Re: [photran] Re: Where to focus development efforts

[Jeffrey Overbey <subscribe-photran@xxxxxxxxxxxx>]

Hi Adrian,

> the multi dimensional arrays problem in the debugger
> ...
> If you can give me a feel for what the problem is with
> this mutli dimensional arrays problem then I might be able to help

If you're interested in working on this problem, that's great.  Photran 
actually uses the CDT (C/C++) debugger as-is -- no changes whatsoever. 
The CDT debugger is just a graphical interface for gdb; it communicates 
with gdb using MI.  What the debugger displays (for multi-dimensional 
arrays or otherwise) directly corresponds to what information it can get 
from gdb about the array.  In turn, gdb gets this information from 
debugging symbols that the compiler embeds in the executable (binary).

I am not a Fortran programmer, so I don't have a good sense of how well 
gdb actually supports various Fortran compilers' binaries.  I do know 
that it's primarily intended to be a C/C++ debugger.  If I compile code 
with a statically-allocated 2x3 integer array in gfortran, it seems the 
gfortran restructures this as a one-dimensional, six-element array... 
and I can't find anything accessible in gdb that tells me it's actually 
2x3.  But I could be missing something.

There are basically two (feasible) ways to fix this problem.  If the 
array dimension information *is* available to gdb but it's being 
ignored, then you could try to fix the CDT debugger.  If gdb just 
doesn't support Fortran multidimensional arrays, then you could add 
support for a different debugger.  (What debugger(s) do Fortran 
programmers use, anyway?)

In either case, I could point you toward some people with CDT/debugger 
experience.

Jeff