GNAT and GCC compatability.

GNAT and GCC compatability.

[Larry Stanbery]

I searched DejaNews for info on this, but found none...

I've currently got GNAT 3.11p, and realized I had a need to compile some C++
code I obtained.  I checked, and, of course, GNAT doesn't install g++ and
the associated header files, etc.  So, I wanted to know if there are things
I need to watch out for -- do I need a specific version of gcc?  Things like
that.

Thanks.

Larry Stanbery
("foo" is not part of my email address.)

Re: GNAT and GCC compatability.

[Preben Randhol]

"Larry Stanbery" <stanbery@foo.earthling.net> writes:

| I searched DejaNews for info on this, but found none...
| 
| I've currently got GNAT 3.11p, and realized I had a need to compile some C++
| code I obtained.  I checked, and, of course, GNAT doesn't install g++ and
| the associated header files, etc.  So, I wanted to know if there are things
| I need to watch out for -- do I need a specific version of gcc?  Things like
| that.

It depends. What kind of system do you have ? Linux, Solaris, DEC
... which distribution. Some C++ programs uses STL templates ++ then
you need either the latest gcc 2.95 (I think) or egcs.

-- 
Preben Randhol     [randhol@pvv.org]    [http://www.pvv.org/~randhol/] 
 "If you had just boarded an airliner and discovered that your team 
  of programmers had been responsible for the flight control software, 
  how many of you would disembark immediately?"             -- unknown

Re: GNAT and GCC compatability.

[Florian Weimer]

Preben Randhol <randhol@pvv.org> writes:

> "Larry Stanbery" <stanbery@foo.earthling.net> writes:
> 
> | I searched DejaNews for info on this, but found none...
> | 
> | I've currently got GNAT 3.11p, and realized I had a need to compile some C++
> | code I obtained.  I checked, and, of course, GNAT doesn't install g++ and
> | the associated header files, etc.  So, I wanted to know if there are things
> | I need to watch out for -- do I need a specific version of gcc?  Things like
> | that.
> 
> It depends. What kind of system do you have ? Linux, Solaris, DEC
> ... which distribution. 

Additional questions are: Are you going to use the GNAT C++ interface?
Has the C++ code already been compiled successfully with a GNU compiler?
Which standard libraries are used?  Is it ISO C++?  (Compiler vendors
often provide different implementations of for-scoping rules, templates,
exception and RTTI, more or less ignoring the standard.  C++ is not Ada.)

Both C++ and the GNU implementation changed a lot in the past few years.
If you know that a certain GCC version compiles the code correctly,
you should probably use that one.  Otherwise, you might want to try
several GCC versions: 2.7.2.3, 2.8.1 and 2.95.1 are the three latest
major releases.

Note that you shouldn't build the C++ compiler from a GNAT-patched
source tree, because some portions of the GCC backend are also changed
and the resulting C++ compiler, which would include these changes as
well, hasn't been tested.

> Some C++ programs uses STL templates ++ then you need either the
> latest gcc 2.95 (I think) or egcs.

There isn't an egcs project anymore.  The egcs development is the current
GCC tree (`GNU Compiler Collection'), GCC 2.95 and 2.95.1 are releases
based on this development tree (i.e., the former egcs tree).

Re: GNAT and GCC compatability.

[Larry Stanbery]

My apologies...  It appears my question was, um, incomplete. =)

I'm running Win NT Workstation (not my decision, unfortunately).  I've got
GNAT 3.11p installed in the default location.  I've found I need g++ (or
equivalent) to compile some C++ code.  Currently, I won't be integrating the
C++ with Ada, but I don't want to prohibit myself from doing such in the
future.  Further, I don't want to cripple my GNAT installation.

So, perhaps this clears it up a bit.  Basically, I'm looking for "ready to
run".

Thanks much for the help.

Larry Stanbery

Re: GNAT and GCC compatability.

[Simon Wright]

Florian Weimer <fw@deneb.cygnus.argh.org> writes:

> Note that you shouldn't build the C++ compiler from a GNAT-patched
> source tree, because some portions of the GCC backend are also changed
> and the resulting C++ compiler, which would include these changes as
> well, hasn't been tested.

The (admittedly minimal) C++ code I've built with such a beast has
given me no problems.

Just one (rather vague) datum, of course!

Re: GNAT and GCC compatability.

[Florian Weimer]

"Larry Stanbery" <stanbery@foo.earthling.net> writes:

> So, perhaps this clears it up a bit.  Basically, I'm looking for "ready to
> run".

http://sourceware.cygnus.com/cygwin/

Note that this has nothing to do with GNAT, ACT or Ada.

Re: GNAT and GCC compatability.

[Robert Dewar]

In article <x7vr9jii9jm.fsf@pogner.moho>,
  Simon Wright <simon@pogner.demon.co.uk> wrote:
> The (admittedly minimal) C++ code I've built
> with such a beast has
> given me no problems.
>
> Just one (rather vague) datum, of course!


No one said that it would be completely inoperative. The errors
which are undoubtedly there are likely to be quite subtle. The
point is that our patches have not been tested on G++, and in
any case there are known weaknesses in 2.8.1 (unpatched) wrt g++


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