REVERSE ENGINEERING OF ASSEMBLY CODE

THE NAVY POSSESSES MILLIONS OF LINES OF REAL-TIME PROGRAMS IN THE CMS-2 HIGH LEVEL LANGUAGE WIDIIN WHICH ARE EMBEDDED NUMEROUS SEGMENTS OF DIRECT CODE IN THE MACRO ASSEMBLY LANGUAGE. THE INTERFACES BETWEEN THE TWO LEVELS OF LANGUAGES ARE IN SOME CASES SPECIFIED THROUGH DIRECTIVES, BUT ARE MOSTLY IMPLICIT. THE REVERSE ENGINEERING MIX OF HIGH LEVEL AND LOW LEVEL LANGUAGES POSES A NEW PROBLEM NOT ATTACKED IN DIE PAST. THE PROPOSAL OFFERS AN INNOVATIVE APPROACH, SIMILAR TO THAT BEING PRESENTLY EMPLOYED IN A NAVY SPONSORED PROJECT FOR REVERSE ENGINEERING CMS-2 PROGRAMS TO ADA. THE PROPOSAL WILL IN FACT CREATE THE CAPABILITY TO REENGINEER MACRO AND MIXED CMS-2/MACRO PROGRAMS. THE BASIC INNOVATION IN THE APPROACH USES AN ENTITY-RELATION--ATTRIBUTE (ERA) GRAPH, FOR BOTH REPRESENTING THE PROGRAM IN MEMORY AND FOR DISPLAYING AND UPDATING IT IN A CASE SYSTEM. THIS REPRESENTATION WILL BE USED BY A VARIETY OF PROPOSED ALGORITHMS THAT EXPLICIDY RESOLVE THE IMPLICIT RELATIONSHIPS AND GREADY SIMPLIFY THE GRAPH. IT IS PROPOSED .D UTILIZE DIGIML'S DECDESIGN AND ITS METHODOLOGY IMPLEMENTATION FACILITY (MIF) FOR CUSTOMIZING DECDESIGN. THIS SYSTEM IS AVAILABLE THIUUGH A COOPERATION AGREEMENT WITH DIGITAL. THE PROPOSED AUTOMATION WILL: 1) DEFINE THE INTERFACES BETWEEN SEGMENTS OF ASSEMBLY LEVEL DIRECT CODE AND THE CMS-2 HIGH LEVEL CODE WITHIN WHICH THEY ARE EMBEDDED, 2) DEFME INTERFACES BETWEEN THESE PROGRAMS AND TILE EXECUTIVE SYSTEM THAT CONTROLS THE COMPUTER OPERATION, 3)PERFORM PROGRAM DECOMPILATION TO CONDENSE THE DIRECT CODE TO A MORE READABLE HIGHER LEVEL LANGUAGE, 4) GENERATE GRAPH REPRESENTATIONS OF THE DESIGN OF THE DIRECT CODE AND ITS INTERFACES TO THE CMS-2 CODE (TREE AND DATAROW GRAPHS), 5) ASSOCIATE EXPLANATORY TEXT WITH THE GRAPHS, 6) DISPLAY THE GRAPHICS AND TEXT TO FACILIMTE UNDERSTANDING BY A USER ENGAGED IN PROGMMMAINTENANCE OR CONVERSION, 7)PROVIDE INTERACTIVE SUPPON FOR GRAPHICALLY UPDATING PROGRAM DESIGN AND 8) PRODUCE DOCUMENTATION IN REPORT FORM. PHASE I WILL CONSIST OF DESIGNING THE PROPOSED SYSTEM. PHASE II WILL CONSIST OF SYSTEM IMPLEMENTATION.