using the open constructed generic method
// so when a closed generic version of the method is invoked the actual type parameters are used
il.Emit(
OpCodes.Ldtoken,
_methodToOverride.IsGenericMethodDefinition
? _methodToOverride.MakeGenericMethod(paramMapper.GenericMethodParameters)
: _methodToOverride);
if (_methodToOverride.DeclaringType.IsGenericType)
{
// if the declaring type is generic, we need to get the method from the target type
il.Emit(OpCodes.Ldtoken, _targetType);
il.Emit(OpCodes.Call, MethodBaseMethods.GetMethodForGenericFromHandle);
}
else
{
il.Emit(OpCodes.Call, MethodBaseMethods.GetMethodFromHandle); // target method
}
EmitLoadConstant(il, _methodParameters.Length);
il.Emit(OpCodes.Newarr, typeof(object)); // object[] parameters
if (_methodParameters.Length > 0)
{
il.Emit(OpCodes.Stloc, parameterArray);
for (int i = 0; i < _methodParameters.Length; ++i)
{
il.Emit(OpCodes.Ldloc, parameterArray);
EmitLoadConstant(il, i);
EmitLoadArgument(il, i);
if (_methodParameters[i].ParameterType.IsValueType || _methodParameters[i].ParameterType.IsGenericParameter)
{
il.Emit(OpCodes.Box, paramMapper.GetParameterType(_methodParameters[i].ParameterType));
}
else if (_methodParameters[i].ParameterType.IsByRef)
{
Type elementType = paramMapper.GetElementType(_methodParameters[i].ParameterType);
il.Emit(OpCodes.Ldobj, elementType);
if (elementType.IsValueType || elementType.IsGenericParameter)
{
il.Emit(OpCodes.Box, elementType);
}
}
il.Emit(OpCodes.Stelem_Ref);
}
il.Emit(OpCodes.Ldloc, parameterArray);
}
il.Emit(OpCodes.Newobj, VirtualMethodInvocationMethods.VirtualMethodInvocation);
il.Emit(OpCodes.Stloc, inputs);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, _proxyInterceptionPipelineField);
il.Emit(OpCodes.Ldloc, inputs);
// Put delegate reference onto the stack
il.Emit(OpCodes.Ldarg_0);
MethodInfo invokeTarget = delegateMethod;
if (delegateMethod.IsGenericMethod)
{
invokeTarget = delegateMethod.MakeGenericMethod(paramMapper.GenericMethodParameters);
}
il.Emit(OpCodes.Ldftn, invokeTarget);
il.Emit(OpCodes.Newobj, InvokeInterceptionBehaviorDelegateMethods.InvokeInterceptionBehaviorDelegate);
// And call the pipeline
il.Emit(OpCodes.Call, InterceptionBehaviorPipelineMethods.Invoke);
il.Emit(OpCodes.Stloc, methodReturn);
// Was there an exception?
Label noException = il.DefineLabel();
il.Emit(OpCodes.Ldloc, methodReturn);
il.EmitCall(OpCodes.Callvirt, IMethodReturnMethods.GetException, null);
il.Emit(OpCodes.Stloc, ex);
il.Emit(OpCodes.Ldloc, ex);
il.Emit(OpCodes.Ldnull);
il.Emit(OpCodes.Ceq);
il.Emit(OpCodes.Brtrue_S, noException);
il.Emit(OpCodes.Ldloc, ex);
if (ReflectionHelper.ExceptionDispatchInfoCaptureMethod != null &&
ReflectionHelper.ExceptionDispatchInfoThrowMethod != null)
{
il.EmitCall(OpCodes.Call, ReflectionHelper.ExceptionDispatchInfoCaptureMethod, null);
il.EmitCall(OpCodes.Callvirt, ReflectionHelper.ExceptionDispatchInfoThrowMethod, null);
}
else
{
il.Emit(OpCodes.Throw);
}
il.MarkLabel(noException);
// handle return value
if (MethodHasReturnValue)
{
il.Emit(OpCodes.Ldloc, methodReturn);
il.EmitCall(OpCodes.Callvirt, IMethodReturnMethods.GetReturnValue, null);
if (ReturnType.IsValueType || ReturnType.IsGenericParameter)
{
il.Emit(OpCodes.Unbox_Any, paramMapper.GetReturnType());
}
else
{
il.Emit(OpCodes.Castclass, paramMapper.GetReturnType());
}
}
// handle byref parameters
if (_methodParameters.Length > 0)
{
int outArgIndex = 0;
foreach (int parameterIndex in OutputParameterIndices)
{
// GetOrDefault parameter value (the address) onto the stack)
Type elementType = paramMapper.GetElementType(_methodParameters[parameterIndex].ParameterType);
EmitLoadArgument(il, parameterIndex);
// GetOrDefault result of output parameter out of the results array
il.Emit(OpCodes.Ldloc, methodReturn);
il.Emit(OpCodes.Callvirt, IMethodReturnMethods.GetOutputs);
EmitLoadConstant(il, outArgIndex);
il.Emit(OpCodes.Callvirt, IListMethods.GetItem);
EmitUnboxOrCast(il, elementType);
// And store the results
il.Emit(OpCodes.Stobj, elementType);
++outArgIndex;
}
}
il.Emit(OpCodes.Ret);
return(methodBuilder);
}
private MethodBuilder CreateDelegateImplementation(MethodInfo callBaseMethod)
{
string methodName = CreateMethodName("DelegateImplementation");
MethodBuilder methodBuilder = _typeBuilder.DefineMethod(methodName,
MethodAttributes.Private | MethodAttributes.HideBySig);
