Patent ID: 7500229

Claim:
A program converting method, comprising a conversion step of converting an input program which is described in an object-oriented language and includes at least one class, wherein the conversion step includes: an input step of inputting the input program; an object analyzing step of analyzing the class in the input program to find out whether an object of the class is created or not, and of recording an analysis result in an object analysis information storing section; an unnecessary process analyzing step of extracting an unnecessary process in accordance with the analysis result stored in the object analysis information storing section, and of recording an analysis result in an unnecessary process information storing section; an unnecessary process deleting step of deleting the unnecessary process in accordance with the analysis result stored in the unnecessary process information storing section; an output step of outputting an object program; and a class analyzing step of analyzing an inheritance relationship of the class after the input step has been performed and before the unnecessary process analyzing step is performed, wherein in the unnecessary process analyzing step, an analysis is performed to find out whether an object of a leaf class included in a class tree to which the class belongs is created or not, and if no object of the leaf class is created, a process on the leaf class is extracted as the unnecessary process, and the leaf class is a class having no children in a class tree.