Re: Debugging Ada

[Adam Beneschan <adam@irvine.com>]

On Dec 21, 11:46 am, Ludovic Brenta <ludo...@ludovic-brenta.org>
wrote:
> awdorrin <awdor...@gmail.com> writes:
> > Ah, I see what you are saying. I don't think that is what is going on
> > in this situation.
>
> > The code I'm working with is a mix of Ada and C, and it was originally
> > written under Ada83.
>
> > The 'SysConfig' package is importing a C character array:
> >   char g_cfg_file_names[100][128]; (up to 100 file names, 128
> > characters each)
> > as:
> >   pragma Import( C, CFG_FILES, "g_cfg_file_names");
>
> > LAN_CFG is part of an enumeration defined in the SysConfig package to
> > map to the index numbers of that array.
>
> OK, I think I understand the problem better too.  Your initial
> description of the problem was:
>
> > Then in the package's main procedure when I try to use the
> > LAN_CFG_FILE, sometimes the value is corrupted.
>
> I'm beginning to think that perhaps the elaboration order varies between
> compilations.  The pragma Import (C, CFG_FILES, "g_cfg_file_names")
> indicates that:
>
> - the Ada language rules require that g_cfg_file_names is elaborated
>   before LAN_CFG_FILE
> - the Ada compiler cannot enforce this rule, so it simply assumes that
>   the rule is followed
> - the C compiler must emit code that elaborates *and* initializes
>   g_cfg_file_names.  It is possible that what you see as "corrupted" is
>   simply an uninitialized value.
> - the binder must emit code that calls the C initialization routine
>   *before* the elaboration of LAN_CFG_FILE

If LAN_CFG_FILE is declared inside a procedure as shown in a previous
post, how can elaboration order be an issue?

                               -- Adam