Wrong context determined for <>/IO::Handle::getline in debug mode

[p5pRT]

Migrated from rt.perl.org#130021 (status was 'open')

Searchable as RT130021$

[p5pRT]

From @KES777

Created by @KES777

Sorry, can not replay to https://rt.perl.org/Public/Bug/Display.html?id=92728
When I logged in I am redirected to​: https://rt.perl.org/SelfService/

When I debug my script and it is use IO​::Handle I got errors issued from​:
https://metacpan.org/source/TODDR/IO-1.36_01/lib/IO/Handle.pm#L437

$ mojo generate lite_ap
$ perl -Ilib -d​:DebugHooks​::Terminal myapp.pl get /
...
DB​::sub DB​::state​: l​:1 d​:0 s​:0 t​:0 lib/IO/Handle.pm​:437 --> IO​::Handle​::_create_getline_subs
DB​::sub DB​::state​: l​:1 d​:1 s​:0 t​:0 lib/Devel/DebugHooks.pm​:100 --> Devel​::DebugHooks​::test
DB​::sub DB​::state​: l​:1 d​:1 s​:0 t​:0 lib/Devel/DebugHooks.pm​:135 --> DB​::emit
DB​::sub DB​::state​: l​:1 d​:1 s​:0 t​:0 lib/Devel/DebugHooks.pm​:147 --> DB​::emit
Unquoted string "croak" may clash with future reserved word at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 2.
String found where operator expected at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 2, near "croak 'usage​: $io->getline()'"
  (Do you need to predeclare croak?)
Unquoted string "croak" may clash with future reserved word at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 8.
String found where operator expected at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 8, near "croak 'usage​: $io->getlines()'"
  (Do you need to predeclare croak?)
Unquoted string "croak" may clash with future reserved word at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 10.
String found where operator expected at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 10, near "croak 'Can\'t call $io->getlines in a scalar context, use $io->getline'"
  (Do you need to predeclare croak?)
syntax error at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 2, near "croak 'usage​: $io->getline()'"
syntax error at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 8, near "croak 'usage​: $io->getlines()'"
syntax error at (eval 4)[lib/Devel/DebugHooks.pm​:1434] line 10, near "croak 'Can\'t call $io->getlines in a scalar context, use $io->getline'"
Compilation failed in require at lib/Mojo/Base.pm line 13.
BEGIN failed--compilation aborted at lib/Mojo/Base.pm line 13.
Compilation failed in require at lib/Mojolicious/Lite.pm line 2.
BEGIN failed--compilation aborted at lib/Mojolicious/Lite.pm line 2.
Compilation failed in require at myapp.pl line 2.
BEGIN failed--compilation aborted at myapp.pl line 2.

I modify IO​::Handle to look like​:
# Special XS wrapper to make them inherit lexical hints from the caller.
_create_getline_subs( <<'END' ) or die $@​;
sub getline {
  DB​::orig_frames;
  die "DDD>>>". __PACKAGE__;
  @​_ == 1 or croak( 'usage​: $io->getline()'. "@​_" );
  my $this = shift;
  return scalar <$this>;
}

sub getlines {
  @​_ == 1 or croak( 'usage​: $io->getlines()' );
  wantarray or
  croak( 'Can\'t call $io->getlines in a scalar context, use $io->getline' );
  my $this = shift;
  return <$this>;
}
1; # return true for error checking
END

DB​::getline(); # line 460

And I get this error​:
DB lib/Devel/DebugHooks.pm 1439 DB​::orig_frames
IO​::Handle lib/IO/Handle.pm 460 DB​::getline
Mojo​::Base lib/Mojo/Base.pm 13 (eval)
main lib/IO/Handle.pm 0 Mojo​::Base​::BEGIN
main lib/IO/Handle.pm 0 (eval)
Mojolicious​::Lite lib/Mojolicious/Lite.pm 2 (eval)
main lib/IO/Handle.pm 0 Mojolicious​::Lite​::BEGIN
main lib/IO/Handle.pm 0 (eval)
main myapp.pl 2 (eval)
main lib/IO/Handle.pm 0 main​::BEGIN
main lib/IO/Handle.pm 0 (eval)

DDD>>>DB at lib/Devel/DebugHooks.pm line 1439.

I suppose context in debugger mode is not determined right by _create_getline_subs
so getline/getlines are created in DB package instead of IO​::Handle
But I may wrong.

Perl Info

Flags:
    category=library
    severity=low
    module=IO::Handle

Site configuration information for perl 5.24.0:

Configured by kes at Tue Jun  7 00:21:02 EEST 2016.

Summary of my perl5 (revision 5 version 24 subversion 0) configuration:
   
  Platform:
    osname=linux, osvers=3.13.0-37-generic, archname=x86_64-linux
    uname='linux kes-desktop 3.13.0-37-generic #64-ubuntu smp mon sep 22 21:28:38 utc 2014 x86_64 x86_64 x86_64 gnulinux '
    config_args='-de -Dprefix=/home/kes/perl5/perlbrew/perls/perl-5.24.0 -Aeval:scriptdir=/home/kes/perl5/perlbrew/perls/perl-5.24.0/bin'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.8.4', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678, doublekind=3
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16, longdblkind=3
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib
    libs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    libc=libc-2.19.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.19'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector'

Locally applied patches:
    Devel::PatchPerl 1.38


@INC for perl 5.24.0:
    /home/kes/perl5/perlbrew/perls/perl-5.24.0/lib/site_perl/5.24.0/x86_64-linux
    /home/kes/perl5/perlbrew/perls/perl-5.24.0/lib/site_perl/5.24.0
    /home/kes/perl5/perlbrew/perls/perl-5.24.0/lib/5.24.0/x86_64-linux
    /home/kes/perl5/perlbrew/perls/perl-5.24.0/lib/5.24.0
    .


