/*
 * Copyright (C) 2010 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
 */

/*
 * Complains about places that return -1 instead of -ENOMEM
 */

#include "smatch.h"
#include "smatch_slist.h"
#include "smatch_extra.h"

static int my_id;

static void match_return(struct expression *ret_value)
{
        struct expression *expr;
        struct sm_state *sm;
        struct stree *stree;
        sval_t sval;

        if (!ret_value)
                return;
        if (returns_unsigned(cur_func_sym))
                return;
        if (returns_pointer(cur_func_sym))
                return;
        if (!get_value(ret_value, &sval) || sval.value != -1)
                return;
        if (get_macro_name(ret_value->pos))
                return;

        stree = __get_cur_stree();

        FOR_EACH_MY_SM(SMATCH_EXTRA, stree, sm) {
                if (!estate_get_single_value(sm->state, &sval) || sval.value != 0)
                        continue;
                expr = get_assigned_expr_name_sym(sm->name, sm->sym);
                if (!expr)
                        continue;
                if (expr->type != EXPR_CALL || expr->fn->type != EXPR_SYMBOL)
                        continue;
                if (!expr->fn->symbol_name)
                        continue;
                /* To be honest the correct check is:
                 * if (strstr(expr->fn->symbol_name->name, "alloc"))
                 *      complain();
                 * But it generates too many warnings and it's too depressing.
                 */
                if (strcmp(expr->fn->symbol_name->name, "kmalloc") != 0 &&
                    strcmp(expr->fn->symbol_name->name, "kzalloc") != 0)
                        continue;

                sm_warning("returning -1 instead of -ENOMEM is sloppy");
                return;

        } END_FOR_EACH_SM(sm);
}

void check_return_enomem(int id)
{
        if (option_project != PROJ_KERNEL)
                return;

        my_id = id;
        add_hook(&match_return, RETURN_HOOK);
}