test/alias2.c

   1 int glob;
   2 int *globp;
   3
   4 int f(int *a, int b, int **c)
   5 {
   6   int *x, *y, *z;
   7
   8   {
   9     {
  10       int *lx;
  11
  12       x = a;
  13       lx = a;
  14       {
  15         /*@-shadow@*/ int *lx; /*@=shadow@*/
  16
  17         *lx = 3; /* 1. use before def */
  18         y = *c;
  19       }
  20       *lx = 4; /* 2. modifies a */
  21     }
  22     x = y; /* x aliases *c */
  23     x = *c;
  24   }
  25
  26   if (b == *a)
  27     {
  28       x = a;   /* okay - x alias a */
  29       *x = 3;  /* 3. modifies *a */
  30       y = &glob;
  31     }
  32   else
  33     {
  34       *x = 3; /* 4. modifies **c */
  35       y = globp;
  36     }
  37
  38   *x = 4; /* 5, 6. bad - may modify *a or **c */
  39   z = a;
  40
  41   if ((**c = b) == 3) /* 7. modifies **c */
  42     {
  43       *y = 3;    /* 8, 9. may modify glob and *globp */
  44       globp = a; /* 10. modifies globp */
  45       a = y;
  46       z = globp;
  47     }
  48   else
  49     {
  50       a = z;
  51     }
  52
  53   *a = 3;     /* 11, 12. modifies glob, *globp through y and z */
  54   *z = 6;     /* 13, 14. modifies *a, *globp */
  55   *globp = 5; /* 15, 16. modifies *globp, *a */
  56   return 3;   /* 17. leaves globp aliasing a */
  57 }
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