Re: [avr-gcc-list] prog_mem limitation?

[Dave N6NZ]

Marc Wetzel wrote:
> > > > Is this the intended behaviour?
> > > > What cause is here the trigger?
> > > >       
> > > I'm not eaxctly sure why they behave differently, but the
> > > latter causes teststring[] to be allocated in the .data
> > > section instead of .progmem.     
> >
> > Probably because the second case does not have the 'static' keyword?
> >
> > Eric
> >   
> Thank you all for your quick answers.   I get it now, but if you ask me: 
> I don't like it.
> I always saw the prog_mem keyword just like a "flash" modifier, don't 
> know from where I got it (IAR maybe?).
>
> Who would need the differentiation of   "static flash" and "flash" ;-)
> But I will never forget again.

To me, locally allocated non-static flash is the nonsensical concept.  A 
locally allocated variable is by nature not permanent, unless static.

Of course, since PROGMEM is only a code section attribute, the compiler 
has no simple way of making semantic checks of that nature.  A warning 
or error would be nice, but I imagine it would be difficult to implement.

avr-gcc follows the C standards very well.  You say: "I don't like it." 
 Sometimes non-standard, non-portable behavior *is* convenient in the 
short term -- but it has unpleasant consequences in the long term.

-dave