New warning 'Useless use of concatenation in void context'

[p5pRT]

Migrated from rt.perl.org#1091 (status was 'resolved')

Searchable as RT1091$

[p5pRT]

From Nick.Ing-Simmons@tiuk.ti.com

 

/home/road35/local/sun4os5/perl5.00558/bin/perl5.00558 -wc tkmail
Using /home/isp/nick/Tk8/blib
Useless use of concatenation in void context at Mail/Status.pm line 10.

Line in question is :

my $dbname = "$ENV{'HOME'}/mail/status.db";

There is no explicit concatenation, and no void context that I can see.
(The computed value is correct by the way.)

Perl Info

Site configuration information for perl 5.00558:

Configured by a0904209 at Wed Jul 28 09:40:23 BST 1999.

Summary of my perl5 (revision 5.0 version 5 subversion 58) configuration:
  Platform:
    osname=solaris, osvers=2.7, archname=sun4-solaris
    uname='sunos pluto 5.7 generic sun4m sparc sunw,sparcstation-10 '
    config_args='-der -O -Dcc=egcs -Doptimize=-O2 -g -Dusemymalloc=n -Dusevfork=false'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
    use64bits=undef usemultiplicity=undef
  Compiler:
    cc='egcs', optimize='-O2 -g', gccversion=egcs-2.91.66 19990314 (egcs-1.1.2 release)
    cppflags='-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -DDEBUGGING -I/usr/local/include'
    ccflags ='-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -DDEBUGGING -I/usr/local/include'
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    alignbytes=8, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='egcs', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /usr/ccs/lib
    libs=-lsocket -lnsl -lgdbm -ldb -ldl -lm -lrt -lc -lcrypt -lsec
    libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
    cccdlflags='-fPIC', lddlflags='-G -L/usr/local/lib'

Locally applied patches:
    


@INC for perl 5.00558:
    /usr/local/lib/perl5.00558/sun4-solaris7
    /usr/local/lib/perl5.00558/share
    /usr/local/lib/perl5.00558/site/sun4-solaris7
    /usr/local/lib/perl5.00558/site/shared
    .


Environment for perl 5.00558:
    HOME=/home/isp/nick
    LANG=C
    LANGUAGE (unset)
    LD_LIBRARY_PATH=/usr/openwin/lib
    LOGDIR (unset)
    PATH=.:./sun4os7:./bin:/home/isp/nick/bin/sun4os7:/home/isp/nick/bin:/usr/local/bin/new:/tools/lan/bin:/tools/eda:/tools/bin:/usr/tiMVP/bin:/usr/local/share/bin:/usr/local/bin:/usr/openwin/bin:/usr/bin:/home/isp/bin:/usr/ccs/bin:/usr/sbin:/opt/SUNWwabi/bin:/opt/SUNWspro/bin:/usr/ucb
    PERL_BADLANG (unset)
    SHELL=/bin/csh

[p5pRT]

From [Unknown Contact. See original ticket]

Nick.Ing-Simmons@​tiuk.ti.com writes​:

This is a bug report for perl from nik@​tiuk.ti.com,
generated with the help of perlbug 1.26 running under perl 5.00558.

-----------------------------------------------------------------
[Please enter your report here]

/home/road35/local/sun4os5/perl5.00558/bin/perl5.00558 -wc tkmail
Using /home/isp/nick/Tk8/blib
Useless use of concatenation in void context at Mail/Status.pm line 10.

Line in question is :

my $dbname = "$ENV{'HOME'}/mail/status.db";

There is no explicit concatenation

Of course there is​: the right-hand-side is a shortcut for

  $ENV{'HOME'} . "/mail/status.db";

I cannot reproduce it here with

  perl -wle "my $dbname = \"$ENV{'HOME'}/mail/status.db\"; print $dbname"

Please try to design a testcase.

Ilya