/// <summary>
/// Weaves the return instructions of the provided method to leave to a new instruction.
/// </summary>
/// <param name="weaver">The method weaver.</param>
/// <param name="storage">The storage variable for any captured return value.</param>
/// <param name="hasMethodInterceptors">Whether method interceptors are present which could change the return value.</param>
/// <returns>The instruction now located at the tail of the method.</returns>
public Instruction WeaveMethodReturnsRoute(MethodEmitter weaver, Variable storage, bool hasMethodInterceptors)
{
var il = weaver.Body.Instructions;
var pos = weaver.GetIL().Position;
var instruction = (Instruction)null;
if (weaver.Target.IsReturn())
{
instruction = hasMethodInterceptors ? Codes.Nop : Codes.Load(storage);
il.Add(instruction);
il.Add(Codes.Return);
for (int i = 0; i < il.Count - 2; i++)
{
if (il[i].OpCode == OpCodes.Ret)
{
var store = Codes.Store(storage);
il[i].OpCode = store.OpCode;
il[i].Operand = store.Operand;
weaver.Body.GetILProcessor().InsertAfter(il[i], Codes.Leave(instruction));
}
}
}
else
{
instruction = Codes.Return;
il.Add(instruction);
for (int i = 0, count = il.Count - 1; i < count; i++)
{
var ix = il[i];
if (ix.OpCode == OpCodes.Ret)
{
ix.OpCode = OpCodes.Leave;
ix.Operand = instruction;
}
}
}
return(instruction);
}
/// <summary>
/// Weaves the interception logic of a property.
/// </summary>
/// <param name="parent"></param>
/// <param name="item"></param>
public void WeavePropertyInterceptors(TypeEmitter parent, PropertyInterceptorInfo item)
{
var property = item.Property;
var getter = property.GetMethod != null ? new MethodEmitter(parent, property.GetMethod) : null;
var setter = property.SetMethod != null ? new MethodEmitter(parent, property.SetMethod) : null;
var count = item.Interceptors.Length;
var weaver = new PropertyEmitter(parent, property);
if (count == 0)
{
return;
}
var gInterceptors = new Variable[count];
var sInterceptors = new Variable[count];
for (int i = 0; i < count; i++)
{
var variables = CreateAttribute(weaver, getter, setter, item.Interceptors[i], item.Field);
gInterceptors[i] = variables[0];
sInterceptors[i] = variables[1];
}
var hasGetter = gInterceptors.Any(i => i != null);
var hasSetter = sInterceptors.Any(i => i != null);
var type = property.PropertyType;
var info = CreatePropertyInfo(weaver);
var field = property.GetBackingField();
var backing = (Variable)null;
if (field != null)
{
var def = field.Resolve();
def.Attributes &= ~Mono.Cecil.FieldAttributes.InitOnly;
backing = new Variable(def);
}
if (getter != null && hasGetter)
{
var il = getter.GetIL();
var result = getter.EmitLocal(property.PropertyType);
il.Body.SimplifyMacros();
il.Position = il.GetFirst();
il.Insert = CodeInsertion.Before;
if (backing != null)
{
il.Emit(Codes.ThisIf(backing));
il.Emit(Codes.Load(backing));
il.Emit(Codes.Store(result));
}
else
{
if (type.IsValueType)
{
il.Emit(Codes.Address(result));
il.Emit(Codes.Init(type));
}
else
{
il.Emit(Codes.Null);
il.Emit(Codes.Store(result));
}
}
il.Try();
var leave = WeaveMethodReturnsRoute(getter, result, true);
var cancel = il.EmitLabel();
