gcc/testsuite/gcc.dg/typedef-redecl.h

   1 /* Redeclaration of typedef (invalid but accepted in system headers)
   2    causes ICE; PR 13656.  Test case by Richard Sandiford <rsandifo@redhat.com>,
   3    reduced from glibc.  */
   4
   5 #pragma GCC system_header
   6 typedef int x;
   7 typedef int x;