wabt | The WebAssembly Binary Toolkit

The WASM module uses SIMD instructions (prefixed with 0xfd, and also known as vector instructions), which were merged into the spec just last month. The latest release of wasm-decompile therefore doesn't have these enabled by default yet, but will in the next release. Meanwhile, you can enable them manually with the --enable-simd command line option. This invocation works for me with the latest release:

Compilers will often inline functions and remove code that isn't used, this is why your C program ends up with everything inside a _start function. As explained in the FAQ you may list functions to export using emcc -s EXPORTED_FUNCTIONS=_main,_matrix in order to prevent them from being inlined or removed. Adding this results in a wasm module with the function correctly exported.

As for running functions directly, the source code for wasmer run has logic to determine which runtime environment should be exposed to the module. However, if you pass -i function, it entirely skips the environment setup and runs your function directly. In this case, the modules fails to initialize because it imports functions from WASI (in order to write things to the console, and get the current clock time).

I believe the reason why wasm32-unknown-unknown works is that it doesn't link to any runtime, and implements dummy interfaces for things that it can't simulate (all filesystem calls result in errors, etc.)

In summary, wasmer run -i function isn't meant to run functions from modules that have imports, it might be possible to patch wasmer-cli for that, but I'm not sure if it would work across all runtime environments.

If you plan to write a lot of WASM in Go, you might want to consider compiling with TinyGo, which is a Go compiler for embedded and WASM.

TinyGo supports a //export or alias //go:export comment directive that does what you're looking for.

I'm copy-pasting the very first example from TinyGo WASM docs:

This was a compiler bug fixed by Chromium in https://chromium-review.googlesource.com/c/v8/v8/+/2551100.

This was the response that I had gotten from one of the developers:

This is indeed a timing issue that has been fixed in https://chromium-review.googlesource.com/c/v8/v8/+/2551100. The problem happens when there are only imported globals, and compilation of the WebAssembly functions finishes before the stream actually finishes. In this case, the offset calculation happens after the compiler uses the offsets, and therefore produces incorrect code.

A workaround is to define one global that is not imported, as this causes the offset calculation to happen earlier.

Seems like sending a small module that only imports globals instead of functions was breaking the code.

Their code had a threading race condition between the stream and the compiler.

In this project the debug information are generated by default because of th -g option added with add_definitions.

The name of the exported Wasm function is defined to be the index.

You already have the actual exported name since you have to import add by its name.

Also see https://developer.mozilla.org/en-US/docs/WebAssembly/Exported_functions where they call testFunc.toString() and the resulting function has name 0.

It's not entirely clear what you need, but I think it's something like the following. An array of --p2p-peer-address options is created, then incorporated into the larger set of common options. Each call to nodeos then has some peer-specific options in addition to the common options.