private void Exit(uint l)
{
if (ctx.labels.Count() < l + 1)
{
Trap("Function corrupt");
}
// Stack appears to consider ElementAt from the front of the list rather than the back
// So paradoxically, it actually counts up (0th element = latest, 1st = second, etc)
LabelObject label = ctx.labels.ElementAt((int)l);
uint n = label.arity;
logger.ConditionalTrace($"Exiting to label: {label}.");
/*
* Pop the values val^n from the stack.
* Repeat l+1 times:
* While the top of the stack is a value, do:
* Pop the value from the stack.
* Assert: due to validation, the top of the stack now is a label.
* Pop the label from the stack.
* Push the values val^n to the stack.
*/
Stack <ValueObject> values = new Stack <ValueObject>();
for (uint i = 0; i < n; i++)
{
values.Push(GetValueOrFail());
}
for (uint i = 0; i < l + 1; i++)
{
while (ctx.Peek() == WebAssemblyStackObjectType.ValueObject)
{
ctx.PopValue();
}
if (ctx.Peek() != WebAssemblyStackObjectType.LabelObject)
{
Trap("Corrupt function");
}
ctx.PopLabel();
}
for (uint i = 0; i < n; i++)
{
ctx.Push(values.Pop());
}
logger.ConditionalTrace($"Jumping to {label.branch_target}.");
ctx.GetCurrentFunction().pc = label.branch_target;
}
public void Push(LabelObject obj)
{
stack_objects.Push(WebAssemblyStackObjectType.LabelObject);
labels.Push(obj);
logger.ConditionalTrace($"Pushed Label: {obj}.");
}
private void Enter(LabelObject obj)
{
ctx.Push(obj);
}