1. A method comprising: identifying, in a computer program file, calls to stop functions, said stop functions comprising functions that interact with external resources, said computer program file comprises a computer program source code listing prepared in a programming language, and said identifying said calls to said stop functions comprises: preparing a list of potential stop functions of said programming language, finding function calls in said computer program source code listing, and filtering said function calls to find said calls to said stop functions; identifying parameters of said calls to said stop functions that are references to said external resources; performing an analysis over said computer program file to find out possible values of said parameters of said calls; comparing said possible values of said parameters of said calls to a list of available resources in order to obtain a list of dependencies on said external resources; and applying format transformation to said possible values of said parameters of said calls to extract said external resource references.