CS 453 Programming Assignment #3 — MeggyJava CheckButton Compiler (Control Flow, Parser Generators, and ASTs)

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. Note that the MeggyJava grammer allows only byte type operands to be used by the multiplication operator.

The Assignment

• modify your PA2 lexer to handle one-line and multi-line comments in Java,
• modify your PA2 parser so that it does syntax-directed construction of an Abstract Syntax Tree (AST) instead of doing code generation,
• perform type checking for the PA2 grammar in a function that accepts an AST as input and calls error with a reasonable message if there is a type error,
• perform code generation to AVR assembly code for the PA2 AST nodes with another function, and
• incrementally add the PA3 features to the lexer, parser, AST creation, type checking, and code generation.
• This time a demo that illustrates the PA3 MeggyJava features will be required! The demo should be videotaped.

Example ASTs

Example ASTs of some test cases are here:

• Byte.java.ast for Byte.java
• CondExpr.java.ast for CondExpr.java
• If.java.ast for If.java
• IfStmt.java.ast for IfStmt.java

Groups for PA3

Groups can be of size 1 to 5 for PA3.

You can create a github repository for PA3 by going to the PA3 assignment in the github classroom for cs453.

Grading Details

    stack build MJCPA3
    stack exec MJCPA3 TestCase.java
    java -jar MJSIM.jar -b -f TestCase.java.s > t1
    
    // Executing the Java-only version with the meggy/ package.
    javac TestCase.java
    java TestCase > t2
    diff t1 t2
   

The input files can be any PA3 MeggyJava program. The InputFile.java.s file must be such that we can run it through the AVR simulator, MJSIM.jar.

If you need additional Haskell libraries, you need to post a message on Piazza indicating you would like to use the external library. We will reply with a .cabal file that will be used to grade ALL projects. This means everyone will then be able to use that same external library.

We highly recommend you use the regression script regress.sh. Read the comments in the file header to see how it works. Create multiple test cases, put them in the WorkingTestCases/ subdirectory and test your mjc compiler against the Java-only output.

For this assignment, there will be no lexer errors, but there will be examples with type errors. Your compiler should catch the first type error and print out a reasonable message. We will be manually comparing your messages to those generated by by the Java compiler, javac. They do not need to be identical, but you do need to catch the errors. The MeggyJava compiler requires the additional error that integer multiplication is not allowed.

You will need to submit a video of your MeggyJr with a MeggyJava program that only demonstrates the features in the PA2 and PA3 grammars. The picture should be named demoPA3.something, where something is .mov or whatever video format you used for PA1. You can talk during the demo.

Submitting the Assignment

• Create a README file that includes your usernames, email addresses, and any information you want the TA to have before grading your assignment. E.g., this part is not working due to..., a favorite quote or joke to amuse the TA, etc. The README file MUST also include the netids and names of people you started working with and then decided to split into separate groups. We need to understand when there are significant code similarities, why those similarities exist. If you decided to build on another group's PA2 code, then the README file must indicate which group you built on.
• The revision-control.txt file should include log output from some revision control system like git or svn. If the PA2 revision control logs are anemic, then we will be putting more requirements for the revision-control.txt file for PA3. Any requirements will be specified at least a week before PA3 is due.
• Put all your files EXCEPT the demo video into a tar ball. Make sure you have a Main.hs.

    tar cvf PA3.tar README revision-control.txt *.hs 
    

• Submit your PA3.tar file using turnin.

    turnin cs453PA3 PA3.tar
    

  EACH person should submit a tar ball. Of course, we expect that tar balls within a group will be identical. Only one person in the group should submit the demo video.

    turnin cs453PA3 PA3demo.mp4
    

Grading

• 5% README file
• 5% revision-control.txt file
• 5% demo file
• 15% Compiler detects first type error for all PA3 grammar productions
• 70% Compiler generates AVR executable by MJSIM.jar for the PA3 MeggyJava grammar.

PA3 Peer Review Criteria

• "Readable source code. Using line breaks to separate logically similar sections of code (for example in the Lexer Token data type)."
• "Would a student in a different University's compiler class find this easy to reason about?"
• Remove all unneeded code from PA2.
• Clean separation of concepts into modules and consistency of the code formating across the different modules.
• How well is the error handling separated out?

Late Policy