smatch_param_set.c

   1 /*
   2  * sparse/smatch_param_set.c
   3  *
   4  * Copyright (C) 2012 Oracle.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * This is for functions like:
  12  *
  13  * int foo(int *x)
  14  * {
  15  *      if (*x == 42) {
  16  *              *x = 0;
  17  *              return 1;
  18  *      }
  19  *      return 0;
  20  * }
  21  *
  22  * If we return 1 that means the value of *x has been set to 0.  If we return
  23  * 0 then we have left *x alone.
  24  *
  25  */
  26
  27 #include "scope.h"
  28 #include "smatch.h"
  29 #include "smatch_slist.h"
  30 #include "smatch_extra.h"
  31
  32 static int my_id;
  33
  34 static struct smatch_state *unmatched_state(struct sm_state *sm)
  35 {
  36         return alloc_estate_empty();
  37 }
  38
  39 static void extra_mod_hook(const char *name, struct symbol *sym, struct smatch_state *state)
  40 {
  41         set_state(my_id, name, sym, state);
  42 }
  43
  44 static void print_one_return_value_param(int return_id, char *return_ranges,
  45                         int param, struct sm_state *sm, char *implied_rl)
  46 {
  47         const char *param_name;
  48
  49         param_name = get_param_name(sm);
  50         if (!param_name)
  51                 return;
  52         if (strcmp(param_name, "$$") == 0)
  53                 return;
  54
  55         sql_insert_return_states(return_id, return_ranges, ADDED_VALUE, param,
  56                         param_name, implied_rl);
  57 }
  58
  59 static void print_return_value_param(int return_id, char *return_ranges, struct expression *expr)
  60 {
  61         struct state_list *my_slist;
  62         struct sm_state *sm;
  63         struct smatch_state *extra;
  64         int param;
  65         struct range_list *rl;
  66
  67         my_slist = get_all_states(my_id);
  68
  69         FOR_EACH_PTR(my_slist, sm) {
  70                 if (!estate_rl(sm->state))
  71                         continue;
  72                 extra = get_state(SMATCH_EXTRA, sm->name, sm->sym);
  73                 if (!estate_rl(extra))
  74                         continue;
  75                 rl = rl_intersection(estate_rl(sm->state), estate_rl(extra));
  76                 if (!rl)
  77                         continue;
  78
  79                 param = get_param_num_from_sym(sm->sym);
  80                 if (param < 0)
  81                         continue;
  82                 if (!sm->sym->ident)
  83                         continue;
  84                 print_one_return_value_param(return_id, return_ranges, param, sm, show_rl(rl));
  85         } END_FOR_EACH_PTR(sm);
  86 }
  87
  88 void register_param_set(int id)
  89 {
  90         my_id = id;
  91
  92         add_extra_mod_hook(&extra_mod_hook);
  93         add_unmatched_state_hook(my_id, &unmatched_state);
  94         add_merge_hook(my_id, &merge_estates);
  95         add_split_return_callback(&print_return_value_param);
  96 }
  97