From: "ara.t.howard" <ara.t.howard@...>
Date: 2007-07-13T06:00:42+09:00
Subject: Re: getting gdb backtrace from ruby exception


On Jul 12, 2007, at 8:10 AM, Alex Fenton wrote:

> Hi
>
> I'm working on a C extension and somewhere in itsomething is  
> raising a NoMethodError. The exception is reported with the line of  
> ruby code that triggered the bad call in the C extension.
>
> As the C code is large and complex (it's a big SWIG project), I'm  
> having trouble finding the problem in the C code. I would use gdb  
> or Microsoft's debugger to look at the stack if it was a C error -  
> but when a Ruby exception is raised, the process exits and there's  
> no stack to inspect.
>
> Ruby's debugger isn't helpful because it only knows about ruby  
> written in ruby.
>
> Is there any way I can get at the C stack at the point of ruby  
> 'raise' from a C extension?
>
> Thanks
> alex
>


cfp:~ > cat core.rb
BEGIN{ at_exit{ Process.kill 'SIGSEGV', Process.pid if $! } }


cfp:~ > cat a.rb
#! /usr/bin/env ruby
require 'core'
p 42
cfp:~ > ruby a.rb
42


cfp:~ > cat b.rb
#! /usr/bin/env ruby
require 'core'
raise


cfp:~ > ruby b.rb
./core.rb:1: [BUG] Segmentation fault
ruby 1.8.6 (2007-03-13) [i686-darwin8.9.1]

Abort trap (core dumped)



-a
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama