size fix

[hchataing]

• Missing () in generated payload size encoder
• Add semantic test for payload size field encoding

[mgeisler]

I looked at the changes and it's not actually clear to me which of them fixes anything?

[mgeisler]

This line looks like it could be a fix. However, on a second look,

(2 + self.payload.len()) as u8

and

2 + (self.payload.len() as u8)

should give the same result, right? Will the 2 literal not be type-inferred to be a u8 here?

Is the problem with very large integers (larger than i32?) which can overflow in some way?

[hchataing]

The issue is more apparent on this declaration:

little_endian_packets

struct Elem {
    _size_(value) : 8,
    value : 8[],
}

packet Parent {
    _size_(_payload_) : 8,
    _payload_,
}

packet Child : Parent {
    b : Elem,
    d : Elem,
}

The generated code for <Child as Packet>::encode contained the following line which was missing parentheses

buf.put_u8(self.b.encoded_len() + self.d.encoded_len() as u8);

[hchataing]

Updated the added semantic test to properly check this output.

[mgeisler]

Yes, now I see the problem clearly! Thanks 🙂