lanx@lanx-1005HA:~$ perl -MO=Concise,-src /tmp/tst_bxref.pl |grep \$a
/tmp/tst_bxref.pl syntax OK
# 5: my $a=1;
4        <0> padsv[$a:3,7] sRM*/LVINTRO ->5
# 8: print($a);
8        <0> padsv[$a:3,7] l ->9
# 15:     my $a=2;
# 15:     my $a=2;
e              <0> padsv[$a:5,6] sRM*/LVINTRO ->f
# 16:     print($a);
i              <0> padsv[$a:5,6] l ->j
# 17:     bla($a);
m                 <0> padsv[$a:5,6] lM ->n
# 21: print($a);
s        <0> padsv[$a:3,7] l ->t