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[perl #70043] Re: [Sysadmins] Perl allows non-sensical operations on reference converted to an integer
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From:
goldstei@ugcs.caltech.edu
Date:
October 27, 2009 01:32
Subject:
[perl #70043] Re: [Sysadmins] Perl allows non-sensical operations on reference converted to an integer
Message ID:
rt-3.6.HEAD-8015-1256626946-1408.70043-75-0@perl.org
# New Ticket Created by goldstei@ugcs.caltech.edu
# Please include the string: [perl #70043]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=70043 >
I'm taking bets on if they think this is a bug or not.
My vote is with no.
>From Joshua David Goldstein <goldstei@ugcs.caltech.edu>, Tue, Oct 27, 2009 at 12:01:03AM -0700:
>
> This is a bug report for perl from goldstei@ugcs.caltech.edu,
> generated with the help of perlbug 1.36 running under perl 5.10.0.
>
>
> -----------------------------------------------------------------
> [Please enter your report here]
>
> I've found that perl will allow you to do all sorts of unreasonable
> operations on references. Here's an example:
> -------
> #!/usr/bin/perl -w
> use strict;
> my $foo = sub { return 0 };
> my $bar = 1;
> print "foo: $foo, bar: $bar\n";
> my $baz = $foo + $bar;
> print "baz: $baz\n";
> -------
> running this produces the output:
> -------
> foo: CODE(0x1c60460), bar: 1
> baz: 29754465
> -------
>
> Now the 'perlref' manpage says:
> "Using a reference as a number produces an integer representing its storage
> location in memory. The only useful thing to be done with this is to compare
> two references numerically to see whether they refer to the same location."
>
> It's easy to see why you'd want to convert to an integer for reference testing,
> but even the documentation says that there's not much useful you can do besides
> that. There is never a case in which this is valid behavior or what the user
> intended to do, so it shouldn't be allowed to happen. Why do I not see an
> error here that says, 'Error: Adding an integer to a reference' or something
> similar?
>
>
> [Please do not change anything below this line]
> -----------------------------------------------------------------
> ---
> Flags:
> category=core
> severity=medium
> ---
> Site configuration information for perl 5.10.0:
>
> Configured by Debian Project at Fri Aug 28 22:30:10 UTC 2009.
>
> Summary of my perl5 (revision 5 version 10 subversion 0) configuration:
> Platform:
> osname=linux, osvers=2.6.26-2-amd64, archname=i486-linux-gnu-thread-multi
> uname='linux puccini 2.6.26-2-amd64 #1 smp fri aug 14 07:12:04 utc 2009 i686 gnulinux '
> config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.10 -Darchlib=/usr/lib/perl/5.10 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.10.0 -Dsitearch=/usr/local/lib/perl/5.10.0 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.10.0 -Dd_dosuid -des'
> hint=recommended, useposix=true, d_sigaction=define
> useithreads=define, usemultiplicity=define
> useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
> use64bitint=undef, use64bitall=undef, uselongdouble=undef
> usemymalloc=n, bincompat5005=undef
> Compiler:
> cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -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 -fno-strict-aliasing -pipe -I/usr/local/include'
> ccversion='', gccversion='4.3.2', 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 =' -L/usr/local/lib'
> libpth=/usr/local/lib /lib /usr/lib /usr/lib64
> libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
> perllibs=-ldl -lm -lpthread -lc -lcrypt
> libc=/lib/libc-2.7.so, so=so, useshrplib=true, libperl=libperl.so.5.10.0
> gnulibc_version='2.7'
> Dynamic Linking:
> dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
> cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib'
>
> Locally applied patches:
>
>
> ---
> @INC for perl 5.10.0:
> /etc/perl
> /usr/local/lib/perl/5.10.0
> /usr/local/share/perl/5.10.0
> /usr/lib/perl5
> /usr/share/perl5
> /usr/lib/perl/5.10
> /usr/share/perl/5.10
> /usr/local/lib/site_perl
> .
>
> ---
> Environment for perl 5.10.0:
> HOME=/afs/.ugcs/user/goldstei
> LANG=en_US
> LANGUAGE (unset)
> LD_LIBRARY_PATH (unset)
> LOGDIR (unset)
> PATH=/afs/.ugcs/user/goldstei/ugcs2/scripts:/usr/ug/bin:/usr/ug/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/ug/adm/bin/scripts:/ug/adm/bin/:/usr/X11R6/bin:/afs/.ugcs/user/goldstei/bin:/afs/.ugcs/user/goldstei/maple10/bin:/mnt/cresol/cresol/ufs/egnor/i386-linux2/bin:/usr/ug/share/scripts:/afs/.ugcs/user/goldstei/ugcs2/scripts:/usr/ug/bin:/usr/ug/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/ug/adm/bin/scripts:/ug/adm/bin/:/usr/X11R6/bin:/afs/.ugcs/user/goldstei/bin:/afs/.ugcs/user/goldstei/maple10/bin:/mnt/cresol/cresol/ufs/egnor/i386-linux2/bin:/usr/ug/share/scripts:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
> PERL_BADLANG (unset)
> SHELL=/bin/zsh
> _______________________________________________
> Sysadmins mailing list
> Sysadmins@ugcs.caltech.edu
> https://hermes.ugcs.caltech.edu/cgi-bin/mailman/listinfo/sysadmins
--
Joshua Goldstein
goldstei@ugcs.caltech.edu
(626)-529-6964
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[perl #70043] Re: [Sysadmins] Perl allows non-sensical operations on reference converted to an integer
by goldstei@ugcs.caltech.edu