Add Data:getFFIPointer. Similar to Data:getPointer but returns a cdata pointer directly (or nil if the FFI isn't available).

It should be preferred instead of Data:getPointer because the latter uses lightuserdata which can't store more all possible memory addresses on some new arm64 architectures, when LuaJIT is used.

src/modules/data/wrap_Data.cpp

@@ -20,6 +20,11 @@
 
 #include "wrap_Data.h"
 
+// Put the Lua code directly into a raw string literal.
+static const char data_lua[] =
+#include "wrap_Data.lua"
+;
+
 namespace love
 {
 namespace data
@@ -44,6 +49,13 @@ int w_Data_getPointer(lua_State *L)
 	return 1;
 }
 
+// Placeholder, overridden by the FFI code when the FFI is available.
+int w_Data_getFFIPointer(lua_State *L)
+{
+	lua_pushnil(L);
+	return 1;
+}
+
 int w_Data_getSize(lua_State *L)
 {
 	Data *t = luax_checkdata(L, 1);
@@ -51,18 +63,40 @@ int w_Data_getSize(lua_State *L)
 	return 1;
 }
 
+// C functions in a struct, necessary for the FFI versions of Data methods.
+struct FFI_Data
+{
+	void *(*getFFIPointer)(Proxy *p);
+};
+
+static FFI_Data ffifuncs =
+{
+	[](Proxy *p) -> void * // getFFIPointer
+	{
+		auto data = luax_ffi_checktype<Data>(p);
+		return data != nullptr ? data->getData() : nullptr;
+	}
+};
+
 const luaL_Reg w_Data_functions[] =
 {
 	{ "getString", w_Data_getString },
 	{ "getPointer", w_Data_getPointer },
+	{ "getFFIPointer", w_Data_getFFIPointer },
 	{ "getSize", w_Data_getSize },
 	{ 0, 0 }
 };
 
+void luax_rundatawrapper(lua_State *L, const love::Type &type)
+{
+	luax_runwrapper(L, data_lua, sizeof(data_lua), "Data.lua", type, &ffifuncs);
+}
+
 int luaopen_data(lua_State *L)
 {
-	luax_register_type(L, &Data::type, w_Data_functions, nullptr);
-	return 0;
+	int n = luax_register_type(L, &Data::type, w_Data_functions, nullptr);
+	luax_rundatawrapper(L, Data::type);
+	return n;
 }
 
 } // data