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         long long max_left;
  18         long long max_right;
  19         char *name;
  20
  21         if (expr->op != '=')
  22                 return;
  23
  24         macro = get_macro_name(&expr->pos);
  25         if (!macro)
  26                 return;
  27         if (strcmp(macro, "min_t"))
  28                 return;
  29
  30         if (!get_absolute_max(expr->left, &max_left))
  31                 return;
  32         if (!get_absolute_max(expr->right, &max_right))
  33                 return;
  34
  35         if (max_left >= max_right)
  36                 return;
  37
  38         name = get_variable_from_expr_complex(expr->right, NULL);
  39         sm_msg("warn: min_t truncates here '%s' (%lld vs %lld)", name, max_left, max_right);
  40         free_string(name);
  41 }
  42
  43 void check_min_t(int id)
  44 {
  45         my_id = id;
  46         if (option_project != PROJ_KERNEL)
  47                 return;
  48         add_hook(&match_assign, ASSIGNMENT_HOOK);
  49 }