Prevent building the clippy plugin in rustbuild

[msizanoen1]

Provided the tool names as defined using tool_extended!(...) are valid binary names as defined in the manifest, this PR avoids building the clippy plugin by passing the --bin flags followed by tool name to Cargo when building extended tools.
If we don't pass the --bin flag, Cargo will build everything by default - including the plugin that causes the failure.
Close #62558

[mati865]

I cannot approve PRs, you need to r? on proper reviewer.

[msizanoen1]

r? @alexcrichton

[msizanoen1]

Some local testing shows that clippy builds sucessfully after this change.

[Mark-Simulacrum]

Can you confirm that all the tools are named the same as the tool? I am not sure that's the case, if it isn't we'll likely want to change the logic here a bit.

[msizanoen1]

I have tested this locally.

Here are the manifests if you want to check:

• https://github.com/rust-lang/cargo/blob/master/Cargo.toml
• https://github.com/rust-lang/rust-clippy/blob/master/Cargo.toml
• https://github.com/rust-lang/miri/blob/master/Cargo.toml
• https://github.com/rust-lang/rls/blob/master/Cargo.toml

[alexcrichton]

Thanks for the PR! I'm sort of confused though as to why this fixes that issue, could you expand in the PR description, the comments, or the commit message about how this fixes the original issue?

[msizanoen1]

I have updated the description.

[alexcrichton]

Could you also place some comments in the source code about how tools are being avoided?

Additionally does this affect rustfmt as well? There I believe we want both the rustfmt and cargo fmt executables.

Could we otherwise update clippy to put the plugin behind an off-by-default feature or move it to a separate crate?

[msizanoen1]

I added a comment.
Also rustfmt should work fine: https://github.com/rust-lang/rustfmt/blob/master/Cargo.toml

[alexcrichton]

Can you expand on your reasoning on why rustfmt will still work? Simply pasting a link to the manifest is pretty opaque and doesn't really mean much to me. It doesn't answer my concern about this probably not building the cargo-fmt executable since it'd only build rustfmt

[msizanoen1]

The tools declaration is here:

rust/src/bootstrap/tool.rs

Lines 642 to 659 in d1fff4a

	tool_extended!((self, builder),
	Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", {};
	CargoClippy, clippy, "src/tools/clippy", "cargo-clippy", {};
	Clippy, clippy, "src/tools/clippy", "clippy-driver", {};
	Miri, miri, "src/tools/miri", "miri", {};
	CargoMiri, miri, "src/tools/miri", "cargo-miri", {};
	Rls, rls, "src/tools/rls", "rls", {
	let clippy = builder.ensure(Clippy {
	compiler: self.compiler,
	target: self.target,
	extra_features: Vec::new(),
	});
	if clippy.is_some() {
	self.extra_features.push("clippy".to_owned());
	}
	};
	Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", {};
	);

As you can see, the cargo-fmt and rustfmt binaries are defined with the same name both in this file and the manifest:
https://github.com/rust-lang/rustfmt/blob/6aec17e4c372d1cda3484a2e292cff8f5995dd64/Cargo.toml#L14-L20

[msizanoen1]

Also I have tested this locally with a full extended build.

[mati865]

Clippy should drop plugin interface as soon as it's CI is fixed: rust-lang/rust-clippy#4714
Is it worth to make additional effort here?

[msizanoen1]

Closed in favor of #66142