Fix Clippy subcommand name

[camelid]

Fixes #5640.

changelog: none

[rust-highfive]

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[camelid]

I wasn't able to verify that this works because clippy won't build for me (it says it can't find rustc_ast). Is there something about this in CONTRIBUTING.md?

EDIT: Oops, didn't see the "basics" docs

[yaahc]

@camelid you probably need to run setup-toolchain.sh

if that's not it lmk and I'll help you dig into the issue.

[camelid]

@yaahc Thanks! I just ran it, though now I'm getting compiler errors. Is this because Clippy depends on rustc internals?

Here's all the errors:

error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields
    --> clippy_lints/src/utils/ast_utils.rs:509:14
     |
509  |             (DocComment(l), DocComment(r)) => l == r,
     |              ^^^^^^^^^^^^^ expected 2 fields, found 1

error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields
    --> clippy_lints/src/utils/ast_utils.rs:509:29
     |
509  |             (DocComment(l), DocComment(r)) => l == r,
     |                             ^^^^^^^^^^^^^ expected 2 fields, found 1

error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields
    --> clippy_lints/src/doc.rs:321:16
     |
321  |         if let AttrKind::DocComment(ref comment) = attr.kind {
     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 2 fields, found 1

error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields
    --> clippy_lints/src/tabs_in_doc_comments.rs:63:16
     |
63   |         if let ast::AttrKind::DocComment(comment) = attr.kind {
     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 2 fields, found 1

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0023`.
error: could not compile `clippy_lints`.

[yaahc]

Is this because Clippy depends on rustc internals?

AFAIK yes. Whenever they change internal APIs we have to update them in clippy to match. I'm a little surprised though because I thought they just finished making it so clippy is tested on every rustc PR to prevent these kinds of breakages but I don't know the details of how the new subtree stuff works so I'm guessing its still possible for breakages to occur.

cc @flip1995 @matthiaskrgr

[ebroto]

@yaahc setup-toolchain.sh still uses rust-lang/rust master's HEAD (including the breaking changes for clippy). There are plans to pin to a nightly, but it's blocked on rust-lang/rustup#2350

@camelid I'm afraid your solution won't work. cargo-clippy correctly calls cargo check setting RUSTC_WRAPPER to point to clippy-driver, which is called by cargo instead of rustc.

If I'm not mistaken, the problem in the issue you linked is that you were using a wrong command-line which is not understood by cargo check, so it errors out.

[flip1995]

@yaahc Clippy has to pass tests in rustc, but the changes to fix clippy have to be synced back to Clippy. Currently the subtree usage only makes it easier to do a rustup. @ebroto pointed out the rest of the story. (See discord why I didn't sync Clippy yet.)

We should fix this issue $somehow, but we definitely need a test for this (after it is fixed).

[camelid]

@yaahc I just opened #5874 to try to make it extra obvious that you need to run a script to set up your toolchain.

[camelid]

@camelid I'm afraid your solution won't work. cargo-clippy correctly calls cargo check setting RUSTC_WRAPPER to point to clippy-driver, which is called by cargo instead of rustc.

Ah, that's unfortunate. It just seems confusing that errors from running cargo clippy make it look like you were running cargo check.

[flip1995]

This produces error: infinite recursion detected when running the cargo clippy command

Closing this, since I think, that this has to be fixed in cargo, rather than Clippy.