asterius

A Haskell to WebAssembly compiler. Work in progress.

What's already present:

• A framework which hijacks normal ghc pipeline and retrieves in-memory representation of raw Cmm.
• A test suite for booting which compiles ghc-prim, integer-simple and base.
• Complete raw Haskell bindings of binaryen.
• A serializable IR, roughly mapping to binaryen IR.

What comes next:

• A code generator/linker which collects relevant Cmm blocks at link-time and uses the binaryen relooper to handle arbitrary jumps.
• An RTS written from scratch in native WebAssembly. Will implement enough primops & libc stubs for an MVP(Minimum Viable Product).
• A test suite for the generated WebAssembly code.

Building

Assumes x64 platform, only tested on Linux for now. Dependencies:

• cmake/make/g++: For building in-tree binaryen
• autoconf/sed: For booting ghc-prim/base
• nodejs: For running tests
• ghc-head built with TABLES_NEXT_TO_CODE disabled and integer library set to integer-simple. Get one via docker pull terrorjack/meikyu:ghc-head
• stack. cabal users need to run hpack first to generate asterius.cabal, and add head.hackage to the project config.

Simply run stack build. Set MAKEFLAGS=-j8 to pass flags to make for parallel building of binaryen. Run stack test asterius:ahc-boot to test if booting works.

Windows users need to run it in an mingw-w64 Win64 shell. stack takes care of installing/launching it by default.

Differences from WebGHC

• Doesn't depend on Emscripten/LLVM. There is no plan to port the C runtime and support C libraries, at least for now.