Re: [next:akpm 129/309] net/core/sock.c:274:36: error: initializer element is not constant

From: Fengguang Wu <fengguang.wu@intel.com>
To: linux-alpha@vger.kernel.org
Cc: Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Matt Turner <mattst88@gmail.com>, Tony Luck <tony.luck@gmail.com>,
	James Bottomley <James.Bottomley@hansenpartnership.com>,
	John David Anglin <dave.anglin@bell.net>,
	Mel Gorman <mgorman@suse.de>,
	kernel-janitors@vger.kernel.org,
	Kyle McMartin <kyle@parisc-linux.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Parisc List <linux-parisc@vger.kernel.org>
Subject: Re: [next:akpm 129/309] net/core/sock.c:274:36: error: initializer element is not constant
Date: Thu, 2 Aug 2012 23:02:09 +0800	[thread overview]
Message-ID: <20120802150209.GA26601@localhost> (raw)
In-Reply-To: <CA+8MBbJkGN+zGBdD5Hg26wW_6E9L_ufoutn7wj+Y+nhtW7WKWg@mail.gmail.com>

On Thu, Jul 26, 2012 at 10:06:41AM -0700, Tony Luck wrote:
> On Tue, Jul 24, 2012 at 10:10 PM, James Bottomley
> <James.Bottomley@hansenpartnership.com> wrote:
> >> Here is the line in sock.i:
> >>
> >> struct static_key memalloc_socks = ((struct static_key) { .enabled =
> >> ((atomic_t) { (0) }) });
> >
> > The above line contains two compound literals.  It also uses a designated
> > initializer to initialize the field enabled.  A compound literal is not a
> > constant expression.
> 
> Seeing the same thing on ia64 building next-20120726.  Same fix works
> for me ... so I'll steal this whole changelog and attributes.

I got the same error for alpha, the same fix applies.
---
From: Mel Gorman <mgorman@suse.de>
Subject: [PATCH] [ALPHA] Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the casts

The following build error occurred during an alpha build:

net/core/sock.c:274:36: error: initializer element is not constant

Dave Anglin says:
> Here is the line in sock.i:
>
> struct static_key memalloc_socks = ((struct static_key) { .enabled =
> ((atomic_t) { (0) }) });

The above line contains two compound literals.  It also uses a designated
initializer to initialize the field enabled.  A compound literal is not a
constant expression.

The location of the above statement isn't fully clear, but if a compound
literal occurs outside the body of a function, the initializer list must
consist of constant expressions.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
---
 arch/alpha/include/asm/atomic.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- linux.orig/arch/alpha/include/asm/atomic.h	2012-05-24 19:03:06.000000000 +0800
+++ linux/arch/alpha/include/asm/atomic.h	2012-08-02 23:01:02.243224220 +0800
@@ -14,8 +14,8 @@
  */
 
 
-#define ATOMIC_INIT(i)		( (atomic_t) { (i) } )
-#define ATOMIC64_INIT(i)	( (atomic64_t) { (i) } )
+#define ATOMIC_INIT(i)		( { (i) } )
+#define ATOMIC64_INIT(i)	( { (i) } )
 
 #define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic64_read(v)	(*(volatile long *)&(v)->counter)
