check_expects_err_ptr.c

   1 /*
   2  * smatch/check_expects_err_ptr.c
   3  *
   4  * Copyright (C) 2010 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 static struct symbol *func_sym;
  14
  15 STATE(argument);
  16 STATE(ok);
  17
  18 static void set_ok(const char *name, struct symbol *sym, struct expression *expr, void *unused)
  19 {
  20         set_state(my_id, name, sym, &ok);
  21 }
  22
  23 static void match_function_def(struct symbol *sym)
  24 {
  25         struct symbol *arg;
  26
  27         func_sym = sym;
  28         FOR_EACH_PTR(func_sym->ctype.base_type->arguments, arg) {
  29                 if (!arg->ident) {
  30                         continue;
  31                 }
  32                 set_state(my_id, arg->ident->name, arg, &argument);
  33         } END_FOR_EACH_PTR(arg);
  34 }
  35
  36 static int get_arg_num(struct expression *expr)
  37 {
  38         struct smatch_state *state;
  39         struct symbol *arg;
  40         struct symbol *this_arg;
  41         int i;
  42
  43         expr = strip_expr(expr);
  44         if (expr->type != EXPR_SYMBOL)
  45                 return -1;
  46         this_arg = expr->symbol;
  47
  48         state = get_state_expr(my_id, expr);
  49         if (!state || state != &argument)
  50                 return -1;
  51
  52         i = 0;
  53         FOR_EACH_PTR(func_sym->ctype.base_type->arguments, arg) {
  54                 if (arg == this_arg)
  55                         return i;
  56                 i++;
  57         } END_FOR_EACH_PTR(arg);
  58
  59         return -1;
  60 }
  61
  62 static void match_is_err(const char *fn, struct expression *expr, void *unused)
  63 {
  64         struct expression *arg;
  65         int arg_num;
  66
  67         arg = get_argument_from_call_expr(expr->args, 0);
  68         arg_num = get_arg_num(arg);
  69         if (arg_num < 0)
  70                 return;
  71         sm_msg("info: expects ERR_PTR %d", arg_num);
  72 }
  73
  74 void check_expects_err_ptr(int id)
  75 {
  76         if (option_project != PROJ_KERNEL)
  77                 return;
  78         if (!option_info)
  79                 return;
  80
  81         my_id = id;
  82         add_hook(&match_function_def, FUNC_DEF_HOOK);
  83         set_default_modification_hook(my_id, &set_ok);
  84         add_function_hook("IS_ERR", &match_is_err, NULL);
  85 }