bug: --decode-internal (and related flags --flamechart / --flamegraph) only work when optimizer is explicitly turned off

[akshatmittal]

Component

Forge

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (9a0f66e 2024-09-26T00:22:17.831423400Z)

What command(s) is the bug in?

No response

Operating System

None

Describe the bug

Any commands that utilizes --decode-internal (including --flamechart and --flamegraph) fail with failed to parse source map: no previous offset if optimizer isn't explicitly turned off.

The command should either throw a more descriptive error asking to disable optimizer or disable it automatically when running the command.

[zerosnacks]

Hi @akshatmittal thanks for your report

Would you be able to provide a minimal reproduction that throws failed to parse source map: no previous offset or point to a code snippet that does?

It will help us greatly narrow down the issue

[akshatmittal]

@zerosnacks Sure, here you go: https://github.com/uniswapfoundation/v4-template (I am working on a different codebase, but this starter repo has the same error)

forge test --decode-internal -vvvvv will throw the error I mentioned. (Narrowing to a single test doesn't change the outcome, but here you go anyway forge test --decode-internal --match-test testCounterHooks -vvvvv) Adding optimizer = false to config does work correctly.

[DaniPopes]

cc @klkvr

[DaniPopes]

Error location: crates/evm/traces/src/debug/sources.rs:103

foundry/crates/evm/traces/src/debug/sources.rs

Lines 85 to 111 in df2e91b

	fn new(bytecode: ContractBytecodeSome, build_id: String, file_id: u32) -> Result<Self> {
	let parse = |b: &Bytecode| {
	// Only parse source map if it's not empty.
	let source_map = if b.source_map.as_ref().map_or(true, |s| s.is_empty()) {
	Ok(None)
	} else {
	b.source_map().transpose()
	};
	// Only parse bytecode if it's not empty.
	let pc_ic_map = if let Some(bytes) = b.bytes() {
	(!bytes.is_empty()).then(|| PcIcMap::new(bytes))
	} else {
	None
	};
	source_map.map(|source_map| (source_map, pc_ic_map))
	};
	let (source_map, pc_ic_map) = parse(&bytecode.bytecode)?;
	let (source_map_runtime, pc_ic_map_runtime) = bytecode
	.deployed_bytecode
	.bytecode
	.map(|b| parse(&b))
	.unwrap_or_else(|| Ok((None, None)))?;
	Ok(Self { source_map, source_map_runtime, pc_ic_map, pc_ic_map_runtime, build_id, file_id })
	}