wrong line number in error message #12573

p5pRT · 2012-11-17T03:07:03Z

Migrated from rt.perl.org#115768 (status was 'open')

Searchable as RT115768$

p5pRT · 2012-11-17T03:07:03Z

From @mauke

Created by @mauke

I think the following is a bug in the core but I'm not sure what's going on:
#!perl
use strict;
use Carp::Always;

if (1)
{
[]->();
}
__END__

Output:
Not a CODE reference at try.pl line 5.

(Expected: ... line 7.)

I can reproduce this with only core modules:
#!perl
use strict;
BEGIN { use Carp (); $SIG{__DIE__} = sub { Carp::croak @_ } }
#use Carp::Always;
if (1)
{
[]->();
}
__END__

Output:
Not a CODE reference at try.pl line 7.
at try.pl line 3.
main::__ANON__('Not a CODE reference at try.pl line 7.\x{a}') called at try.pl line 5

Here only the last part "... called at try.pl line 5" is wrong.

I briefly tried to debug this with PERLDB_OPTS='NonStop=1' perl -d try.pl, but
that makes the problem disappear.

Perl Info


Flags:
    category=core
    severity=low

Site configuration information for perl 5.16.2:

Configured by mauke at Thu Nov  1 15:23:47 CET 2012.

Summary of my perl5 (revision 5 version 16 subversion 2) configuration:
   
  Platform:
    osname=linux, osvers=2.6.32-5-686, archname=i686-linux
    uname='linux debian-vb 2.6.32-5-686 #1 smp sun sep 23 09:49:36 utc 2012 i686 gnulinux '
    config_args='-Dprefix=/home/mauke/usr -Doptimize=-O2 -flto -Dldflags=-fstack-protector -L/usr/local/lib -O2 -flto -Dlddlflags=-shared -O2 -flto -L/usr/local/lib -fstack-protector -Dcf_email=l.mai@web.de -Dperladmin=none -de'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -flto',
    cppflags='-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.7.1', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags ='-fstack-protector -L/usr/local/lib -O2 -flto'
    libpth=/usr/local/lib /lib/../lib /usr/lib/../lib /lib /usr/lib /usr/lib/i486-linux-gnu /usr/lib64
    libs=-lnsl -ldl -lm -lcrypt -lutil -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.11.3.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.11.3'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -flto -L/usr/local/lib -fstack-protector'

Locally applied patches:
    SAVEARGV0 - disable magic open in <ARGV>


@INC for perl 5.16.2:
    /home/mauke/usr/lib/perl5/site_perl/5.16.2/i686-linux
    /home/mauke/usr/lib/perl5/site_perl/5.16.2
    /home/mauke/usr/lib/perl5/5.16.2/i686-linux
    /home/mauke/usr/lib/perl5/5.16.2
    /home/mauke/usr/lib/perl5/site_perl/5.16.1/i686-linux
    /home/mauke/usr/lib/perl5/site_perl/5.16.1
    /home/mauke/usr/lib/perl5/site_perl
    .


Environment for perl 5.16.2:
    HOME=/home/mauke
    LANG=en_US.utf8
    LANGUAGE (unset)
    LC_COLLATE=POSIX
    LD_LIBRARY_PATH=/home/mauke/usr/lib
    LOGDIR (unset)
    PATH=/home/mauke/perl5/perlbrew/bin:/home/mauke/.cabal/bin:/home/mauke/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
    PERLBREW_BASHRC_VERSION=0.55
    PERLBREW_HOME=/home/mauke/.perlbrew
    PERLBREW_ROOT=/home/mauke/perl5/perlbrew
    PERL_BADLANG (unset)
    PERL_UNICODE=SAL
    SHELL=/bin/bash

p5pRT · 2012-11-17T19:13:59Z

From @cpansprout

On Fri Nov 16 19:07:03 2012, mauke- wrote:

This is a bug report for perl from l.mai@web.de,
generated with the help of perlbug 1.39 running under perl 5.16.2.

-----------------------------------------------------------------
[Please describe your issue here]

I think the following is a bug in the core but I'm not sure what's
going on:
#!perl
use strict;
use Carp::Always;

if (1)
{
[]->();
}
__END__

Output:
Not a CODE reference at try.pl line 5.

(Expected: ... line 7.)

