From: ludo@gnu.org (Ludovic Courtès)
To: Mark H Weaver <mhw@netris.org>
Cc: Chaos Eternal <chaoseternal@shlug.org>, 18592@debbugs.gnu.org
Subject: bug#18592: FFI should have portable access to ‘errno’
Date: Sat, 24 Jan 2015 11:33:42 +0100 [thread overview]
Message-ID: <87r3uko4c9.fsf@gnu.org> (raw)
In-Reply-To: <87twzgeh3c.fsf@yeeloong.lan> (Mark H. Weaver's message of "Sat, 24 Jan 2015 03:08:23 -0500")
Mark H Weaver <mhw@netris.org> skribis:
> ludo@gnu.org (Ludovic Courtès) writes:
>
>> Chaos Eternal <chaoseternal@shlug.org> skribis:
>>
>>> Proposals to solve this bug:
>>>
>>> Proposal 1.
>>>
>>> Adding a keyword argument to pointer->procedure, if set to true, the
>>> generated wrapper will check 'errno' immediately after ffi_call and
>>> return the errno as second value.
>>>
>>> the proposed pointer->procedure maybe like this:
>>> pointer->procedure return_type func_ptr arg_types #:return-errno
>>>
>>> Proposal 2.
>>>
>>> let pointer->procedure check return_type, if it is a list:
>>> (func_return_type, 'errno)
>>> then return multiple values, as errno be second value.
>>
>> That’s my favorite because it’s both pragmatic and extensible (we can
>> also add support for h_errno, etc.)
>
> We can't do this, because although it's not documented in our manual, a
> list passed as a foreign type already has a meaning: it means a struct.
> See 'parse_ffi_type' in foreign.c. I mentioned this fact on guile-user:
>
> https://lists.gnu.org/archive/html/guile-user/2012-05/msg00037.html
Indeed, I had forgotten that.
> Of the proposals given here, I would support #1, but maybe there's a
> better option.
I agree #1 is now the best option so far.
Ludo’.
next prev parent reply other threads:[~2015-01-24 10:33 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-30 20:17 bug#18592: FFI should have portable access to ‘errno’ Frank Terbeck
2014-11-11 15:03 ` Mark H Weaver
2014-11-11 20:02 ` Frank Terbeck
2014-11-13 17:12 ` Mark H Weaver
2014-11-22 17:53 ` Chaos Eternal
2015-01-19 20:22 ` Ludovic Courtès
2015-01-24 8:08 ` Mark H Weaver
2015-01-24 8:22 ` Mark H Weaver
2015-01-24 10:33 ` Ludovic Courtès [this message]
2015-12-31 12:33 ` Nala Ginrut
2016-01-04 12:04 ` Nala Ginrut
2016-01-04 16:12 ` Mark H Weaver
2016-01-04 19:14 ` Nala Ginrut
2016-01-05 2:24 ` Chaos Eternal
2016-01-05 7:49 ` tomas
2016-01-05 8:38 ` Nala Ginrut
2016-01-05 15:08 ` Mark H Weaver
2016-01-05 19:21 ` Nala Ginrut
2016-02-18 8:25 ` Nala Ginrut
2016-02-18 13:30 ` Mark H Weaver
2016-02-19 5:02 ` Nala Ginrut
2016-02-26 11:18 ` Nala Ginrut
2016-03-03 17:36 ` Mark H Weaver
2016-03-03 20:32 ` tomas
2016-03-13 17:06 ` Nala Ginrut
2016-06-20 19:55 ` Mark H Weaver
2016-01-05 15:40 ` Mark H Weaver
2016-01-04 16:21 ` Mark H Weaver
2015-01-25 20:59 ` guile
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