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Auto merge of #12303 - GuillaumeGomez:unneedeed_clippy_cfg_attr, r=flip1995
Add `unnecessary_clippy_cfg` lint Follow-up of #12292. r? `@flip1995` changelog: Add `unnecessary_clippy_cfg` lint
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‎CHANGELOG.md

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Original file line numberDiff line numberDiff line change
@@ -5726,6 +5726,7 @@ Released 2018-09-13
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[`unknown_clippy_lints`]: https://rust-lang.github.io/rust-clippy/master/index.html#unknown_clippy_lints
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[`unnecessary_box_returns`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_box_returns
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[`unnecessary_cast`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
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[`unnecessary_clippy_cfg`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_clippy_cfg
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[`unnecessary_fallible_conversions`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fallible_conversions
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[`unnecessary_filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_filter_map
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[`unnecessary_find_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_find_map

‎clippy_lints/src/attrs.rs

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@@ -1,7 +1,9 @@
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//! checks for attributes
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use clippy_config::msrvs::{self, Msrv};
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use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
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use clippy_utils::diagnostics::{
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span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then,
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};
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use clippy_utils::is_from_proc_macro;
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use clippy_utils::macros::{is_panic, macro_backtrace};
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use clippy_utils::source::{first_line_of_span, is_present_in_source, snippet_opt, without_block_comments};
@@ -459,6 +461,30 @@ declare_clippy_lint! {
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"usage of `cfg(feature = \"cargo-clippy\")` instead of `cfg(clippy)`"
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}
461463

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declare_clippy_lint! {
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/// ### What it does
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/// Checks for `#[cfg_attr(clippy, allow(clippy::lint))]`
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/// and suggests to replace it with `#[allow(clippy::lint)]`.
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///
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/// ### Why is this bad?
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/// There is no reason to put clippy attributes behind a clippy `cfg` as they are not
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/// run by anything else than clippy.
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///
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/// ### Example
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/// ```no_run
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/// #![cfg_attr(clippy, allow(clippy::deprecated_cfg_attr))]
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/// ```
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///
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/// Use instead:
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/// ```no_run
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/// #![allow(clippy::deprecated_cfg_attr)]
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/// ```
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#[clippy::version = "1.78.0"]
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pub UNNECESSARY_CLIPPY_CFG,
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suspicious,
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"usage of `cfg_attr(clippy, allow(clippy::lint))` instead of `allow(clippy::lint)`"
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}
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declare_lint_pass!(Attributes => [
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ALLOW_ATTRIBUTES_WITHOUT_REASON,
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INLINE_ALWAYS,
@@ -821,6 +847,7 @@ impl_lint_pass!(EarlyAttributes => [
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NON_MINIMAL_CFG,
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MAYBE_MISUSED_CFG,
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DEPRECATED_CLIPPY_CFG_ATTR,
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UNNECESSARY_CLIPPY_CFG,
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]);
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impl EarlyLintPass for EarlyAttributes {
@@ -958,6 +985,74 @@ fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute, msrv: &Msr
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);
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} else {
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check_deprecated_cfg_recursively(cx, feature_item);
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if let Some(behind_cfg_attr) = items[1].meta_item() {
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check_clippy_cfg_attr(cx, feature_item, behind_cfg_attr, attr);
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}
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}
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}
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}
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fn check_clippy_cfg_attr(
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cx: &EarlyContext<'_>,
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cfg_attr: &rustc_ast::MetaItem,
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behind_cfg_attr: &rustc_ast::MetaItem,
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attr: &Attribute,
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) {
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if cfg_attr.has_name(sym::clippy)
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&& let Some(ident) = behind_cfg_attr.ident()
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// FIXME: replace with `from_symbol` once https://github.com/rust-lang/rust/pull/121230
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// is merged.
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&& Level::from_str(ident.name.as_str()).is_some()
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&& let Some(items) = behind_cfg_attr.meta_item_list()
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{
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let nb_items = items.len();
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let mut clippy_lints = Vec::with_capacity(items.len());
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for item in items {
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if let Some(meta_item) = item.meta_item()
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&& let [part1, _] = meta_item.path.segments.as_slice()
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&& part1.ident.name == sym::clippy
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{
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clippy_lints.push(item.span());
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}
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}
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if clippy_lints.is_empty() {
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return;
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}
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if nb_items == clippy_lints.len() {
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if let Some(snippet) = snippet_opt(cx, behind_cfg_attr.span) {
1023+
span_lint_and_sugg(
1024+
cx,
1025+
UNNECESSARY_CLIPPY_CFG,
1026+
attr.span,
1027+
"no need to put clippy lints behind a `clippy` cfg",
1028+
"replace with",
1029+
format!(
1030+
"#{}[{}]",
1031+
if attr.style == AttrStyle::Inner { "!" } else { "" },
1032+
snippet
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),
1034+
Applicability::MachineApplicable,
1035+
);
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}
1037+
} else {
1038+
let snippet = clippy_lints
1039+
.iter()
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.filter_map(|sp| snippet_opt(cx, *sp))
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.collect::<Vec<_>>()
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.join(",");
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span_lint_and_note(
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cx,
1045+
UNNECESSARY_CLIPPY_CFG,
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clippy_lints,
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"no need to put clippy lints behind a `clippy` cfg",
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None,
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&format!(
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"write instead: `#{}[{}({})]`",
1051+
if attr.style == AttrStyle::Inner { "!" } else { "" },
1052+
ident.name,
1053+
snippet
1054+
),
1055+
);
9611056
}
9621057
}
9631058
}

