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Lua Set Error Handler


Does "PerformCall" expect calling code to setup the stack in someway prior to call? Considering that Lua uses longjmp ubiquitously for error handling, this is not ideal ­čÖé The solution: The easiest solution is to compile Lua as C++. (In Visual Studio, use option /TP; Another example for syntax error is shown below − for a= 1,10 print(a) end When we run the above program, we will get the following output − lua: test2.lua:2: 'do' expected Error Handling wiki This page contains links and discussions on Lua error handling, including exception handling. check over here

Note protected_function_result safely pops its values off the stack when its destructor is called, keeping track of the index and number of arguments that were supposed to be returned. A setjmp/longjmp call pair has undefined behavior if replacing the setjmp and longjmp by catch and throw would invoke any non-trivial destructors for any automatic objects. (Note: I have seen different Args> protected_function_result operator()( Args&&... Why didn't Hans Gruber know what Mr. http://lua-users.org/wiki/ErrorHandling

Lua Error Function

Problem 2: C++ exceptions should not propagate through Lua The scenario: We have written a C++ function and made it available to Lua (via lua_pushcfunction or lua_pushcclosure). Where did the popularity of the `i` variable come from? You can grab a function directly off the stack using the constructor, or pass to it 2 valid functions, which we'll demonstrate a little later. To know more about how function arguments are handled, see this note. ┬źfunction :: Contents :: coroutine┬╗ © Copyright 2016, ThePhD.

In Knights I don't currently wrap Lua API calls in a lua_pcall. (The exception is when I call Lua functions, where I do generally use lua_pcall instead of lua_call.) Therefore, if Passing a level 0 avoids the addition of error position information to the message. What about after the call complete? –greatwolf Aug 15 '13 at 1:43 PerformCall gets called each D3D9-BeginScene to call the render function. Lua_error else ...

c exception error-handling lua share|improve this question edited May 4 '15 at 2:55 asked May 4 '15 at 2:49 Thomas 2,0851730 add a comment| 1 Answer 1 active oldest votes up Lua Pcall Example Why are license plates for bicycles no longer used? The codegolf object Was Harry's concern about Fleur's sister Gabrielle misplaced? find more The default action after a panic is for Lua to abort the program.

return p.result; } As you can see, the general idea is to create a local struct, with a static "run" method, and then lua_pcall that method. Lua Xpcall Example Name (required) Mail (will not be published) (required) Website Knights Development Blog is proudly powered by WordPress Entries (RSS) and Comments (RSS). The error handler function needs to take a single string argument (use type std::string if you want to use a C++ function bound to lua as the error handler) and return None of the type enquiry functions -- lua_is*, lua_type and lua_typename -- will ever throw an error, and neither will the functions which set/get metatables and environments.

Lua Pcall Example

Things would also be a bit messier because you'd have to modify lua_pcallk (the yieldable version of lua_pcall). –siffiejoe May 4 '15 at 4:47 Ah, very good point, I https://www.tutorialspoint.com/lua/lua_error_handling.htm And get rid of the debug.trace call in LuaErrorReport. Lua Error Function The error message identifies the kind or error. Lua Pcall Arguments I write this because of the other errors.

I would either change that to lua_pushvalue(L, -3); or lua_pushstring(L, msg); Lastly, you should also considering passing debug.traceback as the error function to lua_pcall to get a more meaningful stacktrace error Forever Why is water-contaminated fuel bad, but water-injection is not? MUSHclient help. API functions which push complex objects (strings, tables, closures, threads, full userdata) may throw a memory error. Lua Xpcall

I will present this as a series of problems that can occur, and possible solutions to each. It has 7-pointed leaves Why doesn't my (battery-powered) light work in the cold? Should I defragment my SSD? this content While still largely relevant for later versions, there are some differences.The fourth edition targets Lua 5.3 and is available at Amazon and other bookstores.By buying the book, you also help to

function add(a,b) return a+b end add(10) When we build the program, it will build successfully and run. Lual_error A good example of this is the standard liolib.c which uses this strategy to avoid leaking file descriptors. -- RiciLake See Also LuaList:2005-08/msg00054.html - lua_error() and C++ LuaList:2006-10/msg00310.html - Lua error We would like to change this so we get a luaL_traceback traceback in addition to the exception message on top of the stack on lua_pcall failure.

sol::error err = secondwoof; std::string what = err.what(); } This code is much more long-winded than its function counterpart but allows a person to check for errors.

This conversion to a C++ exception is only needed if the C++ code in the call chain allocated memory in the RAII fashion. --DavidManura Lua C API Functions that Raise Errors Additional comments are welcome. ] Linking If you compile Lua in C, you must surround your #include in an extern "C", or use the #include equivalent, else you will Assert and Error Functions In order to handle errors, we often use two functions − assert and error. Lua Error Wow Not the answer you're looking for?

Military Tank drone, why are they not common yet? Note: Panic Functions An alternative strategy would be to install a panic function, using lua_atpanic. Return the result. They could be working on different lua_State which can happen like in the context of a coroutine.

Can you have negative sets? More often, the error needs to be dealt with at a more shallow point in the call chain. The Language Chapter 8. If some error occurs in function f, it does not throw an error.