The only way I can think of to do this in perl is with a source filter. This allows you to effectively re-write the perl to do whatever you want (think lisp macros, but without the regularity of lisp s-exps, hence more complex).

In your case, you could introduce a new keyword (say 'tif' for tracked-if) and rewrite:

tif(xxx) {
  some;
  perl;
  code;
}
[download]

to

if(xxx) {
  some;
  perl;
  code;
}
else {
  print some;
  print perl;
  print code;
}
[download]

The CPAN Filter::Simple module looks like a good place to start, but I don't really have any experience writing these things, to be honest.