Re: USE_LSB_TAG not supported on this platform

[Paul Eggert]

On 02/08/2016 03:01 PM, Herbert J. Skuhra wrote:
> GCC 5 works but clang still fails. If I add
>
> #define alignas _Alignas
>
> to src/lisp.h the build succeeds.

Thanks, could you explain why that "#define" is helpful? On my platform 
(Fedora 23 x86-64, clang 3.7.0) clang's <stdalign.h>, which is in 
/usr/lib/clang/3.7.0/include/stdalign.h, contains this:

#ifndef __cplusplus
#define alignas _Alignas
#define alignof _Alignof
#endif

and src/lisp.h includes <stdalign.h> before using or checking alignas, 
so there should be no need to add "#define alignas _Alignas" to lisp.h.

Is there a file src/stdalign.h in your build directory? If so, why is it 
there, and why does it not define alignas?

Are you building with clang++?  That might explain the situation, but 
why would clang++ be needed?