Re: [PATCH] Identify LWLocks in tracepoints - Mailing list pgsql-hackers

From Andres Freund
Subject Re: [PATCH] Identify LWLocks in tracepoints
Date
Msg-id 20210509185504.svhnhufbulq756vv@alap3.anarazel.de
Whole thread Raw
In response to Re: [PATCH] Identify LWLocks in tracepoints  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [PATCH] Identify LWLocks in tracepoints
List pgsql-hackers
Hi,

On 2021-05-08 13:13:47 -0400, Tom Lane wrote:
> Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
> > On 05.05.21 00:15, Andres Freund wrote:
> >> I'm now getting
> >> /home/andres/src/postgresql/src/backend/storage/lmgr/lwlock.c: In function ‘LWLockAcquire’:
> >> /home/andres/src/postgresql/src/backend/storage/lmgr/lwlock.c:1322:58: warning: suggest braces around empty body
inan ‘if’ statement [-Wempty-body]
 
> >> 1322 |    TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), mode);
> >> |                                                          ^
> 
> > What compiler are you using in this situation?

gcc - I think the warning is pulled in via -Wextra.  I think it's
something sensible to warn about, too easy to end up with misleading
behaviour when statement-like macros are defined empty.


> All of these buildfarm members are now showing this warning:
> 
> calliphoridae    gcc (Debian 10.1.0-6) 10.1.0
> culicidae    gcc (Debian 10.1.0-6) 10.1.0
> flaviventris    gcc (Debian 20200124-1) 10.0.1 20200124 (experimental)
> francolin    gcc (Debian 10.1.0-6) 10.1.0
> piculetœ    gcc (Debian 10.1.0-6) 10.1.0
> rorqual        gcc (Debian 10.1.0-6) 10.1.0
> serinus        gcc (Debian 20200124-1) 10.0.1 20200124 (experimental)
> skink        gcc (Debian 10.1.0-6) 10.1.0

I think those likely are all mine, so it's not too surprising. They all
use something like
CFLAGS => '-Og -ggdb -g3 -Wall -Wextra -Wno-unused-parameter -Wno-sign-compare -Wno-missing-field-initializers
-fno-omit-frame-pointer',


> (I wonder why flaviventris and serinus are still using an "experimental"
> compiler version that is now behind mainstream.)

The upgrade script didn't install the newer version it because it had to
remove some conflicting packages... Should be fixed for runs starting
now.

Greetings,

Andres Freund



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