Environment for perl 5.24.0:
    HOME=/home/kes
    LANG=ru_UA.UTF-8
    LANGUAGE=en
    LC_MESSAGES=en_US.UTF-8
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/kes/perl5/perlbrew/bin:/home/kes/perl5/perlbrew/perls/perl-5.24.0/bin:/home/kes/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
    PERLBREW=command perlbrew
    PERLBREW_BASHRC_VERSION=0.76
    PERLBREW_HOME=/home/kes/.perlbrew
    PERLBREW_MANPATH=/home/kes/perl5/perlbrew/perls/perl-5.24.0/man
    PERLBREW_PATH=/home/kes/perl5/perlbrew/bin:/home/kes/perl5/perlbrew/perls/perl-5.24.0/bin
    PERLBREW_PERL=perl-5.24.0
    PERLBREW_ROOT=/home/kes/perl5/perlbrew
    PERLBREW_VERSION=0.76
    PERL_BADLANG (unset)
    SHELL=/bin/bash

[p5pRT]

From @jkeenan

On Fri, 04 Nov 2016 22​:58​:10 GMT, kes-kes@​yandex.ru wrote​:

Reply-To​: kes-kes@​yandex.ru
Subject​: Wrong context determined for <> in debug mode
From​: kes-kes@​yandex.ru
Cc​: kes-kes@​yandex.ru
Message-Id​: <5.24.0_8991_1478299133@​kes-desktop>
To​: perlbug@​perl.org

This is a bug report for perl from kes-kes@​yandex.ru,
generated with the help of perlbug 1.40 running under perl 5.24.0.

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

This report does not appear to be appropriate for rt.perl.org.

Sorry, can not replay to
https://rt.perl.org/Public/Bug/Display.html?id=92728
When I logged in I am redirected to​: https://rt.perl.org/SelfService/

That RT was closed more than five years ago. It's not clear why you were trying to reply to it.

When I debug my script and it is use IO​::Handle I got errors issued
from​:
https://metacpan.org/source/TODDR/IO-1.36_01/lib/IO/Handle.pm#L437

$ mojo generate lite_ap
$ perl -Ilib -d​:DebugHooks​::Terminal myapp.pl get /
...
DB​::sub DB​::state​: l​:1 d​:0 s​:0 t​:0 lib/IO/Handle.pm​:437 -->
IO​::Handle​::_create_getline_subs
DB​::sub DB​::state​: l​:1 d​:1 s​:0 t​:0 lib/Devel/DebugHooks.pm​:100 -->
Devel​::DebugHooks​::test
DB​::sub DB​::state​: l​:1 d​:1 s​:0 t​:0 lib/Devel/DebugHooks.pm​:135 -->
DB​::emit
DB​::sub DB​::state​: l​:1 d​:1 s​:0 t​:0 lib/Devel/DebugHooks.pm​:147 -->
DB​::emit
Unquoted string "croak" may clash with future reserved word at (eval
4)[lib/Devel/DebugHooks.pm​:1434] line 2.
String found where operator expected at (eval
4)[lib/Devel/DebugHooks.pm​:1434] line 2, near "croak 'usage​: $io-

getline()'"
(Do you need to predeclare croak?)

In my experience, this error message appears when I fail to say​:

#####
use Carp;
#####

Could you try that first?

Thank you very much.

--
James E Keenan (jkeenan@​cpan.org)

[p5pRT]

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

[p5pRT]

From @cpansprout

On Fri, 04 Nov 2016 16​:18​:11 -0700, jkeenan wrote​:

In my experience, this error message appears when I fail to say​:

#####
use Carp;
#####

Could you try that first?

The line in question is actually in IO​::Handle, which already does ‘use Carp’. There appears to be some ugly interaction between a sub that has no nextstate ops and the debugger. I wonder whether it affects subs in the CORE​:: namespace too, as they use a similar trick to run code with the caller’s hints.

--

Father Chrysostomos

[p5pRT]

From @KES777

I minify testcase. This is occur only when I do call to Time​::HiRes​::gettimeofday

$ cat Devel/DB.pm
package DB;

sub DB {
}

use Time​::HiRes qw/ gettimeofday /;
sub sub {
  print "$DB​::sub is called\n";
  # my $t = [ gettimeofday ]; # <<< Uncomment this to get error

  return &$DB​::sub;
}

1;

$ cat t.pl
use IO​::Handle();
1;

$ perl -d​:DB t.pl
...
strict​::unimport is called
strict​::bits is called
IO​::Handle​::_create_getline_subs is called
String found where operator expected at (eval 4)[Devel/DB.pm​:11] line 2, near "croak 'usage​: $io->getline()'"
  (Do you need to predeclare croak?)
syntax error at (eval 4)[Devel/DB.pm​:11] line 2, near "croak 'usage​: $io->getline()'"
Compilation failed in require at t.pl line 1.
BEGIN failed--compilation aborted at t.pl line 1.