Re: [HACKERS] [GENERAL] OS X 10.11.3, psql, bus error 10, 9.5.1
Greg Stark writes: > On 12 Mar 2016 10:58 pm, "Tom Lane" wrote: >> I shall get rid of the const-ness, as well as the lame casting away >> of it, and I think I will also go make buildfarm member longfin use >> "-fno-common". It is truly sad that we apparently have no test >> machine that enforces that const means const ... > It looks like this would also be useful for catching any mistakes where we > might have defined a variable in two different files or missed an "extern". > Though I'm not sure the failures will be very obvious. The answer is that a failure looks like this: duplicate symbol _FeBeWaitSet in: access/common/printtup.o access/transam/parallel.o duplicate symbol _FeBeWaitSet in: access/common/printtup.o commands/async.o duplicate symbol _FeBeWaitSet in: access/common/printtup.o commands/copy.o duplicate symbol _FeBeWaitSet in: access/common/printtup.o libpq/be-secure.o duplicate symbol _FeBeWaitSet in: access/common/printtup.o libpq/auth.o duplicate symbol _FeBeWaitSet in: access/common/printtup.o libpq/hba.o duplicate symbol _FeBeWaitSet in: access/common/printtup.o libpq/pqcomm.o ... etc etc ... See: http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=longfin&dt=2016-03-21%2011%3A49%3A13 http://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=7fa0064092e135415a558dc3c4d7393d14ab6d8e regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [GENERAL] OS X 10.11.3, psql, bus error 10, 9.5.1
On 12 Mar 2016 10:58 pm, "Tom Lane" wrote: > > I wrote: > > That's confusing because it implies that -fno-common is the default, > > which it evidently is not. But anyway, my diagnosis is that you're > > breaking something about the linker's behavior with that switch. > I shall get rid of the const-ness, as well as the lame casting away > of it, and I think I will also go make buildfarm member longfin use > "-fno-common". It is truly sad that we apparently have no test > machine that enforces that const means const ... It looks like this would also be useful for catching any mistakes where we might have defined a variable in two different files or missed an "extern". Though I'm not sure the failures will be very obvious.
Re: [HACKERS] [GENERAL] OS X 10.11.3, psql, bus error 10, 9.5.1
unfortunately, I have to admit to my disgrace, that I'm still no C programmer after all these decades of dabbling in writing code. I just used the flags because someone at some point told me that it was a good idea, turns out, it's not [always]. I shall rebuild 9.5.1 without the -fno-common flag and see if that fixes things. Thanks Tom for spending part of your weekend on this. Chris. > On Mar 12, 2016, at 17:58, Tom Lane wrote: > > I wrote: >> That's confusing because it implies that -fno-common is the default, >> which it evidently is not. But anyway, my diagnosis is that you're >> breaking something about the linker's behavior with that switch. > > Oh! Looking closer, the core dump happens here: > > const printTextFormat pg_utf8format; > > printTextFormat *popt = (printTextFormat *) &pg_utf8format; > > --> popt->name = "unicode"; > > So apparently, the relevant property of "-fno-common" is that it > causes "const" variables to actually get placed in read-only data. > > I think this code is new in 9.5, which'd explain why you didn't see > the failure with older PG versions. It's surely busted though. > > I shall get rid of the const-ness, as well as the lame casting away > of it, and I think I will also go make buildfarm member longfin use > "-fno-common". It is truly sad that we apparently have no test > machine that enforces that const means const ... > > regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [GENERAL] OS X 10.11.3, psql, bus error 10, 9.5.1
I wrote: > That's confusing because it implies that -fno-common is the default, > which it evidently is not. But anyway, my diagnosis is that you're > breaking something about the linker's behavior with that switch. Oh! Looking closer, the core dump happens here: const printTextFormat pg_utf8format; printTextFormat *popt = (printTextFormat *) &pg_utf8format; --> popt->name = "unicode"; So apparently, the relevant property of "-fno-common" is that it causes "const" variables to actually get placed in read-only data. I think this code is new in 9.5, which'd explain why you didn't see the failure with older PG versions. It's surely busted though. I shall get rid of the const-ness, as well as the lame casting away of it, and I think I will also go make buildfarm member longfin use "-fno-common". It is truly sad that we apparently have no test machine that enforces that const means const ... regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
