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debugger does not stop at postponed breakpoints #15773

Open p5pRT opened 7 years ago

p5pRT commented 7 years ago

Migrated from rt.perl.org#130361 (status was 'open')

Searchable as RT130361$

p5pRT commented 7 years ago

From jkahrman@mathworks.com

Created by jkahrman@mathworks.com

Debugger does not stop at postponed breakpoints in perl 5.20

Same behavior in perl5.20 from Debian 8 as perl 5.20 built from source. No customizations to PERL5DB.

http​://www.perlmonks.com/?node_id=1176116

% perl -dwe0

main​::(-e​:1)​: 0   DB\<1> b File​::Temp->new Subroutine File​::Temp not found.

  DB\<2> b postpone File​::Temp​::new   DB\<3> use File​::Temp   DB\<4> x File​::Temp->new 0 File​::Temp=GLOB(0x283db48)   -> *File​::Temp​::$fh   FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### UNEXPECTEDLY did not stop at File​::Temp​::new

  DB\<5> b postpone File​::Temp​::new   DB\<6> x File​::Temp->new 0 File​::Temp=GLOB(0x216aa78)   -> *File​::Temp​::$fh   FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### UNEXPECTEDLY did not stop at File​::Temp​::new

  DB\<7> B * Deleting all breakpoints...   DB\<8> b postpone File​::Temp​::new   DB\<9> x File​::Temp->new 0 File​::Temp=GLOB(0x216abc8)   -> *File​::Temp​::$fh   FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### UNEXPECTEDLY did not stop at File​::Temp​::new

  DB\<10> b File​::Temp​::new   DB\<11> x File​::Temp->new File​::Temp​::new(/.../x86_64/perl/perl-5.20.2-mw-014/lib/5.20.2/File/Temp.pm​:885)​: 885​: my $proto = shift;   DB\<\<12>> c 0 File​::Temp=GLOB(0x216aeb0)   -> *File​::Temp​::$fh   FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### STOPPED at File​::Temp​::new as EXPECTED