var args = il.EmitLocal(Context.Finder.PropertyInterceptionArgs);
il.Emit(getter.Target.IsStatic ? Codes.Null : Codes.This);
il.Emit(Codes.Load(info));
il.Emit(Codes.Load(result));
il.Emit(Codes.Box(type));
il.Emit(Codes.Create(Context.Finder.PropertyInterceptionArgsCtor));
il.Emit(Codes.Store(args));
for (int i = 0; i < count; i++)
{
var inc = gInterceptors[i];
if (inc == null)
{
continue;
}
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyGetInterceptorOnGet));
}
il.Position = leave;
il.Finally();
for (int i = 0; i < count; i++)
{
var inc = gInterceptors[i];
if (inc == null)
{
continue;
}
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyGetInterceptorOnExit));
}
il.Mark(cancel);
il.EndTry();
il.Insert = CodeInsertion.After;
if (setter != null || backing != null)
{
var unchanged = il.EmitLabel();
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyInterceptionArgsIsDirtyGet));
il.Emit(Codes.IfFalse(unchanged));
if (!getter.Target.IsStatic)
{
il.Emit(Codes.This);
}
if (backing == null)
{
var pcount = setter.Target.Parameters.Count - 1;
for (int i = 0; i < pcount; i++)
{
il.Emit(Codes.Arg(setter.Target.Parameters[i]));
}
}
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyInterceptionArgsValueGet));
il.Emit(Codes.Unbox(type));
if (backing != null)
{
il.Emit(Codes.Store(backing));
}
else
{
il.Emit(Codes.Invoke(setter.Target));
}
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyInterceptionArgsValueGet));
il.Emit(Codes.Unbox(type));
il.Emit(Codes.Store(result));
il.Emit(Codes.Nop);
il.Mark(unchanged);
}
il.Emit(Codes.Load(result));
il.Body.InitLocals = true;
il.Body.OptimizeMacros();
}
if (setter != null && hasSetter)
{
var il = setter.GetIL();
il.Body.SimplifyMacros();
il.Position = il.GetFirst();
il.Insert = CodeInsertion.Before;
var args = il.EmitLocal(Context.Finder.PropertyInterceptionArgs);
var cancel = il.EmitLabel();
var argument = new Variable(setter.Target.Parameters.Last());
il.Try();
il.Emit(setter.Target.IsStatic ? Codes.Null : Codes.This);
il.Emit(Codes.Load(info));
il.Emit(Codes.Load(argument));
il.Emit(Codes.Box(type));
il.Emit(Codes.Create(Context.Finder.PropertyInterceptionArgsCtor));
il.Emit(Codes.Store(args));
for (int i = 0; i < count; i++)
{
var inc = sInterceptors[i];
if (inc == null)
{
continue;
}
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertySetInterceptorOnSet));
}
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyInterceptionArgsIsDirtyGet));
il.Emit(Codes.IfFalse(cancel));
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertyInterceptionArgsValueGet));
il.Emit(Codes.Unbox(argument.Type));
il.Emit(Codes.Store(argument));
il.Emit(Codes.Nop);
il.Position = il.Position.Previous;
il.Mark(cancel);
il.Position = il.GetLast();
il.Emit(Codes.Leave(il.Position));
il.Finally();
for (int i = 0; i < count; i++)
{
var inc = sInterceptors[i];
if (inc == null)
{
continue;
}
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
il.Emit(Codes.Load(args));
il.Emit(Codes.Invoke(Context.Finder.PropertySetInterceptorOnExit));
}
il.EndTry();
il.Body.InitLocals = true;
il.Body.OptimizeMacros();
}
}
/// <summary>
/// Weaves the interception logic of a method.
