Re: [PATCH] remote.c: Make packet_check_result return a structure

[Andrew Burgess <aburgess@redhat.com>]

Tom Tromey <tom@tromey.com> writes:

>>>>>> "Alexandra" == Alexandra Hájková <ahajkova@redhat.com> writes:
>
> Alexandra> packet_check_result currently returns an packet_result enum.
> Alexandra> If GDB will recieve an error in a format E.errtext, which
> Alexandra> is possible for some q packets, such errtext is lost if
> Alexandra> treated by packet_check_result.
>
> Thank you for the patch.  I think the general idea makes sense.
>
> Alexandra> There's no infrastructure to test this with a test case so
> Alexandra> I tested this by modifying store_registers_using_G function
> Alexandra> to get an error message:
>
> packet_check_result is isolated enough that, if you wanted, you could
> write unit tests for it.
>
> Alexandra> +/* Keeps packet's return value. If packet's return value is PACKET_ERROR,
> Alexandra> +   err_msg contains an error message string from E.string or the number
> Alexandra> +   stored as a string from E.num.  */
> Alexandra> +struct packet_result
> Alexandra> +{
> Alexandra> +  packet_result (enum packet_status status, std::string err_msg)
> Alexandra> +    : m_status (status),
> Alexandra> +    m_err_msg (std::move (err_msg))
>
> This is formatted strangely.
>
> Alexandra> +  packet_result (enum packet_status status)
> Alexandra> +    : m_status (status)
> Alexandra> +    {
> Alexandra> +      gdb_assert (status != PACKET_ERROR);
>
> Here and elsewhere the "{" is indented too far.
> Also, single-argument constructors should ordinarily be "explicit".

OOI, wondering why you specifically call out single-argument
constructors here?  I was re-reading this page to refresh my knowledge
of 'explicit':

  https://en.cppreference.com/w/cpp/language/explicit

And it seems that marking multi-argument constructors would place the
same restrictions on the constructor as for single-argument
constructors...

Though I guess there's more chance of accidentally assigning a scalar
into a non-scalar object (e.g. packet_result in this case).  Maybe
that's why the single-argument case is being called out?

Anyway, not disagreeing with you, just trying to educate myself.

Thanks,
Andrew

>
> Alexandra> +    }
> Alexandra> +
> Alexandra> +private:
> Alexandra> +  enum packet_status m_status;
> Alexandra> +  std::string m_err_msg;
> Alexandra> +
> Alexandra> +public:
>
> Better IMO to put all the private stuff at the end.
>
> Alexandra> +  enum packet_status
> Alexandra> +  status () const
>
> For methods this all goes on one line.
>
> Alexandra> -static enum packet_result
> Alexandra> +static struct packet_result
>
> Since you're touching this anyway you might as well leave out the
> 'struct' keyword.
>
> Tom