Remove uses of `cfg({any()/all()})` #149791

clubby789 · 2025-12-08T22:12:25Z

~~This implements the followup warning suggested in rust-lang/rfcs#3695~~
~~Lint against an empty cfg(any/all), suggest the boolean literal equivalents.~~
#149791 (comment)

Tracking issue: #131204

rustbot · 2025-12-08T22:12:29Z

Some changes occurred in check-cfg diagnostics

cc @Urgau

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

rustbot · 2025-12-08T22:12:31Z

r? @chenyukang

rustbot has assigned @chenyukang.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

jdonszelmann · 2025-12-08T22:48:39Z

r? jdonszelmann

Urgau · 2025-12-08T22:50:11Z

Can you split-off the FALSE -> false suggestion into it's own PR?

As for the warning it should probably be a lint (so it can be enabled and disabled), but either way the warning will need to go through T-lang first, with a nomination and maybe a crater run.

joshtriplett · 2025-12-08T23:22:06Z

With my T-lang hat on, this seems reasonable. Nominating for discussion of the new lint.

clubby789 · 2025-12-09T02:31:56Z

Running into the above error where

    (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($tokens:tt)*) ), $($rest:tt)*) => {
        #[cfg(all($($m,)* not(any($($not),*))))] cfg_if! { @__identity $($tokens)* }
        cfg_if! { @__items ($($not,)* $($m,)*) ; $($rest)* }
    };

is invoked with no $not, meaning we expand to not(any()) and raise the lint. Inclined to think that we should only lint for the literal any()/all() cases instead

rustbot · 2025-12-09T03:05:53Z

This PR modifies tests/ui/issues/. If this PR is adding new tests to tests/ui/issues/,
please refrain from doing so, and instead add it to more descriptive subdirectories.

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

clubby789 · 2025-12-09T03:06:40Z

Implemented as a pre-expansion early lint

compiler/rustc_attr_parsing/src/context.rs

compiler/rustc_lint/src/early/diagnostics.rs

compiler/rustc_lint/src/empty_cfg_predicate.rs

tests/ui/conditional-compilation/cfg-attr-multi-false.rs

tests/ui/lint/empty-cfg-predicate.rs

tests/ui/lint/empty-cfg-predicate.stderr

jdonszelmann

Though I'm not T-lang, I agree with josh that this is a good lint to add. Just got some comments about the implementation but nothing too major. Just gotta clean some things up :)

View changes since this review

bors · 2025-12-12T10:13:05Z

📌 Commit c96ff2d has been approved by jdonszelmann

It is now in the queue for this repository.

jdonszelmann · 2025-12-12T10:13:28Z

@bors r-

jdonszelmann · 2025-12-12T10:14:38Z

sorry, I do think it's good to change these tests, but could you point me to a test that still tests cfg(all()) and cfg(any()) somewhere? I want to make sure there's still something in ui tests testing the old pattern.

jdonszelmann · 2025-12-12T10:15:12Z

oh I found it myself, ok my bad
@bors r+

bors · 2025-12-12T10:15:14Z

📌 Commit c96ff2d has been approved by jdonszelmann

It is now in the queue for this repository.

…elmann Remove uses of `cfg({any()/all()})` ~~This implements the followup warning suggested in rust-lang/rfcs#3695 ~~Lint against an empty `cfg(any/all)`, suggest the boolean literal equivalents.~~ rust-lang#149791 (comment) Tracking issue: rust-lang#131204

Suggest `cfg(false)` instead of `cfg(FALSE)` Split from rust-lang#149791 cc `@Urgau`

…elmann Remove uses of `cfg({any()/all()})` ~~This implements the followup warning suggested in rust-lang/rfcs#3695 ~~Lint against an empty `cfg(any/all)`, suggest the boolean literal equivalents.~~ rust-lang#149791 (comment) Tracking issue: rust-lang#131204

Suggest `cfg(false)` instead of `cfg(FALSE)` Split from rust-lang#149791 cc ``@Urgau``

…elmann Remove uses of `cfg({any()/all()})` ~~This implements the followup warning suggested in rust-lang/rfcs#3695 ~~Lint against an empty `cfg(any/all)`, suggest the boolean literal equivalents.~~ rust-lang#149791 (comment) Tracking issue: rust-lang#131204

Suggest `cfg(false)` instead of `cfg(FALSE)` Split from rust-lang#149791 cc ```@Urgau```

Suggest `cfg(false)` instead of `cfg(FALSE)` Split from rust-lang#149791 cc ````@Urgau````

…elmann Remove uses of `cfg({any()/all()})` ~~This implements the followup warning suggested in rust-lang/rfcs#3695 ~~Lint against an empty `cfg(any/all)`, suggest the boolean literal equivalents.~~ rust-lang#149791 (comment) Tracking issue: rust-lang#131204

Suggest `cfg(false)` instead of `cfg(FALSE)` Split from rust-lang#149791 cc `````@Urgau`````

…elmann Remove uses of `cfg({any()/all()})` ~~This implements the followup warning suggested in rust-lang/rfcs#3695 ~~Lint against an empty `cfg(any/all)`, suggest the boolean literal equivalents.~~ rust-lang#149791 (comment) Tracking issue: rust-lang#131204

Suggest `cfg(false)` instead of `cfg(FALSE)` Split from rust-lang#149791 cc ```````@Urgau```````

Rollup of 7 pull requests Successful merges: - #149655 (bootstrap: add rustc-dev install target) - #149789 (Cleanup in the attribute parsers) - #149791 (Remove uses of `cfg({any()/all()})`) - #149792 (Suggest `cfg(false)` instead of `cfg(FALSE)`) - #149883 (add regression test for `proc_macro` error subdiagnostics) - #149884 (Clippy subtree update) - #149896 (Add myself(makai410) to the review rotation) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #149792 - clubby789:cfg-FALSE, r=jdonszelmann Suggest `cfg(false)` instead of `cfg(FALSE)` Split from #149791 cc ```````@Urgau```````

Rollup merge of #149791 - clubby789:cfg-bool-lints, r=jdonszelmann Remove uses of `cfg({any()/all()})` ~~This implements the followup warning suggested in rust-lang/rfcs#3695 ~~Lint against an empty `cfg(any/all)`, suggest the boolean literal equivalents.~~ #149791 (comment) Tracking issue: #131204

rustbot added A-attributes Area: Attributes (`#[…]`, `#![…]`) S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Dec 8, 2025

rustbot assigned chenyukang Dec 8, 2025

This comment has been minimized.

Sign in to view

clubby789 force-pushed the cfg-bool-lints branch from d418aea to cb5acfc Compare December 8, 2025 22:35

rustbot assigned jdonszelmann and unassigned chenyukang Dec 8, 2025

clubby789 mentioned this pull request Dec 8, 2025

Suggest cfg(false) instead of cfg(FALSE) #149792

Merged

clubby789 force-pushed the cfg-bool-lints branch from cb5acfc to cf79ee7 Compare December 8, 2025 23:16

joshtriplett added the I-lang-nominated Nominated for discussion during a lang team meeting. label Dec 8, 2025

This comment has been minimized.

Sign in to view

clubby789 force-pushed the cfg-bool-lints branch from cf79ee7 to 06d836b Compare December 9, 2025 03:05

This comment has been minimized.

Sign in to view