/// </summary>
/// <param name="weaver">The method weaver.</param>
/// <param name="item">The method information.</param>
public void WeaveMethodInterceptors(MethodEmitter weaver, MethodInterceptorInfo item)
{
weaver.Body.SimplifyMacros();
var pAttributes = item.Parameters.SelectMany(p => p.Attributes.Select(a => new { p.Index, Attribute = a })).ToArray();
var mAttributes = item.MethodInterceptors;
var rAttributes = item.ReturnInterceptors;
var pInterceptors = new Variable[pAttributes.Length];
var mInterceptors = new Variable[item.MethodInterceptors.Length];
var rInterceptors = new Variable[rAttributes.Length];
var needsEnter = mAttributes.Any(m => m.HasRequiredMethod(Context.Finder.MethodInterceptorOnEnter));
var needsCatch = mAttributes.Any(m => m.HasRequiredMethod(Context.Finder.MethodInterceptorOnException));
var needsExit = mAttributes.Any(m => m.HasRequiredMethod(Context.Finder.MethodInterceptorOnExit));
var needsParams = pAttributes.Any(m => m.Attribute.HasRequiredMethod(Context.Finder.ParameterInterceptorOnEnter));
var needsReturns = rAttributes.Any(m => m.HasRequiredMethod(Context.Finder.MethodReturnInterceptorOnReturn));
var needsMethodArgs = mAttributes.Any(m =>
{
return(m.AttributeType.GetMethod(Context.Finder.MethodInterceptorOnEnter).UsesParameter(0) ||
m.AttributeType.GetMethod(Context.Finder.MethodInterceptorOnException).UsesParameter(0) ||
m.AttributeType.GetMethod(Context.Finder.MethodInterceptorOnExit).UsesParameter(0));
});
var needsParamArgs = pAttributes.Any(m => m.Attribute.AttributeType.GetMethod(Context.Finder.ParameterInterceptorOnEnter).UsesParameter(0));
var needsReturnsArgs = rAttributes.Any(m => m.AttributeType.GetMethod(Context.Finder.MethodReturnInterceptorOnReturn).UsesParameter(0));
var needsMethodCopyArgs = mAttributes.Any(m => m.GetAttribute(Context.Finder.CompilationOptionsAttribute)?.GetProperty("CopyArguments", notFound: false) ?? false);
if (!needsEnter && !needsCatch && !needsExit && !needsParams && !needsReturns)
{
return;
}
var method = weaver.Target;
var il = weaver.GetIL();
il.Position = il.GetFirst();
il.Insert = CodeInsertion.Before;
var result = (Variable)null;
if (weaver.Target.IsReturn())
{
var type = weaver.Target.ReturnType;
result = weaver.EmitLocal(type);
if (type.IsValueType)
{
il.Emit(Codes.Address(result));
il.Emit(Codes.Init(type));
}
else
{
il.Emit(Codes.Null);
il.Emit(Codes.Store(result));
}
}
var leave = WeaveMethodReturnsRoute(weaver, result, mInterceptors.Length > 0);
var cancel = il.EmitLabel();
for (int i = 0, count = pInterceptors.Length; i < count; i++)
{
pInterceptors[i] = CreateAttribute(weaver, pAttributes[i].Attribute);
}
for (int i = 0, count = mInterceptors.Length; i < count; i++)
{
mInterceptors[i] = CreateAttribute(weaver, mAttributes[i]);
}
for (int i = 0, count = rInterceptors.Length; i < count; i++)
{
rInterceptors[i] = CreateAttribute(weaver, rAttributes[i]);
}
foreach (var attribute in mAttributes)
{
weaver.Target.CustomAttributes.Remove(attribute);
}
foreach (var attribute in pAttributes)
{
if (attribute.Index == -1)
{
weaver.Target.CustomAttributes.Remove(attribute.Attribute);
}
else
{
weaver.Target.Parameters[attribute.Index].CustomAttributes.Remove(attribute.Attribute);
}
}
foreach (var attribute in rAttributes)
