Compiling the GNU ada compiler on a new platform

Compiling the GNU ada compiler on a new platform

[Paul Smedley]

Hi All,

I'm wanting to update the GNU ADA compiler for OS/2... I'm currently 
building GCC 4.3.x and 4.4.x on OS/2 (C/C++/fortran) but for ADA 
configure complains about not finding gnat.  The problem is that the 
only gnat compiled for OS/2 was years ago using a different toolchain 
so it's not suitable.

I assume that at some point in time, ada didn't depend on an existing 
gnat, so if I could find that version, I could compile a version of 
gnat to get me started?? Otherwise it's a bit chicken and egg :(

-- 
Cheers,

Paul.

Re: Compiling the GNU ada compiler on a new platform

[Andreas Schwab]

"Paul Smedley" <pauldespam@despamsmedley.id.au> writes:

> I assume that at some point in time, ada didn't depend on an existing 
> gnat, so if I could find that version, I could compile a version of 
> gnat to get me started?? Otherwise it's a bit chicken and egg :(

Gnat needs a relatively recent gnat to compile itself.  You usually
start with a cross compiler.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Compiling the GNU ada compiler on a new platform

[Joe Buck]

On Fri, Aug 21, 2009 at 03:40:57PM -0700, Paul Smedley wrote:
> I'm wanting to update the GNU ADA compiler for OS/2... I'm currently
> building GCC 4.3.x and 4.4.x on OS/2 (C/C++/fortran) but for ADA
> configure complains about not finding gnat.  The problem is that the
> only gnat compiled for OS/2 was years ago using a different toolchain
> so it's not suitable.
> 
> I assume that at some point in time, ada didn't depend on an existing
> gnat, so if I could find that version, I could compile a version of
> gnat to get me started?? Otherwise it's a bit chicken and egg :(

The alternative solution is to build gnat as a cross-compiler, so it
runs on (say) GNU/Linux and produces gnat code for OS/2.  I haven't
done that for gnat, only for other languages, but perhaps someone can
advise you on how to set that up.  Then you can use the cross-compiler
to build a native compiler.

Re: Compiling the GNU ada compiler on a new platform

[Andris Pavenis]

22.08.2009 02:16, Joe Buck kirjoitti:
> On Fri, Aug 21, 2009 at 03:40:57PM -0700, Paul Smedley wrote:
>> I'm wanting to update the GNU ADA compiler for OS/2... I'm currently
>> building GCC 4.3.x and 4.4.x on OS/2 (C/C++/fortran) but for ADA
>> configure complains about not finding gnat.  The problem is that the
>> only gnat compiled for OS/2 was years ago using a different toolchain
>> so it's not suitable.
>>
>> I assume that at some point in time, ada didn't depend on an existing
>> gnat, so if I could find that version, I could compile a version of
>> gnat to get me started?? Otherwise it's a bit chicken and egg :(
>
> The alternative solution is to build gnat as a cross-compiler, so it
> runs on (say) GNU/Linux and produces gnat code for OS/2.  I haven't
> done that for gnat, only for other languages, but perhaps someone can
> advise you on how to set that up.  Then you can use the cross-compiler
> to build a native compiler.

I tried for some last versions cross-native build for DJGPP under Linux.
Not much success for Ada.

About native build:

If there was some port sometimes long ago, then one could do all in several
steps: build for example gcc-3.something including Ada using existing port,
after that move to some newer version. I do not thing that there will be
many steps required.

For DJGPP I initially used used some port I found somewhere when built
first version which included Ada support.

Also:

when building Linux-to-DJGPP cross-compiler (C, C++, Fortran, Objective C,
Objective C++, Ada) I had to bootstrap at first native compiler for Linux
(C and Ada only) or otherwise I have got problems building libada with
native system compiler under Linux.

Andris

Re: Compiling the GNU ada compiler on a new platform

[Richard Kenner]

> I assume that at some point in time, ada didn't depend on an
> existing gnat,

Yeah, but that point in time was close to 20 years ago ...

The best way to do something like this is to make a cross-compiler to OS/2,
build assembler files, copy them into the OS/2 native build treee, assemble
them, and go on from there.  This was the way the GNAT was originally
ported to all its targets.

Re: Compiling the GNU ada compiler on a very old platform

[Geert Bosch]

On Aug 21, 2009, at 18:40, Paul Smedley wrote:

> Hi All,
>
> I'm wanting to update the GNU ADA compiler for OS/2... I'm currently
> building GCC 4.3.x and 4.4.x on OS/2 (C/C++/fortran) but for ADA
> configure complains about not finding gnat.  The problem is that the
> only gnat compiled for OS/2 was years ago using a different toolchain
> so it's not suitable.

I used to maintain the OS/2 port for AdaCore, but that was many years  
ago.
IBM released its last version of OS/2 in 2001. Currently it is almost
impossible to run OS/2 in either real modern hardware or on a  
virtualized
system.

AFAIK, GNAT 3.15p is the last GNAT version with OS/2 support. As the  
OS/2
version was a full implementation of Ada 95, including all annexes,  
passing
all ACATS tests, this version should still be very useful today, if you
have a system running OS/2, that is. If you're interested in developing
Ada applications on OS/2, your best bet is to use GNAT 3.15p.
You'll get a mature well-tested and very fast compiler.

This version might still be able to bootstrap GNAT.

   -Geert

Re: Compiling the GNU ada compiler on a very old platform

[Paul Smedley]

Hi Geert!

On Thu, 27 Aug 2009 01:44:11 UTC, Geert Bosch <bosch@adacore.com> 
wrote:

> 
> On Aug 21, 2009, at 18:40, Paul Smedley wrote:
> > I'm wanting to update the GNU ADA compiler for OS/2... I'm currently
> > building GCC 4.3.x and 4.4.x on OS/2 (C/C++/fortran) but for ADA
> > configure complains about not finding gnat.  The problem is that the
> > only gnat compiled for OS/2 was years ago using a different toolchain
> > so it's not suitable.
> 
> I used to maintain the OS/2 port for AdaCore, but that was many years  
> ago.
> IBM released its last version of OS/2 in 2001. Currently it is almost
> impossible to run OS/2 in either real modern hardware or on a  
> virtualized
> system.
Not quite true - www.ecomstation.com - and it does run in things like 
virtualbox.  I'm running on a quad core system here and all 4 cores 
are recognised.

> AFAIK, GNAT 3.15p is the last GNAT version with OS/2 support. As the  
> OS/2
> version was a full implementation of Ada 95, including all annexes,  
> passing
> all ACATS tests, this version should still be very useful today, if you
> have a system running OS/2, that is. If you're interested in developing
> Ada applications on OS/2, your best bet is to use GNAT 3.15p.
> You'll get a mature well-tested and very fast compiler.
I don't actually NEED this :) Another member of the community inquired
about an updated gnat, so I thought I'd look at it.

With GNAT 3.15p did it also depend on an existing gnat? or that one 
built directory from source?

> This version might still be able to bootstrap GNAT.
It might - but I'm using a different c library :( libc vs emx

-- 
Cheers,

Paul.

Re: Compiling the GNU ada compiler on a very old platform

[Robert Dewar]

Paul Smedley wrote:

> With GNAT 3.15p did it also depend on an existing gnat? or that one 
> built directory from source?

Building GNAT from sources always requires an existing Ada compiler
since the front end is written in Ada. However, binary versions of
3.15p for OS/2 are around.
> 
>> This version might still be able to bootstrap GNAT.
> It might - but I'm using a different c library :( libc vs emx
>