[cfe-commits] tgmath.h

[Douglas Gregor]

On Feb 18, 2009, at 9:30 AM, Howard Hinnant wrote:

> On Feb 18, 2009, at 12:26 PM, Douglas Gregor wrote:
>
>> Committed, with a little twist:
>>
>> typedef void _Argument_type_is_not_arithmetic;
>> static _Argument_type_is_not_arithmetic __tg_promote(...) \
>>   __attribute__((__unavailable__,__overloadable__));
>
> Nice.  The '\' confused me at first, but seems harmless enough.

I guess we could give the attribute a named macro, e.g.,

static _Argument_type_is_not_arithmetic __tg_promote(...)  
__ATTRACT_BAD_TGMATH_ARG

?

>> We're recovering badly from failures when calling __tg_promote. I'm  
>> working on some parser/sema tweaks to improve the situation, and  
>> will send an updated error message when it's done.

Here's what we get now when we try to take the sine of a pointer to  
short:

tgmath_test.c:4:3: error: call to function '__tg_promote' that has  
been intentionally made unavailable
   sin(sp);
   ^~~~~~~
./tgmath.h:293:27: note: instantiated from:
#define sin(__x) __tg_sin(__tg_promote1((__x))(__x))
                           ^
./tgmath.h:56:50: note: instantiated from:
#define __tg_promote1(__x)           (__typeof__(__tg_promote(__x)))
                                                  ^
In file included from tgmath_test.c:1:
./tgmath.h:41:41: note: unavailable function is declared here
static _Argument_type_is_not_arithmetic __tg_promote(...) \
                                         ^
2 diagnostics generated.

	- Doug