Babygo, a go compiler made from scratch

Babygo is a small and simple go compiler. (Smallest and simplest in the world, I believe.) It is made from scratch and can compile itself.

• No dependency to any libraries. Standard libraries and calling of system calls are home made.
• Lexer, parser and code generator are handwritten.
• Emit assemble code which results in a single static binary.

It depends only on as as an assembler and ld as a linker.

Design

Lexer, Parser and AST

The design and logic of ast, lexer and parser are borrowed (or should I say "stolen") from go/ast, go/scanner and go/parser.

Code generator

The design of code generator is borrowed from chibicc , a C compiler.

Remaining parts (Semantic analysis, Type management etc.)

This is purely my design :)

Environment

It supports x86-64 Linux only.

If you are not using Linux, you can use a dedicated docker image for this project.

$ docker pull dqneo/ubuntu-compiler-go
$ ./docker-run

Usage

Currently we are changing CLI design. This section will be updated later

Hello world

# Build babygo
$ go build -o babygo

# Build hello world by babygo
$ ./babygo build -o hello ./example/hello

# Run hello world
$ ./hello
hello world!

How to do self hosting

# Build babygo (1st generation)
$ go build -o babygo

# Build babygo (2nd generation) by babygo 1gen
$ ./babygo build -o babygo2 ./

# Build babygo (3rd generation) by babygo 2gen
$ ./babygo2 build -o ./babygo3 ./

# Check if babygo2 and babygo3 are identical
$ diff ./babygo2 ./babygo3

Test

Run this in the docker container:

$ make test

Reference

• https://golang.org/ref/spec The Go Programming Language Specification
• https://golang.org/pkg/go/parser/ go/parser
• https://sourceware.org/binutils/docs/as/ GNU assembler
• https://github.com/rui314/chibicc C compiler
• https://github.com/DQNEO/minigo Go compiler (my previous work)

License

MIT

Author

@DQNEO