• Welcome to OS2World OLD-STATIC-BACKUP Forum.
 

News:

This is an old OS2World backup forum for reference only. IT IS READ ONLY!!!

If you need help with OS/2 - eComStation visit http://www.os2world.com/forum

Main Menu

Porting free gnat ADA 2005 compiler on OS/2

Started by kim, 2007.06.17, 00:09:25

Previous topic - Next topic

kim


francois

Hi Kim,

I would like to bring a clarification about this port:

Only the ADA 2005 compiler is requested.
The additional tools and GNAT libraries would be a plus but are not vital.
The port of the GPS is NOT requested. It is a GTK+ based application and is probably very difficult to port to a target without GTK+.

I have seen that current GCC repository at Netlabs already has the ADA directory but I ignore if anything has been tempted in this domain. The GNAT compiler is known to be rather complex.

François

Paul Smedley

Quote from: francois on 2007.06.19, 22:43:51
Hi Kim,

I would like to bring a clarification about this port:

Only the ADA 2005 compiler is requested.
The additional tools and GNAT libraries would be a plus but are not vital.
The port of the GPS is NOT requested. It is a GTK+ based application and is probably very difficult to port to a target without GTK+.

I have seen that current GCC repository at Netlabs already has the ADA directory but I ignore if anything has been tempted in this domain. The GNAT compiler is known to be rather complex.

Thanks for the clarification - I'd been meaning to post that the gui would be rather difficult until we get a port of GTK+

I'll try take a look at what's required to build it when I get some free time.

Cheers,

Paul.

obiwan

A while back I saw a post (I believe on the UnixOS/2 mailing list iirc) stating that the GNAT compiler in gcc 3.x is not nearly as good as the one in gcc 4.x because the 3.x compiler first translates the Ada code into C, whereas the 4.x compiler compiles the Ada code directly into bytecode. The general conclusion of the discussion was that the effort required would be more worthwhile after a gcc > 4.0 is ported to OS/2, which, to my knowledge, has not yet been attempted.

I have not confirmed this difference to be fact, but if it were me I would check into it before going too far with the effort.

Then again, if it is true, maybe that would make the 3.x port easier than a 4.x port.

Just my $0.01.

chennecke

Quote from: obiwan on 2007.06.20, 22:33:48
A while back I saw a post (I believe on the UnixOS/2 mailing list iirc) stating that the GNAT compiler in gcc 3.x is not nearly as good as the one in gcc 4.x because the 3.x compiler first translates the Ada code into C, whereas the 4.x compiler compiles the Ada code directly into bytecode. The general conclusion of the discussion was that the effort required would be more worthwhile after a gcc > 4.0 is ported to OS/2, which, to my knowledge, has not yet been attempted.

I have not confirmed this difference to be fact, but if it were me I would check into it before going too far with the effort.

Then again, if it is true, maybe that would make the 3.x port easier than a 4.x port.

Hm... Well, the older GNAT has been widely used for a long time. While a direct compilation is certainly to be preferred, a translation is a lot better than nothing. Using the old one also doesn't mean that you lose all the nice stuff like run-time checking.

francois

From my own experience, the OS/2 port of GNAT (3.15, ADA95) does not suffer from a lack of performance compared to current versions under Windows or Linux (ADA2005). Even more, for my applications, it still provides the best performance close to the Windows version, the Linux version is a step behind. The fact that it generates direct code is not a real argument to me. The weak point for me of the GNAT compiler is not really the performance but the too big size of its executables.

The reason for this port is for me
- to benefit from the ADA2005 related language imporvements
- to use a more modern linker able to cope with recent C or C++
- to get some bug fixes.

François.

Paul Smedley

Quote from: francois on 2007.06.24, 23:10:52
From my own experience, the OS/2 port of GNAT (3.15, ADA95) does not suffer from a lack of performance compared to current versions under Windows or Linux (ADA2005). Even more, for my applications, it still provides the best performance close to the Windows version, the Linux version is a step behind. The fact that it generates direct code is not a real argument to me. The weak point for me of the GNAT compiler is not really the performance but the too big size of its executables.

The reason for this port is for me
- to benefit from the ADA2005 related language imporvements
- to use a more modern linker able to cope with recent C or C++
- to get some bug fixes.

Is there any reason to want the GNAT ada compiler as opposed to the GNU ada compiler? 

Paul Smedley

Quote from: Paul Smedley on 2009.06.27, 03:06:21
Quote from: francois on 2007.06.24, 23:10:52
From my own experience, the OS/2 port of GNAT (3.15, ADA95) does not suffer from a lack of performance compared to current versions under Windows or Linux (ADA2005). Even more, for my applications, it still provides the best performance close to the Windows version, the Linux version is a step behind. The fact that it generates direct code is not a real argument to me. The weak point for me of the GNAT compiler is not really the performance but the too big size of its executables.

The reason for this port is for me
- to benefit from the ADA2005 related language imporvements
- to use a more modern linker able to cope with recent C or C++
- to get some bug fixes.

Is there any reason to want the GNAT ada compiler as opposed to the GNU ada compiler? 

Silly me - from the GNAT website:
"GNAT is a free, high-quality, complete compiler for Ada95, integrated into the GCC compiler system."