Load account and input note `MastForest::advice_map` before execution

[greenhat]

Packages versions

miden-base: 0.9.0

Bug description

When entrypoint for the note script compiled from Rust is called, it loads data segments from the advice provider into the memory.
See counter_note entrypoint - https://github.com/0xMiden/compiler/blob/d0032e7fa22fbad1ff704fc8f9c2367067164129/tests/integration/expected/examples/counter_note.masm?plain=1#L11-L33
But when it is executed as an input note, the AdviceMapKeyNotFound is thrown:

TransactionExecutorError(TransactionProgramExecutionFailed(AdviceMapKeyNotFound { label: SourceSpan { source_id: SourceId(4294967295), start: ByteIndex(0), end: ByteIndex(0) }, source_file: None, key: [10393006917776393985, 11082306316302361448,
      8154980225314320902, 11512975618068632545] }))

I intend to make a PR with a fix - load the note's MastForest::advice_map into the advice provider somewhere in https://github.com/0xPolygonMiden/miden-base/blob/e6fa50d819d68571d49055db479301546de08a8f/crates/miden-lib/src/transaction/inputs.rs?plain=1#L287-L354

Please stop me if I'm on the wrong track.

How can this be reproduced?

Run the cargo make test test_counter_contract_testnet in 0xMiden/compiler#555

Relevant log output

[bobbinth]

Thank you for finding this and for volunteering to fix it!

I intend to make a PR with a fix - load the note's MastForest::advice_map into the advice provider somewhere in https://github.com/0xPolygonMiden/miden-base/blob/e6fa50d819d68571d49055db479301546de08a8f/crates/miden-lib/src/transaction/inputs.rs?plain=1#L287-L354

I'm wondering if this is the right place to add this data to the advice inputs. There are two other alternatives:

• Do it in the constructor of the TransactionHost. Here, we could iterate over all MAST forests in scripts_mast_store and add them to the adv_provider.
• Do it in the TransactionProver and TransactionExecutor (e.g., around here.

Overall, it feels like this functionality should live in the host (because, in a way, it is the host's responsibility to mange MAST forests), but maybe your approach is also fine.

A couple of other things we should keep in mind:

1. We probably need to do the same for account code.
2. And also for any MAST forests loaded from linked libraries (e.g., the standard library and the protocol library).

The first one we can do around the same place you've suggested (and we can do it in the transaction host too, though then we'd need to pass AccountCode into it).

But the second one is somewhat more tricky. The assumption here is that MAST forests can be loaded dynamically through the DataStore interface. And this may require adding interior mutability to the transaction host. And another complication is how this should work in the transaction prover.

To summarize: loading advice data for notes and accounts should be relatively each and can be done either in TransactionInput (as you've suggested) or in the TransactionHost. Loading advice data from libraries, is a bit more tricky. But since we don't have any libraries that use advice data yet, maybe we defer the solution of this specific part to another issue.

Also, cc @igamigo in case you have other ideas on this.