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Re: [Patch] Support DEC-C extensions
- From: Basile Starynkevitch <basile at starynkevitch dot net>
- To: Tristan Gingold <gingold at adacore dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 29 Sep 2011 17:54:02 +0200
- Subject: Re: [Patch] Support DEC-C extensions
- References: <51227D85-9E15-48AB-9381-14B597C1F80B@adacore.com>
On Thu, 29 Sep 2011 17:10:26 +0200
Tristan Gingold <gingold@adacore.com> wrote:
> Hi,
>
> DEC-C, the DEC compiler provided on VMS, has added to ANSI-C at least one extension that is difficult to work-around as it is used in the system headers: varargs without named argument. It makes sense on VMS because of its ABI which pass the number of arguments used.
>
I believe that such an extension is useful on other systems, even when their ABI don't
pass the number of arguments.
The use case I would have in mind is when the signature of the called function (that is
the number & types of arguments) is determined by something else, perhaps a global
variable or data. Think e.g. of a printf-like function, except that the format string is
conventionally assigned to some fixed global before calling it.
Perhaps also the comments and explanation might reflect such kind of usage?
And perhaps then such an extension might be trigerred by a flag which don't even mention
DEC. Eg -fveryvariadic-extensions ?
Regards.
--
Basile STARYNKEVITCH http://starynkevitch.net/Basile/
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