smatch_links.c

   1 /*
   2  * Copyright (C) 2014 Oracle.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 /*
  19  * Some helper functions for managing links.
  20  *
  21  */
  22
  23 #include "smatch.h"
  24 #include "smatch_slist.h"
  25
  26 static struct smatch_state *alloc_link(struct var_sym_list *links)
  27 {
  28         struct smatch_state *state;
  29         static char buf[256] = "";
  30         struct var_sym *tmp;
  31         int cnt = 0;
  32
  33         state = __alloc_smatch_state(0);
  34
  35         FOR_EACH_PTR(links, tmp) {
  36                 cnt += snprintf(buf + cnt, sizeof(buf) - cnt, "%s%s",
  37                                 cnt ? ", " : "", tmp->var);
  38                 if (cnt >= sizeof(buf))
  39                         goto done;
  40         } END_FOR_EACH_PTR(tmp);
  41
  42 done:
  43         state->name = alloc_sname(buf);
  44         state->data = links;
  45         return state;
  46 }
  47
  48 struct smatch_state *merge_link_states(struct smatch_state *s1, struct smatch_state *s2)
  49 {
  50         struct var_sym_list *new_links;
  51
  52         if (s1 == &undefined)
  53                 return s2;
  54         if (s2 == &undefined)
  55                 return s1;
  56
  57         if (var_sym_lists_equiv(s1->data, s2->data))
  58                 return s1;
  59
  60         new_links = clone_var_sym_list(s1->data);
  61         merge_var_sym_list(&new_links, s2->data);
  62
  63         return alloc_link(new_links);
  64 }
  65
  66 void store_link(int link_id, const char *var, struct symbol *sym, const char *link_name, struct symbol *link_sym)
  67 {
  68
  69         struct smatch_state *old_state;
  70         struct var_sym_list *links;
  71
  72         if (!cur_func_sym)
  73                 return;
  74
  75         old_state = get_state(link_id, var, sym);
  76         if (old_state)
  77                 links = clone_var_sym_list(old_state->data);
  78         else
  79                 links = NULL;
  80
  81         add_var_sym(&links, link_name, link_sym);
  82         set_state(link_id, var, sym, alloc_link(links));
  83 }
  84
  85 static void match_link_modify(struct sm_state *sm, struct expression *mod_expr)
  86 {
  87         struct var_sym_list *links;
  88         struct var_sym *tmp;
  89
  90         links = sm->state->data;
  91
  92         FOR_EACH_PTR(links, tmp) {
  93                 set_state(sm->owner - 1, tmp->var, tmp->sym, &undefined);
  94         } END_FOR_EACH_PTR(tmp);
  95         set_state(sm->owner, sm->name, sm->sym, &undefined);
  96 }
  97
  98 void set_up_link_functions(int id, int link_id)
  99 {
 100         if (id + 1 != link_id)
 101                 sm_fatal("FATAL ERROR: links need to be registered directly after the check");
 102
 103         set_dynamic_states(link_id);
 104         add_merge_hook(link_id, &merge_link_states);
 105         add_modification_hook(link_id, &match_link_modify);
 106         // free link at the end of function
 107 }
 108