Re^4: Make debugger break on source lines matching a pattern

We must have different versions of perl, with different call-stack depths in our debuggers.

Using a counter is a simple way of having the state change only before the matching line, and not after:

w $::ctr+=$::{"_<".(caller 3)[1]}[(caller 3)[2]] =~ /\bprint\b/
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The bistable flip-flop seems like it should be perfect for this case, if you take care to use a non-constant always-true expression for the right hand side. Seems like it should. I can't get it to work properly. And now I'm spending more time playing with the debugger than debugging!

But it sure is a fun challenge.

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Re^5: Make debugger break on source lines matching a pattern by LanX (Saint) on Jan 12, 2014 at 11:40 UTC
> The bistable flip-flop seems like it should be perfect for this case, ... I can't get it to work properly. IIRC are watchpoints evaluated code-snippets. Flip-flops are anchored in the op-tree but recompiling generates each time a new op-tree. > We must have different versions of perl, Not sure, I patched my local copy of .perldb a lot... ... Yep sorry, mea culpa, emptying my local .perldb makes `(caller 2)` working. ... Indeed, this watchpoint shows that my patching DB::eval() introduced a new call-frame `Watchpoint 0: @{[ $z++, map { (caller $_)[0..3],"\n" } 1..3 ]} chan +ged: old value: '0', 'DB', '/home/lanx/.perldb', '3', 'DB::eval', ' ', 'DB', '/usr/share/perl/5.10/perl5db.pl', '1953', 'DB::new_eval', ' ', 'Config', '/usr/lib/perl/5.10/Config.pm', '62', 'DB::DB', ' '` [download] ( have to consider using goto ) > And now I'm spending more time playing with the debugger than debugging! Indeed! ( Welcome in the brotherhood ;-) > But it sure is a fun challenge. If you liked this, you might be interested in this: =) YAPC::EU::2012 "IPL - From Debugger to Interactive Shell" See also linked slides and code, it shows some techniques to patch perl5db for your needs. Cheers Rolf ( addicted to the Perl Programming Language)	[reply] [d/l] [select]

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Re^5: Make debugger break on source lines matching a pattern
by LanX (Saint) on Jan 12, 2014 at 11:40 UTC

> The bistable flip-flop seems like it should be perfect for this case, ... I can't get it to work properly.

IIRC are watchpoints evaluated code-snippets. Flip-flops are anchored in the op-tree but recompiling generates each time a new op-tree.

> We must have different versions of perl,

Not sure, I patched my local copy of .perldb a lot...

...

Yep sorry, mea culpa, emptying my local .perldb makes (caller 2) working.

...

Indeed, this watchpoint shows that my patching DB::eval() introduced a new call-frame

Watchpoint 0:    @{[ $z++, map { (caller $_)[0..3],"\n" } 1..3 ]} chan
+ged:
    old value:    '0', 'DB', '/home/lanx/.perldb', '3', 'DB::eval', '
', 'DB', '/usr/share/perl/5.10/perl5db.pl', '1953', 'DB::new_eval', '
', 'Config', '/usr/lib/perl/5.10/Config.pm', '62', 'DB::DB', '
'
[download]

( have to consider using goto )

> And now I'm spending more time playing with the debugger than debugging!

Indeed! ( Welcome in the brotherhood ;-)

> But it sure is a fun challenge.

If you liked this, you might be interested in this: =)

YAPC::EU::2012 "IPL - From Debugger to Interactive Shell"

See also linked slides and code, it shows some techniques to patch perl5db for your needs.

Cheers Rolf

( addicted to the Perl Programming Language)

[reply]
[d/l]
[select]