Message-ID: <31ad2cd1-db94-bdb3-f91a-65ffdb4bef95@gmail.com>
Date: Thu, 13 Jun 2024 07:00:00 +0300
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Subject: Re: Remove dependence on integer wrapping
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To: Tom Lane <tgl@sss.pgh.pa.us>, Joseph Koshakow <koshy44@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 Andres Freund <andres@anarazel.de>, Nathan Bossart <nathandbossart@gmail.com>
References: 
 <CAAvxfHdBPOyEGS7s+xf4iaW0-cgiq25jpYdWBqQqvLtLe_t6tw@mail.gmail.com>
 <ZmZbXK1CNMbkty0W@nathan> <618777.1717984674@sss.pgh.pa.us>
From: Alexander Lakhin <exclusion@gmail.com>
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10.06.2024 04:57, Tom Lane wrote:
> BTW, while I approve of trying to get rid of our need for -fwrapv,
> I'm quite scared of actually doing it.  Whatever cases you may have
> discovered by running the regression tests will be at best the
> tip of the iceberg.  Is there any chance of using static analysis
> to find all the places of concern?

Let me remind you of bug #18240. Yes, that was about float8, but with
-ftrapv we can get into the trap with:
SELECT 1_000_000_000::money * 1_000_000_000::int;
server closed the connection unexpectedly

Also there are several trap-producing cases with date types:
SELECT to_date('100000000', 'CC');
SELECT to_timestamp('1000000000,999', 'Y,YYY');
SELECT make_date(-2147483648, 1, 1);

And one more with array...
CREATE TABLE t (ia int[]);
INSERT INTO t(ia[2147483647:2147483647]) VALUES ('{}');

I think it's not the whole iceberg too.

Best regards,
Alexander