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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: local arrays and stack |
| Date | 2015-03-24 13:42 -0700 |
| Organization | None to speak of |
| Message-ID | <87384urut8.fsf@kst-u.example.com> (permalink) |
| References | (4 earlier) <87k2y7u48c.fsf@kst-u.example.com> <705a5674-dbc9-460a-a72c-50bf1946be01@googlegroups.com> <mepdmh$qso$1@dont-email.me> <87fv8vu1sx.fsf@kst-u.example.com> <kfnpp7yfblo.fsf@x-alumni2.alumni.caltech.edu> |
Tim Rentsch <txr@alumni.caltech.edu> writes:
> Keith Thompson <kst-u@mib.org> writes:
>> Bartc <bc@freeuk.com> writes:
>>> [snip]
>>
>> Does gcc *ever* (generate code to) allocate local non-static
>> arrays on the heap or in static memory? It would have to generate
>> code to explicitly deallocate the array, even in the presence of a
>> goto or longjmp() out of the scope. [snip]
>
> Certainly it would be nice if a compiler did manage to deallocate
> such arrays even in the presence of longjmp(), but strictly
> speaking I'm not sure there is a requirement to do so. So I
> think that's a QoI issue, not a conformance problem. Note that
> for VLA's there is an (informative) explicit remark in the
> Standard about this, in 7.13.2.1 p5. I don't see any text in the
> Standard that makes arrays that are not VLA's different in this
> regard (or for that matter, non-arrays either - if we had a big
> struct we might very well want to allocate it using non-stack
> memory).
The cited remark is:
EXAMPLE The longjmp function that returns control back to the point
of the setjmp invocation might cause memory associated with a
variable length array object to be squandered.
But paragraph 2 specifically addresses VLAs:
... or if the invocation of the setjmp macro was within the scope of
an identifier with variably modified type and execution has left
that scope in the interim, the behavior is undefined.
(If you're going to cite the standard, it would be useful to
copy-and-paste the actual text, or at least summarize it, for those who
don't have a copy handy.)
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-22 01:51 -0700
local arrays and stack asetofsymbols@gmail.com - 2015-03-22 02:23 -0700
Re: local arrays and stack Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-22 13:22 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 01:55 -0700
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-22 15:07 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 01:50 -0700
Re: local arrays and stack Robert Wessel <robertwessel2@yahoo.com> - 2015-03-23 04:26 -0500
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 06:53 -0700
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-23 07:29 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 08:34 -0700
Re: local arrays and stack Robert Wessel <robertwessel2@yahoo.com> - 2015-03-23 19:57 -0500
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-24 04:01 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-24 04:37 -0700
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 13:04 +0100
Re: local arrays and stack glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-24 17:29 +0000
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 20:01 +0100
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-23 08:24 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 08:42 -0700
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-23 16:07 +0000
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 09:15 -0700
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-23 09:16 -0700
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-23 16:34 +0000
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-23 10:12 -0700
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-23 17:44 +0000
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 11:47 -0700
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-23 12:06 -0700
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-23 20:25 +0000
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-23 14:10 -0700
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-23 22:22 +0000
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 23:57 -0700
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 10:28 +0100
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-24 10:44 +0000
Re: local arrays and stack Martin Shobe <martin.shobe@yahoo.com> - 2015-03-24 06:38 -0500
Re: local arrays and stack Martin Shobe <martin.shobe@yahoo.com> - 2015-03-24 09:57 -0500
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 13:22 +0100
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-25 16:07 +0000
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-25 17:42 +0100
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-25 19:06 +0000
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-25 12:26 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-25 13:20 -0700
Re: local arrays and stack Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-25 12:28 -0700
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-25 21:45 +0100
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-25 12:50 -0700
Re: local arrays and stack Bartc <bc@freeuk.com> - 2015-03-25 22:33 +0000
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-25 23:57 +0100
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-25 21:42 +0100
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-25 09:55 -0700
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-25 12:36 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-25 13:04 -0700
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-25 21:52 +0100
Re: local arrays and stack Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-25 15:18 -0700
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-26 00:02 +0100
Re: local arrays and stack Melzzzzz <mel@zzzzz.com> - 2015-03-26 00:47 +0100
Re: local arrays and stack Mel <mel@zzzzz.com> - 2015-03-24 14:58 +0100
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-24 06:58 -0700
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-23 14:34 -0700
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 10:16 +0100
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 09:55 +0100
Re: local arrays and stack Noob <root@127.0.0.1> - 2015-03-24 10:23 +0100
Re: local arrays and stack Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 12:18 -0700
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-24 13:42 -0700
Re: local arrays and stack Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 08:47 -0700
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-23 09:32 -0700
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-23 09:57 -0700
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-23 10:37 -0700
Re: local arrays and stack Xcott Craver <xcottcraver@gmail.com> - 2015-03-23 10:49 -0700
Re: local arrays and stack Keith Thompson <kst-u@mib.org> - 2015-03-23 12:48 -0700
Re: local arrays and stack jt@toerring.de (Jens Thoms Toerring) - 2015-03-23 22:29 +0000
Re: local arrays and stack James Kuyper <jameskuyper@verizon.net> - 2015-03-23 19:03 -0400
Re: local arrays and stack jt@toerring.de (Jens Thoms Toerring) - 2015-03-23 23:36 +0000
Re: local arrays and stack fir <profesor.fir@gmail.com> - 2015-03-24 02:17 -0700
Re: local arrays and stack Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-23 11:56 -0700
Re: local arrays and stack Robert Wessel <robertwessel2@yahoo.com> - 2015-03-23 20:00 -0500
Re: local arrays and stack David Brown <david.brown@hesbynett.no> - 2015-03-24 10:39 +0100
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