From: Alejandro Colomar <alx.manpages@gmail.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: Martin Uecker <uecker@tugraz.at>,
Ingo Schwarze <schwarze@usta.de>,
JeanHeyd Meneide <wg14@soasis.org>,
linux-man@vger.kernel.org, gcc@gcc.gnu.org
Subject: Re: [PATCH] Various pages: SYNOPSIS: Use VLA syntax in function parameters
Date: Sat, 12 Nov 2022 16:35:39 +0100 [thread overview]
Message-ID: <2193ac67-3b8c-b335-6e34-f7cc58062bb8@gmail.com> (raw)
In-Reply-To: <5ae032cd-7a5f-f72b-29ae-6ad7f418da8@codesourcery.com>
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Hi Joseph,
On 11/12/22 15:54, Joseph Myers wrote:
> On Sat, 12 Nov 2022, Alejandro Colomar via Gcc wrote:
>
>> Since it's to be used as an rvalue, not as a lvalue, I guess a
>> postfix-expression wouldn't be the right one.
>
> Several forms of postfix-expression are only rvalues.
>
>>> (with a special rule about how the identifier is interpreted, different
>>> from the normal scope rules)? If so, then ".a = 1" could either match
>>> assignment-expression directly (assigning to the postfix-expression ".a").
>>
>> No, assigning to a function parameter from within another parameter
>> declaration wouldn't make sense. They should be readonly. Side effects
>> should be forbidden, I think.
>
> Such assignments are already allowed. In a function definition, the side
> effects (including in size expressions for array parameters adjusted to
> pointers) take place before entry to the function body.
Then, I'm guessing that rules need to change in a way that .initializer cannot
appear as the left operand of an assignment-expression.
That is, for the following current definition of the assignment-expression (as
of N3054):
assignment-expression:
conditional-expression
unary-expression assignment-operator assignment-expression
The unary-expression cannot be formed by a .initializer.
Would that be doable and sufficient?
Cheers,
Alex
>
> And, in any case, if you did have a constraint disallowing such
> assignments, it wouldn't suffice for syntactic disambiguation (see the
> previous point I made about that; I have some rough notes towards a WG14
> paper on syntactic disambiguation, but haven't converted them into a
> coherent paper).
>
--
<http://www.alejandro-colomar.es/>
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next prev parent reply other threads:[~2022-11-12 15:35 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220826210710.35237-1-alx.manpages@gmail.com>
[not found] ` <Ywn7jMtB5ppSW0PB@asta-kit.de>
[not found] ` <89d79095-d1cd-ab2b-00e4-caa31126751e@gmail.com>
[not found] ` <YwoXTGD8ljB8Gg6s@asta-kit.de>
[not found] ` <e29de088-ae10-bbc8-0bfd-90bbb63aaf06@gmail.com>
[not found] ` <5ba53bad-019e-8a94-d61e-85b2f13223a9@gmail.com>
[not found] ` <CACqA6+mfaj6Viw+LVOG=nE350gQhCwVKXRzycVru5Oi4EJzgTg@mail.gmail.com>
[not found] ` <491a930d-47eb-7c86-c0c4-25eef4ac0be0@gmail.com>
2022-09-02 21:57 ` Alejandro Colomar
2022-09-03 12:47 ` Martin Uecker
2022-09-03 13:29 ` Ingo Schwarze
2022-09-03 15:08 ` Alejandro Colomar
2022-09-03 13:41 ` Alejandro Colomar
2022-09-03 14:35 ` Martin Uecker
2022-09-03 14:59 ` Alejandro Colomar
2022-09-03 15:31 ` Martin Uecker
2022-09-03 20:02 ` Alejandro Colomar
2022-09-05 14:31 ` Alejandro Colomar
2022-11-10 0:06 ` Alejandro Colomar
2022-11-10 0:09 ` Alejandro Colomar
2022-11-10 1:33 ` Joseph Myers
2022-11-10 1:39 ` Joseph Myers
2022-11-10 6:21 ` Martin Uecker
2022-11-10 10:09 ` Alejandro Colomar
2022-11-10 23:19 ` Joseph Myers
2022-11-10 23:28 ` Alejandro Colomar
2022-11-11 19:52 ` Martin Uecker
2022-11-12 1:09 ` Joseph Myers
2022-11-12 7:24 ` Martin Uecker
2022-11-12 12:34 ` Alejandro Colomar
2022-11-12 12:46 ` Alejandro Colomar
2022-11-12 13:03 ` Joseph Myers
2022-11-12 13:40 ` Alejandro Colomar
2022-11-12 13:58 ` Alejandro Colomar
2022-11-12 14:54 ` Joseph Myers
2022-11-12 15:35 ` Alejandro Colomar [this message]
2022-11-12 17:02 ` Joseph Myers
2022-11-12 17:08 ` Alejandro Colomar
2022-11-12 15:56 ` Martin Uecker
2022-11-13 13:19 ` Alejandro Colomar
2022-11-13 13:33 ` Alejandro Colomar
2022-11-13 14:02 ` Alejandro Colomar
2022-11-13 14:58 ` Martin Uecker
2022-11-13 15:15 ` Alejandro Colomar
2022-11-13 15:32 ` Martin Uecker
2022-11-13 16:25 ` Alejandro Colomar
2022-11-13 16:28 ` Alejandro Colomar
2022-11-13 16:31 ` Alejandro Colomar
2022-11-13 16:34 ` Alejandro Colomar
2022-11-13 16:56 ` Alejandro Colomar
2022-11-13 19:05 ` Alejandro Colomar
2022-11-14 18:13 ` Joseph Myers
2022-11-28 22:59 ` Alex Colomar
2022-11-28 23:18 ` Alex Colomar
2022-11-29 0:05 ` Joseph Myers
2022-11-29 14:58 ` Michael Matz
2022-11-29 15:17 ` Uecker, Martin
2022-11-29 15:44 ` Michael Matz
2022-11-29 16:58 ` Uecker, Martin
2022-11-29 17:28 ` Alex Colomar
2022-11-29 16:49 ` Joseph Myers
2022-11-29 16:53 ` Jonathan Wakely
2022-11-29 17:00 ` Martin Uecker
2022-11-29 17:19 ` Alex Colomar
2022-11-29 17:29 ` Alex Colomar
2022-12-03 21:03 ` Alejandro Colomar
2022-12-03 21:13 ` Andrew Pinski
2022-12-03 21:15 ` Martin Uecker
2022-12-03 21:18 ` Alejandro Colomar
2022-12-06 2:08 ` Joseph Myers
2022-11-14 17:52 ` Joseph Myers
2022-11-14 17:57 ` Alejandro Colomar
2022-11-14 18:26 ` Joseph Myers
2022-11-28 23:02 ` Alex Colomar
2022-11-10 9:40 ` G. Branden Robinson
2022-11-10 10:59 ` Alejandro Colomar
2022-11-10 22:25 ` G. Branden Robinson
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