Wasker

Wasker is a WebAssembly compiler. Wasker compiles Wasm binary into ELF format binary.　 Currently, Wasker supports WASI preview 1.

What's new with Wasker

There are already software tools that compile Wasm to native binaries.

What's new with Wasker is, Wasker generates an OS-independent ELF file where WASI calls from Wasm applications remain unresolved.

This unresolved feature allows Wasker's output ELF file to be linked with WASI implementations provided by various operating systems, enabling each OS to execute Wasm applications.

Wasker empowers your favorite OS to serve as a Wasm runtime!

Quick Start

Step1: Install Wasker

Download and install the latest release binary for your architecture:

curl -sSfL "https://github.com/mewz-project/wasker/releases/latest/download/wasker-linux-$(uname -m)-musl" \
  -o /usr/bin/wasker
chmod +x /usr/bin/wasker

Release binaries are fully static (musl + LLVM built from source). No runtime dependencies are required.

Step2: Create Wasm binary

Create any Wasm binary.

example1

Please refer examples for building Wasm from Rust and Go.

git clone https://github.com/mewz-project/wasker.git
cd examples/rust
rustup target add wasm32-wasi
cargo build --target wasm32-wasi

example2

We also provide a pre-built simple Wasm binary.

git clone https://github.com/mewz-project/wasker.git
ls helloworld.wat

Step3: Run Wasker to compile Wasm

example1

$ wasker examples/rust/target/wasm32-wasi/debug/rust.wasm
[2024-03-19T12:10:20Z INFO  wasker::compiler] input: examples/rust/target/wasm32-wasi/debug/rust.wasm
[2024-03-19T12:10:20Z INFO  wasker::compiler] write to ./wasm.ll
[2024-03-19T12:10:20Z INFO  wasker::compiler] write to ./wasm.o, it may take a while
[2024-03-19T12:10:21Z INFO  wasker::compiler] Compile success

example2

wasker helloworld.wat

Step4: Run compiled Wasm

ELF file generated by Wasker is OS-independent: WASI calls from Wasm applications remain unresolved.

Please write your own WASI wrapper for your favorite OS to be linked with Wasker output.

Here, we'll show a tiny example of running Wasker output on Linux.

Link Wasker output and WASI wapper for Linux

gcc -no-pie ./examples/wasi-wrapper/c/wasi-wrapper-linux.c ./wasm.o -o hello

Run!!

./hello

Also please check Mewz, a unikernel OS which has WASI interface. ELF file generated by Wasker can be executed on Mewz without any modification.

Development

Wasker compiler is based on LLVM (LLVM 22 currently).

Option1 : Use Devcontainer

You can try Wasker on browser via Devcontainer.

Option2 : Build from source

Release binaries are fully static and do not depend on the host libc or LLVM packages. If pre-built binaries do not work on your system, please build from source.

Clone repository

git clone git@github.com:mewz-project/wasker.git
cd Wasker

Install LLVM locally

The commands are a little different because you need an LLVM binary built for your architecture. You also need development libraries that LLVM links against (libzstd, libxml2).

AMD64

mkdir -p dependencies/llvm
wget https://github.com/llvm/llvm-project/releases/download/llvmorg-22.1.8/LLVM-22.1.8-Linux-X64.tar.xz -O /tmp/llvm-22.1.8.tar.xz
tar -xvf /tmp/llvm-22.1.8.tar.xz -C dependencies/llvm
export LLVM_SYS_221_PREFIX=$PWD/dependencies/llvm/LLVM-22.1.8-Linux-X64
# Debian/Ubuntu: sudo apt-get install libzstd-dev libxml2-dev

Alternatively, use the Devcontainer (Option 1 above) which installs these dependencies automatically.

AArch64

mkdir -p dependencies/llvm
wget https://github.com/llvm/llvm-project/releases/download/llvmorg-22.1.8/LLVM-22.1.8-Linux-ARM64.tar.xz -O /tmp/llvm-22.1.8.tar.xz
tar -xvf /tmp/llvm-22.1.8.tar.xz -C dependencies/llvm
export LLVM_SYS_221_PREFIX=$PWD/dependencies/llvm/LLVM-22.1.8-Linux-ARM64

Run Wasker

cargo run helloworld.wat