Team members : Cody ADAM ,Arthur ALLAIN, Romain BRIEND, Thomas DELAPART

• 🧱 While Compiler
  • ⭐ Features
  • 🧪 Example
  • 🔨 Build the compiler jar
  • 📟 Run the compiler
  • 📂 Project Structure

Documentation here

🧱 While Compiler

The goal of this project is to create a new programming language and a compiler for it. The language is called While and is a simple imperative language. The compiler is written in Java and compile to Python.

This project has been realised by a group of 4 students of ESIR. The goal of this project is to learn how works and how to write a compiler.

⭐ Features

• Grammar lexer and parser (ANTLR)
• AST generation
• AST Validation
• Three Adress Code generation
• Optimization
• Target code generation
• Runtime library
• Command line interface

🧪 Example

This is an example of a While program that compute the the double of a number.

function double : read X %
for X do X := (cons nil X) od % write X
function main:
read UserInput
%
Output := (cons int (double UserInput))
%
write Output

Note : Standard input and output are available through the main function. Thus the main function is mandatory.

🔨 Build the compiler jar

Requirements

• Maven (building only)
• Java 11 (build and run)

Build the jar

mvn clean
mvn package

The jar is generated in the target folder as whilec.jar.

📟 Run the compiler

The goal of the whilec.jar is to compile a While program into a Python program.

java -jar whilec.jar [filepath] [...arguments?] [...options?]

• filepath : the path of the file to compile (example : java -jar whilec.jar sample/good/for.while)
• argumentsoptional : there are two ways for format the arguments of the program (seperated by a space)
  • 2 0 : using integers that are converted into binary tree (2 become (cons nil (cons nil nil)))
  • (cons nil (cons nil nil)) (cons nil nil) : using the binary tree format directly
  • example : java -jar whilec.jar sample/good/double.while 5
• optionsoptional : the options of the compiler (seperated by a space)
  • -x : execute the program at the end of the compilation
  • -v : verbose mode, display compilation steps with more details
  • -d : debug mode, print AST into a PlantUML file and display the intermediate code in the console
  • -o : optimisation mode, enable optimisation of the intermediate code, during the compilation
  • example : java -jar target/whilec.jar sample/good/for.while -x -v -d -o

Example

java -jar target/whilec.jar sample/good/double.while 5 -x -v -o

Output

###########################################
### STARTING VALIDATION OF double.while ###
###########################################
###########################
### VALIDATION REPORT ###
### 0 ERROR(S) FOUND ###
###########################
File output.py generated at /Project_TLC/output.py
Output value 0 :
_CONS_____ / \ int _CONS_____ / \ NIL _CONS_____ / \ NIL _CONS_____ / \ NIL _CONS_____ / \ NIL _CONS_____ / \ NIL _CONS_ / \ NIL NIL
as Integer: 7 as Boolean: 1 as String: "int"
Pretty print: 6 

📂 Project Structure

📦while-lang
┣ 📂doc // Documentation
┣ 📂grammar // ANTLR grammar
┃ ┗ 📜AST.g
┣ 📂resources // Runtime target libraries
┃ ┣ 📜base.py // Default python runtime
┃ ┗ 📜base_verbose.py // Verbose python runtime
┣ 📂src/main/java
┃ ┣ 📂runner // Main program
┃ ┣ 📂AST // Generated AST
┃ ┣ 📂C3A // Generated 3AC ┃ ┣ 📂translate // Generated target from 3AC
┃ ┗ 📂Validation // Validation system
┃ ┗ 📂Optimization // 3AC code optimization system
┣ 📂sample // Sample while files
┃ ┣ 📂bad // Should raise compiler error
┃ ┗ 📂good // Should compile
┣ 📜.gitignore
┣ 📜ASTPrinted.puml // AST diagram PlantUML for debugging
┣ 📜README.md
┣ 📜generate_grammar.sh // Generate ANTLR grammar
┗ 📜pom.xml // Maven project configuration