{
weaver.Target.MethodReturnType.CustomAttributes.Remove(attribute);
}
foreach (var parameter in item.Parameters)
{
foreach (var attribute in parameter.Attributes)
{
if (parameter.Index == -1)
{
weaver.Target.CustomAttributes.Remove(attribute);
}
else
{
weaver.Target.Parameters[parameter.Index].CustomAttributes.Remove(attribute);
}
}
}
var hasMethod = mInterceptors.Length > 0;
var hasParams = pInterceptors.Length > 0;
var hasReturn = rInterceptors.Length > 0;
var arguments = hasMethod ? CreateArgumentArray(weaver) : null;
var invocation = CreateMethodInfo(weaver);
var mEventArgs = hasMethod && needsMethodArgs?weaver.EmitLocal(Context.Finder.MethodInterceptionArgs, name : "methodEventArgs") : null;
if (hasMethod || hasReturn)
{
if (hasMethod && needsMethodArgs)
{
il.Emit(method.IsStatic ? Codes.Null : Codes.This);
il.Emit(Codes.Load(arguments));
if (result == null)
{
il.Emit(Codes.Null);
}
else
{
il.Emit(Codes.Load(result));
il.Emit(Codes.Box(result.Type));
}
il.Emit(Codes.Load(invocation));
il.Emit(Codes.Create(Context.Finder.MethodInterceptionArgsCtor));
il.Emit(Codes.Store(mEventArgs));
}
il.Try();
}
if (hasParams && needsParams)
{
var pEventArgs = needsParamArgs ? weaver.EmitLocal(Context.Finder.ParameterInterceptionArgs) : null;
for (int i = 0, count = pInterceptors.Length; i < count; i++)
{
var inc = pInterceptors[i];
var parameters = pAttributes[i].Index == -1 ? method.Parameters.ToArray() : new[] { method.Parameters[pAttributes[i].Index] };
for (int j = 0, pCount = parameters.Length; j < pCount; j++)
{
var prm = parameters[j];
var pVariable = new Variable(prm);
var pInfo = CreateParameterInfo(weaver, prm);
var needsCopyArgs = pAttributes[i].Attribute.GetAttribute(Context.Finder.CompilationOptionsAttribute)?.GetProperty("CopyArguments", notFound: false) ?? false;
if (needsParamArgs)
{
il.Emit(method.IsStatic ? Codes.Null : Codes.This);
il.Emit(Codes.Load(pInfo));
il.Emit(Codes.Arg(pVariable));
il.Emit(Codes.Box(prm.ParameterType));
il.Emit(Codes.Create(Context.Finder.ParameterInterceptionArgsCtor));
il.Emit(Codes.Store(pEventArgs));
}
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
if (needsParamArgs)
{
il.Emit(Codes.Load(pEventArgs));
}
else
{
il.Emit(Codes.Null);
}
il.Emit(Codes.Invoke(Context.Finder.ParameterInterceptorOnEnter));
if (needsParamArgs && !prm.IsOut && needsCopyArgs)
{
il.Emit(Codes.Load(pEventArgs));
il.Emit(Codes.Invoke(Context.Finder.ParameterInterceptionArgsValueGet));
il.Emit(Codes.Unbox(prm.ParameterType));
il.Emit(Codes.Store(pVariable));
}
}
}
}
if (hasMethod || hasReturn)
{
if (hasMethod && needsEnter)
{
for (int i = 0, count = mInterceptors.Length; i < count; i++)
{
var inc = mInterceptors[i];
var att = mAttributes[i];
if (att.HasRequiredMethod("OnEnter"))
{
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
if (needsMethodArgs)
{
il.Emit(Codes.Load(mEventArgs));
}
else
{
il.Emit(Codes.Null);
}
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptorOnEnter));
if (needsMethodArgs)
{
var proceed = il.EmitLabel();
il.Emit(Codes.Load(mEventArgs));
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptionArgsCancelGet));
il.Emit(Codes.IfFalse(proceed));
if (result != null && needsMethodArgs)
{
il.Emit(Codes.Load(mEventArgs));
