Published: 26 Jan 2022
OCaml bindings for Binaryen.
Binaryen is a compiler and toolchain infrastructure for WebAssembly. It makes compilation to WebAssembly pretty darn easy.
Here's Binaryen's hello world test in OCaml form:
open Binaryen let wasm_mod = Module.create () (* Create function type for i32 (i32, i32) *) let params = Type.create [| Type.int32; Type.int32 |] let results = Type.int32 (* Get arguments 0 and 1, add them *) let x = Expression.Local_get.make wasm_mod 0 Type.int32 let y = Expression.Local_get.make wasm_mod 1 Type.int32 let add = Expression.Binary.make wasm_mod Op.add_int32 x y (* Create the add function *) (* Note: no additional local variables *) let adder = Function.add_function wasm_mod "adder" params results [||] add let _ = Module.print wasm_mod let _ = Module.dispose wasm_mod
This project aims to provide full feature parity with the Binaryen C API. It's fairly complete, but a few things still need bindings:
Query operations on expressions
Query operations on functions
None of these are particularly challenging to create bindings for—they just haven't been written yet. If you need anything that's missing, feel free to open a PR.
When using this package with
esy, you'll need to ensure that a
python executable exists in one of these locations:
/sbin/python. Esy will only look for python in those locations, and it is not provided for you in the sandbox.
Note: This implicit dependency will be removed in a future version.
MacOS C++ Compiler
When including this library in your
dune MacOS executables, you'll need to specify
-cc clang++ in your
(ocamlopt_flags) stanza. This is required because Binaryen will throw errors for itself to catch and using
clang++ is the only way to handle them correctly. You can find more info on this ocaml issue.
Your stanza could look something like this:
(executable (name example) (public_name example) (package example) + (ocamlopt_flags -cc clang++) (modules example) (libraries binaryen))
These flags likely won't work on other operating systems, so you'll probably need to use
dune-configurator to vary the flags per platform. You can see an example of this in our tests/.
If you are planning to create portable binaries for Windows, it will try to find Cygwin/MinGW locations in your
PATH. To avoid this, you probably want to add this to your
(executable (name example) (public_name example) (package example) + (flags (:standard -ccopt -- -ccopt -static)) (modules example) (libraries binaryen))
These flags might not work on other operating systems (like MacOS), so you'll probably need to use
dune-configurator to vary the flags per platform.
You'll need Node.js and
esy to build this project.
dune will take care of compiling the C stubs, so to build the project you'll only need to run:
This will take a while. Once it's done, you can run the tests: