public override bool Rewrite(CodeDescriptor decompilee, MethodBase callee, StackElement[] args, IDecompiler stack, IFunctionBuilder builder)
{
var ctx = stack.QueryAttribute<AsyncMethodDecompiler>();
if (ctx == null)
throw new InvalidOperationException("Method must be decompiled using AsyncMethodDecompiler.");
if (ctx.ImplStyle == EAsyncImplStyle.Sequential)
return true;
var awaiterCallExpr = stack.ResolveVariableReference(stack.CurrentILIndex, args[1].Expr);
var awaiterCall = awaiterCallExpr as FunctionCall;
if (awaiterCall != null)
{
var waitObject = awaiterCall.Arguments[0];
var asyncCall = waitObject as FunctionCall;
if (asyncCall != null)
{
var cspec = asyncCall.Callee as FunctionSpec;
if (cspec != null &&
cspec.CILRep != null &&
cspec.CILRep.HasCustomOrInjectedAttribute<TickAttribute>())
{
var si = ctx.ForkNextSI();
var pi = new ProceedWithStateInfo()
{
TargetState = si,
TargetWaitState = false,
LambdaTransition = false
};
var fspec = new FunctionSpec(typeof(void))
{
IntrinsicRep = IntrinsicFunctions.ProceedWithState(pi)
};
builder.Call(fspec, LiteralReference.CreateConstant(pi));
return true;
}
}
}
var awaiter = args[1].Sample;
var task = ctx.GetTaskFromAwaiter(awaiter);
if (task != null)
{
if (!task.IsCompleted)
throw new InvalidOperationException("Task not completed - what are you awaiting for?");
var sin = ctx.ForkNextSI();
sin.HasWaitState = true;
var jp = new JoinParams()
{
JoinedTask = task,
Continuation = sin
};
sin.JP = jp;
ctx.ImplementJoin(jp, builder, sin);
}
return true;
}
private void ImplementJoin(JoinParams jp, IAlgorithmBuilder builder, StateInfo sin)
{
Contract.Requires<ArgumentNullException>(jp != null);
Contract.Requires<ArgumentNullException>(builder != null);
Contract.Requires<ArgumentNullException>(sin != null);
var jspec = new FunctionSpec(typeof(bool))
{
IntrinsicRep = IntrinsicFunctions.Join(jp)
};
var jcall = new FunctionCall()
{
Callee = jspec,
Arguments = new Expression[0],
ResultType = typeof(bool)
};
builder.If(jcall);
var pi1 = new ProceedWithStateInfo()
{
TargetState = sin,
TargetWaitState = false,
LambdaTransition = true
};
var pspec1 = new FunctionSpec(typeof(void))
{
IntrinsicRep = IntrinsicFunctions.ProceedWithState(pi1)
};
builder.Call(pspec1, LiteralReference.CreateConstant(pi1));
builder.Else();
var sin2 = sin.Fork(sin.ILState);
var pi2 = new ProceedWithStateInfo()
{
TargetState = sin,
TargetWaitState = true,
LambdaTransition = false
};
var pspec2 = new FunctionSpec(typeof(void))
{
IntrinsicRep = IntrinsicFunctions.ProceedWithState(pi2)
};
builder.Call(pspec2, LiteralReference.CreateConstant(pi2));
builder.EndIf();
if (_curCoFSM != null)
_curCoFSM.Dependencies.Add(jp.JoinedTask);
}