Exports inconsistently leaking from libraries into contracts

[leighmcculloch]

This issue is a lightweight placeholder and needs more details.

@brozorec showed me today a contract build where a contract using the open zeppelin stellar contracts is picking up some random exports from the libraries.

He shared an example here: OpenZeppelin/stellar-contracts#373

This new behaviour has been noticed as part of upgrading both to a new sdk as well as new contract code, so there's a few moving parts and it is possible this is a result of one of those moving parts. But after a cursory look I think this might be a case of exports leaking from libraries to the contract, but in a way that's inconsistent.

The exports being lifted into the cdylib in the example above are contract specs.

We know that control over what exports leak from libraries to the main cdylib being built is very limited in the rust compiler. This is an issue we have explored in:

• Prevent importing contracts into each other or make it safe #1439

[leighmcculloch]

Having the stellar-cli strip out types that are not referenced by functions (stellar/stellar-cli#2030 stellar/stellar-cli#2353) will partially address this problem with post-processing. However it won't address events.

[leighmcculloch]

One way we might be able to also post-process out events is to do something to events so that when they are included in code, there is a code marker, something that we can visibly look for in the resulting wasm to identify that yes that event does end up in the code and does end up getting published. One way to do that would be to look for the name encoded as a symbol in the data section.