B::Deparse and sub line numbers

[Anonymous Monk]

I'm trying to use B::Deparse's output to find out where a subroutine is defined. It seems the line numbers indicate where the subroutine code ends but not where it starts. Here is my test program:

use strict;
use warnings;
#3
sub foo () {
    print("F1");
    print("F2");
    print("F3");
}
#9

And here is "perl -MO=Deparse,-l" output:

#line 8 "foo.pl"
sub foo () {
    use warnings;
    use strict 'refs';
#line 5 "foo.pl"
    print 'F1';
#line 6 "foo.pl"
    print 'F2';
#line 7 "foo.pl"
    print 'F3';
}
foo.pl syntax OK

So the "#line" before the sub declaration is in fact the end of the sub, not its begin. How can I find out where it really starts knowing that pragmas like "strict" do change how the sub is rendered?

[toolic]

I do not know how to convince B::Deparse (or B::Xref for that matter) to give you the starting line number. What do you plan to do with that information once you have it? Maybe the ideas in Re: 'extract' subs from source code can help. Perhaps if you poke around PPI you can figure out how to get the line numbers.

[Anonymous Monk]

The goal is to use B::Deparse to check some properties of the code (kind of lint). The line numbers are needed to report precise information to the developer.

FWIW, yes, I'm aware that B::Lint and Perl::Critic exist.

I will look at PPI but this seems to be quite large...