(*****************************************************************************
                  Object Extraction Specification

    Written by;  Dan Stearns, Summer 1994
    Reference:   Class and object extraction from imperative code
                 JOOP, March-April 1993
    Modification Record:
      7/18/94   First Crack

    Overview:

 *****************************************************************************)

(****  OBJECTS ****)
object CProgram
   components: 
      (HeaderFile and Module)* and Makefile;
   operations: 
      CompileProgram (CProgram) -> (boolean),
      ProcessProgram;
   description:
      (* A compilable C program is the input to the object extractor
      *);
end CProgram;
object Makefile;

operation CompileProgram
   inputs: cp: CProgram;
   outputs: boolean;
   postcondition:  
     (* Either the program compiles or it doesn't *)
     true or false;
end CompileProgram;

operation ProcessProgram
   components:
      DoDataFlowAnalysis,
      FindClass,
      FindInstanceVariable*;
   inputs: cp: CProgram;
   outputs: cp': CProgram;
   precondition:  (* The program must compile or we don't process it *)
     CompileProgram() = true;
   postcondition: cp = cp';
   description:
     (* The object extractor processes the C program and creates
        a set of C++ classes that can be used to port the program to C++
     *);
end ProcessProgram;

object Module
   components: 
      SubProgram* and 
      AggregatedDataStructure*;
   operations:
     (*  Analysis of multiple subprograms in a module can lead to
         discovery of many classes, some of which may be contained
         in others.  If all the instance variables of a class A also
         appear in another class B, B should contain an object of class
         A as one of its instance variables.
     *)
     ExtractClass,
     ExtractInstanceVariable;
   description:
     (* A module is a separate file that can conain data structures
        and subprograms.  The object extractor expects modules to
        contain related subprograms.
     *);
end Module;

object HeaderFile
   components: 
      (AggregatedDataStructure and 
       SubProgramDeclaration)*;
   operations:  ;
   description: ;
end HeaderFile;

object AggregatedDataStructure
   components:  ; 
   operations:  ;
   description: (*  A group of related variables stored together.
                 In the C language, a struct is used.
                 *);
end AggregatedDataStructure;

object SubProgram
   components:
     SubProgramParameter* and
     SubProgramBody;
   operations: 
     ExtractInstanceVariables,
     ExtractRead_StateMethod,
     ExtractConstructor,
     ExtractModify_StateMethod;
   description:
     (*  The parameters in the largest category are the instance
         variables of some class.  Each operation is used according
         to the type of SubProgramParameter as follows:
         use-only     ExtractRead_StateMethod
         define-only  ExtractConstructor
         otherwise    ExtractModify_StateMethod
     *);
end SubProgram;

object SubProgramBody =  string;

object SubProgramParameter
   components:
      Use_onlyParameter or 
      Use_and_setParameter or
      Define_onlyParameter;
   operations: ;
   description: ;
end SubProgramParameter;

operation ExtractInstanceVariables
   inputs:  ;
   outputs: ;
end ExtractInstanceVariables;

object Class
   components:  InstanceVariable* and
                InstanceMethod*;
   operations:  ;
   description: (* A Class is a C++ Class created by the application
                *);
end Class;