/in/foo.cc:5:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~
/in/foo.cc:11:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~
/in/foo.cc:16:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~
/in/foo.cc:21:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~
/in/foo.cc:879:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~
/in/foo.cc:1767:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~
/in/foo.cc:1772:13: warning: #pragma system_header ignored outside include file
 #pragma GCC system_header
             ^~~~~~~~~~~~~