Symbian OS (was: Re: Ada used in General Aviation (GA) applications?)

["Alexander E. Kopilovich" <aek@VB1162.spb.edu>]

Martin Dowie wrote:

>A "Dummies Guide to porting GNAT" covering both processor
>and OS would be a huge help. I'd love to have Ada available for
>SymbianOS (or it's predecessor EPOC32).

Being more or less familiar with Symbian OS (mostly SonyEricsson's flavour -
Symbian 7.0, much less Nokia's Series 60 flavour - Symbian 6.1) I think that
any guide of porting GNAT will not bring you near to that aim.

Actually, current Symbian C++ development toolset consist of C++ compiler
(usually Metrowerks CodeWarrior is used for Symbian 7.0 and MSVC 6.0 for
Symbian 6.1, although there are SDKs for other compilers, for example,
Borland's C++ Builder), resource compiler, linker (with addition for
resources) - all that produces an executable for emulator only - and emulator
itself. Production version of the program (which will be loaded into 
smartphone) has to be compiled and built with another toolset, which is
GCC-based.

So, in principle one may try to port GNAT for Symbian, but there will be
severe haedaches with GCC versions, and you'll not be able to use the emulator
for development.

Then, even if you adapt GNAT for Windows for use with the emulator, you still
be quite restricted, because the emulator has problems with support of tasking
- in Symbian terminology it supports "threads", but not "processes". Well,
C++ development on emulator has the same limitation, so I just warn you that
you should not expect too much from Ada tasking on emulator (if you aren't
going to develop better emulator).

But all that is less than half of work, I think - because there are mountains
of APIs for Symbian (and many of them differ significantly between Symbian's
flavours). And it will be quite serious work to provide Ada bindinds even for
most needed APIs. (As you can expect, those APIs/classes/etc. are only
partially documented, and the source code is not available after EPOC32 R5).

Actually I thought that RR Software's Janus/Ada might be more proper thing
(than GNAT) for targetting at Symbian, and several times I tempted to tell
Randy about this opportunity... but there is a lot of work, and perhaps small
chances that that work will be compensated by sales. If there were interest
and some funding from one of smartphone vendors that use or plan to use
Symbian (Nokia, SonyEricsson, Siemens, Samsung, etc. ... I'm not sure about
Motorola) - it will be another matter, but they still are trying to push Java
(without much success, though - as far as I can see).




Alexander Kopilovich                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia