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

[Thomas Klausner <wiz%NetBSD.org@localhost>]

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
>