Fix for #2237: intermittent Lua data stack overflow.

Use a static unordered_map to allow a function receiving (lua_State* L) to
look up the LuaState instance managing that lua_State. We've thought about
this from time to time already. LuaState's constructor creates the map entry;
its destructor removes it; the new static getParent(lua_State* L) method
performs the lookup.

Migrate lluau::set_interrupts_counter() and check_interrupts_counter() into
LuaState member functions. Add a new mInterrupts counter for them.

Importantly, LuaState::check_interrupts_counter(), which is indirectly called
by a lua_callbacks().interrupt function, no longer performs any Lua stack
operations. Empirically, it seems the Lua engine is capable of interrupting
itself at a moment when re-entry confuses it.

Change previous lluau::set_interrupts_counter(L, 0) calls to
LuaState::getParent(L).set_interrupts_counter(0).

Also add LuaStackDelta class, and a lua_checkdelta() helper macro, to verify
that the Lua data stack depth on exit from a block differs from the depth on
entry by exactly the expected amount. Sprinkle lua_checkdelta() macros in
likely places.

0 files changed, 0 insertions, 0 deletions