Re: Rational Apex Ada Linker

[jcreem@mv.mv.com (Jeff Creem)]

In article <32249623.7C09@harris.com>, Kirk J Horne <khorne@harris.com> wrote:

> The Ada Rational Apex (2.0.8.D) linker appears to include all
> subprograms from imported subsystens into an executable, even if the
> subprograms aren't referenced by the Ada process being built. This
> causes even small Ada processes to become too large and has become an
> obstacle on the SGI where the "GOT overflow" link error occurs. 
> 
> (1) Are any other Rational users having the same problem?    
> (2) Is there a work around?
> (3) Does Rational have a "smart" Ada linker?
> 
> Thanks,
> Kirk Horne
> khorne@rsa.hisd.harris.com

First,

Its always best to send a report to:

support@rational.com


first since if people don't report these problems they will not get the
attention they deserve. (Maybe you already did and just have not heard
back. I just want to make sure.)


I have been "working" with rational for 6 months or so on this issue and
the completely abismal code generation of the Apex product. I have
gone through the proper chanels but Rational says they have never heard
anyone complain about he code generation or huge executables except for me!

In comparing code generated by Apex to code generated by GNAT or
even Rationals SunAda product, Apex produces bloated code which runs about
1.8 - 3.0 time slower.

But you only pay 16,000 to 20,000 for the tool set. The compiler
is really just a bonus. The real reason you want to pay that much is for
the troublesome Language sensitive Editor (that automatically "fixes"
closing parenthesis (like the ] in LISP and we all know what a powerful
bug inducer this is).


Anyhow to make a long story short. I know of know of no fix for the problem.

Try going to your management and telling them that even though you've
already spent multiple thousands on the Apex environment and compiler that
you need a few more thousand to purchase VADSself from rational so that 
you can get reasonable executable sizes.

Or use GNAT. It does not produce code that is quite as tight as the
old SunAda 1.1 (VADSself). But for all I know GNAT is as good as the more recent
VADSself.


Oh, on the brighter side, with the VADS compiler (at least for vxWorks targets)
the linker is very selective about what it brings in and it will even eliminate
procedures from within packages if it determines that they can never be called.