Problem compiling gnutls

[nyjkkyjn at gmail.com]

I'm trying to compile gnutls 3.0.22 through mingw-w64 toolchain on
cygwin.. The configuration step seems to be OK, but when I execute
"make" while processing ex-cxx.cpp in doc/examples I get this error:
        /usr/x86_64-w64-mingw32/sys-root/mingw/include/stdio.h:328:5:
error: previous declaration of 'int                            
asprintf(char**, const char*, ...)' with 'C++' linkage
        ../../gl/stdio.h:1425:1: error: conflicts with new declaration
with 'C' linkage
        /usr/x86_64-w64-mingw32/sys-root/mingw/include/stdio.h:339:5:
error: previous declaration of 'int                            
vasprintf(char**, const char*, char*)' with 'C++' linkage
        ../../gl/stdio.h:1446:1: error: conflicts with new declaration
with 'C' linkage
Is it a problem with the toolchain or else? Is there a workaround?
Thanks, anyway.. I hope someone could help me..