[cfe-dev] Wide strings and clang::StringLiteral.

[Jean-Daniel Dupas]

Le 2 déc. 08 à 15:48, Neil Booth a écrit :

> Jean-Daniel Dupas wrote:-
>
>> I didn't know that C99 supports UCN in identifier.
>> I don't see a lot of informations about it in the C99 spec (except  
>> that
>> UCN may appear in an identifier). Does this mean that this code is  
>> valid
>> ?
>>
>> ---------- test.c -------
>>
>> int main (int argc, char **argv) {
>> 	int h\u00e9 = 0; // hé
>> 	return he\u0301; // hé - using decomposed form
>> }
>> --------------------------
>>
>> Actually, GCC does not support combining character (like COMBINING  
>> ACUTE
>> ACCENT: 0x0301) :
>>
>> test.c:4:9: error: universal character \u0301 is not valid in an
>> identifier
>> test.c: In function ‘main’:
>> test.c:4: error: ‘hé’ undeclared (first use in this function)
>> test.c:4: error: (Each undeclared identifier is reported only once
>> test.c:4: error: for each function it appears in.)
>>
>> Note that the error is correctly displayed anyway.
>
> My front end gives
>
> $ ~/src/c/cfe /tmp/test.c
> "/tmp/test.c", line 3: error: universal character name "\u0301" cannot
>       be used in an identifier
>        return he\u0301; // hé - using decomposed form
>               --^^^^^^
>
> 1 error found compiling "/tmp/bug.c".
>
> So you've chosen an invalid UCN.  The standard lists the acceptable
> UCNs; apparently this isn't one.

The standard define some constaints on UCN, but I don't see why 0x0301  
does not works.

 From WG14/N1124 CommitteeDraft — May 6, 2005: page 53:

“A universal character name shall not specify a character whose short  
identifier is less than 00A0 other than 0024 ($), 0040 (@), or 0060  
(‘),
nor one in the range D800 through DFFF inclusive.)”