/*
 * Copyright (C) 2009 Dan Carpenter.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
 */

#include <fcntl.h>
#include <unistd.h>
#include "parse.h"
#include "smatch.h"
#include "smatch_slist.h"

static int my_id;

/*
 * Print a list of functions that return newly allocated memory.
 */

static struct tracker_list *allocated;

static const char *allocation_funcs[] = {
        "kmalloc",
        "kzalloc",
        "kcalloc",
        "__alloc_skb",
        NULL,
};

static void match_allocation(const char *fn, struct expression *expr,
                             void *info)
{
        char *left_name;
        struct symbol *left_sym;

        left_name = expr_to_var_sym(expr->left, &left_sym);
        if (!left_name || !left_sym)
                goto free;
        if (left_sym->ctype.modifiers & 
            (MOD_NONLOCAL | MOD_STATIC | MOD_ADDRESSABLE))
                goto free;
        add_tracker(&allocated, my_id, left_name, left_sym);
free:
        free_string(left_name);
}

static int returns_new_stuff = 0;
static int returns_old_stuff = 0;
static void match_return(struct expression *ret_value)
{
        char *name;
        struct symbol *sym;
        sval_t tmp;

        if (__inline_fn)
                return;
        if (get_value(ret_value, &tmp) && tmp.value == 0)
                return;
        returns_new_stuff = 1;
        name = expr_to_var_sym(ret_value, &sym);
        if (!name || !sym) {
                returns_old_stuff = 1;
                goto free;
        }
        if (!in_tracker_list(allocated, my_id, name, sym))
                returns_old_stuff = 1;
free:
        free_string(name);
}

static void match_end_func(struct symbol *sym)
{
        if (__inline_fn)
                return;
        if (returns_new_stuff && !returns_old_stuff)
                sm_info("allocation func");
        free_trackers_and_list(&allocated);
        returns_new_stuff = 0;
        returns_old_stuff = 0;
}

void check_allocation_funcs(int id)
{
        int i;

        if (!option_info || option_project != PROJ_KERNEL)
                return;

        my_id = id;
        add_hook(&match_return, RETURN_HOOK);
        add_hook(&match_end_func, AFTER_FUNC_HOOK);
        for (i = 0; allocation_funcs[i]; i++) {
                add_function_assign_hook(allocation_funcs[i],
                                         &match_allocation, NULL);
        }
}