Function getupvalname

depends/lua/src/ldebug.c:558–569

** Checks whether value 'o' came from an upvalue. (That can only happen ** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on ** upvalues.) */

** upvalues.)
*/
static const char *getupvalname (CallInfo *ci, const TValue *o,
                                 const char **name) {
  LClosure *c = ci_func(ci);
  int i;
  for (i = 0; i < c->nupvalues; i++) {
    if (c->upvals[i]->v == o) {
      *name = upvalname(c->p, i);
      return "upvalue";
    }
  }
  return NULL;
}


static const char *varinfo (lua_State *L, const TValue *o) {