Function newupval

lib/lua/src/lfunc.c:65–80

** Create a new upvalue at the given level, and link it to the list of ** open upvalues of 'L' after entry 'prev'. **/

** open upvalues of 'L' after entry 'prev'.
**/
static UpVal *newupval (lua_State *L, StkId level, UpVal **prev) {
  GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
  UpVal *uv = gco2upv(o);
  UpVal *next = *prev;
  uv->v.p = s2v(level);  /* current value lives in the stack */
  uv->u.open.next = next;  /* link it to list of open upvalues */
  uv->u.open.previous = prev;
  if (next)
    next->u.open.previous = &uv->u.open.next;
  *prev = uv;
  if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
    L->twups = G(L)->twups;  /* link it to the list */
    G(L)->twups = L;
  }
  return uv;
}


/*