Re: Tips for conversion from Apex to GNAT

["Jeff Creem" <jcreem@atetola.mv.com>]

Chris Powell <chris.powell@rrds.co.uk> wrote in message
news:38609E9C.B75C9962@rdel.co.uk...
> Does anyone have any tips for converting Apex based Ada system to build
> under GNAT? Some obvious potential pitfalls spring to mind: the
> compatibility of libraries (we cross compile to PowerPC, VxWorks), the
> file extension mapping from Apex .1.ada/.2.ada to .ads/.adb,
> inconsistencies in implementation-defined areas of the compilers...
>
> Perhaps someone has written a wizzo makefile that can build an
> application directly from views in an Apex tower using GNAT?
>
> We are interested to see if the application builds any quicker: we spend
> a lot of time waiting for builds under Apex.
>
> Thanks in advance; Chris Powell.



If you are keeping Apex around and just trying to integrate in GNAT then you
might
want to look to Rational for an RCI license or two which allows other
compilers to
be merged into the Apex environment. Note that to do this you would need
both
licenses and support for actually putting together the RCI customizations.
It is not
rocket science but looks a little daunting until you have done it.

I have used GNAT with Apex (without RCI) for a few years. I have written
several cheezy
scripts to basically build a set of directories with symbolic links to an
existing Apex view (where
the link names follow standard GNAT conventions) and
extract out the Apex imports to build the ADA_INCLUDE_PATH variables. This
was all done at
work so I can not release it but if you have questions I could give you some
tips.


As far as compile speed, GNAT is faster in some cases slower in others but
in general it does feel faster
more often. If you take a look at the Big Book of Linux Ada programming (at
 http://www.vaxxine.com/pegasoft/homes/book.html) and look at the section
http://www.vaxxine.com/pegasoft/homes/5.html on cook (a parallel Make
program), there is a
sample cook file that works with GNAT to distribute your compiles and get it
to go even faster
(note that something like this is also possible with Apex)

Don't be put off by the document being Linux based. Most of the info applies
in any environment
where you can run GNAT.