vc.java

/*
 * vc.java           
 * 
 * Jingling Xue, CSE, UNSW, Sydney NSW 2052, Australia.
 */

package VC;

import VC.Scanner.Scanner;
import VC.Scanner.SourceFile;
import VC.Parser.Parser;
import VC.ASTs.AST;
import VC.TreeDrawer.Drawer;
import VC.TreePrinter.Printer;
import VC.UnParser.UnParser;
import VC.Checker.Checker;
import VC.CodeGen.Emitter;

public class vc {

    private static Scanner scanner;
    private static ErrorReporter reporter;
    private static Parser parser;
    private static Drawer drawer; 
    private static Printer printer;
    private static UnParser unparser;
    private static Checker checker; 
    private static Emitter emitter; 

    private static int drawingAST = 0;
    private static boolean printingAST = false;
    private static boolean unparsingAST = false;
    private static String inputFilename; 
    private static String astFilename = ""; 
    private static String unparsingFilename = ""; 

    private static AST theAST;
 
    private static void cmdLineOptions() {
      System.out.println("\nUsage: java VC.vc [-options] filename");
      System.out.println();
      System.out.println("where options include:");
      System.out.println("	-d [1234]           display the AST (without SourcePosition)");
      System.out.println("	                    1:  the AST from the parser (without SourcePosition)");
      System.out.println("	                    2:  the AST from the parser (with SourcePosition)");
      System.out.println("	                    3:  the AST from the checker (without SourcePosition)");
      System.out.println("	                    4:  the AST from the checker (with SourcePosition)");
      System.out.println("	-t [file]           print the (non-annotated) AST into <file>"); 
      System.out.println("	                    (or filename + \"t\" if <file> is unspecified)"); 
      System.out.println("	-u [file]  	    unparse the (non-annotated) AST into <file>");
      System.out.println("	                    (or filename + \"u\" if <file> is unspecified)"); 
      System.exit(1);
    }

    public static void main(String[] args) {
        int i = 0;
        String arg;

        System.out.println("======= The VC compiler =======\n");

        while (i < args.length && args[i].startsWith("-")) {
          arg = args[i++];
          
          if (arg.startsWith("-d") && !arg.equals("-d")) {
            int n = 0;
            try {
              n = Integer.parseInt(arg.substring(2));
            } catch (NumberFormatException e) {
              System.out.println("[# vc #]: invalid option " + arg); 
              cmdLineOptions();
            }
            if (1 <= n && n <= 4) 
              drawingAST = n;
            else {
              System.out.println("[# vc #]: invalid option " + arg); 
              cmdLineOptions();
            }
          } else if (arg.equals("-d")) {
            if (i < args.length) { 
              if (args[i].equals("1")) {
                drawingAST = 1;
                i++;
              } else if (args[i].equals("2")) {
                drawingAST = 2;
                i++;
              } else if (args[i].equals("3")) {
                drawingAST = 3;
                i++;
              } else if (args[i].equals("4")) {
                drawingAST = 4;
                i++;
              } else {
                System.out.println("[# vc #]: invalid option -d " + args[i]); 
                cmdLineOptions();
              }
            }
          } else if (arg.startsWith("-t")) {
            printingAST = true;
            if (! arg.equals("-t")) 
                astFilename = arg.substring(2);
            else if (i < args.length && !args[i].startsWith("-"))
                astFilename = args[i++];
            // the default is inputFilename + "p"
          } else if (arg.startsWith("-u")) {
            unparsingAST = true;
            if (! arg.equals("-u")) 
                astFilename = arg.substring(2);
            if (i < args.length && !args[i].startsWith("-"))
              unparsingFilename = args[i++];
            // the default is inputFilename + "u"
          } else {
            System.out.println("[# vc #]: invalid option " + arg); 
            cmdLineOptions();
          }
        }
        if (i == args.length) {
          System.out.println("[# vc #]: no input file"); 
          cmdLineOptions();
        } else
           inputFilename = args[i];

        SourceFile source = new SourceFile(inputFilename);

        reporter = new ErrorReporter();

        System.out.println("Pass 1: Lexical and syntactic Analysis");
        scanner  = new Scanner(source, reporter);
        parser   = new Parser(scanner, reporter);

	theAST = parser.parseProgram();

        if (reporter.numErrors == 0) {
          // We unparse and print the AST created by the parser. Both 
          // are useful for debugging the construction of the AST 
          // (Assignment 3).
          // We can also unparse and print the annotated AST from the 
          // checker but this is not as useful.
          if (unparsingAST) {
            if (unparsingFilename.equals(""))
              unparsingFilename = inputFilename + "u";
   	    unparser = new UnParser(unparsingFilename);
            unparser.unparse(theAST); 
            System.out.println("[# vc #]: The unparsed VC program printed to " + unparsingFilename);
          }
          if (printingAST) {
            if (astFilename.equals(""))
              astFilename = inputFilename + "p";
   	    printer = new Printer(astFilename);
            printer.print(theAST); 
            System.out.println("[# vc #]: The linearised AST printed to " + astFilename);
          }
          if (1 <= drawingAST && drawingAST <= 2) {
 	    drawer   = new Drawer();
            if (drawingAST == 2)
              drawer.enableDebugging(); // show SourcePosition
            drawer.draw(theAST); // draw the AST
          }

          System.out.println("Pass 2: Semantic Analysis");
          checker  = new Checker(reporter);
          checker.check(theAST);

          if (reporter.numErrors == 0) {
            System.out.println("Pass 3: Code Generation");
            System.out.println();
            emitter = new Emitter(inputFilename, reporter);
            emitter.gen(theAST);
            if (reporter.numErrors == 0) 
              System.out.println ("Compilation was successful.");
            else
              System.out.println ("Compilation was unsuccessful.");
          } else
            System.out.println ("Compilation was unsuccessful.");

          if (drawingAST >= 3) {
 	    drawer   = new Drawer();
            if (drawingAST == 4)
              drawer.enableDebugging(); // show SourcePosition
            drawer.draw(theAST); // draw the AST
          }
       }
       else 
         System.out.println ("Compilation was unsuccessful.");
    }

}