smatch_local_values.c

   1 /*
   2  * Copyright (C) 2013 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 #include "scope.h"
  19 #include "smatch.h"
  20 #include "smatch_slist.h"
  21 #include "smatch_extra.h"
  22
  23 static int my_id;
  24
  25 /*
  26  * I'm going to store the states of local data at the end of each function.
  27  * Then at the end of the file, I'll combine the possible range lists for
  28  * each state and store the value in the on-disk database.
  29  *
  30  * One issue is that when I read the data back from the in-memory database at
  31  * the end of the file, then I don't have access to type information.  I'll just
  32  * cast everything to "long long" for now, I guess.  We'll see how that works.
  33  */
  34
  35 static char *db_vals;
  36 static int get_vals(void *unused, int argc, char **argv, char **azColName)
  37 {
  38         db_vals = alloc_string(argv[0]);
  39         return 0;
  40 }
  41
  42 int get_local_rl(struct expression *expr, struct range_list **rl)
  43 {
  44         char *name;
  45         struct range_list *tmp;
  46
  47         if (!is_static(expr))
  48                 return 0;
  49         name = expr_to_var(expr);
  50         if (!name)
  51                 return 0;
  52
  53         db_vals = NULL;
  54         run_sql(get_vals,
  55                 "select value from local_values where file = '%s' and variable = '%s';",
  56                 get_filename(), name);
  57         free_string(name);
  58         if (!db_vals)
  59                 return 0;
  60         str_to_rl(&llong_ctype, db_vals, &tmp);
  61         *rl = cast_rl(get_type(expr), tmp);
  62         free_string(db_vals);
  63
  64         return 1;
  65 }
  66
  67 int get_local_max_helper(struct expression *expr, sval_t *sval)
  68 {
  69         struct range_list *rl;
  70
  71         if (!get_local_rl(expr, &rl))
  72                 return 0;
  73         *sval = rl_max(rl);
  74         return 1;
  75 }
  76
  77 int get_local_min_helper(struct expression *expr, sval_t *sval)
  78 {
  79         struct range_list *rl;
  80
  81         if (!get_local_rl(expr, &rl))
  82                 return 0;
  83         *sval = rl_min(rl);
  84         return 1;
  85 }
  86
  87 static struct smatch_state *unmatched_state(struct sm_state *sm)
  88 {
  89         return alloc_estate_empty();
  90 }
  91
  92 static void extra_mod_hook(const char *name, struct symbol *sym, struct smatch_state *state)
  93 {
  94         struct smatch_state *old;
  95         struct smatch_state *new;
  96
  97         if (!sym || !(sym->ctype.modifiers & MOD_STATIC))
  98                 return;
  99         old = get_state(my_id, name, sym);
 100         if (old)
 101                 new = merge_estates(old, state);
 102         else
 103                 new = state;
 104         set_state(my_id, name, sym, new);
 105 }
 106
 107 static void process_states(struct AVL *stree)
 108 {
 109         struct sm_state *sm;
 110         struct smatch_state *extra;
 111         struct range_list *rl;
 112
 113         FOR_EACH_SM(stree, sm) {
 114                 if (sm->owner != my_id)
 115                         continue;
 116                 extra = get_state_stree(stree, SMATCH_EXTRA, sm->name, sm->sym);
 117                 if (extra && estate_rl(extra))
 118                         rl = rl_intersection(estate_rl(sm->state), estate_rl(extra));
 119                 else
 120                         rl = estate_rl(sm->state);
 121                 rl = cast_rl(&llong_ctype, rl);
 122                 mem_sql(NULL,
 123                         "insert into local_values values ('%s', '%s', '%s', %lu);",
 124                         get_filename(), sm->name, show_rl(rl),
 125                         (unsigned long)sm->sym);
 126         } END_FOR_EACH_SM(sm);
 127 }
 128
 129 static int get_initial_value_sym(struct symbol *sym, char *name, sval_t *sval)
 130 {
 131         struct expression *expr_symbol, *deref, *tmp;
 132         char *member_name;
 133
 134         if (!sym)
 135                 return 0;
 136
 137         if (!sym->initializer) {
 138                 *sval = sval_type_val(&llong_ctype, 0);
 139                 return 1;
 140         }
 141         if (sym->initializer->type != EXPR_INITIALIZER)
 142                 return get_value(sym->initializer, sval);
 143
 144         expr_symbol = symbol_expression(sym);
 145         FOR_EACH_PTR(sym->initializer->expr_list, tmp) {
 146                 if (tmp->type != EXPR_IDENTIFIER) /* how to handle arrays?? */
 147                         continue;
 148                 deref = member_expression(expr_symbol, '.', tmp->expr_ident);
 149                 member_name = expr_to_var(deref);
 150                 if (!member_name)
 151                         continue;
 152                 if (strcmp(name, member_name) == 0) {
 153                         free_string(member_name);
 154                         return get_value(tmp->ident_expression, sval);
 155                 }
 156                 free_string(member_name);
 157         } END_FOR_EACH_PTR(tmp);
 158
 159         return 0;
 160 }
 161
 162 static char *cur_name;
 163 static struct symbol *cur_symbol;
 164 static struct range_list *cur_rl;
 165 static void add_current_local(void)
 166 {
 167         sval_t initial;
 168
 169         if (!get_initial_value_sym(cur_symbol, cur_name, &initial)) {
 170                 free_string(cur_name);
 171                 cur_name = NULL;
 172                 cur_rl = NULL;
 173                 return;
 174         }
 175         add_range(&cur_rl, initial, initial);
 176         if (!is_whole_rl(cur_rl))
 177                 sql_insert_local_values(cur_name, show_rl(cur_rl));
 178         free_string(cur_name);
 179         cur_name = NULL;
 180         cur_rl = NULL;
 181 }
 182
 183 static int save_final_values(void *unused, int argc, char **argv, char **azColName)
 184 {
 185         char *name = argv[0];
 186         char *sym_str = argv[1];
 187         char *value = argv[2];
 188         struct range_list *rl;
 189
 190         if (!cur_name) {
 191                 cur_name = alloc_string(name);
 192                 cur_symbol = (struct symbol *)strtoul(sym_str, NULL, 10);
 193         } else if (strcmp(cur_name, name) != 0) {
 194                 add_current_local();
 195                 cur_name = alloc_string(name);
 196                 cur_symbol = (struct symbol *)strtoul(sym_str, NULL, 10);
 197                 cur_rl = NULL;
 198         }
 199
 200         str_to_rl(&llong_ctype, value, &rl);
 201         cur_rl = rl_union(cur_rl, rl);
 202
 203         return 0;
 204 }
 205
 206 static void match_end_file(struct symbol_list *sym_list)
 207 {
 208         mem_sql(save_final_values,
 209                 "select distinct variable, symbol, value from local_values order by variable;");
 210         if (cur_name)
 211                 add_current_local();
 212 }
 213
 214 void register_local_values(int id)
 215 {
 216         my_id = id;
 217
 218         if (!option_info)
 219                 return;
 220
 221         add_extra_mod_hook(&extra_mod_hook);
 222         add_unmatched_state_hook(my_id, &unmatched_state);
 223         add_merge_hook(my_id, &merge_estates);
 224         all_return_states_hook(&process_states);
 225         add_hook(match_end_file, END_FILE_HOOK);
 226         mem_sql(NULL, "alter table local_values add column symbol integer;");
 227 }