Add lua_pushlightuserdatatagged and lua_tolightuserdatatagged

VM/include/lua.h

@@ -159,6 +159,7 @@ LUA_API const char* lua_namecallatom(lua_State* L, int* atom);
 LUA_API int lua_objlen(lua_State* L, int idx);
 LUA_API lua_CFunction lua_tocfunction(lua_State* L, int idx);
 LUA_API void* lua_tolightuserdata(lua_State* L, int idx);
+LUA_API void* lua_tolightuserdatatagged(lua_State* L, int idx, int tag);
 LUA_API void* lua_touserdata(lua_State* L, int idx);
 LUA_API void* lua_touserdatatagged(lua_State* L, int idx, int tag);
 LUA_API int lua_userdatatag(lua_State* L, int idx);
@@ -186,7 +187,7 @@ LUA_API void lua_pushcclosurek(lua_State* L, lua_CFunction fn, const char* debug
 LUA_API void lua_pushboolean(lua_State* L, int b);
 LUA_API int lua_pushthread(lua_State* L);
 
-LUA_API void lua_pushlightuserdata(lua_State* L, void* p);
+LUA_API void lua_pushlightuserdatatagged(lua_State* L, void* p, int tag);
 LUA_API void* lua_newuserdatatagged(lua_State* L, size_t sz, int tag);
 LUA_API void* lua_newuserdatadtor(lua_State* L, size_t sz, void (*dtor)(void*));
 
@@ -370,6 +371,7 @@ LUA_API void lua_unref(lua_State* L, int ref);
 #define lua_pushliteral(L, s) lua_pushlstring(L, "" s, (sizeof(s) / sizeof(char)) - 1)
 #define lua_pushcfunction(L, fn, debugname) lua_pushcclosurek(L, fn, debugname, 0, NULL)
 #define lua_pushcclosure(L, fn, debugname, nup) lua_pushcclosurek(L, fn, debugname, nup, NULL)
+#define lua_pushlightuserdata(L, p) lua_pushlightuserdatatagged(L, p, 0);
 
 #define lua_setglobal(L, s) lua_setfield(L, LUA_GLOBALSINDEX, (s))
 #define lua_getglobal(L, s) lua_getfield(L, LUA_GLOBALSINDEX, (s))

VM/src/lapi.cpp

@@ -505,6 +505,12 @@ void* lua_tolightuserdata(lua_State* L, int idx)
     return (!ttislightuserdata(o)) ? NULL : pvalue(o);
 }
 
+void* lua_tolightuserdatatagged(lua_State* L, int idx, int tag)
+{
+    StkId o = index2addr(L, idx);
+    return (!ttislightuserdata(o) || o->extra[0] != tag) ? NULL : pvalue(o);
+}
+
 void* lua_touserdata(lua_State* L, int idx)
 {
     StkId o = index2addr(L, idx);
@@ -665,9 +671,10 @@ void lua_pushboolean(lua_State* L, int b)
     api_incr_top(L);
 }
 
-void lua_pushlightuserdata(lua_State* L, void* p)
+void lua_pushlightuserdatatagged(lua_State* L, void* p, int tag)
 {
     setpvalue(L->top, p);
+    L->top->extra[0] = tag;
     api_incr_top(L);
 }
 

tests/Conformance.test.cpp

@@ -1667,6 +1667,24 @@ TEST_CASE("UserdataApi")
     CHECK(dtorhits == 42);
 }
 
+TEST_CASE("LightuserdataApi")
+{
+    StateRef globalState(luaL_newstate(), lua_close);
+    lua_State* L = globalState.get();
+
+    void* value = (void*)0x12345678;
+
+    lua_pushlightuserdata(L, value);
+    CHECK(lua_tolightuserdatatagged(L, -1, 0) == value);
+    CHECK(lua_tolightuserdatatagged(L, -1, 1) == nullptr);
+
+    lua_pushlightuserdatatagged(L, value, 1);
+    CHECK(lua_tolightuserdatatagged(L, -1, 0) == nullptr);
+    CHECK(lua_tolightuserdatatagged(L, -1, 1) == value);
+
+    globalState.reset();
+}
+
 TEST_CASE("Iter")
 {
     runConformance("iter.lua");