lkml.org 
[lkml]   [2016]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ARM: ks8695: fix __initdata annotation
Hello Arnd,

On Tue, Feb 09, 2016 at 12:14:15PM +0100, Arnd Bergmann wrote:
> On Tuesday 09 February 2016 10:00:30 Uwe Kleine-König wrote:
> > > diff --git a/arch/arm/mach-ks8695/board-og.c b/arch/arm/mach-ks8695/board-og.c
> > > index 1f4f2f4f25bb..fa1a7c2ca2bb 100644
> > > --- a/arch/arm/mach-ks8695/board-og.c
> > > +++ b/arch/arm/mach-ks8695/board-og.c
> > > @@ -80,7 +80,7 @@ static void __init og_pci_bus_reset(void)
> > > #define S8250_VIRT 0xf4000000
> > > #define S8250_SIZE 0x00100000
> > >
> > > -static struct __initdata map_desc og_io_desc[] = {
> > > +static struct map_desc __initdata og_io_desc[] = {
> >
> > I would have expected that
> >
> > +static struct map_desc og_io_desc[] __initdata = {
> >
> > is the correct variant?
> >
>
> I think those two mean the exact same thing, and we have tons of examples
> for either one in the kernel, unlike the one I removed. I have
> verified that the resulting object files are identical.
>
> Can you point me to some documentation that clarifies which one to use,
> and why?

Having the attribute list after the declarator isn't recommended as
explicit as I remember having read it somewhere in the gcc docs.

info gcc "Attribute Syntax"

has:

An attribute specifier list may appear immediately before a declarator
(other than the first) in a comma-separated list of declarators in a
declaration of more than one identifier using a single list of
specifiers and qualifiers. Such attribute specifiers apply only to the
identifier before whose declarator they appear. For example, in

__attribute__((noreturn)) void d0 (void),
__attribute__((format(printf, 1, 2))) d1 (const char *, ...),
d2 (void)

the 'noreturn' attribute applies to all the functions declared; the
'format' attribute only applies to 'd1'.

(Funny enough, in the example the attribute specifier list doesn't
appear *immediately* before the declarator d0.)

This might be interpreted as "usually the attribute specifier list appears
after the declarator". Other than that I cannot find an explict
recommended placement in the docs. The examples in

info gcc "Variable Attributes"

always have the attribute list after the declarator.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |

\
 
 \ /
  Last update: 2016-02-09 13:01    [W:0.027 / U:16.732 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site