#pragma once
/*
* Copyright (C) 2024 Brett Terpstra
*
* 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 3 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 <https://www.gnu.org/licenses/>.
*/
#ifndef BLT_GP_OPERATIONS_H
#define BLT_GP_OPERATIONS_H
#include <blt/std/types.h>
#include <blt/gp/typesystem.h>
#include <blt/gp/stack.h>
#include <blt/gp/util/meta.h>
#include <functional>
#include <type_traits>
#include <optional>
namespace blt::gp
{
template <typename Return, typename... Args>
struct call_with
{
template <u64 index>
[[nodiscard]] constexpr static size_t getByteOffset()
{
size_t offset = 0;
size_t current_index = 0;
((offset += (current_index++ > index ? stack_allocator::aligned_size<detail::remove_cv_ref<Args>>() : 0)), ...);
(void)current_index;
return offset;
}
template <u64... indices>
void print_args(std::integer_sequence<u64, indices...>)
{
BLT_INFO("Arguments:");
(BLT_INFO("%ld: %s", indices, blt::type_string<Args>().c_str()), ...);
}
template <typename Func, u64... indices, typename... ExtraArgs>
static constexpr Return exec_sequence_to_indices(Func&& func, stack_allocator& allocator, std::integer_sequence<u64, indices...>,
ExtraArgs&&... args)
{
//blt::size_t arg_size = (stack_allocator::aligned_size<detail::remove_cv_ref<Args>>() + ...);
//BLT_TRACE(arg_size);
// expands Args and indices, providing each argument with its index calculating the current argument byte offset
return std::forward<Func>(func)(std::forward<ExtraArgs>(args)...,
allocator.from<detail::remove_cv_ref<Args>>(getByteOffset<indices>())...);
}
template<typename T>
static void call_drop(stack_allocator& read_allocator, const size_t offset)
{
if constexpr (blt::gp::detail::has_func_drop_v<T>)
{
auto [type, ptr] = read_allocator.access_pointer<detail::remove_cv_ref<T>>(offset);
if (!ptr.bit(0))
type.drop();
}
}
static void call_destructors(stack_allocator& read_allocator)
{
if constexpr (sizeof...(Args) > 0)
{
size_t offset = (stack_allocator::aligned_size<detail::remove_cv_ref<Args>>() + ...) - stack_allocator::aligned_size<
detail::remove_cv_ref<typename meta::arg_helper<Args...>::First>>();
((call_drop<Args>(read_allocator, offset), offset -= stack_allocator::aligned_size<detail::remove_cv_ref<Args>>()), ...);
(void)offset;
}
}
template <typename Func, typename... ExtraArgs>
Return operator()(const bool, Func&& func, stack_allocator& read_allocator, ExtraArgs&&... args)
{
constexpr auto seq = std::make_integer_sequence<u64, sizeof...(Args)>();
#if BLT_DEBUG_LEVEL > 0
try
{
#endif
Return ret = exec_sequence_to_indices(std::forward<Func>(func), read_allocator, seq, std::forward<ExtraArgs>(args)...);
call_destructors(read_allocator);
read_allocator.pop_bytes((stack_allocator::aligned_size<detail::remove_cv_ref<Args>>() + ...));
return ret;
#if BLT_DEBUG_LEVEL > 0
} catch (const std::runtime_error& e)
{
print_args(seq);
throw std::runtime_error(e.what());
}
#endif
}
};
template <typename Return, typename, typename... Args>
struct call_without_first : public call_with<Return, Args...>
{
using call_with<Return, Args...>::call_with;
};
template <typename, typename>
class operation_t;
template <typename RawFunction, typename Return, typename... Args>
class operation_t<RawFunction, Return(Args...)>
{
public:
using function_t = RawFunction;
using First_Arg = typename blt::meta::arg_helper<Args...>::First;
constexpr operation_t(const operation_t& copy) = default;
constexpr operation_t(operation_t&& move) = default;
template <typename Functor>
constexpr explicit operation_t(const Functor& functor, const std::optional<std::string_view> name = {}): func(functor), name(name)
{
}
[[nodiscard]] constexpr Return operator()(stack_allocator& read_allocator) const
{
if constexpr (sizeof...(Args) == 0)
{
return func();
}
else
{
return call_with<Return, Args...>()(false, func, read_allocator);
}
}
[[nodiscard]] constexpr Return operator()(void* context, stack_allocator& read_allocator) const
{
// should be an impossible state
if constexpr (sizeof...(Args) == 0)
{
BLT_ABORT("Cannot pass context to function without arguments!");
}
auto& ctx_ref = *static_cast<detail::remove_cv_ref<typename detail::first_arg<Args...>::type>*>(context);
if constexpr (sizeof...(Args) == 1)
{
return func(ctx_ref);
}
else
{
return call_without_first<Return, Args...>()(true, func, read_allocator, ctx_ref);
}
}
template <typename Context>
[[nodiscard]] detail::operator_func_t make_callable() const
{
return [this](void* context, stack_allocator& read_allocator, stack_allocator& write_allocator)
{
if constexpr (detail::is_same_v<Context, detail::remove_cv_ref<typename detail::first_arg<Args...>::type>>)
{
// first arg is context
write_allocator.push(this->operator()(context, read_allocator));
}
else
{
// first arg isn't context
write_allocator.push(this->operator()(read_allocator));
}
};
}
[[nodiscard]] inline constexpr std::optional<std::string_view> get_name() const
{
return name;
}
inline constexpr const auto& get_function() const
{
return func;
}
auto set_ephemeral()
{
is_ephemeral_ = true;
return *this;
}
[[nodiscard]] bool is_ephemeral() const
{
return is_ephemeral_;
}
[[nodiscard]] bool return_has_ephemeral_drop() const
{
return detail::has_func_drop_v<Return>;
}
operator_id id = -1;
private:
function_t func;
std::optional<std::string_view> name;
bool is_ephemeral_ = false;
};
template <typename RawFunction, typename Return, typename Class, typename... Args>
class operation_t<RawFunction, Return (Class::*)(Args...) const> : public operation_t<RawFunction, Return(Args...)>
{
public:
using operation_t<RawFunction, Return(Args...)>::operation_t;
};
template <typename Lambda>
operation_t(Lambda) -> operation_t<Lambda, decltype(&Lambda::operator())>;
template <typename Return, typename... Args>
operation_t(Return (*)(Args...)) -> operation_t<Return(*)(Args...), Return(Args...)>;
template <typename Lambda>
operation_t(Lambda, std::optional<std::string_view>) -> operation_t<Lambda, decltype(&Lambda::operator())>;
template <typename Return, typename... Args>
operation_t(Return (*)(Args...), std::optional<std::string_view>) -> operation_t<Return(*)(Args...), Return(Args...)>;
}
#endif //BLT_GP_OPERATIONS_H