Geth support

[axic]

Apparently native ewasm support in geth could be implemented by using wagon (a wasm interpreter written in Go).

@gballet volunteered to look into this

The tasks are:

• [x] verify that wagon can actually run the official wasm test suite (we don't care about floating point support though)
• [x] integrate wagon into geth
• [x] support all the EEI methods
• [ ] support all the "vm semantics" (part of it is described here but needs to be updated)

For an inspiration see https://github.com/ewasm/hera which does the same thing using binaryen.

[gballet]

Having a look at wagon, it seems to do the job but it panics if it encounters a fault. This is a problem if we are going to use it to run contracts, because we can't have geth panic if some contract code is broken.

I have submitted this PR https://github.com/go-interpreter/wagon/pull/53

[gballet]

This gist shows a unit test that demonstrates how to create a module that offers native functions. So far, that requires making some changes to the wagon code. I will clean up the code and create a PR this week, to get some feedback from the wagon team.

[gballet]

Regarding the panic, the wagon team requested a different approach that is tracked in https://github.com/go-interpreter/wagon/pull/57

[axic]

Great news!

[gballet]

https://github.com/go-interpreter/wagon/pull/58 is the cleaned-up PR asking the wagon people for their comments. I still need to make sure that functions with parameters can be properly called, and then I can start implementing the EEI methods.

[gballet]

both PRs are now integrated, I can now proceed with the EEI

[lrettig]

@gballet update from today: Working on EEI, done with the easy part. Looking into contracts calling other contracts.

[gballet]

Looks like this was missing a reference to the PR that integrates wagon into geth: https://github.com/ethereum/go-ethereum/pull/16957

[axic]

Closing this now.