/* Literal sign folding.
   Copyright (C) 2025 Free Software Foundation, Inc.

GCC 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 3, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "elna/boot/materialization.h"

namespace elna::boot
{
    materialization_error::materialization_error(const source_position position, kind error_kind)
        : diagnostic(position), m_kind(error_kind)
    {
    }

    std::string materialization_error::what() const
    {
        switch (this->m_kind)
        {
            using enum kind;
            case integer_overflow:
                return "Integer literal overflows";
            case real_overflow:
                return "Real literal overflows";
        }
        __builtin_unreachable();
    }

    materialization_visitor::materialization_visitor(const target_info& target)
        : target(target)
    {
    }

    void materialization_visitor::visit(literal<integer_literal> *literal)
    {
        switch (literal->wants_signed)
        {
            using enum integer_sign;
            case negative:
                if (auto negated_literal = literal->value.negate())
                {
                    literal->value = negated_literal.value();
                    if (!literal->has_explicit_size
                            && !literal->value.fit_into(true, target.int_properties.front().size))
                    {
                        add_error<materialization_error>(literal->position(),
                                materialization_error::kind::integer_overflow);
                    }
                }
                else
                {
                    add_error<materialization_error>(literal->position(),
                            materialization_error::kind::integer_overflow);
                }
                break;
            case unmarked:
            {
                const auto target_size = literal->has_explicit_size
                    ? literal->value.size()
                    : target.int_properties.front().size;

                if (!literal->value.fit_into(true, target_size))
                {
                    add_error<materialization_error>(literal->position(),
                            materialization_error::kind::integer_overflow);
                }
                break;
            }
            case _unsigned:
                if (!literal->has_explicit_size
                        && !literal->value.fit_into(false, target.word_properties.front().size))
                {
                    add_error<materialization_error>(literal->position(),
                            materialization_error::kind::integer_overflow);
                }
                break;
        }
    }

    void materialization_visitor::visit(literal<float_literal> *literal)
    {
        if (!literal->value.is_finite())
        {
            add_error<materialization_error>(literal->position(),
                    materialization_error::kind::real_overflow);
        }
    }
}