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/ |
