Front page | perl.perl5.porters |
Postings from October 2003
[perl #24200] string corruption with lvalue sub
Thread Next
From:
perlbug-followup
Date:
October 14, 2003 17:03
Subject:
[perl #24200] string corruption with lvalue sub
Message ID:
rt-24200-65995.2.5728929040902@rt.perl.org
# New Ticket Created by mconst@csua.berkeley.edu
# Please include the string: [perl #24200]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt2/Ticket/Display.html?id=24200 >
This is a bug report for perl from mconst@csua.berkeley.edu,
generated with the help of perlbug 1.34 running under perl v5.8.1.
-----------------------------------------------------------------
[Please enter your report here]
Under perl v5.8.1 on my i386 Debian Linux system, this script:
$foo = "a";
sub bar: lvalue { substr $foo, 0 }
bar = "XXX";
print bar, "\n";
produces the output "X". I would have expected it to output "XXX",
like it does if you make the calls to substr directly instead of
through the lvalue function.
I get the same behaviour with perl v5.6.1 on an i386 FreeBSD system.
If you run the program under a debugging perl, you can actually see
the value change -- substr returns the string I expect, but by the
time bar returns, the value is different:
(./bugtest:2) substr
Pad 0x81c0be0[0x81c1950] sv: 3 sv=0x81c0c1c
STACK 0: MAIN
CX 0: BLOCK => *
retop=const
CX 1: SUB => PVLV("XXX"\0)
(./bugtest:2) leavesublv
STACK 0: MAIN
CX 0: BLOCK => * <T>PVNV("X"\0)
Am I doing something wrong?
[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
category=core
severity=low
---
Site configuration information for perl v5.8.1:
Configured by Debian Project at Tue Sep 30 21:35:53 EST 2003.
Summary of my perl5 (revision 5.0 version 8 subversion 1) configuration:
Platform:
osname=linux, osvers=2.4.22-xfs+ti1211, archname=i386-linux-thread-multi
uname='linux kosh 2.4.22-xfs+ti1211 #1 wed sep 24 21:17:59 est 2003 i686 gnulinux '
config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i386-linux -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8.1 -Darchlib=/usr/lib/perl/5.8.1 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.1 -Dsitearch=/usr/local/lib/perl/5.8.1 -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 -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.1 -Dd_dosuid -des'
hint=recommended, useposix=true, d_sigaction=define
usethreads=define use5005threads=undef 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 -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
optimize='-O3',
cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -I/usr/local/include'
ccversion='', gccversion='3.3.2 20030908 (Debian prerelease)', 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
libs=-lgdbm -ldb -ldl -lm -lpthread -lc -lcrypt
perllibs=-ldl -lm -lpthread -lc -lcrypt
libc=/lib/libc-2.3.2.so, so=so, useshrplib=true, libperl=libperl.so.5.8.1
gnulibc_version='2.3.2'
Dynamic Linking:
dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'
Locally applied patches:
---
@INC for perl v5.8.1:
/etc/perl
/usr/local/lib/perl/5.8.1
/usr/local/share/perl/5.8.1
/usr/lib/perl5
/usr/share/perl5
/usr/lib/perl/5.8.1
/usr/share/perl/5.8.1
/usr/local/lib/site_perl
.
---
Environment for perl v5.8.1:
HOME=/home/mconst
LANG=C
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=/home/mconst/bin:/home/mconst/env/bin:/usr/local/bin:/usr/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin:/usr/games
PERL_BADLANG (unset)
SHELL=/bin/tcsh
Thread Next
-
[perl #24200] string corruption with lvalue sub
by perlbug-followup