freebsd stable - Aug 2017 - 11.1-RELEASE has issue with system headers in pedantic mode (type nullability specifier)

Hi, we noticed that some of our internal packages fail the build on 11.1
now with -pedantic:

*00:31:09.178* Warning: Object directory not changed from original
/tmp/mnt/dncd/work/dncd-20170627161415*00:31:09.178* cc -pipe -g3 -O0
-pipe -fstack-protector -fno-strict-aliasing -Wall -pedantic -O0 -g3
-g3 -O0 -pipe -MD  -MF.depend.main.o -MTmain.o -std=gnu99
-fstack-protector-strong -Wsystem-headers -Werror -Wall
-Wno-format-y2k -Wno-uninitialized -Wno-pointer-sign -Wno-empty-body
-Wno-string-plus-int -Wno-unused-const-variable
-Wno-tautological-compare -Wno-unused-value -Wno-parentheses-equality
-Wno-unused-function -Wno-enum-conversion -Wno-unused-local-typedef
-Wno-address-of-packed-member -Wno-switch -Wno-switch-enum
-Wno-knr-promoted-parameter  -Qunused-arguments  -c main.c -o
main.o*00:31:09.455* In file included from main.c:17:*00:31:09.456*
/usr/include/err.h:63:27: error: type nullability specifier
'_Nullable' is a Clang extension
[-Werror,-Wnullability-extension]*00:31:09.456* void
err_set_exit(void (* _Nullable)(int));*00:31:09.456*
           ^*00:31:09.456* In file included from
main.c:19:*00:31:09.456* /usr/include/signal.h:87:27: error: type
nullability specifier '_Nonnull' is a Clang extension
[-Werror,-Wnullability-extension]*00:31:09.456* int
sigpending(sigset_t * _Nonnull);


I am not sure what the solution might be, perhaps change pedantic to
make this condition non-fatal in pedantic mode?


-Max

One way to defeat this would be to mark those headers with the #pragma
clang system_header. As per:

https://clang.llvm.org/docs/UsersManual.html#id27

-Max

On Mon, Aug 7, 2017 at 6:20 AM, Maxim Sobolev <sobomax at freebsd.org>
wrote:
> Hi, we noticed that some of our internal packages fail the build on 11.1
> now with -pedantic:
>
> *00:31:09.178* Warning: Object directory not changed from original
/tmp/mnt/dncd/work/dncd-20170627161415*00:31:09.178* cc -pipe -g3 -O0 -pipe
-fstack-protector -fno-strict-aliasing -Wall -pedantic -O0 -g3   -g3 -O0 -pipe
-MD  -MF.depend.main.o -MTmain.o -std=gnu99 -fstack-protector-strong
-Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized
-Wno-pointer-sign -Wno-empty-body -Wno-string-plus-int
-Wno-unused-const-variable -Wno-tautological-compare -Wno-unused-value
-Wno-parentheses-equality -Wno-unused-function -Wno-enum-conversion
-Wno-unused-local-typedef -Wno-address-of-packed-member -Wno-switch
-Wno-switch-enum -Wno-knr-promoted-parameter  -Qunused-arguments  -c main.c -o
main.o*00:31:09.455* In file included from main.c:17:*00:31:09.456*
/usr/include/err.h:63:27: error: type nullability specifier '_Nullable'
is a Clang extension [-Werror,-Wnullability-extension]*00:31:09.456* void   
err_set_exit(void (* _Nullable)(int));*00:31:09.456*                            
^*00:31:09.456* In file included from main.c:19:*00:31:09.456*
/usr/include/signal.h:87:27: error: type nullability specifier
'_Nonnull' is a Clang extension
[-Werror,-Wnullability-extension]*00:31:09.456* int     sigpending(sigset_t *
_Nonnull);
>
>
> I am not sure what the solution might be, perhaps change pedantic to make
this condition non-fatal in pedantic mode?
>
>
> -Max
>
>