ThePuzzlemaker / knight.wat

A (very) WIP implementation of Knight (https://github.com/knight-lang) in WAT+WASI because I love pain

knight.wat

A (very) WIP implementation of Knight in WAT+WASI because I love pain

Instructions

You will need to have cargo-make and wasmtime installed. (This will obviously require Rust to be installed previously, as well, which can be done with Rustup)

# Compile
$ makers build
# Run
$ makers run
# Clean
$ makers clean

wat-datagen

A small program to turn binary files into a series of WAT data instructions with comments for name and size.

This is set up in the Makefile.toml to automatically update the data definitions at the end of knight.wat based on the contents of data/.

In the following example, the data/ directory looks like such:

data
├── 00.panic_double_free_msg
├── 01.panic_double_free_ciovec
├── 10.str1
├── 11.str2
└── 99.garbage_u32

This structure (along with the data in the files) produces the following output:

;;DATA BEGIN;;
    ;;; name: panic_double_free_msg
    ;;; size: 0x18
    (global $data_panic_double_free_msg_offset i32 (i32.const 0x00))
    (global $data_panic_double_free_msg_size i32 (i32.const 0x18))
    (data (i32.const 0x00) "panic: double dealloc()\n")

    ;;; name: panic_double_free_ciovec
    ;;; size: 0x08
    (global $data_panic_double_free_ciovec_offset i32 (i32.const 0x18))
    (global $data_panic_double_free_ciovec_size i32 (i32.const 0x08))
    (data (i32.const 0x18) "\00\00\00\00\18\00\00\00")

    ;;; name: str1
    ;;; size: 0x0e
    (global $data_str1_offset i32 (i32.const 0x20))
    (global $data_str1_size i32 (i32.const 0x0e))
    (data (i32.const 0x20) "Hello, world!\n")

    ;;; name: str2
    ;;; size: 0x10
    (global $data_str2_offset i32 (i32.const 0x30))
    (global $data_str2_size i32 (i32.const 0x10))
    (data (i32.const 0x30) "This is a test!\n")

    ;;; name: garbage_u32
    ;;; size: 0x04
    (global $data_garbage_u32_offset i32 (i32.const 0x40))
    (global $data_garbage_u32_size i32 (i32.const 0x04))
    (data (i32.const 0x40) "\00\00\00\00")

    (global $data_end i32 (i32.const 0x44))
;;DATA END;;

Note that the names are based on the extensions (as that was the easiest way to give ordering, by just having NN.name and then that will be alphabetically sorted into the inputs of wat-datagen in Makefile.toml through the shell)

For convenience, each entry is padded to a multiple of 4 (as WASM is 32-bit).

wasm-runner-js

Serve this directory with a web server allowing symlinks, make sure knight.wasm is built, and then navigate to index.html. This has a button "Run!" which will, well, run the WASM. It also has a button "Dump Memory" which will download a memory dump to your computer.

It also has a built-in WASI shim for what knight.wat uses (which will extend in the future) so that it can be run and debugged in a web environment (as I've found that Chrome's debugging tools are quite good for WASM).