sol2/sol/trampoline.hpp
Alexander Hoischen f0396f8e6b Fix Exceptions Always Being Printed
This commit fixes the issue, that exception messages were always printed
to cerr, regardless of SOL_PRINT_ERRORS setting. This also makes the
inclusion of iostream completely optional, reducing binary sizes.

Fixes #652.
2018-06-11 21:27:54 +02:00

217 lines
7.4 KiB
C++

// sol2
// The MIT License (MIT)
// Copyright (c) 2013-2018 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_TRAMPOLINE_HPP
#define SOL_TRAMPOLINE_HPP
#include "types.hpp"
#include "traits.hpp"
#include <exception>
#include <cstring>
#if defined(SOL_PRINT_ERRORS) && SOL_PRINT_ERRORS
#include <iostream>
#endif
namespace sol {
// must push a single object to be the error object
// NOTE: the VAST MAJORITY of all Lua libraries -- C or otherwise -- expect a string for the type of error
// break this convention at your own risk
using exception_handler_function = int(*)(lua_State*, optional<const std::exception&>, string_view);
namespace detail {
inline const char(&default_exception_handler_name())[11]{
static const char name[11] = "sol.\xE2\x98\xA2\xE2\x98\xA2";
return name;
}
// must push at least 1 object on the stack
inline int default_exception_handler(lua_State* L, optional<const std::exception&>, string_view what) {
#if defined(SOL_PRINT_ERRORS) && SOL_PRINT_ERRORS
std::cerr << "[sol2] An exception occurred: ";
std::cerr.write(what.data(), what.size());
std::cerr << std::endl;
#endif
lua_pushlstring(L, what.data(), what.size());
return 1;
}
inline int call_exception_handler(lua_State* L, optional<const std::exception&> maybe_ex, string_view what) {
lua_getglobal(L, default_exception_handler_name());
type t = static_cast<type>(lua_type(L, -1));
if (t != type::lightuserdata) {
lua_pop(L, 1);
return default_exception_handler(L, std::move(maybe_ex), std::move(what));
}
void* vfunc = lua_touserdata(L, -1);
lua_pop(L, 1);
if (vfunc == nullptr) {
return default_exception_handler(L, std::move(maybe_ex), std::move(what));
}
exception_handler_function exfunc = reinterpret_cast<exception_handler_function>(vfunc);
return exfunc(L, std::move(maybe_ex), std::move(what));
}
#ifdef SOL_NO_EXCEPTIONS
template <lua_CFunction f>
int static_trampoline(lua_State* L) noexcept {
return f(L);
}
#ifdef SOL_NOEXCEPT_FUNCTION_TYPE
template <lua_CFunction_noexcept f>
int static_trampoline_noexcept(lua_State* L) noexcept {
return f(L);
}
#else
template <lua_CFunction f>
int static_trampoline_noexcept(lua_State* L) noexcept {
return f(L);
}
#endif
template <typename Fx, typename... Args>
int trampoline(lua_State* L, Fx&& f, Args&&... args) noexcept {
return f(L, std::forward<Args>(args)...);
}
inline int c_trampoline(lua_State* L, lua_CFunction f) noexcept {
return trampoline(L, f);
}
#else
template <lua_CFunction f>
int static_trampoline(lua_State* L) {
#if defined(SOL_EXCEPTIONS_SAFE_PROPAGATION) && !defined(SOL_LUAJIT)
return f(L);
#else
try {
return f(L);
}
catch (const char* cs) {
call_exception_handler(L, optional<const std::exception&>(nullopt), string_view(cs));
}
catch (const std::string& s) {
call_exception_handler(L, optional<const std::exception&>(nullopt), string_view(s.c_str(), s.size()));
}
catch (const std::exception& e) {
call_exception_handler(L, optional<const std::exception&>(e), e.what());
}
#if !defined(SOL_EXCEPTIONS_SAFE_PROPAGATION)
// LuaJIT cannot have the catchall when the safe propagation is on
// but LuaJIT will swallow all C++ errors
// if we don't at least catch std::exception ones
catch (...) {
call_exception_handler(L, optional<const std::exception&>(nullopt), "caught (...) exception");
}
#endif // LuaJIT cannot have the catchall, but we must catch std::exceps for it
return lua_error(L);
#endif // Safe exceptions
}
#ifdef SOL_NOEXCEPT_FUNCTION_TYPE
#if 0
// impossible: g++/clang++ choke as they think this function is ambiguous:
// to fix, wait for template <auto X> and then switch on no-exceptness of the function
template <lua_CFunction_noexcept f>
int static_trampoline(lua_State* L) noexcept {
return f(L);
}
#else
template <lua_CFunction_noexcept f>
int static_trampoline_noexcept(lua_State* L) noexcept {
return f(L);
}
#endif // impossible
#else
template <lua_CFunction f>
int static_trampoline_noexcept(lua_State* L) noexcept {
return f(L);
}
#endif // noexcept lua_CFunction type
template <typename Fx, typename... Args>
int trampoline(lua_State* L, Fx&& f, Args&&... args) {
if (meta::bind_traits<meta::unqualified_t<Fx>>::is_noexcept) {
return f(L, std::forward<Args>(args)...);
}
#if defined(SOL_EXCEPTIONS_SAFE_PROPAGATION) && !defined(SOL_LUAJIT)
return f(L, std::forward<Args>(args)...);
#else
try {
return f(L, std::forward<Args>(args)...);
}
catch (const char* cs) {
call_exception_handler(L, optional<const std::exception&>(nullopt), string_view(cs));
}
catch (const std::string& s) {
call_exception_handler(L, optional<const std::exception&>(nullopt), string_view(s.c_str(), s.size()));
}
catch (const std::exception& e) {
call_exception_handler(L, optional<const std::exception&>(e), e.what());
}
#if !defined(SOL_EXCEPTIONS_SAFE_PROPAGATION)
// LuaJIT cannot have the catchall when the safe propagation is on
// but LuaJIT will swallow all C++ errors
// if we don't at least catch std::exception ones
catch (...) {
call_exception_handler(L, optional<const std::exception&>(nullopt), "caught (...) exception");
}
#endif
return lua_error(L);
#endif
}
inline int c_trampoline(lua_State* L, lua_CFunction f) {
return trampoline(L, f);
}
#endif // Exceptions vs. No Exceptions
template <typename F, F fx>
inline int typed_static_trampoline_raw(std::true_type, lua_State* L) {
return static_trampoline_noexcept<fx>(L);
}
template <typename F, F fx>
inline int typed_static_trampoline_raw(std::false_type, lua_State* L) {
return static_trampoline<fx>(L);
}
template <typename F, F fx>
inline int typed_static_trampoline(lua_State* L) {
return typed_static_trampoline_raw<F, fx>(std::integral_constant<bool, meta::bind_traits<F>::is_noexcept>(), L);
}
} // namespace detail
inline void set_default_exception_handler(lua_State* L, exception_handler_function exf = &detail::default_exception_handler) {
static_assert(sizeof(void*) >= sizeof(exception_handler_function), "void* storage is too small to transport the exception handler: please file a bug on the issue tracker");
void* storage;
std::memcpy(&storage, &exf, sizeof(exception_handler_function));
lua_pushlightuserdata(L, storage);
lua_setglobal(L, detail::default_exception_handler_name());
}
} // sol
#endif // SOL_TRAMPOLINE_HPP