DESTROY optimization?

[p5pRT]

Migrated from rt.perl.org#995 (status was 'resolved')

Searchable as RT995$

[p5pRT]

From smurf@noris.de

I noticed that the sequence

{
  my $foo;
  $foo = new bar();

  Some_Statement (doesn't_use_foo);
  [ more Statements which don't use foo ]
}
sometimes seems to be optimized such that when bar​::DESTROY is called,
caller(1) returns the line number of the first Statement, not the line
number of the end of the block.

I noticed this in a largish multithreaded program.
A small test program of course failed to exhibit the bug. :-(

Log from my program​:
test.pm​:193 Block
test.pm​:195 UnBlock

Lines 192-195​:
my $oblock;
$oblock = new Blocker($self);

my $arg = shift;
[... 400 more lines until the end of that block]

Perl Info

Site configuration information for perl 5.00557:

Configured by smurf at Fri Jul  2 07:57:44 MEST 1999.

Summary of my perl5 (revision 5.0 version 5 subversion 57) configuration:
  Platform:
    osname=linux, osvers=2.2.11-noris-pre1, archname=i686-linux-thread
    uname='linux play 2.2.11-noris-pre1 #23 smp wed jun 30 05:17:45 mest 1999 i686 unknown '
    config_args='-Dusethreads -Uusenm -Duseshrplib=true -Dprefix=/usr/lib/eperl -d -e'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define useperlio=undef d_sfio=undef
    use64bits=undef usemultiplicity=undef
  Compiler:
    cc='cc', optimize='-O2 -g', gccversion=gcc-2.96 19990603 (experimental)
    cppflags='-D_REENTRANT -Dbool=char -DHAS_BOOL -DDEBUGGING -I/usr/local/include'
    ccflags ='-D_REENTRANT -Dbool=char -DHAS_BOOL -DDEBUGGING -I/usr/local/include'
    stdchar='char', d_stdstdio=undef, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lndbm -lgdbm -ldb -ldl -lm -lrt -lpthread -lc -lposix -lcrypt
    libc=/lib/libc-2.1.90.so, so=so, useshrplib=true, libperl=libperl.so
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic -Wl,-rpath,/usr/lib/eperl/lib/5.00557/i686-linux-thread/CORE'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    


@INC for perl 5.00557:
    /usr/lib/eperl/lib/5.00557/i686-linux-thread
    /usr/lib/eperl/lib/5.00557
    /usr/lib/eperl/lib/site_perl/5.00557/i686-linux-thread
    /usr/lib/eperl/lib/site_perl/5.00557
    .


Environment for perl 5.00557:
    HOME=/home/smurf
    LANG (unset)
    LANGUAGE (unset)
    LC_CTYPE=C
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/pop/bin:/usr/src/STATUS/bin:/home/smurf/bin:/home/smurf/bin:/bin:/usr/bin:/usr/local/bin:.:/usr/X11R6/bin:/usr/share/tex/bin/i586-linux
    PERL_BADLANG (unset)
    SHELL=/bin/bash