About

This repository contains a Scheme implementation written in Scheme itself. It features a compiler that translates Scheme code into native machine code, currently supporting x64, x86, AArch64, and RISC-V64 architectures.

The compiler is capable of bootstrapping - meaning it can compile its own source code and produce a fully functional binary, provided gcc and glibc are available.

Once bootstrapped, the resulting binary (referred to as compiler-0.out) can successfully recompile the compiler's source code and passes all included test cases. Additionally, the compiler supports cross-compilation, although it does not link against the C standard library during this process.

For example, in order to get riscv64 compiler from x64:

1. On an x64 machine, use compiler-x86_64.out to compile the compiler source with the RISC-V64 backend, producing compiler-riscv64.x86_64.out.
2. Still on the x64 machine, use compiler-riscv64.x86_64.out to compile the same source again, resulting in compiler-riscv.o.
3. On a RISC-V64 machine, compile and link the output:
   gcc runtime.c compiler-riscv.o -o compiler-riscv64.out
4. You now have a native RISC-V64 compiler (compiler-riscv64.out) and a cross-compiler (compiler-riscv64.x86_64.out) targeting RISC-V64 from x64.

For more details, see the CHANGELOG.

Prerequisite to run the compiler

• x86_64 CPU
• Fedora OS, or Fedora WSL, https://docs.fedoraproject.org/en-US/cloud/wsl/
• Installing dependecies (refer to dockerfile)

How to use

source activate.sh
# Compile lib64.o and runtime.o
make make-lib runtime.o TARGET_ARCH=x86-64 SCM_CC="./compiler-x86_64.out" -j
# to run
./compiler-x86_64.out lib64.o test/test-unary.scm
# to compile and run
./compiler-x86_64.out -o a.out lib64.o test/test-unary.scm
./a.out

Features used/supported

• pair-based pattern matcher
• Garbage collector
• C-FFI
• fixnum, ascii characters, boolean, vector, string, symbol, closure
• assignment
• tail call
• seperate compilation
• primitives are value procedures when occurs in operand position
• variadic procedure, primitive case lambda, apply, tail call apply

Naming Convention for scheme compiler

• compiler-<host=target>.out – Runs on and generates code for the same architecture.
• compiler-i686.out – Targets the 32-bit variant of the x86_64 architecture.
• compiler-x86_64.out – Targets the 64-bit variant of the x86_64 architecture.
• compiler-arm64.out - ditto
• compiler-riscv64.out - ditto

Platform Dependent Implementation

• C: getpid is available on *nix system.
• C: getenv is available on *nix system.

Reference

• Compiler Explorer
• List of ABI
• An Incremental Approach to Compiler Construction
• A Nanopass Framework for Compiler Education
• Scheme Workshop Keynote: Andy Keep
• Workshop: Mixing Mutability into the Nanopass Framework
• x86 ISA Reference
• Félix Cloutier's x86 ISA Reference
• GNU assembler as
• Scheme Style Guide
• Scheme Variable Name Convention
• Rabbit: a compiler for scheme
• Fixing Letrec
• Fixing Letrec (reloaded)
• Optimizing Closures in O(0)-time