[Rd] how to trace what crashes R

[Dirk Eddelbuettel]

On Wed, Jan 24, 2007 at 11:15:49AM -0800, Vladimir Eremeev wrote:
> The problem is. R crashes with the "segmentation violation".
> Tracing with the insight and with simple Rprintf's gave me that crash occurs
> on the call of the function deeply in the snns kernel. 
> That is, R correctly calls C wrapper, it calls the kernel function from the
> so called "user interface" part, it calls another C function from the
> internals, and that one calls the third C function. 
> And the segmentation fault occurs on the call of that function, it doesn't
> do anything, its arguments have correct values, and it works in the other
> situations, for example, when I run executables from the SNNS (either gui
> version of the simulator, or batch interpreter).
> Moreover, I don't think the reason in the incorrect arguments, since the
> called function doesn't do anything. 
> Rprintf in the very beginning of its body doesn't work (I traced it in
> console mode of R).
> 
> How could I trace, what happens?

Compile snns with debugging support, compile R with debugging, start R
as 

   $ R -d gdb		## or ddd if you have it
   
and use the debugger.  There is a lot of useful information in the
fine manual on 'R Extensions'.

Dirk

-- 
Hell, there are no rules here - we're trying to accomplish something. 
                                                  -- Thomas A. Edison