[ID 20000729.003] segfault with (??{ qr/blah/ })

This is a bug report for perl from jfriedl@fummy.dsl.yahoo.com,
generated with the help of perlbug 1.28 running under perl v5.6.0.


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[Please enter your report here]

Hiho,
The following program segfaults with 5.6.0:

    #!/usr/local/bin/perl -w
    use strict;
    use re 'debugcolor';
    use re 'eval';

    "AXB" =~ /A (??{ qr[X] }) B/x;

    print "matched [$&]\n";


Here's a gdb session:


    jfriedl@fummy> gdb perl
    GNU gdb 4.18
    Copyright 1998 Free Software Foundation, Inc.
    GDB is free software, covered by the GNU General Public License, and you are
    welcome to change it and/or distribute copies of it under certain conditions.
    Type "show copying" to see the conditions.
    There is absolutely no warranty for GDB.  Type "show warranty" for details.
    This GDB was configured as "i386-mandrake-linux"...
    (gdb) run /tmp/foo4
    Starting program: /usr/src/perl-5.6.0/perl /tmp/foo4
    Compiling REx `A (??{ qr[X] }) B'
    size 8 Compiling REx `X'
    size 3 first at 1
       1: EXACT <X>(3)
       3: END(0)
    anchored `X' at 0 (checking anchored isall) minlen 1 
    first at 1
       1: EXACT <A>(5234)
       3: END(0)
    anchored `A' at 0 (checking anchored isall) minlen 1 
    Guessing start of match, REx `A (??{ qr[X] }) B' against `AXB'...
    Found anchored substr `A' at offset 0...
    Guessed: match at offset 0
    Matching REx `A (??{ qr[X] }) B' against `AXB'
      Setting an EVAL scope, savestack=3
       0 <AXB>             |  1:  EXACT <A>
       1 <AXB>             |5234:  LOGICAL[2]
       1 <AXB>             |5235:  EVAL

    Program received signal SIGSEGV, Segmentation fault.
    0x401cc8a1 in S_regmatch (prog=0x812b01c) at re_exec.c:2302
    2302                PL_op = (OP_4tree*)PL_regdata->data[n];
    (gdb) where
    #0  0x401cc8a1 in S_regmatch (prog=0x812b01c) at re_exec.c:2302
    #1  0x401cabe9 in S_regtry (prog=0x812afe0, startpos=0x80fc348 "AXB") at re_exec.c:1715
    #2  0x401ca4ed in my_regexec (prog=0x812afe0, stringarg=0x80fc348 "AXB", strend=0x80fc34b "", 
	strbeg=0x80fc348 "AXB", minend=0, sv=0x81283d0, data=0x0, flags=3) at re_exec.c:1509
    #3  0x8096cfd in Perl_pp_match () at pp_hot.c:1027
    #4  0x80949ed in Perl_runops_standard () at run.c:27
    #5  0x805bd4e in S_run_body (oldscope=1) at perl.c:1401
    #6  0x805bad8 in perl_run (my_perl=0x80f0858) at perl.c:1325
    #7  0x8059903 in main (argc=2, argv=0xbffff374, env=0xbffff380) at perlmain.c:52


Don't know if the following will help, but FWIW here are some current values...

    (gdb) print n
    $1 = 0
    (gdb) print PL_regdata
    $2 = (struct reg_data *) 0x0
    (gdb) print prog
    $3 = (regnode *) 0x812b01c
    (gdb) print *prog
    $4 = {flags = 1 '\001', type = 51 '3', next_off = 5233}
    (gdb) print *scan
    $5 = {flags = 222 ',A^(B', type = 75 'K', next_off = 2}
    (gdb) print scan
    $6 = (regnode *) 0x81301e4
    (gdb) print scan
    $7 = (regnode *) 0x81301e4
    (gdb) print *scan
    $8 = {flags = 222 ',A^(B', type = 75 'K', next_off = 2}
    (gdb) print PL_curcop
    $11 = (COP *) 0x812b070
    (gdb) print *PL_curcop
    $12 = {op_next = 0x812af68, op_sibling = 0x812afa0, op_ppaddr = 0x8094aa0 <Perl_pp_nextstate>, op_targ = 0, 
      op_type = 174, op_seq = 2208, op_flags = 1 '\001', op_private = 0 '\000', cop_label = 0x0, 
      cop_stash = 0x80f08e0, cop_filegv = 0x80f0ab4, cop_seq = 169, cop_arybase = 0, cop_line = 6, cop_warnings = 0x0}
    (gdb) print PL_curpad
    $13 = (SV **) 0x80f7190
    (gdb) print *PL_curpad
    $14 = (SV *) 0x80efdd0
    (gdb) print **PL_curpad
    $15 = {sv_any = 0x0, sv_refcnt = 2147483616, sv_flags = 8388608}
    (gdb) 



[Please do not change anything below this line]
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---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl v5.6.0:

Configured by jfriedl at Sat Jul 29 20:09:33 PDT 2000.

Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration:
  Platform:
    osname=linux, osvers=2.2.15, archname=i686-linux
    uname='linux fummy.dsl.yahoo.com 2.2.16 #6 smp sun jul 23 11:26:16 pdt 2000 i686 unknown '
    config_args='-ds -e -A optimize=-g'
    hint=previous, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=undef d_sfio=undef uselargefiles=define 
    use64bitint=undef use64bitall=undef uselongdouble=undef usesocks=undef
  Compiler:
    cc='cc', optimize='-O2 -g', gccversion=pgcc-2.91.66 19990314 (egcs-1.1.2 release)
    cppflags='-fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64'
    ccflags ='-fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64'
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    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, 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 -lc -lposix -lcrypt
    libc=/lib/libc-2.1.1.so, so=so, useshrplib=false, libperl=libperl.a
  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 v5.6.0:
    /home/jfriedl/lib/perl
    /home/jfriedl/lib/perl/yahoo
    /usr/local/lib/perl5/5.6.0/i686-linux
    /usr/local/lib/perl5/5.6.0
    /usr/local/lib/perl5/site_perl/5.6.0/i686-linux
    /usr/local/lib/perl5/site_perl/5.6.0
    /usr/local/lib/perl5/site_perl
    .

---
Environment for perl v5.6.0:
    HOME=/home/jfriedl
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH=/usr/local/pgsql/lib:/home/jfriedl/src/rvplayer5.0
    LOGDIR (unset)
    PATH=/home/jfriedl/bin:/home/jfriedl/common/bin:/usr/local/gcc-2.95.2/bin:.:/usr/local/pgsql/bin:/usr/local/bin:/usr/X11R6/bin:/bin:/usr/bin:/usr/sbin:/sbin:/home/jfriedl/src/rvplayer5.0
    PERLLIB=/home/jfriedl/lib/perl:/home/jfriedl/lib/perl/yahoo
    PERL_BADLANG (unset)
    SHELL=/bin/tcsh

• [ID 20000729.003] segfault with (??{ qr/blah/ }) by Jeffrey Friedl
• RE: [ID 20000729.003] segfault with (??{ qr/blah/ }) by Fisher Mark