A Compiler

A compiler that translates a Java-like language into SaM (a JVM simulator) for educational purposes.

Table of Contents

• Built With
• Features
• Getting Started
  • Prerequisites
  • Installation
• Development
  • Building Jar
  • Running Tests
• Usage
• Implementation Details

Built With

• Java
• SaM Assembly

Features

• Multi-pass compilation process
• Comprehensive symbol table management
• Type checking and error handling
• Support for:
  • Basic arithmetic and logical operations
  • Control flow statements (if-else, while loops)
  • Method declarations and invocations
  • String operations and manipulation
  • Object-oriented programming constructs (no inheritance yet)

Getting Started

Prerequisites

• Java JDK 8 or higher
• SaM Assembler and Runtime

Installation

1. Clone the repository

   git clone https://github.com/lebinary/compiler.git

2. Enter Directory

   cd compiler

Development

This starter code package includes a gradle build configuration and JUnit test cases to help you in completing the assignment. You should follow the gradle installation instructions for your system at https://gradle.org/install/ and make sure you have Java version 11 or later installed as the build file targets Java 11.

Building Jar

You can build the JAR file with

gradle build

which will leave the jar file at build/libs/compiler.jar

If you have some tests failing and want to build a jar anyway, you can skip tests using

gradle build -x test

On some platforms you may need to use the included gradlew or gradlew.bat scripts instead of calling gradle directly.

Running Tests

Any IDE with gradle support can run the test cases, but they can also be run manually from the commandline by

gradle test

Usage

1. Prepare a source code file (e.g., program.lo) Example source code:

   int main() {
       String message;
       message = "Hello, World!";
       return 0;
   }

2. Build jar file of the compiler, a compiler.jar file should be created in /build/libs

   gradle build --rerun-tasks

3. Run the jar file to generate a SAM file

   java -jar compiler.jar program.lo output.sam

4. Start the Stack Abstract Machine simulator

   java -Dfile.encoding=UTF8 -jar SaM-2.6.3.jar

5. Load the generated SAM file output.sam and run the simulator!

Implementation Details

Compiler Structure

The compiler implements a two-pass compilation strategy:

1. First Pass: Symbol Table Population

   • Collects variable and method declarations
   • Performs scope analysis
   • Validates declarations and signatures

2. Second Pass: Code Generation

   • Generates SaM assembly code
   • Performs type checking
   • Manages memory allocation
   • Handles control flow