sol2/examples/source/script_error_handling.cpp
2022-11-09 18:33:16 -05:00

104 lines
3.0 KiB
C++

#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include <iostream>
int main(int, char**) {
std::cout << "=== script error handling ===" << std::endl;
sol::state lua;
std::string code = R"(
bad&$#*$syntax
bad.code = 2
return 24
)";
/* OPTION 1 */
// Handling code like this can be robust
// If you disable exceptions, then obviously you would
// remove the try-catch branches, and then rely on the
// `lua_atpanic` function being called and trapping errors
// there before exiting the application
{
// script_default_on_error throws / panics when the
// code is bad: trap the error
try {
int value = lua.script(
code, sol::script_default_on_error);
// This will never be reached
std::cout << value << std::endl;
SOL_ASSERT(value == 24);
}
catch (const sol::error& err) {
std::cout << "Something went horribly wrong: "
"thrown error"
<< "\n\t" << err.what() << std::endl;
}
}
/* OPTION 2 */
// Use the script_pass_on_error handler
// this simply passes through the protected_function_result,
// rather than throwing it or calling panic
// This will check code validity and also whether or not it
// runs well
{
sol::protected_function_result result
= lua.script(code, sol::script_pass_on_error);
SOL_ASSERT(!result.valid());
if (!result.valid()) {
sol::error err = result;
sol::call_status status = result.status();
std::cout << "Something went horribly wrong: "
<< sol::to_string(status) << " error"
<< "\n\t" << err.what() << std::endl;
}
}
/* OPTION 3 */
// This is a lower-level, more explicit way to load code
// This explicitly loads the code, giving you access to any
// errors plus the load status then, it turns the loaded
// code into a sol::protected_function which is then called
// so that the code can run you can then check that too, for
// any errors The two previous approaches are recommended
{
sol::load_result loaded_chunk = lua.load(code);
SOL_ASSERT(!loaded_chunk.valid());
if (!loaded_chunk.valid()) {
sol::error err = loaded_chunk;
sol::load_status status = loaded_chunk.status();
std::cout << "Something went horribly wrong "
"loading the code: "
<< sol::to_string(status) << " error"
<< "\n\t" << err.what() << std::endl;
}
else {
// Because the syntax is bad, this will never be
// reached
SOL_ASSERT(false);
// If there is a runtime error (lua GC memory
// error, nil access, etc.) it will be caught here
sol::protected_function script_func
= loaded_chunk
.get<sol::protected_function>();
sol::protected_function_result result
= script_func();
if (!result.valid()) {
sol::error err = result;
sol::call_status status = result.status();
std::cout
<< "Something went horribly wrong "
"running the code: "
<< sol::to_string(status) << " error"
<< "\n\t" << err.what() << std::endl;
}
}
}
std::cout << std::endl;
return 0;
}