[cfe-commits] [PATCH] Support for universal character names in identifiers

[Richard Smith]

On Wed, Dec 19, 2012 at 4:24 PM, Richard Smith <richard at metafoo.co.uk> wrote:
> On Wed, Dec 19, 2012 at 1:18 PM, Eli Friedman <eli.friedman at gmail.com> wrote:
>> On Tue, Dec 18, 2012 at 11:01 PM, Chris Lattner <clattner at apple.com> wrote:
>>>
>>> On Dec 18, 2012, at 8:40 PM, Eli Friedman <eli.friedman at gmail.com> wrote:
>>>
>>>>>> Oh, I see... so the idea is to hack up getCharAndSize instead of
>>>>>> calling isUCNAfterSlash/ConsumeUCNAfterSlash where we expect a UCN,
>>>>>> use a marker which essentially means "saw a UCN".
>>>>>>
>>>>>> Seems like a workable approach; I don't think it actually helps any
>>>>>> with error recovery (I'm pretty sure we can't diagnose anything
>>>>>> without knowing what kind of token we're forming), but I think it will
>>>>>> make the patch simpler.  I'll try to hack up a new version of my
>>>>>> patch.
>>>>>
>>>>> Attached.
>>>>
>>>> And, I've discovered a rather large weakness of this approach:
>>>> actually writing a correct implementation of getCharAndSizeSlow which
>>>> returns a special value for UCNs is painful at best.  I might have to
>>>> abandon this route.
>>>
>>> How terrible would it be to make getChar* return a uint32_t codepoint?  Would that fix the problem?
>>
>> That doesn't even help; the issue is that checking for a UCN itself
>> requires calling getCharAndSize
>
> Why? Behavior is undefined if line splicing produces a UCN, and UCNs
> can't contain trigraphs.

Oh. That rule is only in C++. As you were, then...