19  * Say we have a line like:
  20  * foo = bar / 8;
  21  * Assume we don't know anything about bar.  Well, now we know that foo is less
  22  * than UINT_MAX / 8.  Which might be useful, but it probably is misleading
  23  * useless knowledge.  Up to now we have ignored those but now we have said to
  24  * store them.
  25  *
  26  * It also works if you have something like "foo = (int)(char)unknown_var;".
  27  *
  28  * I feel like this data doesn't have to be perfect, it just has to be better
  29  * than nothing and that will help eliminate some false positives.
  30  *
  31  */
  32 
  33 #include "smatch.h"
  34 #include "smatch_slist.h"
  35 #include "smatch_extra.h"
  36 
  37 static int my_id;
  38 





  39 static void extra_mod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
  40 {
  41         struct smatch_state *abs;
  42         struct range_list *rl;
  43 
  44         abs = get_state(my_id, name, sym);
  45         if (!abs || !estate_rl(abs))
  46                 return;
  47         rl = rl_intersection(estate_rl(abs), estate_rl(state));
  48         set_state(my_id, name, sym, alloc_estate_rl(clone_rl(rl)));
  49 }
  50 
  51 static void pre_merge_hook(struct sm_state *cur, struct sm_state *other)
  52 {
  53         struct smatch_state *extra;
  54         struct range_list *rl;
  55 
  56         extra = get_state(SMATCH_EXTRA, cur->name, cur->sym);
  57         if (!extra || !estate_rl(extra))
  58                 return;

  19  * Say we have a line like:
  20  * foo = bar / 8;
  21  * Assume we don't know anything about bar.  Well, now we know that foo is less
  22  * than UINT_MAX / 8.  Which might be useful, but it probably is misleading
  23  * useless knowledge.  Up to now we have ignored those but now we have said to
  24  * store them.
  25  *
  26  * It also works if you have something like "foo = (int)(char)unknown_var;".
  27  *
  28  * I feel like this data doesn't have to be perfect, it just has to be better
  29  * than nothing and that will help eliminate some false positives.
  30  *
  31  */
  32 
  33 #include "smatch.h"
  34 #include "smatch_slist.h"
  35 #include "smatch_extra.h"
  36 
  37 static int my_id;
  38 
  39 void set_real_absolute(struct expression *expr, struct smatch_state *state)
  40 {
  41         set_state_expr(my_id, expr, clone_estate(state));
  42 }
  43 
  44 static void extra_mod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
  45 {
  46         struct smatch_state *abs;
  47         struct range_list *rl;
  48 
  49         abs = get_state(my_id, name, sym);
  50         if (!abs || !estate_rl(abs))
  51                 return;
  52         rl = rl_intersection(estate_rl(abs), estate_rl(state));
  53         set_state(my_id, name, sym, alloc_estate_rl(clone_rl(rl)));
  54 }
  55 
  56 static void pre_merge_hook(struct sm_state *cur, struct sm_state *other)
  57 {
  58         struct smatch_state *extra;
  59         struct range_list *rl;
  60 
  61         extra = get_state(SMATCH_EXTRA, cur->name, cur->sym);
  62         if (!extra || !estate_rl(extra))
  63                 return;