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[perl #121048] illegal sub declaration crashes

From:
Zefram
Date:
January 21, 2014 20:52
Subject:
[perl #121048] illegal sub declaration crashes
Message ID:
rt-4.0.18-10100-1390337520-16.121048-75-0@perl.org
# New Ticket Created by  Zefram 
# Please include the string:  [perl #121048]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=121048 >



This is a bug report for perl from zefram@fysh.org,
generated with the help of perlbug 1.39 running under perl 5.19.7.


-----------------------------------------------------------------
[Please describe your issue here]

$ perl -lwe 'BEGIN <> { }'
Use of uninitialized value at -e line 1.
zsh: segmentation fault  perl -lwe 'BEGIN <> { }'

This takes a funny path through the tokeniser.  "BEGIN" and a few other
keywords get treated as if "sub" had been said first.  The "sub" handler
has an explicit check for unexpected stuff preceding the body:

$ perl -lwe 'sub BEGIN <> { }'
Illegal declaration of subroutine main::BEGIN at -e line 1.

But the "sub" handler doesn't apply this check if the "sub" keyword
wasn't really there.

I haven't looked into what actually makes this crash.  In theory the
check should be entirely redundant: if the next token isn't one of the
permitted ones then a simple syntax error should result.

[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=low
---
Site configuration information for perl 5.19.7:

Configured by zefram at Mon Dec 23 19:18:49 GMT 2013.

Summary of my perl5 (revision 5 version 19 subversion 7) configuration:
   
  Platform:
    osname=linux, osvers=3.2.0-4-amd64, archname=x86_64-linux-thread-multi
    uname='linux barba.rous.org 3.2.0-4-amd64 #1 smp debian 3.2.46-1 x86_64 gnulinux '
    config_args='-des -Dprefix=/home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52 -Duselargefiles -Dusethreads -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dusedevel -Uversiononly -Ui_db'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.7.2', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib /usr/lib
    libs=-lnsl -ldb -ldl -lm -lcrypt -lutil -lpthread -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.15'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E -Wl,-rpath,/home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52/lib/5.19.7/x86_64-linux-thread-multi/CORE'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector'


---
@INC for perl 5.19.7:
    /home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52/lib/site_perl/5.19.7/x86_64-linux-thread-multi
    /home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52/lib/site_perl/5.19.7
    /home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52/lib/5.19.7/x86_64-linux-thread-multi
    /home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52/lib/5.19.7
    .

---
Environment for perl 5.19.7:
    HOME=/home/zefram
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/zefram/usr/perl/perl_install/perl-5.19.7-i64-f52/bin:/home/zefram/usr/perl/util:/home/zefram/pub/x86_64-unknown-linux-gnu/bin:/home/zefram/pub/common/bin:/usr/bin:/bin:/usr/local/bin:/usr/games
    PERL_BADLANG (unset)
    SHELL=/usr/bin/zsh




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