fasm

A mini assembly language for the Fuel Virtual Machine (FuelVM).

Features

• Lightweight (~350 lines of code) and written in Typescript
• Compiles directly to FuelVM assembly
• Debugging information included
• Clean errors with line numbers
• Simplistic syntax and grammar
• Supports:
  • Single line comments
  • Static and relative jump labels
  • Data management
  • Error code and error mangement
  • Custom register labeling and management
  • Basic equality (largely for visbility)
  • All FuelVM opcodes
  • Supportive dictionaries (gm, gtf, reserved registers)
• Meant as a learning tool for Fuel, the FuelVM and for improving the performance of Sway
• Open Source under MIT

Example:

# FASM example
# Loop 5 times, add 1 to index, then log gm, gtf codes and my_data, then return 1
reg.max = movi 5

.loop
reg.index = addi reg.index 1
jnei reg.index reg.max .loop.rel

# Log gm.tx_start code, gtf.tx_length code, my_data and return 1
reg.data_start = addi reg.is data.my_data.start
reg.data_length = movi data.my_data.len
logd gm.tx_start gtf.tx_length reg.data_start reg.data_length
ret reg.one

my_data: 0xabcdef
second_data: 0x0011223344

FASM Language Rules

Comments: # My Comment
Jump label: .my_label
Relative jump label: .my_label.rel
Data start pointer: data.my_data.start # program length + data position
Data length pointer: data.my_data.len
Data end pointer: data.my_data.end # program length + data position + data len
Total Data length: data.len
Reserved registers: reg.zero, reg.one, reg.is
Errors: error.my_error # first use assigns, secondary use references, starts from 0 and counts up
Custom register labeling: reg.my_new_reg # first use assigns, secondary use refers, starts at 16 (up to 64)
Custom register equality assignment: reg.max = movi 5 # is the same as movi reg.max 5

To install dependencies:

bun install

To build:

bun run build

To test:

bun test

Browser

There is an editor included in the fasm.dev.

Features:

• Code examples
• Auto complete
• Syntax highlighting
• ACE configurations
• Output Console

This can be run locally using a simple server:

bun run build
python3 -m http.server 8080
# Go to http://localhost:8080/fast.dev/

API

The primary API exports the compile function below:

export function compile(input: string = ""): CompileResult

Grammar File

This repo comes with a complete ACE grammar file:

./grammar/grammar.json

Compiler Design

• A single function written in TS
• Does multiple passes (likely 4-6)
• Is designed around single code line grammar
• Designed to work around the FuelVM opcodes directly
• Register and error manager just counts up (no free pointer logic just yet)
• Max 48 custom registers can be assigned

Contributors

• Special thanks to the Fuel Client team and the Fuel Typescript team

Todo

• More tests