gcc/testsuite/gcc.dg/pack-test-4.c

   1 /* PR c/11885
   2    Bug: flag4 was allocated into the same byte as the other flags.
   3    { dg-options "" }
   4    { dg-do run } */
   5
   6 extern void abort (void);
   7
   8 typedef unsigned char uint8_t;
   9
  10 typedef struct {
  11     uint8_t flag1:2;
  12     uint8_t flag2:1;
  13     uint8_t flag3:1;
  14
  15     uint8_t flag4;
  16
  17 } __attribute__ ((packed)) MyType;
  18
  19 int main (void)
  20 {
  21   MyType a;
  22   MyType *b = &a;
  23
  24   b->flag1 = 0;
  25   b->flag2 = 0;
  26   b->flag3 = 0;
  27
  28   b->flag4 = 0;
  29
  30   b->flag4++;
  31
  32   if (b->flag1 != 0)
  33     abort ();
  34
  35   return 0;
  36 }