What is the standard of review for a demurrer based on a statute of limitations?

^6. Our standard of review is well-established: "On review from an order sustaining a demurrer, 'we examine the complaint de novo to determine whether it alleges facts sufficient to state a cause of action under any legal theory, such facts being assumed true for this purpose. [Citations.]' [Citation.] We may also consider matters that have been judicially noticed. [Citations.] ' "A demurrer based on a statute of limitations will not lie where the action may be, but is not necessarily, barred. [Citation.] In order for the bar. . . to be raised by demurrer, the defect must clearly and affirmatively appear on the face of the complaint; it is not enough that the complaint shows that the action may be barred." ' " (Committee for Green Foothills v. Santa Clara County Bd. of Supervisors (2010) 48 Cal.4th 32, 42.)