1. Install Emscripten v3.1.74. On a Mac with Brew:

   wget https://raw.githubusercontent.com/Homebrew/homebrew-core/d6f9b7309b9a2fed49a0083bb13de362bb3db965/Formula/e/emscripten.rb && \
   brew install emscripten.rb

   (Last tested with emscripten 3.1.74. NOTE emscripten v4 seems to have a breaking change.)

2. Check that you have emmake, emcc, and node in your path. If you don't have node in your path, you can locally modify the script in the next step where it says NODE=node. (Node is only used to run a quick sanity check after compiling.)

3. In the repo directory, run meteor/make-emscripten.sh.

4. That's it. If everything worked, the build product is build/minisat.js.

Notes:

• The "native" part of logic-solver is in meteor/logic-solver.cc. If you add functions to it, you need to also list them in make-emscripten.sh.

• We wrap the entire Emscripten output in a closure, so that we can create multiple instances of the entire C environment (including the heap). MiniSat's C++ classes are slightly leaky, and it doesn't seem wise to have multiple solver instances sharing a heap on the "native" side. Better to fully isolate instances, and not rely on (or even call) the destructor.

• There's heap allocation instrumentation, hackily implemented, that doesn't actually run unless you put the compiler in debug mode (see comment in the make script about the -g flag). You can enable the instrumentation by passing ENABLE_INSTRUMENTATION=true as an environment variable, e.g.:

  ENABLE_INSTRUMENTATION=true ./meteor/make-emscripten.sh

• You want to leave minification on (no -g flag or ENABLE_INSTRUMENTATION env var), because unlike client-side code served by Meteor (which is minified anyway), Node runs this code directly. Minification actually helps the JS compile time quite a bit!