WebAssembly SDK

A toolkit for creating WebAssembly modules.

Installing Wasdk

Installing from NPM

npm install wasdk

Installing from GitHub

This is recommended if you want to contribute to the wasdk project.

Clone this repository and run:

npm run installdeps

and to build sources:

npm run build

To download all necessary pre-compiled binaries for your operating system, which includes: Emscripten, Binaryen, SpiderMonkey, LLVM and Clang:

wasdk sdk --install

And clean up (built sourced and download binaries):

npm run clean

Usage

Wasdk includes a variety of tools which accessible through the wasdk command:

Compiling Modules

wasdk ez test/malloc.json -o malloc.js

This producs several files:

• malloc.asm.js: asm.js code
• malloc.wasm: WebAssembly Binary
• malloc.wast WebAssembly Text
• malloc.js: Node / Browser runtime environment.

Running Modules

wasdk js dist/wasm-shell.js malloc.wasm

This creates a lightweight WebAssembly environemnt and runs the malloc.wasm file. At the moment, this only works with the malloc.wasm file.

Viewing WebAssembly Compiled Machine Code

Use the disassemble command to view the compiled machine code for a WebAssembly program. This code is generated by the ION compiler (used in the Firefox Web Browser). It should be fairly similar to the code produced by other browser engines.

wasdk disassemble test/universe.wast

(module
  (export "answer" (func $answer))
  (func $answer (result i32)
    (return (i32.const 42))
  )
)

Compiled x86/AMD64 Code:

Total Code Size: 5.00 Bytes
100.00%    5          Func 0:
Func 0:
  sub rsp, 8                                        ; 0x000050 48 83 ec 08
  mov eax, 0x2a                                     ; 0x000054 b8 2a 00 00 00
  nop                                               ; 0x000059 66 90
  add rsp, 8                                        ; 0x00005b 48 83 c4 08
  ret                                               ; 0x00005f c3

SDK Management

wasdk sdk --install

wasdk sdk --clean

Testing

npm test