Perl Info ``` Flags: category=core severity=medium Site configuration information for perl 5.20.2: Configured by Debian Project at Mon Jan 11 23:24:04 UTC 2016. Summary of my perl5 (revision 5 version 20 subversion 2) configuration: Platform: osname=linux, osvers=3.16.0-4-amd64, archname=x86_64-linux-gnu-thread-multi uname='linux themisto 3.16.0-4-amd64 #1 smp debian 3.16.7-ckt20-1+deb8u1 (2015-12-14) x86_64 gnulinux ' config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Dldflags= -Wl,-z,relro -Dlddlflags=-shared -Wl,-z,relro -Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.20 -Darchlib=/usr/lib/x86_64-linux-gnu/perl/5.20 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/x86_64-linux-gnu/perl5/5.20 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.20.2 -Dsitearch=/usr/local/lib/x86_64-linux-gnu/perl/5.20.2 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Duse64bitint -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -Ui_libutil -Uversiononly -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.20.2 -des' hint=recommended, useposix=true, d_sigaction=define useithreads=define, usemultiplicity=define use64bitint=define, use64bitall=define, uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2 -g', cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include' ccversion='', gccversion='4.9.2', gccosandvers='' intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16 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/4.9/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=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt perllibs=-ldl -lm -lpthread -lc -lcrypt libc=libc-2.19.so, so=so, useshrplib=true, libperl=libperl.so.5.20 gnulibc_version='2.19' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib -fstack-protector' Locally applied patches: DEBPKG:debian/cpan_definstalldirs - Provide a sensible INSTALLDIRS default for modules installed from CPAN. DEBPKG:debian/db_file_ver - http://bugs.debian.org/340047 Remove overly restrictive DB_File version check. DEBPKG:debian/doc_info - Replace generic man(1) instructions with Debian-specific information. DEBPKG:debian/enc2xs_inc - http://bugs.debian.org/290336 Tweak enc2xs to follow symlinks and ignore missing @INC directories. DEBPKG:debian/errno_ver - http://bugs.debian.org/343351 Remove Errno version check due to upgrade problems with long-running processes. DEBPKG:debian/libperl_embed_doc - http://bugs.debian.org/186778 Note that libperl-dev package is required for embedded linking DEBPKG:fixes/respect_umask - Respect umask during installation DEBPKG:debian/writable_site_dirs - Set umask approproately for site install directories DEBPKG:debian/extutils_set_libperl_path - EU:MM: set location of libperl.a under /usr/lib DEBPKG:debian/no_packlist_perllocal - Don't install .packlist or perllocal.pod for perl or vendor DEBPKG:debian/prefix_changes - Fiddle with *PREFIX and variables written to the makefile DEBPKG:debian/fakeroot - Postpone LD_LIBRARY_PATH evaluation to the binary targets. DEBPKG:debian/instmodsh_doc - Debian policy doesn't install .packlist files for core or vendor. DEBPKG:debian/ld_run_path - Remove standard libs from LD_RUN_PATH as per Debian policy. DEBPKG:debian/libnet_config_path - Set location of libnet.cfg to /etc/perl/Net as /usr may not be writable. DEBPKG:debian/mod_paths - Tweak @INC ordering for Debian DEBPKG:debian/module_build_man_extensions - http://bugs.debian.org/479460 Adjust Module::Build manual page extensions for the Debian Perl policy DEBPKG:debian/prune_libs - http://bugs.debian.org/128355 Prune the list of libraries wanted to what we actually need. DEBPKG:fixes/net_smtp_docs - [rt.cpan.org #36038] http://bugs.debian.org/100195 Document the Net::SMTP 'Port' option DEBPKG:debian/perlivp - http://bugs.debian.org/510895 Make perlivp skip include directories in /usr/local DEBPKG:debian/deprecate-with-apt - http://bugs.debian.org/747628 Point users to Debian packages of deprecated core modules DEBPKG:debian/squelch-locale-warnings - http://bugs.debian.org/508764 Squelch locale warnings in Debian package maintainer scripts DEBPKG:debian/skip-upstream-git-tests - Skip tests specific to the upstream Git repository DEBPKG:debian/patchlevel - http://bugs.debian.org/567489 List packaged patches for 5.20.2-3+deb8u3 in patchlevel.h DEBPKG:debian/skip-kfreebsd-crash - http://bugs.debian.org/628493 [perl #96272] Skip a crashing test case in t/op/threads.t on GNU/kFreeBSD DEBPKG:fixes/document_makemaker_ccflags - http://bugs.debian.org/628522 [rt.cpan.org #68613] Document that CCFLAGS should include $Config{ccflags} DEBPKG:debian/find_html2text - http://bugs.debian.org/640479 Configure CPAN::Distribution with correct name of html2text DEBPKG:debian/perl5db-x-terminal-emulator.patch - http://bugs.debian.org/668490 Invoke x-terminal-emulator rather than xterm in perl5db.pl DEBPKG:debian/cpan-missing-site-dirs - http://bugs.debian.org/688842 Fix CPAN::FirstTime defaults with nonexisting site dirs if a parent is writable DEBPKG:fixes/memoize_storable_nstore - [rt.cpan.org #77790] http://bugs.debian.org/587650 Memoize::Storable: respect 'nstore' option not respected DEBPKG:debian/regen-skip - Skip a regeneration check in unrelated git repositories DEBPKG:fixes/regcomp-mips-optim - [perl #122817] http://bugs.debian.org/754054 Downgrade the optimization of regcomp.c on mips and mipsel due to a gcc-4.9 bug DEBPKG:debian/makemaker-pasthru - http://bugs.debian.org/758471 Pass LD settings through to subdirectories DEBPKG:fixes/perldoc-less-R - [rt.cpan.org #98636] http://bugs.debian.org/758689 Tell the 'less' pager to allow terminal escape sequences DEBPKG:fixes/pod_man_reproducible_date - http://bugs.debian.org/759405 Support POD_MAN_DATE in Pod::Man for the left-hand footer DEBPKG:fixes/io_uncompress_gunzip_inmemory - http://bugs.debian.org/747363 [rt.cpan.org #95494] Fix gunzip to in-memory file handle DEBPKG:fixes/socket_test_recv_fix - http://bugs.debian.org/758718 [perl #122657] Compare recv return value to peername in socket test DEBPKG:fixes/hurd_socket_recv_todo - http://bugs.debian.org/758718 [perl #122657] TODO checking the result of recv() on hurd DEBPKG:fixes/regexp-performance - [0fa70a0] http://bugs.debian.org/777556 [perl #123743] simpify and speed up /.*.../ handling DEBPKG:fixes/failed_require_diagnostics - http://bugs.debian.org/781120 [perl #123270] Report inaccesible file on failed require DEBPKG:fixes/array-cloning - http://bugs.debian.org/779357 [perl #124127] [902d169] fix cloning arrays with unused elements DEBPKG:fixes/perldb-threads - http://bugs.debian.org/779357 [perl #124127] [41ef2c6] lib/perl5db.pl: Restore noop lock prototype DEBPKG:fixes/CVE-2015-8607_file_spec_taint_fix - ensure File::Spec::canonpath() preserves taint DEBPKG:fixes/encode-unicode-bom - http://bugs.debian.org/798727 [rt.cpan.org #107043] Address https://rt.cpan.org/Public/Bug/Display.html?id=107043 DEBPKG:debian/encode-unicode-bom-doc - http://bugs.debian.org/798727 Document Debian backport of Encode::Unicode fix @INC for perl 5.20.2: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.20.2 /usr/local/share/perl/5.20.2 /usr/lib/x86_64-linux-gnu/perl5/5.20 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.20 /usr/share/perl/5.20 /usr/local/lib/site_perl . Environment for perl 5.20.2: HOME=/home/jkahrman LANG=en_US.utf8 LANGUAGE (unset) LD_LIBRARY_PATH= LOGDIR (unset) PATH=/usr/local/bin:/usr/bin:/bin:/sbin PERL_BADLANG (unset) SHELL=/usr/local/bin/tcsh ```
p5pRT commented 7 years ago

