Re: [PATCH] ARM gas: handle {...} operands in macros

["Jan Beulich" <JBeulich at suse dot com>]

>>> On 03.06.13 at 18:01, Richard Earnshaw <rearnsha@arm.com> wrote:
> On 03/06/13 16:58, Jan Beulich wrote:
>>>>> On 03.06.13 at 17:49, Richard Earnshaw <rearnsha@arm.com> wrote:
>>> On 28/05/13 20:18, Roland McGrath wrote:
>>>> Here's another case where the presumptions about whitespace stripping don't
>>>> mesh with macros quite right.  There may be more cases affected; I didn't
>>>> try to add test cases for all of them.
>>>>
>>>> OK for trunk and 2.23?
>>>
>>> This seems all wrong to me.  If you're having to pretend that all these
>>> special characters are symbol characters, then something else must be
>>> fundamentally wrong.  That makes this patch a crutch for something else
>>> that's broken.
>>>
>>> I think you need to dig further into why macros aren't working properly.
>>>    Is it the implementation of macros, the documentation, or your
>>> expectations that are wrong?
>>
>> Others (including me) have done this before - it's an effect of
>> how the scrubber works, eating whitespace that it thinks isn't
>> necessary. It's been years back that I looked into that, but iirc
>> in the end I was told to better leave the scrubber untouched to
>> not risk breakage elsewhere. So one or the other workaround
>> needs to be found anyway...
>>
> This is more than just the white-space scrubbing.  It's changing the 
> definition of what characters are legal in symbols.  I'm concerned that 
> that may have other potential implications for parsing as well.

Oh, yes, I understand that this has the potential for breakage
elsewhere. But that was true for the earlier addition of [ and ] too.
Perhaps there are other solutions, but likely much more intrusive
to the code.

Jan