Convert to a true DLL engine

luprex/cpp/core/luastack.hpp

@@ -158,12 +158,10 @@
 #include "wrap-set.hpp"
 #include <cstring>
 
-extern "C" {
 #include "lua.h"
 #include "lauxlib.h"
 #include "lualib.h"
 #include "eris.h"
-}
 
 class LuaSlot : public eng::nevernew {
 protected:

luprex/cpp/drv/driver-linux.cpp

@@ -217,17 +217,11 @@ static int console_read(char *bytes, int nbytes) {
     return read(0, bytes, nbytes);
 }
 
-// Load the DLL if it's not already loaded. Stores
-// the handle in a global variable.
-static void load_engine_dll() {
-    // Not actually implemented yet.  Currently, the engine
-    // is linked right into the executable.
-}
-
 static void call_init_engine_wrapper(EngineWrapper *w) {
-    load_engine_dll();
     using InitFn = void (*)(EngineWrapper *);
-    InitFn initfn = (InitFn)dlsym(RTLD_DEFAULT, "init_engine_wrapper");
+    void *dll_handle = dlopen("./luprex.so", RTLD_NOW | RTLD_LOCAL);
+    assert(dll_handle != nullptr);
+    InitFn initfn = (InitFn)dlsym(dll_handle, "init_engine_wrapper");
     assert(initfn != nullptr);
     initfn(w);
 }