Re: clearing opfuncid vs. parallel query

Robert Haas <robertmhaas@gmail.com> writes:
> On Thu, Oct 22, 2015 at 4:32 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I'm not sure that you could get to a point where you were
>> generating this stuff from anything that wasn't in essence an arcane
>> representation of the .c files.  It might be slightly harder to make
>> errors of omission that way, but I'm suspicious that that would come at
>> the cost of a net loss of readability.

> That is possible, but the current situation isn't good either.
> Despite everybody's best efforts, we mess this up more than is really
> desirable. Commit b8fe12a83622b350dc6849f8bb933bd8a86c1424 fixed bugs
> in a whole bunch of preceding commits, and I wonder if anybody else
> would have found those if Noah hadn't.  It's just too easy to miss
> these things today.  If generating the .c files isn't practical,
> another alternative worth exploring would be a tool to cross-check
> them against the .h files.

Yeah, I could get on board with that.  It doesn't seem terribly hard:
just make sure that all fields mentioned in the struct declaration are
mentioned in each relevant routine.  (Cases where we intentionally skip
a field could be handled by adding a no-op macro, eg "COPY_IGNORE(foo);")

It would be nice if we could also check that the macro type is sane for
the field datatype (eg, not use COPY_SCALAR_FIELD() for a pointer field).
But that would probably increase the difficulty very substantially for
just a small gain in error detection.
        regards, tom lane