Re: gcc knows about sincos even though NetBSD doesn't

It seems that sincos is now built in to GCC. Also, the suggested header 
location is hard-coded in GCC.

Sigh

On 30/07/22 08:25, Thomas Klausner wrote:
> On Fri, Jul 29, 2022 at 05:46:08PM +0200, Thomas Klausner wrote:
>> Hi!
>>
>> With -current as of about a week ago (gcc 10.3.0) I see a confusing
>> warning.
> 
> I've just updated and tried - it's the same with gcc 10.4.0.
>   Thomas
> 
>> The following test input:
>>
>> #include <limits.h>
>>
>> int main() {
>> return sincos();
>> }
>>
>> when compiled with "gcc -o test test.c" gives:
>>
>>
>> test.c: In function ‘main’:
>> test.c:4:8: warning: implicit declaration of function ‘sincos’ [-Wimplicit-function-declaration]
>>      4 | return sincos();
>>        |        ^~~~~~
>> test.c:4:8: warning: incompatible implicit declaration of built-in function ‘sincos’
>> test.c:2:1: note: include ‘<math.h>’ or provide a declaration of ‘sincos’
>>      1 | #include <limits.h>
>>    +++ |+#include <math.h>
>>      2 |
>> test.c:4:8: error: too few arguments to function ‘sincos’
>>      4 | return sincos();
>>        |        ^~~~~~
>>
>>
>> The first part is fine, but the warning to include math.h is
>> misguided, since NetBSD does not have sincos at all.
>>
>> (see also https://gitlab.gnome.org/GNOME/gtk/-/issues/5070 )
>>
>>   Thomas
>>