I can reproduce this with only core modules:
#!perl
use strict;
BEGIN { use Carp (); $SIG{__DIE__} = sub { Carp::croak @_ } }
#use Carp::Always;
if (1)
{
[]->();
}
__END__

Output:
Not a CODE reference at try.pl line 7.
at try.pl line 3.
main::__ANON__('Not a CODE reference at try.pl line 7.\x{a}')
called at try.pl line 5

Here only the last part "... called at try.pl line 5" is wrong.

I briefly tried to debug this with PERLDB_OPTS='NonStop=1' perl -d
try.pl, but
that makes the problem disappear.

Could this be related to #111982?

--

Father Chrysostomos

p5pRT · 2012-11-17T19:14:00Z

The RT System itself - Status changed from 'new' to 'open'

p5pRT · 2012-11-17T20:28:28Z

From @mauke

On 17.11.2012 20:13, Father Chrysostomos via RT wrote:

On Fri Nov 16 19:07:03 2012, mauke- wrote:

This is a bug report for perl from l.mai@web.de,
generated with the help of perlbug 1.39 running under perl 5.16.2.

-----------------------------------------------------------------
[Please describe your issue here]

I think the following is a bug in the core but I'm not sure what's
going on:
#!perl
use strict;
use Carp::Always;

if (1)
{
[]->();
}
__END__

Output:
Not a CODE reference at try.pl line 5.

(Expected: ... line 7.)

I can reproduce this with only core modules:
#!perl
use strict;
BEGIN { use Carp (); $SIG{__DIE__} = sub { Carp::croak @_ } }
#use Carp::Always;
if (1)
{
[]->();
}
__END__

Output:
Not a CODE reference at try.pl line 7.
at try.pl line 3.
main::__ANON__('Not a CODE reference at try.pl line 7.\x{a}')
called at try.pl line 5

Here only the last part "... called at try.pl line 5" is wrong.

I briefly tried to debug this with PERLDB_OPTS='NonStop=1' perl -d
try.pl, but
that makes the problem disappear.

Could this be related to #111982?

That bug is about some compilation errors (such as an undeclared
variable under 'use strict') having a caller location of end-of-script
(because perl performs some checks only after it has reached the end of
the code).

It doesn't seem to be immediately related because:
- this is a runtime error, not compile time
- the bogus line number doesn't point to the end of the script
- in fact, it points to an *earlier* statement (the 'if' controlling the
block)

But maybe there's a deeper connection?

p5pRT · 2012-11-17T21:12:37Z

From @cpansprout

On Sat Nov 17 12:28:28 2012, mauke- wrote:

On 17.11.2012 20:13, Father Chrysostomos via RT wrote:

Could this be related to #111982?

That bug is about some compilation errors (such as an undeclared
variable under 'use strict') having a caller location of end-of-script
(because perl performs some checks only after it has reached the end of
the code).

It doesn't seem to be immediately related because:
- this is a runtime error, not compile time
- the bogus line number doesn't point to the end of the script
- in fact, it points to an *earlier* statement (the 'if' controlling the
block)

But maybe there's a deeper connection?

That was just a hunch, based on a quick reading. It’s probably unrelated.

In this case I suspect it has to do with a nextstate op being optimised
away so a different nextstate op is active. Again, I haven’t looked at
it carefully, as I am in the middle of fixing 5 more memory leaks I’ve
just discovered.

--

Father Chrysostomos

p5pRT · 2012-11-19T02:09:20Z

From @ikegami

On Sat, Nov 17, 2012 at 4:12 PM, Father Chrysostomos via RT <
perlbug-followup@perl.org> wrote:

In this case I suspect it has to do with a nextstate op being optimised
away so a different nextstate op is active.

$ perl -MO=Concise -e'if (1)
{
[]->();
}
'
7 <@> leave[1 ref] vKP/REFC ->(end)
1 <0> enter ->2
2 <;> nextstate(main 3 -e:1) v:{ ->3 <--- This is the one that is
used.
- <@> scope vK ->7
- <0> ex-nextstate v ->3 <--- This would have the
correct info, but optimised away
6 <1> entersub[t1] vKS/TARG,1 ->7
- <1> ex-list K ->6
3 <0> pushmark s ->4
- <1> ex-rv2cv K ->-
5 <@> anonlist sK* ->6
4 <0> pushmark s ->5
-e syntax OK

p5pRT · 2012-11-19T02:43:54Z

From @cpansprout

On Sun Nov 18 18:09:20 2012, ikegami@adaelis.com wrote:

On Sat, Nov 17, 2012 at 4:12 PM, Father Chrysostomos via RT <
perlbug-followup@perl.org> wrote:

In this case I suspect it has to do with a nextstate op being optimised
away so a different nextstate op is active.

