Horton

Re: BUG #18240: Undefined behaviour in cash_mul_flt8() and friends

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: exclusion@gmail.com, pgsql-bugs@lists.postgresql.org
Date: 2023-12-12T09:03:43Z
Lists: pgsql-bugs 
On Mon, Dec 11, 2023 at 10:05:53AM -0500, Tom Lane wrote:
> Yeah, approximately none of cash.c pays any attention to the risks
> of overflow/underflow.  Improving that situation would be a good
> finger exercise for some aspiring hacker, perhaps.  Although I bet
> somebody will ask again why it is that we continue to support the
> money type.

AFAIK, we discourage the use of money in the wiki for quite a few
years:
https://wiki.postgresql.org/wiki/Don%27t_Do_This#Don.27t_use_money

And numeric has much better code coverage and support.  I am wondering
whether we've reached the point where it would be better to remove it
entirely from the tree, and just tell people to use numeric.  This has
a cost for upgrades, where we should cross check for its use but there
is already check_for_data_type_usage() to do this job so the facility
is there.
--
Michael

Commits

  1. Add overflow checks to money type.

  2. Reduce dependency to money data type in main regression test suite