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Groups > comp.lang.c > #139421
| Subject | Re: calling argumentless function with argument |
|---|---|
| Newsgroups | comp.lang.c |
| References | <g99egeFi15cU1@mid.uni-berlin.de> <q0o1u7$769$1@dont-email.me> |
| From | Bart <bc@freeuk.com> |
| Message-ID | <gLMXD.21659$Fi6.17101@fx12.am4> (permalink) |
| Organization | virginmedia.com |
| Date | 2019-01-04 17:30 +0000 |
On 04/01/2019 16:34, David Brown wrote:
> On 04/01/2019 17:04, Jens Thoms Toerring wrote:
>> Hi,
>>
>> is there anything to worry about if one calls a function
>> that takes no arguments with an argument like this?
>>
>> void foo(void); // defined somewhere else
>>
>> int main(void)
>> {
>> void (*p)() = foo;
>> p(4);
>> }
>
> It is undefined behaviour. It is likely to "work" in most cases (the
> argument would be put onto the stack or into a register, and then
> ignored by the called function).
>
> However, if the compiler is using a "callee cleanup" calling convention
> rather than "caller cleanup", you'll be in trouble. "Caller cleanup" is
> the traditional for C, especially on *nix systems. But "callee cleanup"
> is used with a variety of calling conventions on Windows (like MS
> fastcall, stdcall, etc.). If your call requires putting anything on the
> stack instead of just registers, you'll get in trouble.
If it's C calling C, then I think caller clean-up is always used (from
what I've seen on Windows anyway), otherwise it would be harder to
implement variadic functions such as printf.
Calling foreign functions from C might be more of a problem.
(My language/compiler always used callee clean-up within its functions.
Such a think would not work.)
>> Admittedly a bit of a hack, but could be useful in some
>> circumstances...
>
> In what circumstances would it be useful?
You have a function pointer intended to call a range of functions some
of which have a parameter, and some don't. But you want to use the same,
consistent function pointer type and the same call code. Then you want
those functions without a parameter to ignore it.
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calling argumentless function with argument jt@toerring.de (Jens Thoms Toerring) - 2019-01-04 16:04 +0000
Re: calling argumentless function with argument David Brown <david.brown@hesbynett.no> - 2019-01-04 17:34 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-04 17:30 +0000
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-04 09:50 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-05 05:58 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-05 07:56 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-05 10:56 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-05 14:55 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 01:29 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 02:20 +0000
Re: calling argumentless function with argument Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-01-06 02:51 +0000
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 12:12 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 11:53 +0000
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 12:58 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 11:45 +0000
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 12:58 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 12:24 +0000
Re: calling argumentless function with argument Keith Thompson <kst-u@mib.org> - 2019-01-06 04:34 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 13:41 +0100
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 04:10 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 13:51 +0100
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 13:56 +0100
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 05:20 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 16:08 +0100
Re: calling argumentless function with argument Keith Thompson <kst-u@mib.org> - 2019-01-06 15:59 -0800
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 13:42 +0000
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 06:22 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 16:19 +0100
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 07:42 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 08:05 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 08:30 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 17:44 +0100
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 08:54 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-07 08:02 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-07 08:07 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-07 09:16 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-07 09:40 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-07 09:57 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-09 02:23 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 16:17 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 16:56 +0000
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 09:12 -0800
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 12:39 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 18:26 +0100
Re: calling argumentless function with argument Bart <bc@freeuk.com> - 2019-01-06 18:52 +0000
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-06 02:32 -0800
Re: calling argumentless function with argument Keith Thompson <kst-u@mib.org> - 2019-01-06 04:38 -0800
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 13:42 +0100
Re: calling argumentless function with argument Robert Wessel <robertwessel2@yahoo.com> - 2019-01-06 10:27 -0600
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-06 17:47 +0100
Re: calling argumentless function with argument David Brown <david.brown@hesbynett.no> - 2019-01-04 19:30 +0100
Re: calling argumentless function with argument Keith Thompson <kst-u@mib.org> - 2019-01-04 10:55 -0800
Re: calling argumentless function with argument Robert Wessel <robertwessel2@yahoo.com> - 2019-01-05 00:16 -0600
Re: calling argumentless function with argument queequeg@trust.no1 (Queequeg) - 2019-01-07 10:43 +0000
Re: calling argumentless function with argument Robert Wessel <robertwessel2@yahoo.com> - 2019-01-07 16:25 -0600
Re: calling argumentless function with argument Barry Schwarz <schwarzb@dqel.com> - 2019-01-04 09:54 -0800
Re: calling argumentless function with argument Thiago Adams <thiago.adams@gmail.com> - 2019-01-04 10:26 -0800
Re: calling argumentless function with argument Keith Thompson <kst-u@mib.org> - 2019-01-04 12:07 -0800
Re: calling argumentless function with argument James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-01-04 15:03 -0500
Re: calling argumentless function with argument Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-01-05 00:04 +0000
Re: calling argumentless function with argument James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-01-05 22:36 -0500
Re: calling argumentless function with argument jt@toerring.de (Jens Thoms Toerring) - 2019-01-05 13:17 +0000
Re: calling argumentless function with argument fir <profesor.fir@gmail.com> - 2019-01-05 06:06 -0800
Re: calling argumentless function with argument David Brown <david.brown@hesbynett.no> - 2019-01-05 15:42 +0100
Re: calling argumentless function with argument Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-01-05 14:58 +0000
Re: calling argumentless function with argument "Pascal J. Bourguignon" <pjb@informatimago.com> - 2019-01-05 16:11 +0100
Re: calling argumentless function with argument Richard Damon <Richard@Damon-Family.org> - 2019-01-05 11:23 -0500
Re: calling argumentless function with argument Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-01-05 16:53 +0000
Re: calling argumentless function with argument Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-01-06 00:46 +0000
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