Re: [PATCH v2 1/6] Add new macros for page-aligned data and bss sections.

[Sam Ravnborg <sam@ravnborg.org>]

On Fri, May 01, 2009 at 10:18:20AM -0700, H. Peter Anvin wrote:
> Sam Ravnborg wrote:
> > On Fri, May 01, 2009 at 09:33:13AM -0700, H. Peter Anvin wrote:
> >> Tim Abbott wrote:
> >>> On Fri, 1 May 2009, Sam Ravnborg wrote:
> >>>
> >>>> On Thu, Apr 30, 2009 at 03:54:08PM -0400, Tim Abbott wrote:
> >>>>> +#define __PAGE_ALIGNED_DATA	.section ".data.page_aligned", "aw", @progbits
> >>>>> +#define __PAGE_ALIGNED_BSS	.section ".bss.page_aligned", "aw", @nobits
> >>>> It is my understanding that the linker will automatically
> >>>> assume nobits for section names starting with .bss and likewise
> >>>> progbits for section names starting with .data - so we can leave them out?
> >>> I believe that is correct.
> >>>
> >> ... but that doesn't mean it's the right thing to do.
> >>
> >> It's better to be fully explicit when macroizing this kind of stuff.
> >> This is part of why macroizing it is good: it means we end up with *one*
> >> place that determines this stuff, not some magic heuristics in the linker.
> > 
> > Do you know if we can use % in place of @?
> > I could see that gas supports both - at least in trunk in cvs.
> > 
> 
> I think it might depend on the architecture(!)... but it would
> definitely have to be an issue with testing a bunch of different versions.
> 
> What's wrong with @?
arm does not support it :-(
I recall it denote a comment in arm assembler.

I could do some magic to detect the ARM case but I'm reluctant to do so.
I could also ignore the arm issue for now as it is not used by arm,
but that strikes me as the wrong approach.


	Sam