check_min_t.c

   1 /*
   2  * smatch/check_min_t.c
   3  *
   4  * Copyright (C) 2011 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "smatch.h"
  11
  12 static int my_id;
  13
  14 static void match_assign(struct expression *expr)
  15 {
  16         const char *macro;
  17         sval_t max_left, max_right;
  18         char *name;
  19
  20         if (expr->op != '=')
  21                 return;
  22
  23         macro = get_macro_name(expr->pos);
  24         if (!macro)
  25                 return;
  26         if (strcmp(macro, "min_t"))
  27                 return;
  28
  29         if (!get_absolute_max(expr->left, &max_left))
  30                 return;
  31         if (!get_absolute_max(expr->right, &max_right))
  32                 return;
  33
  34         if (sval_cmp(max_left, max_right) >= 0)
  35                 return;
  36
  37         name = get_variable_from_expr_complex(expr->right, NULL);
  38         sm_msg("warn: min_t truncates here '%s' (%s vs %s)", name, sval_to_str(max_left), sval_to_str(max_right));
  39         free_string(name);
  40 }
  41
  42 void check_min_t(int id)
  43 {
  44         my_id = id;
  45         if (option_project != PROJ_KERNEL)
  46                 return;
  47         add_hook(&match_assign, ASSIGNMENT_HOOK);
  48 }