cc -pipe -O   -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/wcscasecmp_l.c -o wchar/wcscasecmp_l -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread -lrt  -lrt -lcrypt
wchar/wcscasecmp_l.c: In function 'main':
wchar/wcscasecmp_l.c:13:7: error: implicit declaration of function 'wcscasecmp_l'; did you mean 'wcscasecmp'? [-Werror=implicit-function-declaration]
  if ( wcscasecmp_l(L"foo", L"FOO", locale) != 0 )
       ^~~~~~~~~~~~
       wcscasecmp
cc1: some warnings being treated as errors