From: "George Spelvin" <linux@sciencehorizons.net>
To: geert@linux-m68k.org, linux@sciencehorizons.net,
torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] test/hash: Fix warning in preprocessor symbol evaluation
Date: 29 May 2016 15:07:12 -0400 [thread overview]
Message-ID: <20160529190712.14364.qmail@ns.sciencehorizons.net> (raw)
In-Reply-To: <20160529185355.12968.qmail@ns.sciencehorizons.net>
> But here's an alternative. Geert, what do you think of this?
Never mind; that doesn't work. Plain gcc-4.9 passes, it, but it's the
"-Wundef" flag that the kernel uses that triggers it.
So we're back to Geert's original suggestion.
Acked-by: George Spelvin <linux@sciencehorizons.net>
==>$ cat foo.c
#ifndef FOO
This is a test.
#elif FOO == 1
This is another test
#elif FOO + 0 == 1
who knows
#endif
==>$ gcc-6 -W -Wall -Wundef -E foo.c
# 1 "foo.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 31 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 32 "<command-line>" 2
# 1 "foo.c"
This is a test.
==>$ gcc-4.9 -W -Wall -Wundef -E foo.c
# 1 "foo.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 1 "<command-line>" 2
# 1 "foo.c"
foo.c:3:7: warning: "FOO" is not defined [-Wundef]
#elif FOO == 1
^
foo.c:5:7: warning: "FOO" is not defined [-Wundef]
#elif FOO + 0 == 1
^
This is a test.
next prev parent reply other threads:[~2016-05-29 19:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-29 17:28 [PATCH 1/2] test/hash: Fix warning in two-dimensional array init Geert Uytterhoeven
2016-05-29 17:28 ` [PATCH 2/2] test/hash: Fix warning in preprocessor symbol evaluation Geert Uytterhoeven
2016-05-29 18:53 ` George Spelvin
2016-05-29 19:07 ` George Spelvin [this message]
2016-05-29 18:43 ` [PATCH 1/2] test/hash: Fix warning in two-dimensional array init George Spelvin
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