Re: Import a type from C

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

Robert A Duff <bobduff@shell01.TheWorld.com> writes:

> "Frank J. Lhota" <NOSPAM.lhota.adarose@verizon.net> writes:
> 
> > ...only the crude pack pragma / command line option ...
> 
> What's the "pack pragma".  Is this standard C, or something supported by
> some C compilers?  (Which compilers?)

gcc supports "__attribute__ ((packed))". It applies to structs, or
fields within structs (not arrays).

I'm on a flight project that has a lot of inherited C code, and some
new Ada code (all by me). The previous project used -fpacked command
line flag for all the C code. But we are also switching operating
systems, and the new one can't tolerate -fpacked. So we have to add
__attribute__ ((packed)) all over the place. But some people want to
run unit tests using Microsoft Visual C (why, I'm not sure :). So we
use a #define to get rid of the __attribute__.

I keep saying "see how much easier this is in Ada". Some of them are
beginning to hear it :).

-- 
-- Stephe