// sol2 // The MIT License (MIT) // Copyright (c) 2013-2022 Rapptz, ThePhD and contributors // Permission is hereby granted, free of charge, to any person obtaining a copy of // this software and associated documentation files (the "Software"), to deal in // the Software without restriction, including without limitation the rights to // use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of // the Software, and to permit persons to whom the Software is furnished to do so, // subject to the following conditions: // The above copyright notice and this permission notice shall be included in all // copies or substantial portions of the Software. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS // FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR // COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. #ifndef SOL_METATABLE_HPP #define SOL_METATABLE_HPP #include <sol/table_core.hpp> #include <sol/usertype.hpp> namespace sol { template <typename base_type> class basic_metatable : public basic_table<base_type> { typedef basic_table<base_type> base_t; friend class state; friend class state_view; protected: basic_metatable(detail::no_safety_tag, lua_nil_t n) : base_t(n) { } basic_metatable(detail::no_safety_tag, lua_State* L, int index) : base_t(L, index) { } basic_metatable(detail::no_safety_tag, lua_State* L, ref_index index) : base_t(L, index) { } template <typename T, meta::enable<meta::neg<meta::any_same<meta::unqualified_t<T>, basic_metatable>>, meta::neg<std::is_same<base_type, stack_reference>>, meta::neg<std::is_same<lua_nil_t, meta::unqualified_t<T>>>, is_lua_reference<meta::unqualified_t<T>>> = meta::enabler> basic_metatable(detail::no_safety_tag, T&& r) noexcept : base_t(std::forward<T>(r)) { } template <typename T, meta::enable<is_lua_reference<meta::unqualified_t<T>>> = meta::enabler> basic_metatable(detail::no_safety_tag, lua_State* L, T&& r) noexcept : base_t(L, std::forward<T>(r)) { } template <typename R, typename... Args, typename Fx, typename Key, typename = std::invoke_result_t<Fx, Args...>> void set_fx(types<R(Args...)>, Key&& key, Fx&& fx) { set_resolved_function<R(Args...)>(std::forward<Key>(key), std::forward<Fx>(fx)); } template <typename Fx, typename Key, meta::enable<meta::is_specialization_of<meta::unqualified_t<Fx>, overload_set>> = meta::enabler> void set_fx(types<>, Key&& key, Fx&& fx) { set(std::forward<Key>(key), std::forward<Fx>(fx)); } template <typename Fx, typename Key, typename... Args, meta::disable<meta::is_specialization_of<meta::unqualified_t<Fx>, overload_set>> = meta::enabler> void set_fx(types<>, Key&& key, Fx&& fx, Args&&... args) { set(std::forward<Key>(key), as_function_reference(std::forward<Fx>(fx), std::forward<Args>(args)...)); } template <typename... Sig, typename... Args, typename Key> void set_resolved_function(Key&& key, Args&&... args) { set(std::forward<Key>(key), as_function_reference<function_sig<Sig...>>(std::forward<Args>(args)...)); } public: using base_t::lua_state; basic_metatable() noexcept = default; basic_metatable(const basic_metatable&) = default; basic_metatable(basic_metatable&&) = default; basic_metatable& operator=(const basic_metatable&) = default; basic_metatable& operator=(basic_metatable&&) = default; basic_metatable(const stack_reference& r) : basic_metatable(r.lua_state(), r.stack_index()) { } basic_metatable(stack_reference&& r) : basic_metatable(r.lua_state(), r.stack_index()) { } template <typename T, meta::enable_any<is_lua_reference<meta::unqualified_t<T>>> = meta::enabler> basic_metatable(lua_State* L, T&& r) : base_t(L, std::forward<T>(r)) { #if SOL_IS_ON(SOL_SAFE_REFERENCES) auto pp = stack::push_pop(*this); constructor_handler handler {}; stack::check<basic_metatable>(lua_state(), -1, handler); #endif // Safety } basic_metatable(lua_State* L, int index = -1) : basic_metatable(detail::no_safety, L, index) { #if SOL_IS_ON(SOL_SAFE_REFERENCES) constructor_handler handler {}; stack::check<basic_metatable>(L, index, handler); #endif // Safety } basic_metatable(lua_State* L, ref_index index) : basic_metatable(detail::no_safety, L, index) { #if SOL_IS_ON(SOL_SAFE_REFERENCES) auto pp = stack::push_pop(*this); constructor_handler handler {}; stack::check<basic_metatable>(lua_state(), -1, handler); #endif // Safety } template <typename T, meta::enable<meta::neg<meta::any_same<meta::unqualified_t<T>, basic_metatable>>, meta::neg<std::is_same<base_type, stack_reference>>, meta::neg<std::is_same<lua_nil_t, meta::unqualified_t<T>>>, is_lua_reference<meta::unqualified_t<T>>> = meta::enabler> basic_metatable(T&& r) noexcept : basic_metatable(detail::no_safety, std::forward<T>(r)) { #if SOL_IS_ON(SOL_SAFE_REFERENCES) if (!is_table<meta::unqualified_t<T>>::value) { auto pp = stack::push_pop(*this); constructor_handler handler {}; stack::check<basic_metatable>(base_t::lua_state(), -1, handler); } #endif // Safety } basic_metatable(lua_nil_t r) noexcept : basic_metatable(detail::no_safety, r) { } template <typename Key, typename Value> basic_metatable<base_type>& set(Key&& key, Value&& value); template <typename Sig, typename Key, typename... Args> basic_metatable& set_function(Key&& key, Args&&... args) { set_fx(types<Sig>(), std::forward<Key>(key), std::forward<Args>(args)...); return *this; } template <typename Key, typename... Args> basic_metatable& set_function(Key&& key, Args&&... args) { set_fx(types<>(), std::forward<Key>(key), std::forward<Args>(args)...); return *this; } void unregister() { using ustorage_base = u_detail::usertype_storage_base; lua_State* L = this->lua_state(); auto pp = stack::push_pop(*this); int top = lua_gettop(L); stack_reference mt(L, -1); stack::get_field(L, meta_function::gc_names, mt.stack_index()); if (type_of(L, -1) != type::table) { lua_settop(L, top); return; } stack_reference gc_names_table(L, -1); stack::get_field(L, meta_function::storage, mt.stack_index()); if (type_of(L, -1) != type::lightuserdata) { lua_settop(L, top); return; } ustorage_base& base_storage = *static_cast<ustorage_base*>(stack::get<void*>(L, -1)); std::array<string_view, 6> registry_traits; for (std::size_t i = 0; i < registry_traits.size(); ++i) { u_detail::submetatable_type smt = static_cast<u_detail::submetatable_type>(i); stack::get_field<false, true>(L, smt, gc_names_table.stack_index()); registry_traits[i] = stack::get<string_view>(L, -1); } // get the registry stack_reference registry(L, raw_index(LUA_REGISTRYINDEX)); registry.push(); // eliminate all named entries for this usertype // in the registry (luaL_newmetatable does // [name] = new table // in registry upon creation) for (std::size_t i = 0; i < registry_traits.size(); ++i) { u_detail::submetatable_type smt = static_cast<u_detail::submetatable_type>(i); const string_view& gcmetakey = registry_traits[i]; if (smt == u_detail::submetatable_type::named) { // use .data() to make it treat it like a c string, // which it is... stack::set_field<true>(L, gcmetakey.data(), lua_nil); } else { // do not change the values in the registry: they need to be present // no matter what, for safety's sake // stack::set_field(L, gcmetakey, lua_nil, registry.stack_index()); } } // destroy all storage and tables base_storage.clear(); // 6 strings from gc_names table, // + 1 registry, // + 1 gc_names table // + 1 light userdata of storage // + 1 registry // 10 total, 4 left since popping off 6 gc_names tables lua_settop(L, top); } }; } // namespace sol #endif // SOL_METATABLE_HPP