$ perl -MO=Concise,-src tst_b_xref4.pl|perl -pe 'substr $_, -1, 0, " "x(48-length$_) . "  #:$1" if /(^#|nextstate|var\d+)/;'
tst_b_xref4.pl syntax OK
j  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
# 1: for (                                       #:#
2     <;> nextstate(main 3 tst_b_xref4.pl:1) v:{ ->3  #:nextstate
4     <1> preinc[t2] vK/1 ->5
-        <1> ex-rv2sv sKRM/1 ->4
3           <#> gvsv[*var1] s ->4                #:var1