List <LocalBuilder> outOrRefLocals = new List <LocalBuilder>();
var paramMapper = new MethodOverrideParameterMapper(_methodToOverride);
paramMapper.SetupParameters(methodBuilder, _targetTypeParameterMapper);
methodBuilder.SetReturnType(typeof(IMethodReturn));
// Adding parameters
methodBuilder.SetParameters(typeof(IMethodInvocation), typeof(GetNextInterceptionBehaviorDelegate));
// Parameter
methodBuilder.DefineParameter(1, ParameterAttributes.None, "inputs");
// Parameter
methodBuilder.DefineParameter(2, ParameterAttributes.None, "getNext");
methodBuilder.SetCustomAttribute(new CustomAttributeBuilder(CompilerGeneratedAttributeMethods.CompilerGeneratedAttribute, new object[0]));
ILGenerator il = methodBuilder.GetILGenerator();
if (!_methodToOverride.IsAbstract)
{
Label done = il.DefineLabel();
LocalBuilder ex = il.DeclareLocal(typeof(Exception));
LocalBuilder baseReturn = null;
LocalBuilder parameters = null;
if (MethodHasReturnValue)
{
baseReturn = il.DeclareLocal(paramMapper.GetParameterType(_methodToOverride.ReturnType));
}
LocalBuilder retval = il.DeclareLocal(typeof(IMethodReturn));
il.BeginExceptionBlock();
// Call the base method
il.Emit(OpCodes.Ldarg_0);
if (_methodParameters.Length > 0)
{
parameters = il.DeclareLocal(typeof(IParameterCollection));
il.Emit(OpCodes.Ldarg_1);
il.EmitCall(OpCodes.Callvirt, IMethodInvocationMethods.GetArguments, null);
il.Emit(OpCodes.Stloc, parameters);
for (int i = 0; i < _methodParameters.Length; ++i)
{
il.Emit(OpCodes.Ldloc, parameters);
EmitLoadConstant(il, i);
il.EmitCall(OpCodes.Callvirt, IListMethods.GetItem, null);
if (_methodParameters[i].ParameterType.IsByRef)
{
// For out or ref, create a local variable for it, initialize, and
// pass address of the local to the base class call.
Type referredToType = paramMapper.GetElementType(_methodParameters[i].ParameterType);
LocalBuilder refShadow = il.DeclareLocal(referredToType);
outOrRefLocals.Add(refShadow);
EmitUnboxOrCast(il, referredToType);
il.Emit(OpCodes.Stloc, refShadow);
il.Emit(OpCodes.Ldloca, refShadow);
}
else
{
EmitUnboxOrCast(il, paramMapper.GetParameterType(_methodParameters[i].ParameterType));
}
}
}
MethodInfo baseTarget = callBaseMethod;
if (baseTarget.IsGenericMethod)
{
baseTarget = callBaseMethod.MakeGenericMethod(paramMapper.GenericMethodParameters);
}
il.Emit(OpCodes.Call, baseTarget);
if (MethodHasReturnValue)
{
il.Emit(OpCodes.Stloc, baseReturn);
}
// Generate the return value
il.Emit(OpCodes.Ldarg_1);
if (MethodHasReturnValue)
{
il.Emit(OpCodes.Ldloc, baseReturn);
if (ReturnType.IsValueType || ReturnType.IsGenericParameter)
{
il.Emit(OpCodes.Box, paramMapper.GetReturnType());
}
}
else
{
il.Emit(OpCodes.Ldnull);
}
// Set up output parameters - note the collection returned to the
// IMethodReturn object contains ALL parameter values, inputs and
// outputs.
EmitLoadConstant(il, _methodParameters.Length);
il.Emit(OpCodes.Newarr, typeof(object));
if (_methodParameters.Length > 0)
{
LocalBuilder outputParamArray = il.DeclareLocal(typeof(object[]));
il.Emit(OpCodes.Stloc, outputParamArray);
int outputParameterNum = 0;
for (int paramNum = 0; paramNum < _methodParameters.Length; ++paramNum)
{
il.Emit(OpCodes.Ldloc, outputParamArray);
EmitLoadConstant(il, paramNum);
if (_methodParameters[paramNum].ParameterType.IsByRef)
{
il.Emit(OpCodes.Ldloc, outOrRefLocals[outputParameterNum]);
EmitBox(il, outOrRefLocals[outputParameterNum].LocalType);
++outputParameterNum;
}
else
{
il.Emit(OpCodes.Ldloc, parameters);
EmitLoadConstant(il, paramNum);
il.Emit(OpCodes.Callvirt, IListMethods.GetItem);
}
il.Emit(OpCodes.Stelem_Ref);
}
il.Emit(OpCodes.Ldloc, outputParamArray);
}
il.Emit(OpCodes.Callvirt, IMethodInvocationMethods.CreateReturn);
il.Emit(OpCodes.Stloc, retval);
il.BeginCatchBlock(typeof(Exception));
il.Emit(OpCodes.Stloc, ex);
// Create an exception return
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Ldloc, ex);
il.EmitCall(OpCodes.Callvirt, IMethodInvocationMethods.CreateExceptionMethodReturn, null);
il.Emit(OpCodes.Stloc, retval);
il.EndExceptionBlock();
il.MarkLabel(done);
il.Emit(OpCodes.Ldloc, retval);
il.Emit(OpCodes.Ret);
}
else
{
// exception-throwing implementation
il.Emit(OpCodes.Ldarg_1);
il.EmitCall(OpCodes.Call, BuildAbstractMethodInvokedExceptionMethod, null);
il.EmitCall(OpCodes.Callvirt, IMethodInvocationMethods.CreateExceptionMethodReturn, null);
il.Emit(OpCodes.Ret);
}
return(methodBuilder);
}
