/*
 * Copyright (C) 2013 Oracle.
 *
 * 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 "smatch.h"

ALLOCATOR(var_sym, "var_sym structs");

struct var_sym *alloc_var_sym(const char *var, struct symbol *sym)
{
        struct var_sym *tmp;

        tmp = __alloc_var_sym(0);
        tmp->var = alloc_string(var);
        tmp->sym = sym;
        return tmp;
}

struct var_sym_list *expr_to_vsl(struct expression *expr)
{
        struct expression *unop;
        struct var_sym_list *ret = NULL;
        char *var;
        struct symbol *sym;

        expr = strip_expr(expr);
        if (!expr)
                return NULL;

        if ((expr->type == EXPR_PREOP && expr->op == '*')) {
                unop = strip_expr(expr->unop);

                if (unop->type == EXPR_SYMBOL)
                        goto one_var;
                return expr_to_vsl(unop);
        }

        if (expr->type == EXPR_BINOP ||
            expr->type == EXPR_LOGICAL ||
            expr->type == EXPR_COMPARE) {
                struct var_sym_list *left, *right;

                left = expr_to_vsl(expr->left);
                right = expr_to_vsl(expr->right);
                ret = combine_var_sym_lists(left, right);
                free_var_syms_and_list(&left);
                free_var_syms_and_list(&right);
                return ret;
        }

        if (expr->type == EXPR_DEREF)
                return expr_to_vsl(expr->deref);

one_var:
        var = expr_to_var_sym(expr, &sym);
        if (!var || !sym) {
                free_string(var);
                return NULL;
        }
        add_var_sym(&ret, var, sym);
        return ret;
}

int cmp_var_sym(const struct var_sym *a, const struct var_sym *b)
{
        int ret;

        if (a == b)
                return 0;
        if (!b)
                return -1;
        if (!a)
                return 1;

        ret = strcmp(a->var, b->var);
        if (ret < 0)
                return -1;
        if (ret > 0)
                return 1;

        if (!b->sym && a->sym)
                return -1;
        if (!a->sym && b->sym)
                return 1;
        if (a->sym < b->sym)
                return -1;
        if (a->sym > b->sym)
                return 1;

        return 0;
}

void add_var_sym(struct var_sym_list **list, const char *var, struct symbol *sym)
{
        struct var_sym *tmp, *new;

        if (in_var_sym_list(*list, var, sym))
                return;
        new = alloc_var_sym(var, sym);

        FOR_EACH_PTR(*list, tmp) {
                if (cmp_var_sym(tmp, new) < 0)
                        continue;
                else if (cmp_var_sym(tmp, new) == 0) {
                        return;
                } else {
                        INSERT_CURRENT(new, tmp);
                        return;
                }
        } END_FOR_EACH_PTR(tmp);
        add_ptr_list(list, new);
}

void add_var_sym_expr(struct var_sym_list **list, struct expression *expr)
{
        char *var;
        struct symbol *sym;

        var = expr_to_var_sym(expr, &sym);
        if (!var || !sym)
                goto free;
        add_var_sym(list, var, sym);
free:
        free_string(var);
}

static void free_var_sym(struct var_sym *vs)
{
        free_string(vs->var);
        __free_var_sym(vs);
}

void del_var_sym(struct var_sym_list **list, const char *var, struct symbol *sym)
{
        struct var_sym *tmp;

        FOR_EACH_PTR(*list, tmp) {
                if (tmp->sym == sym && strcmp(tmp->var, var) == 0) {
                        DELETE_CURRENT_PTR(tmp);
                        free_var_sym(tmp);
                        return;
                }
        } END_FOR_EACH_PTR(tmp);
}

int in_var_sym_list(struct var_sym_list *list, const char *var, struct symbol *sym)
{
        struct var_sym *tmp;

        FOR_EACH_PTR(list, tmp) {
                if (tmp->sym == sym && strcmp(tmp->var, var) == 0)
                        return 1;
        } END_FOR_EACH_PTR(tmp);
        return 0;
}

struct var_sym_list *clone_var_sym_list(struct var_sym_list *from_vsl)
{
        struct var_sym *tmp, *clone_vs;
        struct var_sym_list *to_vsl = NULL;

        FOR_EACH_PTR(from_vsl, tmp) {
                clone_vs = alloc_var_sym(tmp->var, tmp->sym);
                add_ptr_list(&to_vsl, clone_vs);
        } END_FOR_EACH_PTR(tmp);
        return to_vsl;
}

void merge_var_sym_list(struct var_sym_list **dest, struct var_sym_list *src)
{
        struct var_sym *tmp;

        FOR_EACH_PTR(src, tmp) {
                add_var_sym(dest, tmp->var, tmp->sym);
        } END_FOR_EACH_PTR(tmp);
}

struct var_sym_list *combine_var_sym_lists(struct var_sym_list *one, struct var_sym_list *two)
{
        struct var_sym_list *to_vsl;

        to_vsl = clone_var_sym_list(one);
        merge_var_sym_list(&to_vsl, two);
        return to_vsl;
}

int var_sym_lists_equiv(struct var_sym_list *one, struct var_sym_list *two)
{
        struct var_sym *one_tmp, *two_tmp;

        if (one == two)
                return 1;

        if (ptr_list_size((struct ptr_list *)one) != ptr_list_size((struct ptr_list *)two))
                return 0;

        PREPARE_PTR_LIST(one, one_tmp);
        PREPARE_PTR_LIST(two, two_tmp);
        for (;;) {
                if (!one_tmp && !two_tmp)
                        return 1;
                if (one_tmp->sym != two_tmp->sym)
                        return 0;
                if (strcmp(one_tmp->var, two_tmp->var) != 0)
                        return 0;
                NEXT_PTR_LIST(one_tmp);
                NEXT_PTR_LIST(two_tmp);
        }
        FINISH_PTR_LIST(two_tmp);
        FINISH_PTR_LIST(one_tmp);

        return 1;
}

void free_var_sym_list(struct var_sym_list **list)
{
        __free_ptr_list((struct ptr_list **)list);
}

void free_var_syms_and_list(struct var_sym_list **list)
{
        struct var_sym *tmp;

        FOR_EACH_PTR(*list, tmp) {
                free_var_sym(tmp);
        } END_FOR_EACH_PTR(tmp);
        free_var_sym_list(list);
}