Re: [gpsd-dev] ✘GPSD_API

[Bernd Zeimetz]

hi,

> I've been looking at gps.h and at these two constants:
> 
> #define GPSD_API_MAJOR_VERSION 6       /* bump on incompatible changes */
> #define GPSD_API_MINOR_VERSION 1       /* bump on compatible changes */
> 
> It is not clear to me what constitutes a compatible channge and
> what is an incompatible change.

I understand it as in:
- stuff that only adds symbols to libgps and/or adding stuff to the api
without breaking it: compatible change
- removing or changing symbols in libgps: incompatible change

> For example, was the recent addition of oscillator_t osc to gps_data_t
> a compatible change that should have incremented the minor rev?

I'm pretty sure that breaks the abi as you are chaging the size of structs.

> I'm guessing that if I added a field to satellite_t skyview, which is in
> gps_data_t, that would be an incompatible change?o

same here.

Also you might want to look into
/* FIXME! next lib rev need to add a place to put PPS precision */


> I also have some other changes that likely need to go in gpsdata_t. For
> example, there are two distinct types of satellites_used and
> satellites_visible.  One type is the number reported by the GPS and the
> other is a could of sats seen so far in sucessive GPGSA dn GPGSV.  But
> gpsdata_t has place for only one type and they keep over-wrting each
> other...

you also might want to read
http://www.catb.org/esr/structure-packing/



-- 
 Bernd Zeimetz                            Debian GNU/Linux Developer
 http://bzed.de                                http://www.debian.org
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