CS 453 Programming Assignment #3 — MeggyJava for Buttons

Due Thursday March 5 (by 11:59pm)

Introduction

This assignment can be done with your CS 453 programming partner.

In this assignment you will be writing a program that parses, type checkes, and generates code for the PA3 subset of the MeggyJava language that includes the detection of button presses (Meggy.checkButton), the use of the delay function (Meggy.delay), the function for reading the screen pixel values (Meggy.getPixel), the while statement, the if statement, byte casts, plus, minus, and times, and boolean expressions. Notice the dangling else syntax, and the unary minus syntax.

Java, and therefore MeggyJava allows int, byte mixed type expressions for addition, subtraction, comparison, and negation. This is relevant for type checking as well as code generation.

You will

modify your PA2 compiler to do syntax-directed construction of an Abstract Syntax Tree (AST) instead of doing code generation using the provided AST classes,
perform type checking for the PA2 grammar in an AST visitor,
perform code generation to AVR assembly code for the PA2 AST nodes using a visitor,
incrementally add the PA3 grammar rules to the parser, implement the rules AST creation, type checking, and code generation, and
add a test to ensure that the name of the main class matches the program's filename.

Example ASTs of some test cases are here:

The Assignment

Download and untar PA3Start.tar.gz from ~cs453/public/. Study the file structure. Copy the provided starter code into a copy of your PA2/ project. All of the AST nodes and visitor pattern are provided. Additionally, there are some example AST visitors in ast_visitors/. See CheckTypes.java for the start of the type checking visitor.

Most importantly there is a regression testing directory called TestCasesMeggy/. This includes the regression testing script for your generated MJ.jar. See the README in that directory for more information.

The input files for your compiler can be any PA3 MeggyJava program. The PA3 test cases you wrote for PA1 are possible test cases for MJ.jar you will create. Plan on writing more test cases as well. Additionally, the InputFile.java.s file must be such that we can run it through the MJSIM simulator. See the Meggy Sim instructions for usage notes. You will also be able to assemble and link the program with the run time library and run it on the Meggy Jr device by using the provided build process.

For more details about the AVR instructions see the 06-AVR.txt notes.

For this assignment, type checking will be performed with a visitor. Your goal is to match the type error messages that are printed by the provided MJ.jar reference compiler made available in ~cs453/public/ or by matching javac. The grading will ensure that your type error messages occur when javac error messages occur. The error messages do not have to be an exact match.

Submitting the Assignment

Make sure you test your implementations thoroughly.
Include a README file explaining the file structure (your test files) and other comments you want your TA to know (e.g. features not implemented).
The subversion.txt file should include output from the following:
```
svn log
svn info
    
```
Submit assignment using checkin utility. Only submit one assignment per group. Make sure to call the tar ball PA3.tar.
```
~cs453/bin/checkin PA3 PA3.tar
```

Sanity Check (procedure TA will use to grade your assignment):

    
    tar -xf PA3.tar
    cd PA3

    // We will also run the test cases with different arg_opts files.
    java -jar MJ.jar TestCase.java
    java -jar MJSIM.jar TestCase.java.s > t1
    javac TestCase.java
    java TestCase > t2
    diff t1 t2

Late Policy

Late assignments will be accepted up to 48 hours past the due date for a 10% deduction. The assignment will not be accepted past this period. Late means anything after 11:59pm on the day the assignment is due, including 12 midnight.