modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/compile/20010605-2.c (about)

     1  /* Origin: Joseph Myers <jsm28@cam.ac.uk>.  */
     2  /* As an extension, GCC allows a struct or union to be cast to its own
     3     type, but failed to allow this when a typedef was involved.
     4     Reported as PR c/2735 by <cowan@ccil.org>.  */
     5  union u { int i; };
     6  typedef union u uu;
     7  union u a;
     8  uu b;
     9  
    10  void
    11  foo (void)
    12  {
    13    a = (union u) b;
    14    a = (uu) b;
    15    b = (union u) a;
    16    b = (uu) a;
    17  }