Re: [Plplot-devel] Problem builiding the Python bindings on Windows using MS VC/C++

[Alan W. I. <ir...@be...>]

On 2013-10-19 18:48-0000 Arjen Markus wrote:

> HI Alan,
>
> from a first glance, I think they are false alarms - they show up in clean-up code. But
> that is only a preliminary conclusion from just a glance.

Hi Arjen:

Well, there are 74 such instances.  I agree the first one for tmp8
seems to be associated with cleanup code for failure conditions
associated with the fail: label.  But that is worth fixing since if a
Python user enters the wrong argument type, for example, we don't want
the whole of python to segfault because of that uninitialized
variable.  And once that uninitialized variable result is fixed in
bindings/python/plplotcmodule.i, it will automatically fix a
significant fraction of the remaining 74 such instances in the code
generated by swig. Which may leave some uninitialized variable in that
code that has even bigger impact than the uninitialized variables in
cleanup code for failure conditions that we have already identified.
Or as you say this code cleanup might not have any impact on the
different Python-C results we get for the MinGW compiler (and which
Andrew might still be able to confirm for the closely related gcc
compiler as well on 32-bit Linux.) But the code cleanup is worthwhile
in its own right so let me have a first crack at that.

I plan to use the -Wuninitialized' gcc option which is supposed to
detect possible uninitialized variables. But if MSVC does a
better job of detecting such conditions, I might need you to do
another evaluation with it after I have fixed everything that is
mentioned by the gcc -Wuninitialized' option for the Python interface.

More later....

Alan

__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
__________________________