Patent ID: 7792853

Claim:
A method for presenting and mapping data flow between devices of a legacy program, wherein the legacy program comprises legacy constructs and a plurality of data variables within the legacy program, comprising the steps of: defining grammar of the legacy program comprising: representing said grammar of the legacy program in a language database comprising a language definition table that defines attributes of syntax of legacy language used to construct said legacy program, and a language reserved words table that defines reserve words of the legacy language and unique reserved word identifiers (IDs) associated with the reserved words; building a program relational database of said legacy program using said grammar, comprising: creating database tables for one or more of program tokens in source statements of the legacy program, data variables defined in the legacy program, and files and said devices used in the legacy program; and relating each of said program tokens with one or more of a reserved word identifier (ID) when the program token is a reserved word and a variable identifier (ID) when the program token is a data variable, as defined by the grammar of the legacy program; defining the usage type of data variables within the legacy programs; grouping legacy program into blocks of code by using execution flow indicators of the reserved words as defined by the grammar of the legacy language for building a program block table comprising a unique block identifier (ID) for each of said blocks of code; and mapping and presenting the relation between said blocks of code referenced by said program block table and the data variables.