CSE 431S (Spring 2008)

Final Project

Setup

• In this lab, you continue your work from your solution to Lab 6. So you can continue with the files you have or copy them into a new project and go from there.

  However:

  • I don't give you a course solution to try for the final code generator. Continue working with your Lab 6 code generator and work toward a solution that handles the test files and any extra credit you wish to do.
  • You will need to replace your build.xml file with this build.xml file, which runs the proper tests.
  • You will have to reinstall the coursesolutions jar file in the usual place.

    The problem in the old version was that the scanner didn't know about true and false, so they were processed as identifiers instead of reserved keywords).

  • Be sure to copy the test files into the TestFiles directory of your project.
  • If you are trying for extra credit and need the scanner to find ++ and -- as tokens, then try this coursesolutions jar instead of the one above. Let me know how it works.

Notes

• You will no doubt notice some strange notation in the Test Files. The method calls and field acccesses are annotated so that you don't have to look in any other source or class files to determine types.

  Java overloads the period symbol in references to methods, statics, and fields. Given

  w.x.y.z we can't tell whether this is some static field z in a class w.x.y, or perhaps y is a static field in class w.x and z is a field of the instance Y

  To simplify matters, the notation for fields and methods is as follows:

  • The period symbol is used only within a class reference. Thus, w.x.y.z is class z in package w.x.y.
  • To reference a static field or method of a class, use two colons (::), so that java.lang.System::out is the System.out output stream.
  • To reference a field of an instance, use ->. Thus, (obj)->a references field a using the reference obj
  • Methods work the same way. To call a static method, use: java.lang.Math::abs(num).
  • All references and methods also include the return type of the result, which appears after a single colon. Thus, the reference above for System.out is really java.lang.System::out : java.io.PrintStream and to print something using println (java.lang.System::out : java.io.PrintStream) -> println : void ("hello") and the absolute value method would be java.lang.Math :: abs : int (num)
• Documentation on the JVM instruction set and Jasmin can be found on the Lab 5 page.
• Unless you are attempting extra credit, CodeGenVisitor.java is the only file you should submit.
• Any extra credit must be arranged in advance with the instructor.

• Your assignment must generate object code for the constructs found in the test files: expressions, assignment statements, if, while, return, "short-circuiting and", "short-circuiting or", "and", "or", method invocations and declarations.
• One issue you will have to confront is how to handle Boolean-valued expressions. The Java interperter does not have a built-in notion of what a Boolean value is nor how it should be represented.
• Extra credit is available, and can be applied to exams or quizzes. A topic list appears below, but you are welcome to propose your own extensions. However, before you begin on any extra credit, you must consult with the instructor so the scope of the work is agreed upon in advance.
  Pre/post increment/decrement
  • Floating point primitive types
  • Semantic analysis: widening
  • Semantic analysis: coercion to general type
  • Compile == and != into .equals method calls
  • Arrays
  • Extendable primitive types
  • Checking for assignment to "this" -- it's illegal
  • Processing of field declarations -- the .field directive for Jasmin
  • Processing of constructors
  • Accurate declaration for .locals
  • Emitting "short" forms for iload and aload, so that they take
  • Handling "new" and constructor calls one byte instead of two. For example, iload_1 instead of iload 1.

  Submitting your project

  To turn in your work, do one of the following:
  • If you are not doing any extra credit, just send your CodeGenVisitor.java file to legrand@cs. Be sure your name appears at the top of the source file.
  • If you are doing any extra credit, then zip your entire workspace project and send it as an attachment to legrand@cs. Your workspace must include examples in the TestFiles directory that exercise your extra credit features, and the build.xml file must be augmented to run tests on those files as well. Be sure your name appears in comments at the top of any files you have changed.

    I must be able to run your build.xml file in my environment, so everything you turn in must be in the workspace or in the course's standard jar files.