Re: [HACKERS] compiler warning with VS 2017 - Mailing list pgsql-hackers

From Petr Jelinek
Subject Re: [HACKERS] compiler warning with VS 2017
Date
Msg-id 19523cbf-5843-d89f-c476-cb0d79f7d380@2ndquadrant.com
Whole thread Raw
In response to Re: [HACKERS] compiler warning with VS 2017  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [HACKERS] compiler warning with VS 2017  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On 05/05/17 06:50, Tom Lane wrote:
> Haribabu Kommi <kommi.haribabu@gmail.com> writes:
>> I am getting a compiler warning when I build the latest HEAD PostgreSQL with
>> visual studio 2017.
>> The code at the line is,
>> tuple->values[i] = (char *) (Size)0xdeadbeef; /* make bad usage more obvious */
> 
> Yeah, you're not the first to complain about this.  To my mind that
> coding is not pretty, not cute, and not portable: there's not even
> a good reason to believe that dereferencing the pointer would result
> in a crash.  Perhaps the author can explain to us why this is better
> than just assigning NULL.
> 
> Actually, looking around a bit there, it's not even clear why
> we should be booby-trapping the value of an unchanged column in
> the first place.  So I'd say that not only is the code dubious
> but the comment is inadequate too.

Hmm, as far as I can recollect this is just leftover debugging code that
was intended to help ensure that we are checking the "changed"
everywhere we are supposed to (since I changed handling of these
structured quite a bit during development). Should be changed to NULL,
that's what we usually do in this type of situation.

--  Petr Jelinek                  http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training &
Services



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