gcc/testsuite/gcc.dg/pr56341-1.c

   1 /* { dg-do run } */
   2 /* { dg-options "-fstrict-volatile-bitfields" } */
   3
   4 extern void abort (void);
   5
   6 struct test0
   7 {
   8   unsigned char b1[2];
   9 } __attribute__((packed, aligned(2)));
  10
  11 struct test1
  12 {
  13   volatile unsigned long a1;
  14   unsigned char b1[4];
  15 } __attribute__((packed, aligned(2)));
  16
  17 struct test2
  18 {
  19   struct test0 t0;
  20   struct test1 t1;
  21   struct test0 t2;
  22 } __attribute__((packed, aligned(2)));
  23
  24 struct test2 xx;
  25 struct test2 *x1 = &xx;
  26
  27 #define MAGIC 0x12345678
  28
  29 void test0 (struct test2* x1)
  30 {
  31   x1->t1.a1 = MAGIC;
  32 }
  33
  34 int main()
  35 {
  36   test0 (x1);
  37   if (xx.t1.a1 != MAGIC)
  38     abort ();
  39   return 0;
  40 }