Awesome

wabt.js

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

<a href="https://github.com/AssemblyScript/wabt.js/actions?query=workflow%3ABuild"><img src="https://img.shields.io/github/actions/workflow/status/AssemblyScript/wabt.js/build.yml?branch=main&label=build&logo=github" alt="Build status" /></a> <a href="https://www.npmjs.com/package/wabt"><img src="https://img.shields.io/npm/v/wabt.svg?label=latest&color=007acc&logo=npm" alt="npm version" /></a> <a href="https://www.npmjs.com/package/wabt"><img src="https://img.shields.io/npm/v/wabt/nightly.svg?label=nightly&color=007acc&logo=npm" alt="npm nightly version" /></a>

Usage

$> npm install wabt

require("wabt")().then(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 --save-exact wabt@nightly

or you can use one of the previous versions instead if necessary. Note the --save-exact when using a nightly.

Usage with a CDN

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

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

API

• parseWat(filename: string, buffer: string | Uint8Array, options?: WasmFeatures): WasmModule<br /> Parses a WebAssembly text format source to a module.

• readWasm(buffer: Uint8Array, options: ReadWasmOptions & WasmFeatures): WasmModule<br /> Reads a WebAssembly binary to a module.

• WasmModule<br /> A class representing a WebAssembly module.

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

• ReadWasmOptions<br /> Options modifying the behavior of readWasm.

  • readDebugNames: boolean<br /> Reads textual names from the name section.

• ToTextOptions<br /> Options modifying the behavior of WasmModule#toText.

  • foldExprs: boolean
  • inlineExport: boolean

• ToBinaryOptions<br /> Options modifying the behavior of WasmModule#toBinary.

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

• ToBinaryResult<br /> Result object of WasmModule#toBinary.

  • buffer: Uint8Array<br /> The wasm binary buffer.
  • log: string<br /> Generated log output.

• WasmFeatures<br /> WebAssembly features to legalize. Finished features are enabled by default.

  • exceptions: boolean<br /> Exception handling (proposal).
  • mutable_globals: boolean<br /> Import/Export mutable globals (proposal).
  • sat_float_to_int: boolean<br /> Non-trapping Float-to-int Conversions (proposal).
  • sign_extension: boolean<br /> Sign-extension operators (proposal).
  • simd: boolean<br /> 128-bit packed SIMD (proposal).
  • threads: boolean<br /> Threading (proposal).
  • function_references: boolean<br /> Typed function references (proposal).
  • multi_value: boolean<br /> Multi-value (proposal).
  • tail_call: boolean<br /> Tail Call (proposal).
  • bulk_memory: boolean<br /> Bulk Memory Operations and Conditional Segment Initialization (proposal).
  • reference_types: boolean<br /> Reference Types (proposal).
  • annotations: boolean<br /> Custom Annotation Syntax for the Wasm Text Format (proposal).
  • code_metadata: boolean<br /> Code metadata (convention).
  • gc: boolean<br /> Garbage collection (proposal).
  • memory64: boolean<br /> 64-bit memory (proposal).
  • extended_const: boolean<br /> Extended constant expressions (proposal).
  • relaxed_simd: boolean<br /> Relaxed SIMD (proposal).

CLI

Node.js ports of the following command line tools are included in the package as well:

• wasm2c converts a WebAssembly binary file to a C source and header.
• wasm2wat translates from WebAssembly binary format to text format.
• wat2wasm translates from WebAssembly text format to binary format.
• wasm-decompile decompiles a wasm binary into readable C-like syntax.
• wasm-interp decodes and runs a WebAssembly binary file using a stack-based interpreter.
• wasm-objdump prints information about a wasm binary. Similiar to objdump.
• wasm-stats shows stats for a WebAssembly module.
• wasm-strip removes sections of a WebAssembly binary file.
• wasm-validate validates a file in WebAssembly binary format.

The tools can also be run ad hoc (without explicitly installing the package), for example with:

$> npx -p wabt wasm2wat myModule.wasm -o myModule.wat