test/linked6.c

   1 typedef struct _node *node;
   2
   3 typedef struct {
   4   char *val;
   5 } *item;
   6
   7 struct _node {
   8   /*@only@*/ item val;
   9   /*@null@*/ node next;
  10 }
  11
  12 extern void keeper (/*@keep@*/ item iv);
  13
  14 void node_free1 (/*@only@*/ node n)
  15 {
  16   free (n); /* 2 errors: must free n->next, n->val */
  17 }
  18
  19 void node_free2 (/*@only@*/ node n)
  20 {
  21   node nn = n->next;
  22   keeper (n->val);
  23   free (n); /* okay */
  24 } /* error - nn not released */
  25
  26 void node_free3 (/*@only@*/ node n)
  27 {
  28   node nn = n->next;
  29   keeper (n->val);
  30   free (n); /* okay */
  31   if (nn != NULL) {
  32     node_free1 (nn); /* okay (error for null) */
  33   }
  34 } /* okay */
  35