(update: the first one has been edited to fix problems/bad style since I first pressed submit. Oopsie.)

use strict;
my @result;
my $one = "a" =~ /./;

sub add {
  my($vA,$vB) = @_;
  ($vA,$vB) = ($vA^$vB,($vA&$vB)<<$one) while $vB;
  return $vA;
}

my $val = $one;
do {
  push @result, $val;
  $val = add($val,$one);
} until $one.$one eq $val;
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... or, without any lines preceeding it in the file it's in ...

sub f {  die if $::f_A;
         die if $::f_B;
         die if $::f_C;
         die if $::f_D;
         die if $::f_E;
         die if $::f_F;
         die if $::f_G;
         die if $::f_H;
         die if $::f_I;
         die if $::f_J; }
my @vars = map { "::f_$_" } qw(A B C D E F G H I J);

my @result;

foreach (@vars) {
  $$_ = "true";
  eval { f() };
  push @result, $@ =~ /line ([^.]+)\./;
  $$_ = undef;
}
[download]

update: A very, very cheap solution: (doesn't work on EBCDIC systems, sorry)

my @result = split " ", "pasarauatawavayaxapq"^"AAAAAAAAAAAAAAAAAAAA";
[download]