Re: Debugger bugfix

[John Swensen]

On Nov 24, 2008, at 5:26 AM, David Bateman wrote:

> John Swensen wrote:
> > Attached is a changeset to fix a bug I encountered in the  
> > debugger.  The problem was in the  
> > bp_table::do_get_breakpoint_list(...) function where there is a  
> > loop over an STL iterator which calls out_of_date_check() in each  
> > iteration.  The problem occurred because out_of_date_check(), in  
> > turn, will call remove_all_breakpoints_in_file() when the file has  
> > changed, which modifies the object STL map being iterated over.
> >
> > So I added another set of loops to take care of processing out-of- 
> > date breakpoints before building up the list of breakpoints for  
> > dbstatus().
> >
> > John Swensen
> John,
>
> This patch looks right to me, but can you give an example of Octave  
> code that causes the bug to manifest? Is this related to the thread
>
> http://www-old.cae.wisc.edu/pipermail/octave-maintainers/2008-September/008657.html
>
> and continued in
>
> http://www-old.cae.wisc.edu/pipermail/octave-maintainers/2008-October/008831.html
>
> Cheers
> David
>
> --
> David Bateman                                 
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I don't think this bug had anything to do with those threads.  This  
was much more basic.  Try the following:

1) Add a breakpoint to a function
2) Call dbstatus
3) Modify the file in which the breakpoint was set (e.g. add and empty  
new line)
4) Call dbstatus and watch octave crash

I think the behavior is unique to dbstatus because it was modifying  
the STL::map while in the middle of iterating through it, because of  
the out of date check on the file.

John Swensen