Re: Back branches vs. gcc 4.8.0 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Back branches vs. gcc 4.8.0
Date
Msg-id 14723.1365201520@sss.pgh.pa.us
Whole thread Raw
In response to Re: Back branches vs. gcc 4.8.0  (Peter Geoghegan <pg@heroku.com>)
List pgsql-hackers
Peter Geoghegan <pg@heroku.com> writes:
> On Fri, Apr 5, 2013 at 11:14 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> It also strikes me that we ought to take this as a warning sign
>> that we need to work on getting rid of coding like the above in favor
>> of genuine "flexible arrays", before the gcc boys think of some other
>> overly-cute optimization based on the assumption that an array declared
>> with a fixed size really is fixed.

> The traditional argument against that has been that that's a C99
> feature.

Well, we already have a solution for that, see FLEXIBLE_ARRAY_MEMBER.
But up to now we've just supposed that that was a code beautification
thing and there was no particular urgency to convert all applicable
places to use that notation.

Since there's a potential to break code with such changes (we'd have to
fix any uses of sizeof on the struct type), it's been very far down the
to-do list.  But now it appears that we're taking risks if we *don't*
change it.
        regards, tom lane



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