--
-- Initialize some very basic things
+function core.error_handler(err, level)
+ return debug.traceback(tostring(err), level)
+end
do
local function concat_args(...)
local n, t = select("#", ...), {...}
Functions: bit.tobit, bit.tohex, bit.bnot, bit.band, bit.bor, bit.bxor, bit.lshift, bit.rshift, bit.arshift, bit.rol, bit.ror, bit.bswap
See http://bitop.luajit.org/ for advanced information.
+
+Error Handling
+--------------
+
+When an error occurs that is not caught, Minetest calls the function
+`minetest.error_handler` with the error object as its first argument. The second
+argument is the stack level where the error occurred. The return value is the
+error string that should be shown. By default this is a backtrace from
+`debug.traceback`. If the error object is not a string, it is first converted
+with `tostring` before being displayed. This means that you can use tables as
+error objects so long as you give them `__tostring` metamethods.
+
+You can override `minetest.error_handler`. You should call the previous handler
+with the correct stack level in your implementation.
std::string script_get_backtrace(lua_State *L)
{
- lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE);
+ lua_getglobal(L, "debug");
+ lua_getfield(L, -1, "traceback");
lua_call(L, 0, 1);
std::string result = luaL_checkstring(L, -1);
- lua_pop(L, 1);
+ lua_pop(L, 2);
return result;
}
return lua_error(L); // Rethrow as a Lua error.
}
+int script_error_handler(lua_State *L)
+{
+ lua_getglobal(L, "core");
+ lua_getfield(L, -1, "error_handler");
+ if (!lua_isnil(L, -1)) {
+ lua_pushvalue(L, 1);
+ } else {
+ // No Lua error handler available. Call debug.traceback(tostring(#1), level).
+ lua_getglobal(L, "debug");
+ lua_getfield(L, -1, "traceback");
+ lua_getglobal(L, "tostring");
+ lua_pushvalue(L, 1);
+ lua_call(L, 1, 1);
+ }
+ lua_pushinteger(L, 2); // Stack level
+ lua_call(L, 2, 1);
+ return 1;
+}
+
/*
* Note that we can't get tracebacks for LUA_ERRMEM or LUA_ERRERR (without
* hacking Lua internals). For LUA_ERRMEM, this is because memory errors will
CUSTOM_RIDX_SCRIPTAPI,
CUSTOM_RIDX_GLOBALS_BACKUP,
CUSTOM_RIDX_CURRENT_MOD_NAME,
- CUSTOM_RIDX_BACKTRACE,
+ CUSTOM_RIDX_ERROR_HANDLER,
CUSTOM_RIDX_HTTP_API_LUA,
CUSTOM_RIDX_METATABLE_MAP,
// Pushes the error handler onto the stack and returns its index
#define PUSH_ERROR_HANDLER(L) \
- (lua_rawgeti((L), LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE), lua_gettop((L)))
+ (lua_rawgeti((L), LUA_REGISTRYINDEX, CUSTOM_RIDX_ERROR_HANDLER), lua_gettop((L)))
#define PCALL_RESL(L, RES) { \
int result_ = (RES); \
std::string script_get_backtrace(lua_State *L);
// Wrapper for CFunction calls that converts C++ exceptions to Lua errors
int script_exception_wrapper(lua_State *L, lua_CFunction f);
+// Acts as the error handler for lua_pcall
+int script_error_handler(lua_State *L);
// Takes an error from lua_pcall and throws it as a LuaError
void script_error(lua_State *L, int pcall_result, const char *mod, const char *fxn);
#endif
lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);
- // Add and save an error handler
- lua_getglobal(m_luastack, "debug");
- lua_getfield(m_luastack, -1, "traceback");
- lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE);
- lua_pop(m_luastack, 1); // pop debug
+ lua_pushcfunction(m_luastack, script_error_handler);
+ lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_ERROR_HANDLER);
// Add a C++ wrapper function to catch exceptions thrown in Lua -> C++ calls
#if USE_LUAJIT