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptionArgsReturnGet));
il.Emit(Codes.Unbox(result.Type));
il.Emit(Codes.Store(result));
}
il.Emit(Codes.Leave(leave));
il.Mark(proceed);
}
}
}
if (needsMethodArgs && needsMethodCopyArgs && arguments != null)
{
CopyArgumentArrayToParameters(weaver, arguments);
}
}
il.Position = leave;
if (hasMethod && needsCatch)
{
var exception = il.EmitLocal(Context.Finder.Exception);
il.Catch(exception);
for (int i = 0, count = mInterceptors.Length; i < count; i++)
{
var inc = mInterceptors[i];
var att = mAttributes[i];
if (att.HasRequiredMethod("OnException"))
{
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
if (needsMethodArgs)
{
il.Emit(Codes.Load(mEventArgs));
}
else
{
il.Emit(Codes.Null);
}
il.Emit(Codes.Load(exception));
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptorOnException));
}
}
if (needsExit || needsReturns)
{
il.Emit(Codes.Nop);
il.Emit(Codes.Leave(leave));
}
}
if (needsExit || needsReturns)
{
il.Finally(leave);
}
if (hasMethod)
{
if (result != null && needsMethodArgs)
{
il.Emit(Codes.Load(mEventArgs));
il.Emit(Codes.Load(result));
il.Emit(Codes.Box(weaver.Target.ReturnType));
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptionArgsReturnSet));
}
if (needsExit)
{
for (int i = 0, count = mInterceptors.Length; i < count; i++)
{
var inc = mInterceptors[i];
var att = mAttributes[i];
if (att.HasRequiredMethod("OnExit"))
{
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
if (needsMethodArgs)
{
il.Emit(Codes.Load(mEventArgs));
}
else
{
il.Emit(Codes.Null);
}
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptorOnExit));
}
}
}
il.Mark(cancel);
}
if (hasReturn && needsReturns && result != null)
{
var rEventArgs = needsReturnsArgs ? il.EmitLocal(Context.Finder.MethodReturnInterceptionArgs) : null;
if (needsReturnsArgs)
{
il.Emit(method.IsStatic ? Codes.Null : Codes.This);
il.Emit(Codes.Load(result));
il.Emit(Codes.Box(result.Type));
il.Emit(Codes.Load(invocation));
il.Emit(Codes.Create(Context.Finder.MethodReturnInterceptionArgsCtor));
il.Emit(Codes.Store(rEventArgs));
}
for (int i = 0, count = rInterceptors.Length; i < count; i++)
{
var inc = rInterceptors[i];
var att = rAttributes[i];
if (att.HasRequiredMethod("OnReturn"))
{
il.Emit(Codes.ThisIf(inc));
il.Emit(Codes.Load(inc));
if (needsReturnsArgs)
{
il.Emit(Codes.Load(rEventArgs));
}
else
{
il.Emit(Codes.Null);
}
il.Emit(Codes.Invoke(Context.Finder.MethodReturnInterceptorOnReturn));
}
}
if (needsReturnsArgs)
{
il.Emit(Codes.Load(rEventArgs));
il.Emit(Codes.Invoke(Context.Finder.MethodReturnInterceptionArgsValueGet));
il.Emit(Codes.Unbox(result.Type));
il.Emit(Codes.Store(result));
}
}
if (!needsExit && !needsReturns)
{
il.Emit(Codes.Nop);
il.Emit(Codes.Leave(leave));
}
il.EndTry();
il.Insert = CodeInsertion.After;
if (hasMethod && arguments != null)
{
CopyArgumentArrayToReferences(weaver, arguments);
}
if (hasMethod && needsMethodArgs && result != null)
{
il.Emit(Codes.Nop);
il.Emit(Codes.Load(mEventArgs));
il.Emit(Codes.Invoke(Context.Finder.MethodInterceptionArgsReturnGet));
il.Emit(Codes.Unbox(weaver.Target.ReturnType));
}
else if (hasMethod && result != null)
{
il.Emit(Codes.Nop);
il.Emit(Codes.Load(result));
}
}
weaver.Body.InitLocals = true;
weaver.Body.OptimizeMacros();
}