Re: [PATCH 5/5] arch/um: remove duplicate structure fieldinitialization

From: AmÃrico Wang
Date: Mon Sep 21 2009 - 12:01:55 EST


On Sat, Sep 19, 2009 at 09:49:47PM +0200, Julia Lawall wrote:
>From: Julia Lawall <julia@xxxxxxx>
>
>The definition of uml_netdev_ops has initializations of a local function
>and eth_mac_addr for its ndo_set_mac_address field. This change uses only
>the local function.
>
>The semantic match that finds this problem is as follows:
>(http://coccinelle.lip6.fr/)
>
>// <smpl>
>@r@
>identifier I, s, fld;
>position p0,p;
>expression E;
>@@
>
>struct I s =@p0 { ... .fld@p = E, ...};
>
>@s@
>identifier I, s, r.fld;
>position r.p0,p;
>expression E;
>@@
>
>struct I s =@p0 { ... .fld@p = E, ...};
>
>@script:python@
>p0 << r.p0;
>fld << r.fld;
>ps << s.p;
>pr << r.p;
>@@
>
>if int(ps[0].line)!=int(pr[0].line) or int(ps[0].column)!=int(pr[0].column):
> cocci.print_main(fld,p0)
>// </smpl>


Hmm, C99 said:
"
The initialization shall occur in initializer list order, each
initializer provided for a particular subobject overriding any
previously listed initializer for the same subobject [...]
"

I am wondering why gcc doesn't (can't?) complain about this?

>
>Signed-off-by: Julia Lawall <julia@xxxxxxx>
>

Acked-by: WANG Cong <xiyou.wangcong@xxxxxxxxx>

>---
> arch/um/drivers/net_kern.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
>diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
>index a74245a..d17a623 100644
>--- a/arch/um/drivers/net_kern.c
>+++ b/arch/um/drivers/net_kern.c
>@@ -379,7 +379,6 @@ static const struct net_device_ops uml_netdev_ops = {
> .ndo_tx_timeout = uml_net_tx_timeout,
> .ndo_set_mac_address = uml_net_set_mac,
> .ndo_change_mtu = uml_net_change_mtu,
>- .ndo_set_mac_address = eth_mac_addr,
> .ndo_validate_addr = eth_validate_addr,
> };
>
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