A method and system for creating a library method stub in source code form corresponding to an original library call in machine-executable form. The library method stub is created in a predefined programming language by use of a library method signature associated with the original library call, at least one idiom sentence, and a call invoking the original library call. Creating the library method stub includes composing source code of the library method stub by matching the at least one idiom sentence with idiom-stub mappings predefined for each basic idiom of at least one basic idiom. The original library call appears in sequential code. The library method signature specifies formal arguments of the original library call. The at least one idiom sentence summarizes memory operations performed by the original library call on the formal arguments. The created library method stub is stored in a database.