smatch_passes_array_size.c

   1 /*
   2  * Copyright (C) 2017 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 "smatch.h"
  19 #include "smatch_extra.h"
  20
  21 static int find_param_eq(struct expression *expr, int size)
  22 {
  23         struct expression *arg;
  24         sval_t val;
  25         int i;
  26
  27         i = -1;
  28         FOR_EACH_PTR(expr->args, arg) {
  29                 i++;
  30                 if (!get_implied_value(arg, &val))
  31                         continue;
  32                 if (val.value == size)
  33                         return i;
  34         } END_FOR_EACH_PTR(arg);
  35
  36         return -1;
  37 }
  38
  39 static void match_call(struct expression *expr)
  40 {
  41         struct expression *arg;
  42         struct symbol *type, *arg_type;
  43         int size, bytes;
  44         int i, nr;
  45         char buf[16];
  46         char elem_count[8];
  47         char byte_count[8];
  48
  49         snprintf(elem_count, sizeof(elem_count), "%d", ELEM_COUNT);
  50         snprintf(byte_count, sizeof(byte_count), "%d", BYTE_COUNT);
  51
  52         i = -1;
  53         FOR_EACH_PTR(expr->args, arg) {
  54                 i++;
  55                 type = get_type(arg);
  56                 if (!type || (type->type != SYM_PTR && type->type != SYM_ARRAY))
  57                         continue;
  58                 arg_type = get_arg_type(expr->fn, i);
  59                 if (arg_type != type)
  60                         continue;
  61
  62                 size = get_array_size(arg);
  63                 if (size > 0) {
  64                         nr = find_param_eq(expr, size);
  65                         if (nr >= 0) {
  66                                 snprintf(buf, sizeof(buf), "==$%d", nr);
  67                                 sql_insert_caller_info(expr, ELEM_COUNT, i, buf, elem_count);
  68                                 continue;
  69                         }
  70                 }
  71                 bytes = get_array_size_bytes(arg);
  72                 if (bytes > 0) {
  73                         nr = find_param_eq(expr, bytes);
  74                         if (nr >= 0) {
  75                                 snprintf(buf, sizeof(buf), "==$%d", nr);
  76                                 sql_insert_caller_info(expr, BYTE_COUNT, i, buf, byte_count);
  77                                 continue;
  78                         }
  79                 }
  80         } END_FOR_EACH_PTR(arg);
  81 }
  82
  83 void register_passes_array_size(int id)
  84 {
  85         add_hook(&match_call, FUNCTION_CALL_HOOK);
  86 }
  87