bcomp

bcomp is a small BASIC compiler written in Rust. It lexes and parses a subset of pretty BASIC-like syntax, and then uses cranelift to lower it into real assembly.

Current Status

Heres what actually work right now if you ran this program:

• BASIC Expressions, which include: identifiers, numbers, strings, chars, separators, arithmetic operators, and comparison operators
• Statement lists (each line is a statement), print, return, end, and rem
• Cranelift object emission for main (each file is loaded as a seperate main)
• print uses libc calls for strings, chars, and numeric expressions
• Tiny program CLI that uses clap

Not implemented yet:

• Variables and assignment lowering
• Control-flow expressions and keywords like if, goto, for, next, and gosub
• Floats in any way shape or form
• Multifile linkage (likely never supported)

Requirements

• Rust 2024

Build

cargo build

or

cargo build --release

Usage

Compile a .bsc source file to an object file:

cargo run -- tests/input/print.bsc

By default, bcomp writes the object next to the input with an .o extension. Use -o to choose an output path:

cargo run -- tests/input/print.bsc -o print.o

The generated object currently expects libc symbols such as printf, so link it with your platform C compiler:

cc print.o -o print

Example

Input:

print "HELLO WORLD";

Compile:

cargo run -- tests/input/print.bsc -o print.o
cc print.o -o print
./print

Development

Run the test suite:

cargo test

Run lint checks:

cargo clippy --all-targets --all-features

The crate currently denies warnings and Clippy's all and pedantic groups, so small changes may still need a formatting or lint pass before they compile cleanly.

References

• Let's make a Teeny Tiny compiler
• Cranelift documentation

License

MIT. See LICENSE.