Main.java

import syntaxtree.*;
import visitor.*;
import java.io.*;

public class Main {
    public static void main (String [] args) throws Exception {

        //Printing an error message if there aren't any input files.
        if(args.length < 1){
            System.err.println("Usage: java Main <inputFile1> <inputFile2> ... <inputFileN> ");
            System.exit(1);
        }

        FileInputStream fis = null;


        try{

            for (String s: args) {
                System.out.println("Type check on program: "+s);
                System.out.print("\n");    

                //Parsing the input program.
                fis = new FileInputStream(s);
                MiniJavaParser parser = new MiniJavaParser(fis);
                System.err.println("Program parsed successfully.");
                System.out.print("\n");    
                Goal root = parser.Goal();        
            
                //If the parsing was successful, we move on to the FirstVisitor which will create the Symbol Table and perform declaration checks.
                FirstVisitor eval = new FirstVisitor();

                boolean decl_error = false;

                try{ 
                    root.accept(eval, null);
                }catch(Exception ouch){ //If we encounter any declaration errors, the semantic check ends. 

                    System.out.println("We encountered at least one declaration error! ");  
                    System.out.print("\n");      
                    decl_error = true;

                }

                //We encountered a declaration error, so now we move on to the next program.
                if(decl_error == true){
                    continue;
                }
            
                //Checking if the symbol table has a object from a class that was never declared. If so, we stop the semantic check.
                //This is the only check performed in the main function. All other checks are in the Visitor files.
                for (int counter = 0; counter < eval.idList.size(); counter++) { 		      
                    String id_check = eval.idList.get(counter);
                    if( !(eval.visitor_sym.classId_table.containsKey(id_check)) ){

                        System.out.println("We encountered at least one declaration error! ");    
                        System.out.print("\n");    
                        decl_error = true;
                
                    }
                }
                
                if(decl_error == true){
                    continue;
                }

    
                //Our program is free of declaration errors, so now we go to the second visitor which will perform type checking.
                SecondVisitor eval2 = new SecondVisitor(eval.visitor_sym);
                
                boolean type_error = false;

                try{
                    root.accept(eval2, null);
                }catch(Exception ouch){ //If we encounter any type errors, the semantic check ends. 
                    System.out.println("We encountered at least one type error! ");   
                    System.out.print("\n");     
                    type_error = true;
                }

                //We encountered a type error, so now we move on to the next program.
                if (type_error == true){
                    continue;
                }
        

                System.out.println("Our program is free of type errors, moving on to the offset table: ");    
                System.out.print("\n");    

                //Creating the offset table with the OffsetTable class.
                OffsetTable ot = new OffsetTable(eval.visitor_sym);
                ot.OutputCreator();
                System.out.print("\n");    

            }

        }

        catch(ParseException ex){
            System.out.println(ex.getMessage());
        }

        catch(FileNotFoundException ex){
            System.err.println(ex.getMessage());
        }

        finally{

            try{
                if(fis != null) fis.close();
            }
            catch(IOException ex){
                System.err.println(ex.getMessage());
            }
        }


    }


}