test/union.c

   1 typedef union _ut
   2 {
   3   int x;
   4   int y;
   5   int *ox;
   6   /*@dependent@*/ int *dx;
   7   struct { int a; int b; int *ip; } st;
   8 } *ut;
   9
  10 extern /*@only@*/ /*@out@*/ void *smalloc (size_t);
  11
  12 ut ut_create1 (/*@unused@*/ int a)
  13 {
  14   ut u = (ut) smalloc (sizeof (*u));
  15
  16   return u; /* 1. Returned union u contains no defined field */
  17 }
  18
  19 ut ut_create2 (int a)
  20 {
  21   ut u = (ut) smalloc (sizeof (*u));
  22
  23   u->x = a;
  24   return u;
  25 }
  26
  27 ut ut_create3 (int a)
  28 {
  29   ut u = (ut) smalloc (sizeof (*u));
  30
  31   u->x = a;
  32   u->y = a;
  33   return u; /* [Not anymore. Returned union u has 2 defined fields: x, y */
  34 }
  35
  36 ut ut_create4 (int *t)
  37 {
  38   ut u = (ut) smalloc (sizeof (*u));
  39
  40   u->ox = t; /* 2. Implicitly temp storage t assigned to implicitly only */
  41   return u;
  42 }
  43
  44 ut ut_create5 (int *t)
  45 {
  46   ut u = (ut) smalloc (sizeof (*u));
  47
  48   u->dx = t; /* 3. Implicitly temp storage t assigned to dependent: u->dx = t */
  49   return u;
  50 }
  51
  52 ut ut_create6 (void)
  53 {
  54   ut u = (ut) smalloc (sizeof (*u));
  55
  56   u->st.a = 3;
  57   return u; /* 4. Returned storage u->st contains 2 undefined fields: b, ip */
  58 }
  59
  60 ut ut_create7 (int *p)
  61 {
  62   ut u = (ut) smalloc (sizeof (*u));
  63
  64   u->st.a = 3;
  65   u->st.b = 4;
  66   u->st.ip = p; /* 5. Implicitly temp storage p assigned to implicitly only */
  67   return u;
  68 }
  69
  70 void ut_mangle1 (ut u)
  71 {
  72   free (u->ox);
  73 } /* 6. Released storage u->ox reachable from parameter */
  74
  75 void ut_mangle2 (ut u)
  76 {
  77   free (u->st.ip);
  78 } /* 7. Released storage u->st.ip reachable from parameter */
  79
  80 void ut_mangle3 (ut u)
  81 {
  82   free (u->st.ip);
  83   u->x = 3; /* This one's a toughy... */
  84 } /* 8. Released storage u->st.ip reachable from parameter */