wabt.js

wabt.js is a port of WABT to the Web, allowing you to manipulate WebAssembly modules using a JavaScript API.

Usage

$> npm install wabt

var wabt = require("wabt")();

var wasm = ...; // a buffer holding the contents of a wasm file

var myModule = wabt.readWasm(wasm, { readDebugNames: true });
myModule.applyNames();

var wast = myModule.toText({ foldExprs: false, inlineExport: false });

console.log(wast);

The buildbot also publishes nightly versions once a day if there have been changes. The latest nightly can be installed through

$> npm install wabt@nightly

or you can use one of the previous versions instead if necessary.

Usage with a CDN

• From GitHub via jsDelivr:
  https://cdn.jsdelivr.net/gh/AssemblyScript/wabt.js@VERSION/index.js
• From npm via jsDelivr:
  https://cdn.jsdelivr.net/npm/wabt@VERSION/index.js
• From npm via UNPKG:
  https://unpkg.com/wabt@VERSION/index.js

Replace VERSION with a specific version or omit it (not recommended in production) to use master/latest.

API

• parseWat(filename: string, buffer: string | Uint8Array): WasmModule
  Parses a wst source to a module.

• readWasm(buffer: Uint8Array, options: ReadWasmOptions): WasmModule
  Reads a wasm binaryen to a module.

• WasmModule
  A class representing a WebAssembly module.

  • validate(): void
    Validates the module. Throws if not valid.
  • resolveNames(): void
    Resolves names to indexes.
  • generateNames(): void
    Generates textual names for function types, globals, labels etc.
  • applyNames(): void
    Applies textual names. Throws on error.
  • toText(options: ToTextOptions): string
    Converts the module to wat text format.
  • toBinary(options: ToBinaryOptions): ToBinaryResult
    Converts the module to a wasm binary.
  • destroy(): void
    Disposes the module and frees its resources.

• ReadWasmOptions
  Options modifying the behavior of readWasm.

  • readDebugNames: boolean
    Reads textual names from the name section.

• ToTextOptions
  Options modifying the behavior of WasmModule#toText.

  • foldExprs: boolean
  • inlineExport: boolean

• ToBinaryOptions
  Options modifying the behavior of WasmModule#toBinary.

  • log: boolean
  • canonicalize_lebs: boolean
  • relocatable: boolean
  • write_debug_names: boolean

• ToBinaryResult
  Result object of WasmModule#toBinary.

  • buffer: Uint8Array
    The wasm binary buffer.

  • log: string
    Generated log output.