This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: Calling va_start multiple times vs __va_copy




On Wed, 8 Aug 2001, robertlipe@usa.net (Robert Lipe) wrote:
> Date: Wed, 8 Aug 2001 08:35:56 -0500
> To: Sebastian Ude <ude@handshake.de>
> From: robertlipe@usa.net (Robert Lipe)
> CC: gcc@gcc.gnu.org
> Subject: Re: Calling va_start multiple times vs __va_copy
> 
> Sebastian Ude wrote:
> 
> > Is it legitime to parse the optional arguments in a variadic function
> > multiple times _without_ copying the va_list through (__)va_copy ?
> 
> The standard doesn't appear to forbid it.  In the non-normative text
> if Plauger's "The Standard C Library" it says "Once ou execute va_end
> you must not again execute va_arg unless you first execute va_start to
> initiate a rescan."    This appears to give extra credence to the 
> restartability.
> 
> > Can a va_list be started multiple times through va_start ?
> 
> As long as there are matching va_ends, yes.
> 
> > But, __va_copy does not belong to the ISO standard, right ? 
> 
> '__va_copy' does not, but 'va_copy' does appear in C99.

Okay, thanks for the information.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]