wabt VS cross

https://github.com/WebAssembly/wabt/blob/main/wasm2c/README.... is a straightforward way to take an untrusted application (compiled already to wasm) and turn it into C that you can embed into your application or compile to a linkable DLL. I believe this approach has been used to sandbox untrusted libraries in production by Mozilla: https://hacks.mozilla.org/2021/12/webassembly-and-back-again...

As long as this is happening, might as well try some of my favorites: https://github.com/wasm3/wasm3, https://github.com/WebAssembly/wabt, https://github.com/bytecodealliance/wasmtime

This seems sort of like understanding machine code vs assembly; it's much easier to learn WAT and translate to/from WASM as necessary using the wabt tools [0].

Either way its super cool how simple WebAssembly is, you can really get your hands dirty and understand exactly every detail of how your program runs!

[0] https://github.com/WebAssembly/wabt

You mean this? https://github.com/WebAssembly/wabt/blob/main/wasm2c/README....

That seems like quite an undertaking. But at that point, It would make sense to cut out WASM entirely like https://datastation.multiprocess.io/blog/2022-05-12-sqlite-i...

The .wat file can be compiled to a .wasm using wat2wasm which is part of the WebAssembly Toolkit CLI tools:

it is in C++ https://github.com/WebAssembly/wabt/blob/main/src/tools/wat2wasm.cc

I don't think you are building an application that will use Native Client technologies How to extract source code from Native Client .nexe file, migrate to WebAssembly? #1864 so that would be superfluous, and frankly, useless in your case.

I'm trying to get a basic Rust webassembly program, then porting it to C via wasm2c. The example works, but when I use wasm-bindgen and analyze it with wasm2wat, I get an import "env". The issue is that in C (wasm2c) it comes out as struct Z_env_instance_t; and I can't instantiate it (as in Z_env_instance_t env; to pass it's address to Z_wasm_client_bg_instantiate.

To compile a program with musl on a glibc system you can use cross-rs!

I cross compile to Mac, bsd, windows, etc cross ... Works great for me with either docker or podman.

If docker is available for you, https://github.com/cross-rs/cross is another and reliable way to solve this kind of problem. I do use it regularly.

We are using https://github.com/cross-rs/cross.

There is some built-in support in rustc for cross-compiling, but getting the build to actually work can be tricky due to the need for an appropriate linker. Instead, we’re going to use the Cross crate, which used to be maintained by the Rust Embedded Working Group Tools group.

I have used cross before to cross compile from Linux to other Linux. It has a section on it's wiki about this. Maybe that could be of help.

You can use cross to build your application and copy the artifacts into an alpine armv7 container. It would also build faster due to using cross compilation rather than QEMU.

Looks like cross is the easiest way to get something cross-compiled but its Mac support is blocked behind building your own build image. Even that repo says that it might be broken.

Bonus: if you’re working with Rust and doing a lot of cross platform stuff, check out cross. It runs QEMU in docker so you can run tests on a bunch of different emulated targets easily- literally a one line setup, it’s kind of magical.

It's also not as naturally cross-compilable as Go, though that's partly a side-effect of not accepting being a semi-closed ecosystem to achieve that and cross exists as a stop-gap while things like cargo-zigbuild explore less drastic options.