webpack-emscripten

Two-phases Emscripten loader for webpack Forked from the simpler wasm-tool/emscripten where an import could be on a simple C file.

The objective fo the this two-phases loader is to separate C/C++ compilation and "linking to WebAssembly" and allow the JS to C++ connections permitted, e.g., by Embind. It allows a flexible embedding of C/C++ classes and objects within JS code.

Installation

Copy the loaders into webpack within your directory. emcc must be available in the $PATH, see http://kripken.github.io/emscripten-site/docs/getting_started/downloads.html.

Create or enrich the webpack config as below or see the example directory.

Usage: webpack

module.exports = {
  // ...
  module: {
    rules: [
      {
        test: /\.cpp$/,
        loader: path.resolve('webpack/cpp-loader.js')
      }
      {
        test: /\.cp$/,
        loader: path.resolve('webpack/cpp-loader.js')
      }
      {
        test: /\.emsc.js$/,
        loader: path.resolve('webpack/cpp-packager.js'),
        options : 
        {
          cfiles : 
          [
            'src/AClass.cpp'
          ]
         }
      }
    ]
  },
  // ...
};

Create a placeholder EmscriptenModule.emsc.js file (which can be empty).

You can then import it in JS to obtain a promise that delivers the Emscripten's runtime object where, for example, classes resulting of Embind can be directly invoked.

import await emscriptenRuntime from './EmscriptenModule.emsc.js';

See the example.

TODOs

• Find a way to avoid the window.emi hack (see webpack's issue 10890) so that promises are properly used as results of an import

About

This project is being maintained by Paul Libbrecht so as to contribute to the development for CabriLog SAS. The project forks from wasm-tool/emscripten by Sven Sauleau and uses help from, among others, Tobias Koppers, Alexander Akait (here), and Will Scott (here).