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Fixed handling Lua errors in nested callbacks (#3755)

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This commit is contained in:
Mattes D 2017-06-09 12:16:31 +02:00 committed by Lukas Pioch
parent 7922e6addb
commit 3c4e443ddc
4 changed files with 60 additions and 3 deletions
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12
Server/Plugins/Debuggers/Debuggers.lua
View File

@ -2279,6 +2279,18 @@ end
function HandleConsoleTestErr(a_Split, a_EntireCmd)
cRoot:Get():GetDefaultWorld():ForEachEntity(
function (a_CBEntity)
error("This error should not abort the server")
end
)
end
function HandleConsoleTestJson(a_Split, a_EntireCmd)
LOG("Testing Json parsing...")
local t1 = cJson:Parse([[{"a": 1, "b": "2", "c": [3, "4", 5], "d": true }]])

6
Server/Plugins/Debuggers/Info.lua
View File

@ -350,6 +350,12 @@ g_PluginInfo =
HelpString = "Tests inter-plugin calls with various values"
},
["testerr"] =
{
Handler = HandleConsoleTestErr,
HelpString = "Tests the server's ability to recover from errors in callbacks (GH #3733)",
},
["testjson"] =
{
Handler = HandleConsoleTestJson,

8
src/Bindings/LuaState.cpp
View File

@ -1454,8 +1454,12 @@ bool cLuaState::CallFunction(int a_NumResults)
LOGWARNING("Error in %s calling function %s()", m_SubsystemName.c_str(), CurrentFunctionName.c_str());
// Remove the error handler and error message from the stack:
ASSERT(lua_gettop(m_LuaState) == 2);
lua_pop(m_LuaState, 2);
auto top = lua_gettop(m_LuaState);
if (top < 2)
{
LogStackValues(Printf("The Lua stack is in an unexpected state, expected at least two values there, but got %d", top).c_str());
}
lua_pop(m_LuaState, std::min(2, top));
return false;
}

37
src/Bindings/LuaState.h
View File

@ -105,6 +105,41 @@ public:
#define ASSERT_LUA_STACK_BALANCE(...)
#endif
/** Makes sure that the Lua state's stack has the same number of elements on destruction as it had on construction of this object (RAII).
Can only remove elements, if there are less than expected, throws. */
class cStackBalancePopper
{
public:
cStackBalancePopper(cLuaState & a_LuaState):
m_LuaState(a_LuaState),
m_Count(lua_gettop(a_LuaState))
{
}
~cStackBalancePopper()
{
auto curTop = lua_gettop(m_LuaState);
if (curTop > m_Count)
{
// There are some leftover elements, adjust the stack:
m_LuaState.LogStackValues(Printf("Re-balancing Lua stack, expected %d values, got %d:", m_Count, curTop).c_str());
lua_pop(m_LuaState, curTop - m_Count);
}
else if (curTop < m_Count)
{
// This is an irrecoverable error, rather than letting the Lua engine crash undefinedly later on, abort now:
LOGERROR("Unable to re-balance Lua stack, there are elements missing. Expected at least %d elements, got %d.", m_Count, curTop);
throw std::runtime_error(Printf("Unable to re-balance Lua stack, there are elements missing. Expected at least %d elements, got %d.", m_Count, curTop));
}
}
protected:
cLuaState & m_LuaState;
int m_Count;
};
/** Provides a RAII-style locking for the LuaState.
Used mainly by the cPluginLua internals to provide the actual locking for interface operations, such as callbacks. */
class cLock
@ -704,7 +739,7 @@ public:
template <typename FnT, typename... Args>
bool Call(const FnT & a_Function, Args &&... args)
{
ASSERT_LUA_STACK_BALANCE(m_LuaState);
cStackBalancePopper balancer(*this);
m_NumCurrentFunctionArgs = -1;
if (!PushFunction(std::forward<const FnT &>(a_Function)))
{