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From: Comeau At9Fans <comeauat9fans@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] assembly syntax in plan 9
Date: Tue, 17 Jan 2012 14:21:53 -0500	[thread overview]
Message-ID: <CAE9W7-gbF_97VeiX4X7QGvN2ugfx6d08=Gq8DGKXrGVXZi=jCg@mail.gmail.com> (raw)
In-Reply-To: <CFE0D78F-3C9A-4DB5-A3F2-13A8FC54BD74@bitblocks.com>

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On Mon, Jan 16, 2012 at 2:03 PM, Bakul Shah <bakul@bitblocks.com> wrote:

> How do you deal with longjmp?
>

I don't have it in front of me, but I do seem to recall the Standard allows
that the VLA might still be around though, believe it has an example with
said, for better or worse...  Anyway, at some point we're able to detect
that the previous VLA(s) is no longer active and "toss" them.


> On Jan 16, 2012, at 10:51 AM, Comeau At9Fans <comeauat9fans@gmail.com>
> wrote:
>
> On Mon, Jan 16, 2012 at 10:41 AM, Bakul Shah <bakul@bitblocks.com> wrote:
>
>> A frame pointer is needed for C99's variable length arrays but not
>> otherwise. Only an issue if ever plan9 C is extended to handle C99 or C1x.
>> gcc has to do the right thing even with -fno-frame-pointer.
>>
>
> What we do in problematic cases with Comeau is to generate code to arrange
> for the allocation of the VLA on the heap.  I'm not saying this is perfect,
> but at least it gets the feature implementable and up and running as "a
> portable implementation" versus perhaps not being able to implement it at
> all on some platforms.
>
> --
Greg Comeau / 4.3.10.1 with C++0xisms now in beta!
Comeau C/C++ ONLINE ==>     http://www.comeaucomputing.com/tryitout
World Class Compilers:  Breathtaking C++, Amazing C99, Fabulous C90.
Comeau C/C++ with Dinkumware's Libraries... Have you tried it?

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  parent reply	other threads:[~2012-01-17 19:21 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-16 12:30 Alexander Kapshuk
2012-01-16 13:08 ` Charles Forsyth
2012-01-16 13:27   ` Alexander Kapshuk
2012-01-16 15:41   ` Bakul Shah
2012-01-16 18:51     ` Comeau At9Fans
2012-01-16 19:03       ` Bakul Shah
2012-01-16 19:39         ` Charles Forsyth
2012-01-17 19:27           ` Comeau At9Fans
     [not found]         ` <CAOw7k5iYxoVUHYYxf1Dg9ESWwTon_aGFxhNkuyUGbkXwiKO9DA@mail.gmail.c>
2012-01-16 19:49           ` erik quanstrom
2012-01-17 19:29             ` Comeau At9Fans
2012-01-16 20:11         ` Joel C. Salomon
2012-01-16 23:18           ` Bakul Shah
2012-01-17 19:31           ` Comeau At9Fans
2012-01-17 19:21         ` Comeau At9Fans [this message]
2012-01-18 17:48           ` Bakul Shah
2012-01-18 18:32             ` Comeau At9Fans
2012-01-16 16:07   ` Joel C. Salomon
2012-01-16 16:27     ` erik quanstrom
2012-01-16 16:40     ` Charles Forsyth
2012-01-16 16:54     ` Bakul Shah

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