check_initializer_deref.c

   1 /*
   2  * sparse/check_initializer_deref.c
   3  *
   4  * Copyright (C) 2009 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 STATE(derefed);
  15 STATE(oktocheck);
  16
  17 static void underef(const char *name, struct symbol *sym, struct expression *expr, void *unused)
  18 {
  19         set_state(my_id, name, sym, &oktocheck);
  20 }
  21
  22 static void record_dereferenced_vars(struct expression *expr)
  23 {
  24         struct symbol *sym;
  25         char *name;
  26
  27         if (!expr || expr->type != EXPR_DEREF)
  28                 return;
  29
  30         expr = expr->deref;
  31
  32         if (!strcmp(show_special(expr->op), "*"))  {
  33                 name = get_variable_from_expr(expr->unop, &sym);
  34                 if (name && sym) {
  35                         set_state_expr(my_id, expr->unop, &derefed);
  36                         add_modification_hook(name, &underef, NULL);
  37                 }
  38                 free_string(name);
  39         }
  40         record_dereferenced_vars(expr->unop);
  41 }
  42
  43 static void match_declarations(struct symbol *sym)
  44 {
  45         if (!sym->initializer)
  46                 return;
  47         record_dereferenced_vars(sym->initializer);
  48 }
  49
  50
  51 static void match_condition(struct expression *expr)
  52 {
  53         struct symbol *sym;
  54         char *name;
  55
  56         expr = strip_expr(expr);
  57         name = get_variable_from_expr(expr, &sym);
  58         if (!name || !sym)
  59                 goto free;
  60
  61         if (get_state_expr(my_id, expr) == &derefed) {
  62                 sm_msg("warn: variable derefenced in initializer '%s'",
  63                         name);
  64                 set_state_expr(my_id, expr, &oktocheck);
  65         }
  66 free:
  67         free_string(name);
  68 }
  69
  70
  71 void check_initializer_deref(int id)
  72 {
  73         my_id = id;
  74         set_default_state(my_id, &oktocheck);
  75         add_hook(&match_declarations, DECLARATION_HOOK);
  76         add_hook(&match_condition, CONDITION_HOOK);
  77 }