L4Compiler

L4Compiler is a simple L4 language compiler written in C++17, implementing the full compilation pipeline. Developed through four lab stages, it progressively adds support for advanced language features, optimization passes, and runtime checks.

Features

• Flex based L4 lexer (Lexer.l).
• Bison-generated LALR(1) parser (Parser.y) producing an Abstract Syntax Tree (AST).
• Static type checking, scope management, symbol tables, and memory-safety validation.
• Custom IR with Control‑Flow Graph (CFG), supporting optimization passes such as dead code elimination, and variable coalescing.
• Register Allocation: Graph‑coloring allocator with spill handling and calling‑convention support.
• IR-to-assembly translation via X86Translator.
• ASMGenerator emits AT&T‑syntax x86-32 / x86-64 code with Position‑Independent Code (PIC) support.
• Perform simple optimizations during code generation
• Generate AT&T-syntax x86-32 and x86-64 assembly output
• Provide a command-line interface for compiling source files
• Include unit tests powered by GoogleTest
• Support JSON-based configuration and resource loading for individual unit test cases

Repository Structure

L4Compiler/
├── .github/              # CI workflows (GitHub Actions)
├── build.sh              # Convenience script: configure & build
├── run.sh                # Wrapper: compile source → binary
├── test.sh               # Wrapper: run unit tests
├── CMakeLists.txt        # Root CMake configuration
├── include/              # Vendored headers (FlexLexer, cxxopts, nlohmann/json, spdlog, Boost)
├── src/                  # Core compiler implementation
│   ├── core/             # Parser, AST, CFG, IR, semantic analyzer, ASMGenerator
│   ├── model/            # AST & IR data structures, CFG basic blocks
│   ├── handlers/         # IR generation and translation handlers
│   ├── driver/           # CLI entrypoint & orchestration (API.cpp)
│   ├── L4Compiler.cpp    # Main wrapper
│   └── CMakeLists.txt    # Add subdirectories & define `compiler` target
├── test/                 # GoogleTest suite (FetchContent for gtest)
├── resources/            # JSON configs and test inputs
└── COPYING               # GPL-3.0 License

Prerequisites

• A C++17-compatible compiler (e.g., g++, clang++)
• CMake 3.17 or higher
• Bash (for the provided build and run scripts)

Installation

1. Clone the repository

2. Build with CMake:

   mkdir build
   cd build
   cmake -DBUILD_TEST_CASES=ON [-DBUILD_UNITY=ON] .. 
   make

3. Or use the helper scripts:

   ./build.sh                # Configure and build

Usage

Compile a source file:

# Direct invocation:
build/bin/compiler -i path/to/source.txt -o path/to/output_binary [--r64] [-d]

# Using provided wrapper scripts:
./run.sh path/to/source.txt path/to/output_binary
./test.sh

Run the full test suite:

./test.sh

Configuration

JSON Tests: Located under resources/tests/, where each file defines inputs and expected outputs.

Dependencies

• cxxopts – Lightweight C++ command line parser
• nlohmann/json – JSON library for modern C++
• spdlog – Fast C++ logging library
• fmtlib – Formatting library (bundled with spdlog)
• GNU Flex – Lexical analyzer generator
• GNU Bison – Parser generator
• GoogleTest – Unit testing framework
• Boost – A collection of peer-reviewed, portable C++ libraries covering common tasks such as smart pointers, data structures, algorithms, threading, serialization, and more.

Resources

All test cases and their associated configurations are located in the resources/ folder.

Contributing

Contributions, issues, and feature requests are welcome! Please open an issue or submit a pull request on GitHub.