Date: Mon, 26 Jul 2021 15:35:29 -0400
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: Michael Paquier <michael@paquier.xyz>,
	Postgres hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Some code cleanup for pgbench and pg_verifybackup
Message-ID: <202107261935.tad2ojwemn3v@alvherre.pgsql>
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On 2021-Jul-26, Fabien COELHO wrote:

> > - pgbench and pg_verifybackup make use of pg_log_fatal() to report
> > some failures in code paths dedicated to command-line options, which
> > is inconsistent with all the other tools that use pg_log_error().
> 
> The semantics for fatal vs error is that an error is somehow handled while a
> fatal is not. If the log message is followed by an cold exit, ISTM that
> fatal is the right call, and I cannot help if other commands do not do that.
> ISTM more logical to align other commands to fatal when appropriate.

I was surprised to discover a few weeks ago that pg_log_fatal() did not
terminate the program, which was my expectation.  If every single call
to pg_log_fatal() is followed by exit(1), why not make pg_log_fatal()
itself exit?  Apparently this coding pattern confuses many people -- for
example pg_verifybackup.c lines 291ff fail to exit(1) after "throwing" a
fatal error, while the block at lines 275 does the right thing.

(In reality we cannot literally just exit(1) in pg_log_fatal(), because
there are quite a few places that do some other thing after the log
call and before exit(1), or terminate the program in some other way than
exit().)

-- 
Álvaro Herrera           39°49'30"S 73°17'W  —  https://www.EnterpriseDB.com/
Essentially, you're proposing Kevlar shoes as a solution for the problem
that you want to walk around carrying a loaded gun aimed at your foot.
(Tom Lane)