Variable tracking in program debugging

A method and system for structuring program code to implement program debugging of the program code using tracking of variables. A first variable to be tracked and a first expression associated with the first variable are determined. The program code includes the first variable and the first expression. A reverse scanning of the program code is performed to search for a first assignment expression within a first assignment statement that assigns a value of the first assignment expression to the first variable. In response to finding the first assignment expression via the reverse scanning, a first watch point for determining a true/false value of the first expression is inserted into the program code after the first assignment statement.