gcc/testsuite/gcc.dg/pr56997-2.c

   1 /* Test volatile access to unaligned field.  */
   2 /* { dg-do run } */
   3 /* { dg-require-effective-target size32plus } */
   4 /* { dg-options "-fstrict-volatile-bitfields" } */
   5
   6 extern void abort (void);
   7
   8 #define test_type unsigned int
   9 #define MAGIC 0x1020304u
  10
  11 typedef struct s{
  12  unsigned char Prefix;
  13  test_type Type;
  14 }__attribute((__packed__)) ss;
  15
  16 volatile ss v;
  17 ss g;
  18
  19 void __attribute__((noinline))
  20 foo (test_type u)
  21 {
  22   v.Type = u;
  23 }
  24
  25 test_type __attribute__((noinline))
  26 bar (void)
  27 {
  28   return v.Type;
  29 }
  30
  31 int main()
  32 {
  33   test_type temp;
  34   foo(MAGIC);
  35   __builtin_memcpy(&g, (void *)&v, sizeof(g));
  36   if (g.Type != MAGIC)
  37     abort ();
  38
  39   g.Type = MAGIC;
  40   __builtin_memcpy((void *)&v, &g, sizeof(v));
  41   temp = bar();
  42   if (temp != MAGIC)
  43     abort ();
  44   return 0;
  45 }