A debugger allows a programmer to select the granularity of a line step function. Using a debugger step statement, the programmer can specify line step, statement step, or automatic selection. When the user specifies line step in the debugger statement, the debugger functions in true line step mode, where a line of source code is executed for each step. When the user specifies statement step in the debugger statement, the debugger functions in statement step mode, where a statement is executed for each step. When the user specifies automatic selection in the debugger statement, the program is analyzed, and a decision regarding whether to use line step or statement step is made based on the characteristics of the program and based on user-specified selection criteria. In this manner the function of the debugger when line stepping can vary according to the programmer's needs.