From @jkeenan

On Fri\, 16 Dec 2016 18​:33​:04 GMT\, jkahrman@​mathworks.com wrote​:

This is a bug report for perl from jkahrman@​mathworks.com\, generated with the help of perlbug 1.40 running under perl 5.20.2.

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

Debugger does not stop at postponed breakpoints in perl 5.20

Same behavior in perl5.20 from Debian 8 as perl 5.20 built from source. No customizations to PERL5DB.

http​://www.perlmonks.com/?node_id=1176116

% perl -dwe0

main​::(-e​:1)​: 0 DB\<1> b File​::Temp->new Subroutine File​::Temp not found.

DB\<2> b postpone File​::Temp​::new DB\<3> use File​::Temp DB\<4> x File​::Temp->new 0 File​::Temp=GLOB(0x283db48) -> *File​::Temp​::$fh FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### UNEXPECTEDLY did not stop at File​::Temp​::new

DB\<5> b postpone File​::Temp​::new DB\<6> x File​::Temp->new 0 File​::Temp=GLOB(0x216aa78) -> *File​::Temp​::$fh FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### UNEXPECTEDLY did not stop at File​::Temp​::new

DB\<7> B * Deleting all breakpoints... DB\<8> b postpone File​::Temp​::new DB\<9> x File​::Temp->new 0 File​::Temp=GLOB(0x216abc8) -> *File​::Temp​::$fh FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### UNEXPECTEDLY did not stop at File​::Temp​::new

DB\<10> b File​::Temp​::new DB\<11> x File​::Temp->new File​::Temp​::new(/.../x86_64/perl/perl-5.20.2-mw- 014/lib/5.20.2/File/Temp.pm​:885)​: 885​: my $proto = shift; DB\<\<12>> c 0 File​::Temp=GLOB(0x216aeb0) -> *File​::Temp​::$fh FileHandle({*File​::Temp​::$fh}) => fileno(3)

########### STOPPED at File​::Temp​::new as EXPECTED

Confirmed that problem exists in 5.24.0 as well.

-- James E Keenan (jkeenan@​cpan.org)

p5pRT commented 7 years ago

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

p5pRT commented 7 years ago

From jkahrman@mathworks.com

A co-worker had some time to investigate the issue and sent me the following. I haven't yet had time to investigate further.


I think it may need this​:

  --- perl-5.20.2/lib/5.20.2/perl5db.pl 2016-12-01 17​:08​:48.088626441 -0500   +++ perl5db.pl 2017-01-18 12​:07​:29.552135518 -0500   @​@​ -6204\,6 +6204\,7 @​@​

  # Copy the breakpoint in and delete it from %postponed.   $dbline{$i} = delete $postponed{$subname};   + _set_breakpoint_enabled_status($file\, $i\, 1);   } ## end if ($i)  
  # find_sub didn't find the sub.

With some printf-style debugging it seems the built-in DB​::postponed() hook (described in perldebguts) is getting hit when the file is compiled\, and the area of the code above is attempting to set the breakpoint. But then when DB​::DB() is hit for that line\, DB​::_DB__determine_if_we_should_break() says "nope" because _is_breakpoint_enabled($filename\, $line) said it was not enabled.

This enabled-ness is implemented in $breakpoints_data{$filename}{$line}{enabled} = $bool. I suspect this is a new thing\, and someone forgot to check whether new breakpoints were also being enabled everywhere they are being set.

Which makes me wonder if this problem will show up in other constructs...

p5pRT commented 7 years ago

From jkahrman@mathworks.com

After further testing of the postponed feature with the fix and comparing to 5.8.8 behavior\, I seem to have made a mistake in my recording of the expected behavior.

While postponed breakpoints ARE broken in (at least) 5.20 and later\, I was under the impression that they behaved like regular breakpoints when the file was already loaded. They do not\, even in 5.8.8.

So while my first test case IS a regression\, my second and third test cases are not.

p5pRT commented 7 years ago

From [Unknown Contact. See original ticket]

After further testing of the postponed feature with the fix and comparing to 5.8.8 behavior\, I seem to have made a mistake in my recording of the expected behavior.

While postponed breakpoints ARE broken in (at least) 5.20 and later\, I was under the impression that they behaved like regular breakpoints when the file was already loaded. They do not\, even in 5.8.8.

So while my first test case IS a regression\, my second and third test cases are not.