// sol2 // The MIT License (MIT) // Copyright (c) 2013-2021 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_ENVIRONMENT_HPP #define SOL_ENVIRONMENT_HPP #include <sol/table.hpp> namespace sol { template <typename base_type> struct basic_environment : basic_table<base_type> { private: typedef basic_table<base_type> base_t; public: using base_t::lua_state; basic_environment() noexcept = default; basic_environment(const basic_environment&) = default; basic_environment(basic_environment&&) = default; basic_environment& operator=(const basic_environment&) = default; basic_environment& operator=(basic_environment&&) = default; basic_environment(const stack_reference& r) : basic_environment(r.lua_state(), r.stack_index()) { } basic_environment(stack_reference&& r) : basic_environment(r.lua_state(), r.stack_index()) { } basic_environment(lua_State* L, new_table nt) : base_t(L, std::move(nt)) { } template <bool b> basic_environment(lua_State* L, new_table t, const basic_reference<b>& fallback) : basic_environment(L, std::move(t)) { stack_table mt(L, new_table(0, 1)); mt.set(meta_function::index, fallback); this->set(metatable_key, mt); mt.pop(); } basic_environment(env_key_t, const stack_reference& extraction_target) : base_t(detail::no_safety, extraction_target.lua_state(), (stack::push_environment_of(extraction_target), -1)) { #if SOL_IS_ON(SOL_SAFE_REFERENCES_I_) constructor_handler handler {}; stack::check<env_key_t>(this->lua_state(), -1, handler); #endif // Safety lua_pop(this->lua_state(), 2); } template <bool b> basic_environment(env_key_t, const basic_reference<b>& extraction_target) : base_t(detail::no_safety, extraction_target.lua_state(), (stack::push_environment_of(extraction_target), -1)) { #if SOL_IS_ON(SOL_SAFE_REFERENCES_I_) constructor_handler handler {}; stack::check<env_key_t>(this->lua_state(), -1, handler); #endif // Safety lua_pop(this->lua_state(), 2); } basic_environment(lua_State* L, int index = -1) : base_t(detail::no_safety, L, index) { #if SOL_IS_ON(SOL_SAFE_REFERENCES_I_) constructor_handler handler {}; stack::check<basic_environment>(L, index, handler); #endif // Safety } basic_environment(lua_State* L, ref_index index) : base_t(detail::no_safety, L, index) { #if SOL_IS_ON(SOL_SAFE_REFERENCES_I_) auto pp = stack::push_pop(*this); constructor_handler handler {}; stack::check<basic_environment>(L, -1, handler); #endif // Safety } template <typename T, meta::enable<meta::neg<meta::any_same<meta::unqualified_t<T>, basic_environment>>, 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_environment(T&& r) noexcept : base_t(detail::no_safety, std::forward<T>(r)) { #if SOL_IS_ON(SOL_SAFE_REFERENCES_I_) if (!is_environment<meta::unqualified_t<T>>::value) { auto pp = stack::push_pop(*this); constructor_handler handler {}; stack::check<basic_environment>(lua_state(), -1, handler); } #endif // Safety } basic_environment(lua_nil_t r) noexcept : base_t(detail::no_safety, r) { } template <typename T, meta::enable<is_lua_reference<meta::unqualified_t<T>>> = meta::enabler> basic_environment(lua_State* L, T&& r) noexcept : base_t(detail::no_safety, L, std::forward<T>(r)) { #if SOL_IS_ON(SOL_SAFE_REFERENCES_I_) if (!is_environment<meta::unqualified_t<T>>::value) { auto pp = stack::push_pop(*this); constructor_handler handler {}; stack::check<basic_environment>(lua_state(), -1, handler); } #endif // Safety } template <typename T> bool set_on(const T& target) const { lua_State* L = target.lua_state(); auto pp = stack::push_pop(target); int target_index = pp.index_of(target); #if SOL_LUA_VERSION_I_ < 502 // Use lua_setfenv this->push(); int success_result = lua_setfenv(L, target_index); return success_result != 0; #else // If this is a C function, the environment is always placed in // the first value, as is expected of sol2 (all upvalues have an empty name, "") if (lua_iscfunction(L, target_index) != 0) { const char* maybe_upvalue_name = lua_getupvalue(L, target_index, 1); if (maybe_upvalue_name == nullptr) { return false; } string_view upvalue_name(maybe_upvalue_name); if (upvalue_name == "") { this->push(); const char* success = lua_setupvalue(L, target_index, 1); if (success == nullptr) { // left things alone on the stack, pop them off lua_pop(L, 1); return false; } return true; } return false; } else { // Must search for the right upvalue target on index for (int upvalue_index = 1;; ++upvalue_index) { const char* maybe_upvalue_name = lua_getupvalue(L, target_index, upvalue_index); if (maybe_upvalue_name == nullptr) { break; } string_view upvalue_name(maybe_upvalue_name); if (upvalue_name == "_ENV") { this->push(); const char* success = lua_setupvalue(L, target_index, upvalue_index); if (success == nullptr) { // left things alone on the stack, pop them off lua_pop(L, 1); break; } // whether or not we succeeded, we found _ENV // so we need to break return true; } lua_pop(L, 1); } // if we get here, // we did not find an _ENV here... return false; } #endif } }; template <typename T, typename E> bool set_environment(const basic_environment<E>& env, const T& target) { return env.set_on(target); } template <typename E = reference, typename T> basic_environment<E> get_environment(const T& target) { lua_State* L = target.lua_state(); auto pp = stack::pop_n(L, stack::push_environment_of(target)); return basic_environment<E>(L, -1); } struct this_environment { optional<environment> env; this_environment() : env(nullopt) { } this_environment(environment e) : env(std::move(e)) { } this_environment(const this_environment&) = default; this_environment(this_environment&&) = default; this_environment& operator=(const this_environment&) = default; this_environment& operator=(this_environment&&) = default; explicit operator bool() const { return static_cast<bool>(env); } operator optional<environment>&() { return env; } operator const optional<environment>&() const { return env; } operator environment&() { return env.value(); } operator const environment&() const { return env.value(); } }; namespace stack { template <> struct unqualified_getter<env_key_t> { static environment get(lua_State* L, int index, record& tracking) { tracking.use(1); return get_environment(stack_reference(L, raw_index(index))); } }; template <> struct unqualified_getter<this_environment> { static this_environment get(lua_State* L, int, record& tracking) { tracking.use(0); lua_Debug info; // Level 0 means current function (this C function, which may or may not be useful for us?) // Level 1 means next call frame up the stack. (Can be nothing if function called directly from C++ with lua_p/call) int pre_stack_size = lua_gettop(L); if (lua_getstack(L, 1, &info) != 1) { if (lua_getstack(L, 0, &info) != 1) { lua_settop(L, pre_stack_size); return this_environment(); } } if (lua_getinfo(L, "f", &info) == 0) { lua_settop(L, pre_stack_size); return this_environment(); } stack_reference f(L, -1); environment env(env_key, f); if (!env.valid()) { lua_settop(L, pre_stack_size); return this_environment(); } return this_environment(std::move(env)); } }; } // namespace stack } // namespace sol #endif // SOL_ENVIRONMENT_HPP