This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug preprocessor/9449] UCNs not recognized in identifiers (c++/c99)
- From: "joseph at codesourcery dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 15 Sep 2005 22:53:45 -0000
- Subject: [Bug preprocessor/9449] UCNs not recognized in identifiers (c++/c99)
- References: <20030127145600.9449.rearnsha@arm.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From joseph at codesourcery dot com 2005-09-15 22:53 -------
Subject: Re: UCNs not recognized in identifiers
(c++/c99)
On Thu, 15 Sep 2005, geoffk at gcc dot gnu dot org wrote:
> ------- Additional Comments From geoffk at gcc dot gnu dot org 2005-09-15 22:34 -------
> (In reply to comment #39)
> > Another reason why spelling needs preserving (in addition to implementing #
> > correctly) is for the constraints on duplicate macro definitions.
> >
> > #define foo \u00c1
> > #define foo \u00C1
> >
> > is invalid (different spelling in replacement), as is
>
> We discussed this on the list and decided that this was probably a defect in the C standard, since the
> Rationale says that the kind of implementation we have now is supposed to be permitted, and jsm said
> he'd file a DR. How's that going?
I don't believe I said I'd file a DR unless I saw a defect. There is no
defect because models A or C need to be implemented by an
implementation-defined mapping (documented as such; we don't even document
the removal of trailing whitespace from lines; of course anything
replacing UCNs with the characters they designate only in certain places
is a pain to document because it doesn't fit in with the C model of phases
of translation). Doug Gwyn's reading in reflector message 10751,
Yes, "spelling" is meant in terms of the source code characters.
The idea is to permit simple strcmp-like checking by the preprocessor.
seems fine to me - implementations permitting the above in the input
source must end up with the source looking different from the above after
phase 1.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9449