redundant_closure triggers for macro

[matthiaskrgr]

I was using the get_version_info!() macro and got warnings that the imported code contains redundant closures on places where I used it.

https://github.com/rust-lang/rust-clippy/blob/master/rustc_tools_util/src/lib.rs

Can we disable the lint for code imported via macros?

[flip1995]

Huh? Can you provide an example? The get_version_info!() macro doesn't contain closures, so the lint shouldn't trigger at all. Or am I missing something?

rust-clippy/rustc_tools_util/src/lib.rs

Lines 4 to 25 in 027dde9

	macro_rules! get_version_info {
	() => {{
	let major = env!("CARGO_PKG_VERSION_MAJOR").parse::<u8>().unwrap();
	let minor = env!("CARGO_PKG_VERSION_MINOR").parse::<u8>().unwrap();
	let patch = env!("CARGO_PKG_VERSION_PATCH").parse::<u16>().unwrap();
	let crate_name = String::from(env!("CARGO_PKG_NAME"));
	let host_compiler = $crate::get_channel();
	let commit_hash = option_env!("GIT_HASH").map(str::to_string);
	let commit_date = option_env!("COMMIT_DATE").map(str::to_string);
	VersionInfo {
	major,
	minor,
	patch,
	host_compiler,
	commit_hash,
	commit_date,
	crate_name,
	}
	}};
	}

[matthiaskrgr]

matthiaskrgr/cargo-cache@81ffeeb

Yeah it was updated to not contain closures but the crates.io version still contains closures.

[matthiaskrgr]

Anyway, what I mean is, if we report code imported by macros, these macros could also come from third party crates and issuing a lint warning looks like a false positive since the warning cannot be fixed by modifying the root crate.

[flip1995]

Ah that makes sense. We once had an in_external_macro function in utils, but I think it isn't possible anymore to get this information from rustc.

[phansch]

rustc now has a in_external_macro function: https://doc.rust-lang.org/nightly/nightly-rustc/rustc/lint/fn.in_external_macro.html