# README

wasmvm

This is a wrapper around the CosmWasm VM. It allows you to compile, initialize and execute CosmWasm smart contracts from Go applications, in particular from x/wasm.

Structure

This repo contains both Rust and Go code. The rust code is compiled into a dll/so to be linked via cgo and wrapped with a pleasant Go API. The full build step involves compiling rust -> C library, and linking that library to the Go code. For ergonomics of the user, we will include pre-compiled libraries to easily link with, and Go developers should just be able to import this directly.

Supported Platforms

Requires Rust 1.55+ and Go 1.17+.

The Rust implementation of the VM is compiled to a library called libwasmvm. This is then linked to the Go code when the final binary is built. For that reason not all systems supported by Go are supported by this project.

Linux (tested on Ubuntu, Debian, and CentOS7, Alpine) and macOS is supported. We are working on Windows (#288).

Builds of libwasmvm

Our system currently supports the following builds. In general we can only support targets that are supported by Wasmer's singlepass backend, which for example excludes all 32 bit systems.

OS family	Arch	Linking	Supported	Note
Linux (glibc)	x86_64	shared	✅libwasmvm.x86_64.so
Linux (glibc)	x86_64	static	🚫	Would link libwasmvm statically but glibc dynamically as static glibc linking is not recommended. Potentially interesting for Osmosis.
Linux (glibc)	aarch64	shared	✅libwasmvm.aarch64.so
Linux (glibc)	aarch64	static	🚫
Linux (musl)	x86_64	shared	🚫	Possible but not needed
Linux (musl)	x86_64	static	✅libwasmvm_muslc.x86_64.a
Linux (musl)	aarch64	shared	🚫	Possible but not needed
Linux (musl)	aarch64	static	✅libwasmvm_muslc.aarch64.a
macOS	x86_64	shared	✅libwasmvm.dylib	Fat/universal library with multiple archs (#294)
macOS	x86_64	static	🚫
macOS	aarch64	shared	✅libwasmvm.dylib	Fat/universal library with multiple archs (#294)
macOS	aarch64	static	🚫
Windows (mingw)	x86_64	shared	🏗wasmvm.dll	See #288
Windows (mingw)	x86_64	static	🚫
Windows (mingw)	aarch64	shared	🚫
Windows (mingw)	aarch64	static	🚫

Docs

Run (cd libwasmvm && cargo doc --no-deps --open).

Design

Please read the Documentation to understand both the general Architecture, as well as the more detailed Specification of the parameters and entry points.

Development

There are two halfs to this code - go and rust. The first step is to ensure that there is a proper dll built for your platform. This should be api/libwasmvm.X, where X is:

so for Linux systems
dylib for MacOS
dll for Windows - Not currently supported due to upstream dependency

If this is present, then make test will run the Go test suite and you can import this code freely. If it is not present you will have to build it for your system, and ideally add it to this repo with a PR (on your fork). We will set up a proper CI system for building these binaries, but we are not there yet.

To build the rust side, try make build-rust and wait for it to compile. This depends on cargo being installed with rustc version 1.47+. Generally, you can just use rustup to install all this with no problems.