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From: "joseph at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/50581] stdarg doesn't support array types
Date: Sat, 01 Oct 2011 18:46:00 -0000 [thread overview]
Message-ID: <bug-50581-4-jdLeabBsnA@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-50581-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50581
--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-10-01 18:45:43 UTC ---
On Sat, 1 Oct 2011, Wolfgang at Solfrank dot net wrote:
> > Passing va_list as a function argument is generally hard, whether or not
> > variadic, since you don't know whether it will be passed by reference or
> > by value or what the type of the address of a va_list parameter will be.
> > Portable code needs to pass a pointer to va_list or a structure containing
> > va_list or use some other such means of avoiding dependence on whether
> > va_list is an array.
>
> Huh? What about vprintf and friends? They are defined to take a va_list as
> their last parameter.
There are some things you can do - for example, calling those functions in
accordance with the rules given in the C standard. There are various
things that cause problems - for example, taking the address of a
parameter declared as a va_list (because the parameter type may have been
changed from va_list to pointer-to-element-of-va_list as part of the
parameter type adjustment of parameters declared as arrays, so the type of
¶meter may not be va_list *).
next prev parent reply other threads:[~2011-10-01 18:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-30 15:49 [Bug c/50581] New: " Wolfgang at Solfrank dot net
2011-09-30 20:13 ` [Bug c/50581] " joseph at codesourcery dot com
2011-10-01 11:07 ` Wolfgang at Solfrank dot net
2011-10-01 14:08 ` joseph at codesourcery dot com
2011-10-01 14:43 ` Wolfgang at Solfrank dot net
2011-10-01 18:46 ` joseph at codesourcery dot com [this message]
2011-10-02 16:09 ` Wolfgang at Solfrank dot net
2011-10-02 19:48 ` svfuerst at gmail dot com
2022-01-03 2:38 ` pinskia at gcc dot gnu.org
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