Plan-based program slicing

A system of generating a slice from a plan-based representation of a program, the system comprising:

• one or more processors coupled to one or more memory units;
• a logic unit for constructing, using one or more processors, a plan representation of a program, wherein the plan representation comprisesa plurality of nodes, edges, and ports,
• wherein a node represents at least one of an operation associated with data input/output (I/O) in the program, a test specification associated with a branch in control flow of the program, or a join specification associated with a point in the program where control and data flow are joined,
• wherein a port represents at least one of a data port or a control port, wherein a data edge connects a data port on a first node to a data port on a second node, and wherein a control edge connects a control port on a third node to a control port on a fourth node, such that an edge defines control;
• or data flow among the nodes;
• a logic unit for receiving one or more slicing criteria from a user, wherein the slicing criteria comprise one or more variable occurrences or statements from the program;
• a logic unit for associating each variable occurrence in the set of slicing criteria to a corresponding data edge in the first plan representation;
• a logic for associating each statement in the set of slicing criteria to a corresponding node or edge in the first plan representation;
• a logic unit for adding input or source ports associated with the set of slicing criteria to a second plan representation;
• a logic unit for iteratively adding input control or data ports to the second plan representation according to control or data dependence, respectively, of ports in the second plan representation;
• a logic unit for adding one or more ports, nodes, or edges to the second plan representation to complete control or data flows in the second plan representation;
• a logic unit for adding a minimal set of join specifications to the second plan representation to prevent fan-in control;
• a logic unit for adding a minimal set of test specifications to the second plan representation to prevent fan-in of control;
• and
• a logic unit for converting the second plan representation to source code of the program;
• and
• a logic unit for generating a slice from the plan representation according to the slicing criteria.

A computer program product comprising logic code stored in a non-transitory storage medium, wherein execution of the logic code on a computer causes the computer to:

• construct a first plan representation of a program, wherein the first plan representation comprises a plurality of nodes, edges, and ports,
• wherein a node represents at least one of an operation associated with data input/output (I/O) in the program, a test specification associated with a branch in control flow of the program, or a join specification associated with a point in the program where control and data flow are joined,
• wherein a port represents at least one of a data port or a control port, wherein a data edge connects a data port on a first node to a data port on a second node, and wherein a control edge connects a control port on a third node to a control port on a fourth node, such that an edge defines control or data flow among the nodes;
• associate each variable occurrence in a set of slicing criteria to a corresponding data edge in the first plan representation;
• associate each statement in the set of slicing criteria to a corresponding node or edge in the first plan representation;
• add input or source ports associated with the set of slicing criteria to a second plan representation;
• iteratively add input control or data ports to the second plan according to control or data dependence, respectively, of ports in the second plan representation;
• add one or more ports, nodes, or edges to the second plan representation to complete control or data flows in the second plan representation;
• add a minimal set of join specifications to the second plan to prevent fan-in of control;
• add a minimal set of test specifications to the second plan to prevent fan-in of control;
• convert the second plan representation to source code of the program;
• generate a slice from the plan representation according to the slicing criteria.