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Date:   Sun, 17 Sep 2023 17:08:20 +0200
From:   Willy Tarreau <w@1wt.eu>
To:     Thomas =?iso-8859-1?Q?Wei=DFschuh?= <linux@weissschuh.net>
Cc:     Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Shuah Khan <shuah@kernel.org>, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH 2/4] tools/nolibc: avoid unused parameter warnings for
 ENOSYS fallbacks
Message-ID: <20230917150820.GA14418@1wt.eu>
References: <20230914-nolibc-syscall-nr-v1-0-e50df410da11@weissschuh.net>
 <20230914-nolibc-syscall-nr-v1-2-e50df410da11@weissschuh.net>
 <20230917025851.GE9646@1wt.eu>
 <2bd688b7-5f1b-44ca-a41b-6e90dc3e8557@t-8ch.de>
 <20230917094827.GA11081@1wt.eu>
 <1ef57a1e-89d3-4eb6-be12-3045a31f99e4@t-8ch.de>
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On Sun, Sep 17, 2023 at 05:07:18PM +0200, Thomas Wei?schuh wrote:
> On 2023-09-17 11:48:27+0200, Willy Tarreau wrote:
> > [..]
> > > Maybe the macro-equivalent of this?
> > > 
> > > static inline int __nolibc_enosys(...)
> > > {
> > > 	return -ENOSYS;
> > > }
> > > 
> > > The only-vararg function unfortunately needs C23 so we can't use it.
> > >
> > > It's clear to the users that this is about ENOSYS and we don't need a
> > > bunch of new macros similar.
> > 
> > I like it, I didn't think about varargs, it's an excellent idea! Let's
> > just do simpler, start with a first arg "syscall_num" that we may later
> > reuse for debugging, and just mark this one unused:
> > 
> >   static inline int __nolibc_enosys(int syscall_num, ...)
> >   {
> > 	(void)syscall_num;
> >   	return -ENOSYS;
> >   }
> 
> But which syscall_num to use, as the point of __nolibc_enosys() would be
> that no syscall number is available and the defines are missing.

good point :-)

> For debugging we could add a string argument, though.

That works for me.

Willy