$ perl -MO=Concise -e'if (1)
{
[]->();
}
'
7 <@> leave[1 ref] vKP/REFC ->(end)
1 <0> enter ->2
2 <;> nextstate(main 3 -e:1) v:{ ->3 <--- This is the one
that is
used.
- <@> scope vK ->7
- <0> ex-nextstate v ->3 <--- This would have the
correct info, but optimised away
6 <1> entersub[t1] vKS/TARG,1 ->7
- <1> ex-list K ->6
3 <0> pushmark s ->4
- <1> ex-rv2cv K ->-
5 <@> anonlist sK* ->6
4 <0> pushmark s ->5
-e syntax OK

Aha, so it looks as though pp_ctl.c:pp_caller needs to use
util.c:S_closest_cop.

Debugging without looking at the code seems to be working. :-)

--

Father Chrysostomos

p5pRT · 2013-09-01T18:43:04Z

From @cpansprout

Fixed in 2550212.

--

Father Chrysostomos

p5pRT · 2013-09-01T18:43:05Z

@cpansprout - Status changed from 'open' to 'resolved'

p5pRT · 2013-09-01T23:12:34Z

From @cpansprout

On Sun Sep 01 11:43:04 2013, sprout wrote:

Fixed in 2550212.

Though, actually, there are some cases where it doesn’t work, (e.g.,
eval "s{}\n{foo()}e"), because the context stack has no pointer to the
entersub op, but rather its ->op_next. Sometimes ->op_next is null (in
that subst example).

Would it be reasonable to put the entersub op in the context stack (as
retop) and have pp_leavesub do retop->op_next instead of just retop?

--

Father Chrysostomos

p5pRT · 2013-09-02T00:26:53Z

@cpansprout - Status changed from 'resolved' to 'open'

GWHAYWOOD · 2023-01-27T18:12:46Z

Is this still open? I think I'm hitting it with some of my code. In a script of about 5700 lines, around line 5040 I have something like

if( ! $something )
{
write_log( message, line_number );
...
}

When the message gets printed, the line_number that's logged is the line number for the if() conditional. This doesn't happen everywhere that I do this sort of thing, just occasionally and for no reason that I've managed to spot so far. If there's a NO-OP line inserted between the opening curly brace and the log statement, the line number that's logged is correct.

if( ! $something )
{
my $unused = 0;
write_log( message, line_number );
...
}

Perl on Debian 11.4:

$ perl -v

This is perl 5, version 28, subversion 1 (v5.28.1) built for i686-linux-gnu-thread-multi-64int
(with 65 registered patches, see perl -V for more detail)

demerphq · 2023-01-28T04:01:37Z

There are alas multiple versions of the bug. If you check the PRs there is an example I found some time back.

I really wish we as a community would focus more effort on fixing issues like this. I've put a fair bit of effort in the last cycle fixing some of the related issues, but there is so much more to do. I really think when we get error message data wring we make perl look bad to newbies, and we frustrate even the oldest and most experienced greybeard.

p5pRT closed this as completed Sep 1, 2013

p5pRT added Severity Low distro-Linux type-core labels Oct 19, 2019

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wrong line number in error message #12573

wrong line number in error message #12573

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wrong line number in error message #12573

wrong line number in error message #12573

Comments

p5pRT commented Nov 17, 2012

p5pRT commented Nov 17, 2012

From @mauke

Created by @mauke

p5pRT commented Nov 17, 2012

From @cpansprout

p5pRT commented Nov 17, 2012

p5pRT commented Nov 17, 2012

From @mauke

p5pRT commented Nov 17, 2012

From @cpansprout

p5pRT commented Nov 19, 2012

From @ikegami

p5pRT commented Nov 19, 2012

From @cpansprout

p5pRT commented Sep 1, 2013

From @cpansprout

p5pRT commented Sep 1, 2013

p5pRT commented Sep 1, 2013

From @cpansprout

p5pRT commented Sep 2, 2013

GWHAYWOOD commented Jan 27, 2023

demerphq commented Jan 28, 2023