[GRASS5] problem with G_get_null_value_row &/or mapset searches in my own program

[Roger Bivand]

On Sat, 3 May 2003, Scott W Mitchell wrote:

> cflow sounds like a good tool to know about, thanks.  I hadn't got to 
> checking whether or not those functions were even called.
> 
Reading thousands of lines of code is easier for a computer!

> My guess is that I've abused a pointer somewhere, or am somehow else 
> tramping on memory, leading to a misleading error.
> 
Electric Fence, maybe? Or another tool to try to help find memory bugs? 
They are tiresome, everybody has them, keep trying!

> I'll have to comb through my assignments looking for mistakes.
> 
> Thanks...
> 
> Scott
> 
> On Saturday, May 3, 2003, at 04:29 Canada/Eastern, Roger Bivand wrote:
> 
> > On Sat, 3 May 2003, Glynn Clements wrote:
> >
> >>
> >> Scott W Mitchell wrote:
> >>
> >>
> >>> I've compared my program to others in the source tree, and as far as 
> >>> I
> >>> can see I am using it identically.  So I got it into a debugger and
> >>> found that the core dump is actually happening "further in", when
> >>> G_get_cell_hd calls G_is_reclass ...
> >>
> >> I don't see how G_get_null_value_row() can end up calling
> >> G_get_cellhd().
> >
> > As far as I can see using cflow (an old but trusted utility for 
> > printing a
> > graph of a function's call hierarchy) G_get_null_value_row() does not 
> > call
> > G_get_cellhd(), nor do any of the functions called by it all the way
> > through its call hierarchy.
> >
> > Although this isn't relevant here, Markus did ask me to remind him 
> > about
> > cflow, which, since it comes from the same era as much of the code (at
> > least in libes/gis), does show what is calling what, or what is called 
> > by
> > what if inverted.
> >
> > Roger
> >
> > -- 
> > Roger Bivand
> > Economic Geography Section, Department of Economics, Norwegian School 
> > of
> > Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
> > Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
> > e-mail: Roger.Bivand at nhh.no
> >
> > _______________________________________________
> > grass5 mailing list
> > grass5 at grass.itc.it
> > http://grass.itc.it/mailman/listinfo/grass5
> >
> ------
> Scott W. Mitchell						smitch at geog.utoronto.ca
> Department of Geography					Phone: (613) 730-5375
> University of Toronto at Mississauga	UTM fax: (905) 828-5273
> 3359 Mississauga Road					Local fax (613) 822-5143
> Mississauga, ON L5L 1C6					Canada
> 
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand at nhh.no