[ID 20000124.006] variable type in (?{ code }) construction

[Makoto Ishisone <ishisone@sra.co.jp>]

This is a bug report for perl from ishisone@sra.co.jp,
generated with the help of perlbug 1.27 running under perl 5.00503.


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If variable interpolation takes place in a regular expression,
perl seems to consider lexical variables in (?{ code }) construct 
as global variables.

The following little script exhibits the problem:

-----------------------------------------------------------
#! /usr/local/bin/perl -w

use strict;
use re 'eval';

my ($a, $x, $y) = ('a', 0, 0);
$_ = 'a';

# No variable interpolation occurs in RE.
# This will print "$x=1" as expected.
/  a (?{ $x = 1 }) /xo and print "\$x=$x\n";

# A variable interpolation occurs in RE.
# This will print "$y=0, $::y=1" which seems to be a bug.
/ $a (?{ $y = 1 }) /xo and print "\$y=$y, \$::y=$::y\n";
-----------------------------------------------------------

The output is:

Name "main::y" used only once: possible typo at ./rebug.pl line 15.
$x=1				<-- seems OK
$y=0, $::y=1			<-- seems wrong


Both $x and $y are lexical, but when evaluating the second RE,
assignment is done to the global variable $::y.

I also checked with 5.00563, and got the same result.

-----------------------------------------------------------------

---
This perlbug was built using Perl 5.00503 - Wed May 19 12:05:03 JST 1999
It is being executed now by  Perl 5.00563 - Tue Jan 25 12:05:18 JST 2000.

Site configuration information for perl 5.00503:

Configured by ishisone at Wed May 19 12:05:03 JST 1999.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=freebsd, osvers=2.2.8-release, archname=i386-freebsd
    uname='freebsd srapc459.sra.co.jp 2.2.8-release freebsd 2.2.8-release #0: fri apr 16 11:14:40 jst 1999 ishisone@srapc459.sra.co.jp:usrsrcsyscompilesrapc459_slim i386 '
    hint=previous, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='cc', optimize='-O', gccversion=2.7.2.1
    cppflags='-I/usr/local/include'
    ccflags ='-I/usr/local/include'
    stdchar='char', d_stdstdio=undef, usevfork=true
    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='ld', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib
    libs=-lm -lxpg4 -lc -lcrypt
    libc=/usr/lib/libc.so.3.1, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
    cccdlflags='-DPIC -fpic', lddlflags='-Bshareable  -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl 5.00503:
    /amd/a/srapc451/mnt3/home/mgr/ishisone/lib/perl5
    /usr/local/lib/perl5/5.00503/i386-freebsd
    /usr/local/lib/perl5/5.00503
    /usr/local/lib/perl5/site_perl/5.005/i386-freebsd
    /usr/local/lib/perl5/site_perl/5.005
    .

---
Environment for perl 5.00503:
    HOME=/amd/a/srapc451/mnt3/home/mgr/ishisone
    LANG=ja_JP.EUC
    LANGUAGE (unset)
    LC_COLLATE=C
    LC_TIME=C
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/amd/a/srapc451/mnt3/home/mgr/ishisone/bin:/amd/a/srapc451/mnt3/home/mgr/ishisone/bin/i386-freebsd2:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin:/usr/sra/bin:/usr/local/tdoc/bin:/usr/local/emacs/bin:/usr/new/mh:/usr/local/bin/mh:/usr/local/v6/bin:/usr/local/v6/sbin:/usr/ucb:/usr/bin:/usr/new:/bin:/etc:/usr/etc:/usr/sbin:/sbin:/amd/a/srapc451/mnt3/home/mgr/ishisone/bin/lastresort:
    PERL5LIB=/amd/a/srapc451/mnt3/home/mgr/ishisone/lib/perl5
    PERL_BADLANG (unset)
    SHELL=/usr/local/bin/bash

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Follow-Ups from:

Ilya Zakharevich <ilya@math.ohio-state.edu>

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