memcheck/tests/leak-cycle.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include "leak.h"
   4 #include "../memcheck.h"
   5
   6 struct n {
   7         struct n *l;
   8         struct n *r;
   9         // This ensures it's the same size on 32-bit and 64-bit platforms.
  10         char padding[ 2 * (8 - sizeof(struct n*)) ];
  11 };
  12
  13 struct n *mk(struct n *l, struct n *r)
  14 {
  15         struct n *n = malloc(sizeof(struct n));
  16         n->l = l;
  17         n->r = r;
  18
  19         return n;
  20 }
  21
  22 static struct n *mkcycle()
  23 {
  24         register struct n *a, *b, *c;
  25
  26         a = mk(0,0);
  27         b = mk(a,0);
  28         c = mk(b,0);
  29         a->l = c;
  30
  31         return a;
  32 }
  33
  34
  35 int main()
  36 {
  37         DECLARE_LEAK_COUNTERS;
  38
  39         struct n *volatile c1, *volatile c2;
  40
  41         GET_INITIAL_LEAK_COUNTS;
  42
  43         /* two simple cycles */
  44         c1 = mkcycle();
  45         c2 = mkcycle();
  46
  47         c1 = c2 = 0;
  48
  49         /* one cycle linked to another */
  50         c1 = mkcycle();
  51         c2 = mkcycle();
  52
  53         /* This is to make sure we end up merging cliques; see
  54            mc_leakcheck.c */
  55         if (c1 < c2)
  56                 c2->r = c1;
  57         else
  58                 c1->r = c2;
  59
  60         c1 = c2 = 0;
  61
  62         /* two linked cycles */
  63         c1 = mkcycle();
  64         c2 = mkcycle();
  65
  66         c1->r = c2;
  67         c2->r = c1;
  68
  69         c1 = c2 = 0;
  70
  71         CLEAR_CALLER_SAVED_REGS;
  72
  73         GET_FINAL_LEAK_COUNTS;
  74
  75         PRINT_LEAK_COUNTS(stderr);
  76
  77         return 0;
  78 }