gcc/testsuite/gcc.dg/reg-vol-struct-1.c

   1 /* Test cases of structures with volatile fields declared register:
   2    should be allowed unless register name given but explicitly taking
   3    the address forbidden.  */
   4 /* Origin: Joseph Myers <jsm@polyomino.org.uk> */
   5
   6 /* { dg-do compile } */
   7
   8 struct S { volatile int field; };
   9
  10 void
  11 f (void)
  12 {
  13   register struct S a;
  14   register struct S b[2];
  15   register struct S c __asm__("nosuchreg"); /* { dg-error "object with volatile field" "explicit reg name" } */
  16   &a; /* { dg-warning "address of register" "explicit address" } */
  17   b; /* { dg-warning "address of register" "implicit address" } */
  18 }