feat(forge, cast): add RunArgs generate_local_signatures to enable trace with local contracts functions and events

[byteshijinn]

Motivation

Supply a fast way to add all project contracts functions and events to signatures makes them decode correctly.

Solution

This PR introduces such a possibility using a cli argument --generate-local-signatures for cast run.

[mattsse]

supportive, though we can solve this a bit differently

lmk if anything's unclear

[mattsse]

This needs docs+explainer

[mattsse]

perhaps a better solution than doing the preprocess step would be to provide the local signatures here:

so they can be merged with this here

foundry/crates/cli/src/utils/cmd.rs

Lines 393 to 396 in eef87de

	.with_signature_identifier(SignaturesIdentifier::new(
	Config::foundry_cache_dir(),
	config.offline,
	)?)

[byteshijinn]

I implemented it in run.rs to make it optional, and handle_traces as a public method I wanted to change it as little as possible until I understood all others crates package if refered to it.

[byteshijinn]

In fact, it makes more sense for this function to be executed at forge compile time, and it apears in cast run as a shortcut entry to avoid typing the command twice.

[mattsse]

we already have this type here

foundry/crates/evm/traces/src/identifier/signatures.rs

Lines 14 to 18 in edb3a4b

	#[derive(Debug, Default, Serialize, Deserialize)]
	struct CachedSignatures {
	events: BTreeMap<String, String>,
	functions: BTreeMap<String, String>,
	}

we should prevent duplicating this and instead find a way to reuse the existing type

we can make the type pub instead and also make this a helper function:

foundry/crates/evm/traces/src/identifier/signatures.rs

Lines 44 to 56 in eef87de

	let identifier = if let Some(cache_path) = cache_path {
	let path = cache_path.join("signatures");
	trace!(target: "evm::traces", ?path, "reading signature cache");
	let cached = if path.is_file() {
	fs::read_json_file(&path)
	.map_err(|err| warn!(target: "evm::traces", ?path, ?err, "failed to read cache file"))
	.unwrap_or_default()
	} else {
	if let Err(err) = std::fs::create_dir_all(cache_path) {
	warn!(target: "evm::traces", "could not create signatures cache dir: {:?}", err);
	}
	CachedSignatures::default()
	};

[byteshijinn]

I defined it again because I find it does not exported. For maintenance reasons, I think you're right. At first I was just using it for myself so I didn't think about it that much, I'll spend some time refactoring the code next.

[byteshijinn]

I updated my code. please check again @mattsse