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

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

I've filed an upstream bug about this:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106529

 Thomas


On Sun, Aug 14, 2022 at 09:31:13AM +1200, Lloyd Parkes wrote:
> 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
> > >