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Date: Thu, 13 Jun 2013 11:18:30 +0800
From: Fengguang Wu <fengguang.wu@intel.com>
To: Zach Brown <zab@redhat.com>
Cc: Josef Bacik <jbacik@fusionio.com>, kbuild-all@01.org,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [josef-btrfs:master 61/69] fs/btrfs/delayed-inode.c:393:1:
 warning: control reaches end of non-void function
Message-ID: <20130613031830.GC11199@localhost>
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 <20130612193211.GB8389@lenny.home.zabbo.net>
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On Wed, Jun 12, 2013 at 12:32:11PM -0700, Zach Brown wrote:
> >    fs/btrfs/delayed-inode.c: In function 'get_ins_del_root':
> > >> fs/btrfs/delayed-inode.c:393:1: warning: control reaches end of non-void function [-Wreturn-type]
> > 
> > vim +393 fs/btrfs/delayed-inode.c
> > 
> >    385	static struct rb_root *get_ins_del_root(struct btrfs_delayed_node *delayed_node,
> >    386						int ins_del)
> >    387	{
> >    388		if (ins_del == BTRFS_DELAYED_INSERTION_ITEM)
> >    389			return &delayed_node->ins_root;
> >    390		if (ins_del == BTRFS_DELAYED_DELETION_ITEM)
> >    391			return &delayed_node->del_root;
> >    392		BUG();
> >  > 393	}
> 
> Hrmph.
> 
> Is this false positive worth working around?  What version of gcc is
> this from?

gcc (Debian 4.7.1-6) 4.7.1

> I'd expect the unreachable() in BUG() to silence this
> warning on modern gcc.

Yeah it's strange why gcc still complain about that. Anyway I'll
detect and ignore this kind of false positive in my report scripts.

Thanks,
Fengguang