Forum: Ruby Tracing method definition in core and stdlibs?

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F8fd54072606eaf5603484e756672034?d=identicon&s=25 John Wells (Guest)
on 2009-03-20 14:00
(Received via mailing list)
Hi guys,

I'm interested in tracing method definition in core and stdlibs.
However, I'm not sure how to hook in the process at such an early
stage.

For example, if I put the following code in trace.rb:

[Class, Module].each do |n|
   n.class_eval do |clz|
     def method_added(x)
       puts "Method==#{x}"
     end
   end
 end


And then call

$ ruby -rtrace.rb -e 'puts "test"'

I only see two "Method==" outputted...both "Method==method_added", and
both obviously in response to this code itself.

Is there a way to hook in earlier?

Thanks,
John
E0d864d9677f3c1482a20152b7cac0e2?d=identicon&s=25 Robert Klemme (Guest)
on 2009-03-20 17:26
(Received via mailing list)
On 20.03.2009 13:56, John Wells wrote:
>      end
>
> Is there a way to hook in earlier?

Probably not as many methods of the standard library are define in C
code and I doubt that will trigger a method_added.

Btw, what do you need that for?

Cheers

  robert
F8fd54072606eaf5603484e756672034?d=identicon&s=25 John Wells (Guest)
on 2009-03-20 17:45
(Received via mailing list)
On Fri, Mar 20, 2009 at 12:22 PM, Robert Klemme
<shortcutter@googlemail.com> wrote:
>>     def method_added(x)
>> I only see two "Method==" outputted...both "Method==method_added", and
>> both obviously in response to this code itself.
>>
>> Is there a way to hook in earlier?
>
> Probably not as many methods of the standard library are define in C code
> and I doubt that will trigger a method_added.
>
> Btw, what do you need that for?

Yes, but I'd expect to see a good bit that were ruby too, correct?

I'd like to create a utility method that would allow me to easily see
everywhere a method (file name, line number) is defined...I have it
working for scripts I write myself, but only going forward from that
script scope...not back through the libs. So I'd like to hook in
early...before any ruby files are loaded at all.
F8fd54072606eaf5603484e756672034?d=identicon&s=25 John Wells (Guest)
on 2009-03-20 19:49
(Received via mailing list)
On Fri, Mar 20, 2009 at 12:42 PM, John Wells
<lists@sourceillustrated.com> wrote:
> Yes, but I'd expect to see a good bit that were ruby too, correct?
>
> I'd like to create a utility method that would allow me to easily see
> everywhere a method (file name, line number) is defined...I have it
> working for scripts I write myself, but only going forward from that
> script scope...not back through the libs. So I'd like to hook in
> early...before any ruby files are loaded at all.


Is there any way to accomplish this in 1.8.x?

Thanks,
John
E0d864d9677f3c1482a20152b7cac0e2?d=identicon&s=25 Robert Klemme (Guest)
on 2009-03-21 11:20
(Received via mailing list)
On 20.03.2009 19:45, John Wells wrote:
> Is there any way to accomplish this in 1.8.x?
Lack of responses to me indicates that you probably need to hack Ruby's
C core to achieve what you want.  If you just want to see method
definitions you can as well get Ruby sources and search through them.

Kind regards

  robert
F8fd54072606eaf5603484e756672034?d=identicon&s=25 John Wells (Guest)
on 2009-03-21 14:19
(Received via mailing list)
On Sat, Mar 21, 2009 at 6:17 AM, Robert Klemme
<shortcutter@googlemail.com> wrote:
> Lack of responses to me indicates that you probably need to hack Ruby's C
> core to achieve what you want.  If you just want to see method definitions
> you can as well get Ruby sources and search through them.

Thanks Robert. I wasn't thinking properly about it. I believe you were
correct in saying most everything loaded before doing a simple puts is
just C code...the more I thought about it (and after running strace to
verify), it seems that no external ruby libs are loaded up by the
interpreter assuming that your code doesn't do any specific requires.
So, the code I showed gave no results correctly...but if you change it
to:

$ ruby -rtrace.rb -e 'require "net/http"'

You get the expected results. So, in lieu of having rubinius, I think
that's the best you can expect. Everything else you'd have to dive
into the C for. And honestly, I don't really care about the C...I'm
more interested in being able to debug libraries and gems that are
more promiscuous than they should be.

I appreciate your help and guidance.

John
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