how can I get here?

perl5ever has asked for the wisdom of the Perl Monks concerning the following question:

A tool I've discovered that would be very useful to have is one that would help you explore the ways in which a subroutine could get called.

For instance, using grep it is easy to locate lines where a method or subroutine is called. However, I also want to know the name of the subroutine that call is located in. And then I want to explore how that routine can get called, and so forth.

For my needs static analysis of the program text is sufficient.

Does anyone know of a tool which can help you explore code this way?

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Re: how can I get here? by Anonymous Monk on Apr 30, 2009 at 21:50 UTC
B::Xref?	[reply]
Re^2: how can I get here? by perl5ever (Pilgrim) on Apr 30, 2009 at 22:57 UTC
Didn't know about this - thanks for pointing it out.	[reply]
Re: how can I get here? by Corion (Patriarch) on Apr 30, 2009 at 21:41 UTC
PPI analyzes your source code and gives you a tree representation. I guess you can then search that tree for references (by name) to your subroutine and then visit the parents of these references until you find an enclosing named subroutine.	[reply]
Re: how can I get here? by otto (Beadle) on Apr 30, 2009 at 22:29 UTC
In someways you should first consider how much code you need to examine and your timeframe. Do you spend 5 days goofing with the computer when if you simply printed and read the code, taking notes, would provide the overview you need. And it only took 2 days. Look at cpan with keywords like, `profile, debug, dbug, trace`, etc. grep'ing is problematic in that method calls are on objects, but you need to know what the object is to be able to know which method is meant. `Moose` provides meta info on classes etc. Code needs to be written using it... `Debug::Trace` has a unique approach. There have been various attempts at providing a filter for Doxygen*.	[reply] [d/l] [select]
Re: how can I get here? by quinkan (Monk) on Apr 30, 2009 at 23:29 UTC
For Perl, have a look at the OptiPerl IDE, which provides this facility (and lots of other things). Click on subroutines, find a list, select one from the list and find both source and points in code where subroutine is called. Very handy tool.	[reply]
Re: how can I get here? by Clarendon4 (Acolyte) on May 01, 2009 at 07:34 UTC
Try peg - it's a grep-like command line tool that has an option -z to show context. It's at: http://cpan.mirrors.uk2.net/authors/id/A/AD/ADAVIES/peg-2.20 You supply an expression (typically a regexp) which will be true for the context lines you want. So to recursively search files beneath your cwd you'd run: `peg yoursubname -z "/^\s*sub /"` Common context matching code can be stored in peg's user initialization files (see the docs for the details) and then called using a label. I use the single letters 'p' for Perl subroutine context and 'c' for C function/struct context. So in practise you would simply run: `peg -z p yoursubname`	[reply] [d/l] [select]
Re: how can I get here? by DrHyde (Prior) on May 01, 2009 at 10:05 UTC
Some really ugly code I wrote many years ago might help. Or it might not. perl-dep.	[reply]
Re: how can I get here? by jvector (Friar) on May 01, 2009 at 22:32 UTC
It's not a 'static' analysis, and therefore would p(ossi\|roba)bly give you only a subset of the information you seek per trial, but Devel::NYTProf might give you a helpful view. "Oh.. /that/ Christmas"	[reply]