Installing Emscripten

This document assumes that you are installing Emscripten on a fresh installation of OS X 10.8 Mountain Lion.

Prereqs

Before installing Emscripten, you will need to install and configure its dependencies.

Xcode Command Line Tools

Before proceeding, you should install the Xcode command line tools. These provide a base set of common utilities, compilers and other tools. You can install the tools either through Xcode or directly from Apple’s website.

To install the Command Line Tools via Xcode:

• If you haven’t already, install Xcode.

  • Open the Finder
  • Navigate to /Applications
  • Open the App Store
  • Search for Xcode
  • Click the FREE button
  • Enter your Apple ID and password
  • When the download completes, Xcode will be in your Applications folder

• Open Xcode in /Applications

• Choose Xcode > Preferences... in the menu bar

• Click the Downloads tab in the toolbar

• If it is not already selected, click the Components tab in the Downloads section of Preferences

• Click the Install button next to Command Line Tools in the table

• Enter your username and password, and wait for the download to complete

To install the Command Line Tools manually:

• Go to https://developer.apple.com/mac, click Sign in, and enter your Apple ID username and password

  • If you have set up your Apple ID as a developer account, click the Register button below the username and password field and do so first

• Scroll to the bottom and click View all downloads in the Additional Downloads section

• In the list of available downloads, look for and click on the most recent version of the Command Line Tools. As of this writing, that is “Command Line Tools (OS X Mountain Lion) for Xcode - April 2013”

• Click the link next to the disk image icon to download them

• When the download completes, open ~/Downloads and double click the .dmg to mount it

• In the .dmg, run the installer

Homebrew

Homebrew is a package manager for OS X that makes it much easier to install and configure the other utilities Emscripten depends on. More information is available at http://mxcl.github.io/homebrew/.

To install Homebrew, copy and paste ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)" into Terminal and follow the script’s instructions. When it is done, run brew doctor, brew update and brew upgrade. If you already have Homebrew installed, make sure to run brew update and brew upgrade before proceeding.

Other Utilities

With Homebrew installed, you can now use it to install other utilities Emscripten depends on. These are based on https://gist.github.com/nathanhammond/1974955.

• brew install node spidermonkey closure-compiler yuicompressor
• brew install llvm --with-clang

Getting the Source

At this point, you’re ready to install Emscripten. First, you’ll need to get the source. To do so, open a Terminal, cd to the directory you want Emscripten to reside at, and run git clone git://github.com/kripken/emscripten.git

Finalizing Installation

To begin, cd into the directory you cloned Emscripten into in the previous step. Then, run python emcc. This will write out a configuration file at ~/.emscripten. Open this file in your editor of choice and replace the line LLVM_ROOT = os.path.expanduser(os.getenv('LLVM') or '/usr/bin') # directory with the line LLVM_ROOT = os.path.expanduser(os.getenv('LLVM') or '/usr/local/Cellar/llvm/3.2/bin') # directory

Then, run python emcc again. If everything worked, you should see a few lines ending with emcc: no input files. If you receive an error instead, consult the official Emscripten documentation at https://github.com/kripken/emscripten/wiki/Tutorial.

You are now ready to use Emscripten.