/// <summary>
/// Weave field into current aspect
/// </summary>
/// <param name="il">IL Generator</param>
/// <param name="field">Field</param>
/// <param name="fieldMethod">Field Method</param>
private void BlockField(Mono.Cecil.Cil.ILProcessor il, Mono.Cecil.FieldDefinition field, MethodInfo fieldMethod)
{
var fieldName = field.Name;
// Return if it is a backing field
if (fieldName.IndexOf("k__BackingField") >= 0)
{
return;
}
var aspect = field.GetCustomAttribute <MemberInterceptionAspect>() ?? field.DeclaringType.GetCustomAttribute <MemberInterceptionAspect>()
?? field.DeclaringType.Module.Assembly.GetCustomAttribute <MemberInterceptionAspect>();
if (!ILWeaver.IsValidAspectFor(field, aspect))
{
return;
}
var fieldType = field.FieldType;
var isStatic = field.IsStatic;
var fieldLocal = il.DeclareLocal(fieldType);
var memberLocal = il.DeclareLocal(typeof(MemberContext));
var aspectField = ILWeaver.TypeFieldAspects[field.DeclaringType.FullName][aspect.GetType().FullName];
// Store current get field value
il.Emit(Mono.Cecil.Cil.OpCodes.Stloc, fieldLocal);
// MemberContext(object instance, string locationName, object value)
il.Emit(isStatic ? Mono.Cecil.Cil.OpCodes.Ldnull : Mono.Cecil.Cil.OpCodes.Ldarg_0);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldstr, fieldName);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, fieldLocal);
if (fieldType.IsValueType)
{
il.Emit(Mono.Cecil.Cil.OpCodes.Box, fieldType);
}
il.Emit(Mono.Cecil.Cil.OpCodes.Newobj, MemberContextCtor);
il.Emit(Mono.Cecil.Cil.OpCodes.Stloc, memberLocal);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldsfld, aspectField);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, memberLocal);
il.Emit(Mono.Cecil.Cil.OpCodes.Callvirt, fieldMethod);
// Load value back to stack and reflect changes if any
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, memberLocal);
il.Emit(Mono.Cecil.Cil.OpCodes.Callvirt, MemberContextValueMethod);
// Convert to expected type
il.Emit(fieldType.IsValueType ? Mono.Cecil.Cil.OpCodes.Unbox_Any : Mono.Cecil.Cil.OpCodes.Isinst, fieldType);
}
/// <summary>
/// Weave event invoke
/// </summary>
/// <param name="il">IL Generator</param>
/// <param name="method">Method</param>
/// <param name="field">Field</param>
private void BlockInvokeEvent(Mono.Cecil.Cil.ILProcessor il, Mono.Cecil.MethodDefinition method, Mono.Cecil.FieldDefinition field)
{
var isStatic = method.IsStatic;
var eventContext = il.DeclareLocal(typeof(EventContext));
var locals = new List <Mono.Cecil.Cil.VariableDefinition>();
var objLocal = il.DeclareLocal(typeof(object[]));
var parameters = method.Parameters;
var parameterLength = parameters.Count;
var fieldDeclaringType = field.DeclaringType;
var aspect = field.GetCustomAttribute <EventInterceptionAspect>() ?? fieldDeclaringType.GetCustomAttribute <EventInterceptionAspect>()
?? fieldDeclaringType.Module.Assembly.GetCustomAttribute <EventInterceptionAspect>();
if (!ILWeaver.IsValidAspectFor(field, aspect, allowEvents: true))
{
return;
}
var aspectField = ILWeaver.TypeFieldAspects[fieldDeclaringType.FullName][aspect.GetType().FullName];
il.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4, parameterLength);
il.Emit(Mono.Cecil.Cil.OpCodes.Newarr, typeof(object));
il.Emit(Mono.Cecil.Cil.OpCodes.Stloc, objLocal);
for (var i = 0; i < parameterLength; i++)
{
var parameter = parameters[i];
var parameterType = parameter.ParameterType;
var local = il.DeclareLocal(parameterType);
il.Emit(Mono.Cecil.Cil.OpCodes.Stloc, local);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, objLocal);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4, parameterLength - i - 1);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, local);
if (parameterType.IsValueType)
{
il.Emit(Mono.Cecil.Cil.OpCodes.Box, parameterType);
}
il.Emit(Mono.Cecil.Cil.OpCodes.Stelem_Ref);
locals.Add(local);
}
if (!isStatic)
{
il.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_0);
}
il.Emit(Mono.Cecil.Cil.OpCodes.Ldnull);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4, 1);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, objLocal);
il.Emit(Mono.Cecil.Cil.OpCodes.Newobj, EventContextCtor);
il.Emit(Mono.Cecil.Cil.OpCodes.Stloc, eventContext);
//InvokeEventMethod
il.Emit(Mono.Cecil.Cil.OpCodes.Ldsfld, aspectField);
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, eventContext);
il.Emit(Mono.Cecil.Cil.OpCodes.Callvirt, InvokeEventMethod);
//Restore original invoke event parameters
//locals.Reverse();
foreach (var local in locals)
{
il.Emit(Mono.Cecil.Cil.OpCodes.Ldloc, local);
}
}
