PL/0 Compiler

A Rust-based compiler for the PL/0 programming language, designed for educational purposes to demonstrate compiler construction. This project implements a lexer, parser, abstract syntax tree (AST) generation, intermediate representation (IR) generation, and code generation targeting x86-64 & ARM64 assembly. Table of Contents Introduction (#introduction) PL/0 Language Syntax (#pl0-language-syntax) Sample Program (#sample-program) Features (#features) Directory Structure (#directory-structure) Getting Started (#getting-started) Usage (#usage) Roadmap (#roadmap) Contributing (#contributing) License (#license)

Introduction

PL/0 is a minimalist programming language used to teach compiler design principles. This project provides a Rust implementation of a PL/0 compiler, showcasing key compiler components: lexical analysis, parsing, AST construction, IR generation, and code generation for x86-64 assembly. The compiler is a work-in-progress, with active development on IR optimization and assembly emission.

PL/0 Programming Language Syntax

PL/0 supports structured programming with variables, arithmetic, conditionals, loops, and procedures. Its syntax is inspired by Pascal, making it simple to parse and understand. Below are the key constructs:

Sample Program

var x, y, z; begin x := 1; { Initialize x to 1 } y := 2; { Initialize y to 2 } z := x + y; { Compute sum } if z > 2 then z := z - 1 { Decrement if sum > 2 } else z := z + 1; { Increment otherwise } while x < 10 do { Loop until x reaches 10 } x := x + 1; writeInt(z); { Output z } end.

This sample program demonstrates variable declarations, assignments, conditionals, and loops in PL/0.

Features Lexer: Tokenizes PL/0 source code into a stream of tokens. Parser: Constructs an AST from tokens (in progress). AST: Represents program structure using a tree (partially implemented). IR Generator: Translates AST to intermediate representation (work in progress). Code Generator: Emits x86-64 assembly with register allocation and spilling (in development). Error Handling: Provides detailed error messages for invalid syntax or semantics. Static Link Support: Handles nested procedures via static links.

Getting Started Prerequisites

Rust (version 1.50 or later)

Installation

Clone the repository:

bash

git clone https://github.com/vyommani/pl0c.git cd pl0c

Usage

To compile and run the PL/0 compiler:

bash

cargo build

Contributions are welcome! Please open an issue or submit a pull request if you have any suggestions or improvements.

Steps to Contribute

Fork the repository.
Create a new branch (git checkout -b feature-branch).
Commit your changes (git commit -am 'Add new feature').
Push to the branch (git push origin feature-branch).
Open a pull request.

License

This project is licensed under the MIT License. See the LICENSE file for details.