GCC Feature question

GCC Feature question

[Michael Lovett]

Hiya

Does the current GCC (3.2x) support the try/finally construct?

We are porting apps to UNIX from Windows but so far can't find a compiler with try/finally. It is such a useful, convenient construct it is hard to imagine structured programming without it.

Does anyone know if this is planned for the future if it isn't available now?

Thanks so much!
Michael Lovett

Re: GCC Feature question

[Aldy Hernandez]

>>>>> "Michael" == Michael Lovett <mlovett@morpace.com> writes:

 > Hiya
 > Does the current GCC (3.2x) support the try/finally construct?

Before Richard and Uli publicly kick my butt...

That's me.  I was supposed to have done this.  I have it partially
finished.  It's just missing the important bits for passing through
exceptions.

I'll hopefully be finishing this up in the next week or two, but since
we are in code freeze, it won't make it until 3.3.

 > We are porting apps to UNIX from Windows but so far can't find a compiler =
 > with try/finally. It is such a useful, convenient construct it is hard to =
 > imagine structured programming without it.

C or C++?  With C++ you can emulate it with constructors, albeit ugly.

 > Does anyone know if this is planned for the future if it isn't available =
 > now?

Yes it is.  Blame me.

(Mr. Procrastinator) Aldy

Re: GCC Feature question

[Jason Merrill]

On 27 Sep 2002 20:42:56 -0700, Aldy Hernandez <aldyh@redhat.com> wrote:

>  > We are porting apps to UNIX from Windows but so far can't find a
>  > compiler with try/finally. It is such a useful, convenient construct
>  > it is hard to imagine structured programming without it.
>
> C or C++?  With C++ you can emulate it with constructors, albeit ugly.

It's not *that* ugly.  For C++ using a destructor encourages you to write
reusable finalization code.

Jason

Re: GCC Feature question

[Tim Prince]

On Friday 27 September 2002 19:57, Michael Lovett wrote:
> Hiya
>
> Does the current GCC (3.2x) support the try/finally construct?
>
> We are porting apps to UNIX from Windows but so far can't find a compiler
> with try/finally. It is such a useful, convenient construct it is hard to
> imagine structured programming without it.
>
> Does anyone know if this is planned for the future if it isn't available
> now?
>
> Thanks so much!
> Michael Lovett
To the extent this stuff is supported in the cygwin win32api, you may be able 
to adapt it to reconcile its conflicts with other g++ targets.  You may find 
further information in the cygwin FAQ and, of course source code.  It's 
certainly considered more of a library than a compiler thing.
-- 
Tim Prince

Re: GCC Feature question

[Aldy Hernandez]

>>>>> "Tim" == Tim Prince <tprince@computer.org> writes:

 > To the extent this stuff is supported in the cygwin win32api, you may be able 
 > to adapt it to reconcile its conflicts with other g++ targets.  You may find 
 > further information in the cygwin FAQ and, of course source code.  It's 
 > certainly considered more of a library than a compiler thing.

Huh?

How are you going to do this in library code?

while (1) {
        try {
                if (blah)
                        break;
        } finally {
                puts("exiting loop");
        }
}

Re: GCC Feature question

[Michael Lovett]

Well, sometimes there are things you want to do locally in your code that don't necessarily involve object destruction, and you'd like these things to happen whether or not an exception was thrown. These are the types of things we are anxious for try/finally.

M

>>> Jason Merrill <jason@redhat.com> 10/01/02 01:30PM >>>
On 27 Sep 2002 20:42:56 -0700, Aldy Hernandez <aldyh@redhat.com> wrote:

>  > We are porting apps to UNIX from Windows but so far can't find a
>  > compiler with try/finally. It is such a useful, convenient construct
>  > it is hard to imagine structured programming without it.
>
> C or C++?  With C++ you can emulate it with constructors, albeit ugly.

It's not *that* ugly.  For C++ using a destructor encourages you to write
reusable finalization code.

Jason

Re: GCC Feature question

[Jason Merrill]

On Fri, 04 Oct 2002 15:06:41 -0400, "Michael Lovett" <mlovett@morpace.com> wrote:

> Well, sometimes there are things you want to do locally in your code that
> don't necessarily involve object destruction, and you'd like these things
> to happen whether or not an exception was thrown. These are the types of
> things we are anxious for try/finally.

No, they don't necessarily involve object destruction, but they can
certainly be written using a destructor, perhaps for a local class.
Usually they involve cleaning up after initialization code earlier in the
function, in which case writing them as a constructor/destructor pair makes
a lot of sense.

And it's portable C++, which try/finally isn't.

Jason