smatch_returns.c

   1 /*
   2  * Copyright (C) 2011 Oracle.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 #include "smatch.h"
  19 #include "smatch_slist.h"
  20 #include "smatch_extra.h"
  21
  22 int RETURN_ID;
  23
  24 struct return_states_callback {
  25         void (*callback)(void);
  26 };
  27 ALLOCATOR(return_states_callback, "return states callbacks");
  28 DECLARE_PTR_LIST(callback_list, struct return_states_callback);
  29 static struct callback_list *callback_list;
  30
  31 DECLARE_PTR_LIST(stree_stack_stack, struct stree_stack);
  32 static void push_stree_stack(struct stree_stack_stack **stack_stack, struct stree_stack *stack)
  33 {
  34         add_ptr_list(stack_stack, stack);
  35 }
  36
  37 static struct stree_stack *pop_stree_stack(struct stree_stack_stack **stack_stack)
  38 {
  39         struct stree_stack *stack;
  40
  41         stack = last_ptr_list((struct ptr_list *)*stack_stack);
  42         delete_ptr_list_last((struct ptr_list **)stack_stack);
  43         return stack;
  44 }
  45
  46 static struct stree_stack *return_stree_stack;
  47 static struct stree_stack_stack *saved_stack_stack;
  48 static struct stree *all_return_states;
  49 static struct stree_stack *saved_stack;
  50
  51 void all_return_states_hook(void (*callback)(void))
  52 {
  53         struct return_states_callback *rs_cb = __alloc_return_states_callback(0);
  54
  55         rs_cb->callback = callback;
  56         add_ptr_list(&callback_list, rs_cb);
  57 }
  58
  59 static void call_hooks(void)
  60 {
  61         struct return_states_callback *rs_cb;
  62         struct stree *orig;
  63
  64         orig = __swap_cur_stree(all_return_states);
  65         FOR_EACH_PTR(callback_list, rs_cb) {
  66                 rs_cb->callback();
  67         } END_FOR_EACH_PTR(rs_cb);
  68         __swap_cur_stree(orig);
  69 }
  70
  71 static void match_return(int return_id, char *return_ranges, struct expression *expr)
  72 {
  73         struct stree *stree;
  74
  75         stree = clone_stree(__get_cur_stree());
  76         merge_stree_no_pools(&all_return_states, stree);
  77         push_stree(&return_stree_stack, stree);
  78 }
  79
  80 static void match_end_func(struct symbol *sym)
  81 {
  82         /*
  83          * FIXME: either this isn't needed or we need to copy a stree into the
  84          * return_stree_stack as well.
  85          */
  86         merge_stree(&all_return_states, __get_cur_stree());
  87         call_hooks();
  88 }
  89
  90 static void match_save_states(struct expression *expr)
  91 {
  92         push_stree(&saved_stack, all_return_states);
  93         all_return_states = NULL;
  94
  95         push_stree_stack(&saved_stack_stack, return_stree_stack);
  96         return_stree_stack = NULL;
  97 }
  98
  99 static void match_restore_states(struct expression *expr)
 100 {
 101         /* This free_stree() isn't needed is it?? */
 102         free_stree(&all_return_states);
 103
 104         all_return_states = pop_stree(&saved_stack);
 105         return_stree_stack = pop_stree_stack(&saved_stack_stack);
 106 }
 107
 108 struct stree *get_all_return_states(void)
 109 {
 110         return all_return_states;
 111 }
 112
 113 struct stree_stack *get_all_return_strees(void)
 114 {
 115         return return_stree_stack;
 116 }
 117
 118 static void free_resources(struct symbol *sym)
 119 {
 120         free_stree(&all_return_states);
 121         free_stack_and_strees(&return_stree_stack);
 122 }
 123
 124 void register_returns_early(int id)
 125 {
 126         RETURN_ID = id;
 127
 128         set_dynamic_states(RETURN_ID);
 129         add_split_return_callback(match_return);
 130 }
 131
 132 void register_returns(int id)
 133 {
 134         add_hook(&match_end_func, END_FUNC_HOOK);
 135         add_hook(&match_save_states, INLINE_FN_START);
 136         add_hook(&match_restore_states, INLINE_FN_END);
 137         add_hook(&free_resources, AFTER_FUNC_HOOK);
 138 }