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Method for analyzing influence among data items in programs

IP.com Disclosure Number: IPCOM000241313D
Publication Date: 2015-Apr-16
Document File: 2 page(s) / 25K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for analyzing transition of data items in program codes. We defined DPG (Data Propagation Graph), consisting of nodes which represent reference or update of data items, and edges which are classified to data dependency or data propagation. Data dependency is a term defined in “Program Slicing” area. Data propagation means transfer of data value performed by statements such as MOVE, ADD. DPG is useful to extract design information from existing COBOL programs.

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Method for analyzing influence among data items in programs

Disclosed is a method for analyzing transition of data items in program codes. We defined DPG (Data Propagation Graph), consisting of nodes which represent reference or update of data items, and edges which are classified to data dependency or data propagation. Data dependency is a term defined in "Program Slicing" area. Data propagation means transfer of data value performed by statements such as MOVE, ADD. DPG is useful to extract design information from existing COBOL programs.

DPG is a graph G which consists of set of nodes N, and set of edges E.

N is a set of nodes which represent updates and references of data items in program statements. E is a set of directed edges, categorized to data propagation or data dependency. A data propagation edge starts from a reference node to an update node, while a data dependency edge starts from an update node to a reference node. Data propagation arises from MOVE statement, COMPUTE statement, and so on. It means that a value of referenced data item influences a value of updated data item. Data dependency arises from relations of plural statements. It means that an update to a data item in a statement "reaches" subsequent statement which contains a reference to the same data item. The strict sense of "reach" is defined in a computer science discipline called "Program Slicing".

The below figure shows generation of DPG from a sample program code fragment.

In the pr...