A module for rewriting application code as a failure-atomic transaction is disclosed. An application delineates a code fragment that is to become a failure-atomic transaction by writing a tx_begin( ) and tx_end( ) functions into its code. A module detects the tx_begin( ) and tx_end( ) functions and rewrites the code fragment as a failure-atomic transaction. The rewritten code is then available to be executed by the application. The rewritten code stores values and locations of stores to persistent memory locations so that the transaction can be either undone or redone in the case of an application error or a power failure. If the transaction is an undo type of transaction, the application can be rolled back to a state prior to the failure. If the transaction is a redo type of transaction, the application can be advanced to a correct state after the error.