D:\tmp>perl -MO=Concise,-src tst_b_xref3.pl|find "var"
tst_b_xref3.pl syntax OK
# 1: unless ($var1) {
3              <#> gvsv[*var1] s ->4
# 5:     $var3++;
7                    <#> gvsv[*var3] s ->8
# 2:     $var2++;
d                    <#> gvsv[*var2] s ->e