wine FTBFS with mingw64 gcc 11: undefined reference to `sincos'

[Dean Greer]

Hi Jacek

I’ve tested compiling wine-6.8 with mingw-gcc-11.1.0 (stock) with the
provided patch applied and the compile finished without issue.

Thanks,

Dean aka Gcenx

On Fri, May 14, 2021 at 1:28 PM Jacek Caban <jacek at codeweavers.com> wrote:

> Hi Alex,
>
> On 5/14/21 3:01 AM, Alex Xu (Hello71) wrote:
> > Hi,
> >
> > I tried building wine 6.8 with mingw. All fine, just one problem, it
> > reports error "undefined reference to `sincos'". Why, you may ask, since
> > wine never calls sincos function? Well, it seems to be because mingw gcc
> > 11 enables sincos optimization: [0]. But, wine uses -nodefaultlibs,
> > intending to provide libc functions with msvcrt; however, wine msvcrt
> > doesn't implement any sincos. So, there is a mismatch: gcc accepts mingw
> > claim to implement sincos (ok since mingwex implements it), then
> > generates call to sincos, then fails at link time (because msvcrt does
> > not implement it).
> >
> > After adding -fno-builtin-{sin,cos}{,f} to CFLAGS, wine compiled and ran
> > OK.
> >
> > This issue seems to be worked around for winelib builds by adding
> > -fno-builtin, so that gcc will not generate sincos (or most other
> > problematic functions).
> >
> > I think this issue could be worked around by adding those -fno-builtin-*
> > flags for mingw builds. However, I think the sin/cos->sincos
> > optimization is a good one, so maybe we could instead add sincos
> > forwarder in msvcrt (calling sin+cos separately in case sincos is not
> > implemented in libc?).
> >
> > CCed mingw-w64-public at lists.sourceforge.net due to potential relevance
> > and felixonmars at archlinux.org due to maintaining wine and mingw-gcc on
> > Arch. You may need to subscribe in order to reply all. I look forward to
> > hearing your thoughts.
>
>
> I think that the decision was unfortunate on GCC side, but there is
> little we can do. We will probably need to provide it in msvcrt
> importlibs. Please try the attached patch, it should help.
>
>
> Thanks,
>
> Jacek
>
>
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