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(struct sm_state *sm, struct expression *mod_expr)
  19 {
  20         if (sm->state != &ok)
  21                 set_state(my_id, sm->name, sm->sym, &ok);
  22 }
  23
  24 static void match_function_def(struct symbol *sym)
  25 {
  26         struct symbol *arg;
  27
  28         func_sym = sym;
  29         FOR_EACH_PTR(func_sym->ctype.base_type->arguments, arg) {
  30                 if (!arg->ident) {
  31                         continue;
  32                 }
  33                 set_state(my_id, arg->ident->name, arg, &argument);
  34         } END_FOR_EACH_PTR(arg);
  35 }
  36
  37 static int get_arg_num(struct expression *expr)
  38 {
  39         struct smatch_state *state;
  40         struct symbol *arg;
  41         struct symbol *this_arg;
  42         int i;
  43
  44         expr = strip_expr(expr);
  45         if (expr->type != EXPR_SYMBOL)
  46                 return -1;
  47         this_arg = expr->symbol;
  48
  49         state = get_state_expr(my_id, expr);
  50         if (!state || state != &argument)
  51                 return -1;
  52
  53         i = 0;
  54         FOR_EACH_PTR(func_sym->ctype.base_type->arguments, arg) {
  55                 if (arg == this_arg)
  56                         return i;
  57                 i++;
  58         } END_FOR_EACH_PTR(arg);
  59
  60         return -1;
  61 }
  62
  63 static void match_is_err(const char *fn, struct expression *expr, void *unused)
  64 {
  65         struct expression *arg;
  66         int arg_num;
  67
  68         arg = get_argument_from_call_expr(expr->args, 0);
  69         arg_num = get_arg_num(arg);
  70         if (arg_num < 0)
  71                 return;
  72         sm_msg("info: expects ERR_PTR %d", arg_num);
  73 }
  74
  75 void check_expects_err_ptr(int id)
  76 {
  77         if (option_project != PROJ_KERNEL)
  78                 return;
  79         if (!option_info)
  80                 return;
  81
  82         my_id = id;
  83         add_hook(&match_function_def, FUNC_DEF_HOOK);
  84         add_modification_hook(my_id, &set_ok);
  85         add_function_hook("IS_ERR", &match_is_err, NULL);
  86 }