swift-demangle.wasm

A Swift demangling library compiled to WebAssembly, allowing you to demangle Swift symbol names in web browsers and Node.js environments.

Overview

Swift uses name mangling to encode type information and other metadata into symbol names during compilation. This results in cryptic symbol names like $sSi1soiyS2i_SitFZ which correspond to human-readable function signatures like static Swift.Int.- infix(Swift.Int, Swift.Int) -> Swift.Int.

This package provides a WebAssembly-compiled Swift demangler that can convert these mangled names back to their readable form, making it useful for:

• Crash report analysis
• Development tools and IDEs
• Symbol inspection utilities

Installation

npm install swift-demangle-wasm

Usage

Node.js

import init from "swift-demangle-wasm";

const demangle = await init();
const result = demangle("$sSi1soiyS2i_SitFZ");
console.log(result);
// Output: "static Swift.Int.- infix(Swift.Int, Swift.Int) -> Swift.Int"

Browser

import init from "swift-demangle-wasm";

// The browser version requires loading the WASM module
const response = await fetch("path/to/swift-demangle.wasm");
const demangle = await init({ module: response });

const result = demangle("$sSi1soiyS2i_SitFZ");
console.log(result);
// Output: "static Swift.Int.- infix(Swift.Int, Swift.Int) -> Swift.Int"

API Reference

init(options?: InitializeOptions): Promise<Demangler>

Initializes the WASM module and returns a demangler function.

Parameters:

• options (optional): Initialization options
  • module: A Response object or ArrayBuffer containing the Wasm module (required for browser environments)

Returns:

• Promise<Demangler>: A promise that resolves to a demangler function

Demangler(mangledName: string): string

Demangles a Swift symbol name.

Parameters:

• mangledName: The mangled Swift symbol name to demangle

Returns:

• string: The demangled, human-readable symbol name. If demangling fails, returns the original input.

Building from Source

If you want to build this project yourself, you'll need to set up the Swift WebAssembly toolchain.

Prerequisites

Swift 6.2+ toolchain from swift.org

Environment Setup

Before building, you need to configure your shell environment to use the correct Swift toolchain and SDK:

# Set up the Swift toolchain path
export PATH=$HOME/Library/Developer/Toolchains/swift-6.2-RELEASE.xctoolchain/usr/bin:$PATH

# Install Swift SDK for WebAssembly if you haven't installed it
swift sdk install https://download.swift.org/swift-6.2-release/wasm/swift-6.2-RELEASE/swift-6.2-RELEASE_wasm.artifactbundle.tar.gz --checksum fe4e8648309fce86ea522e9e0d1dc48e82df6ba6e5743dbf0c53db8429fb5224

# Install dependency packages
npm install

Building

To build package:

./build.sh

Testing

To run tests after building:

npm test

This runs both Node.js and browser tests using Vitest.

License

MIT