‎clippy_lints/src/declared_lints.rs

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Original file line numberDiff line numberDiff line change
@@ -60,6 +60,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
6060
crate::attrs::MISMATCHED_TARGET_OS_INFO,
6161
crate::attrs::NON_MINIMAL_CFG_INFO,
6262
crate::attrs::SHOULD_PANIC_WITHOUT_EXPECT_INFO,
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crate::attrs::UNNECESSARY_CLIPPY_CFG_INFO,
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crate::attrs::USELESS_ATTRIBUTE_INFO,
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crate::await_holding_invalid::AWAIT_HOLDING_INVALID_TYPE_INFO,
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crate::await_holding_invalid::AWAIT_HOLDING_LOCK_INFO,

‎tests/ui/unnecessary_clippy_cfg.rs

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@@ -0,0 +1,23 @@
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//@no-rustfix
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3+
#![warn(clippy::unnecessary_clippy_cfg)]
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#![cfg_attr(clippy, deny(clippy::non_minimal_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#![cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#![cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#![cfg_attr(clippy, deny(clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#[cfg_attr(clippy, deny(clippy::non_minimal_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#[cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#[cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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#[cfg_attr(clippy, deny(clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
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//~^ ERROR: no need to put clippy lints behind a `clippy` cfg
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pub struct Bar;
22+
23+
fn main() {}

‎tests/ui/unnecessary_clippy_cfg.stderr

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error: no need to put clippy lints behind a `clippy` cfg
2+
--> tests/ui/unnecessary_clippy_cfg.rs:13:1
3+
|
4+
LL | #[cfg_attr(clippy, deny(clippy::non_minimal_cfg))]
5+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `#[deny(clippy::non_minimal_cfg)]`
6+
|
7+
= note: `-D clippy::unnecessary-clippy-cfg` implied by `-D warnings`
8+
= help: to override `-D warnings` add `#[allow(clippy::unnecessary_clippy_cfg)]`
9+
10+
error: no need to put clippy lints behind a `clippy` cfg
11+
--> tests/ui/unnecessary_clippy_cfg.rs:15:36
12+
|
13+
LL | #[cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg))]
14+
| ^^^^^^^^^^^^^^^^^^^^^^^
15+
|
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= note: write instead: `#[deny(clippy::non_minimal_cfg)]`
17+
18+
error: no need to put clippy lints behind a `clippy` cfg
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--> tests/ui/unnecessary_clippy_cfg.rs:17:36
20+
|
21+
LL | #[cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
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| ^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^
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|
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= note: write instead: `#[deny(clippy::non_minimal_cfg,clippy::maybe_misused_cfg)]`
25+
26+
error: no need to put clippy lints behind a `clippy` cfg
27+
--> tests/ui/unnecessary_clippy_cfg.rs:19:1
28+
|
29+
LL | #[cfg_attr(clippy, deny(clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
30+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `#[deny(clippy::non_minimal_cfg, clippy::maybe_misused_cfg)]`
31+
32+
error: no need to put clippy lints behind a `clippy` cfg
33+
--> tests/ui/unnecessary_clippy_cfg.rs:4:1
34+
|
35+
LL | #![cfg_attr(clippy, deny(clippy::non_minimal_cfg))]
36+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `#![deny(clippy::non_minimal_cfg)]`
37+
38+
error: no need to put clippy lints behind a `clippy` cfg
39+
--> tests/ui/unnecessary_clippy_cfg.rs:6:37
40+
|
41+
LL | #![cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg))]
42+
| ^^^^^^^^^^^^^^^^^^^^^^^
43+
|
44+
= note: write instead: `#![deny(clippy::non_minimal_cfg)]`
45+
46+
error: no need to put clippy lints behind a `clippy` cfg
47+
--> tests/ui/unnecessary_clippy_cfg.rs:8:37
48+
|
49+
LL | #![cfg_attr(clippy, deny(dead_code, clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
50+
| ^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^
51+
|
52+
= note: write instead: `#![deny(clippy::non_minimal_cfg,clippy::maybe_misused_cfg)]`
53+
54+
error: no need to put clippy lints behind a `clippy` cfg
55+
--> tests/ui/unnecessary_clippy_cfg.rs:10:1
56+
|
57+
LL | #![cfg_attr(clippy, deny(clippy::non_minimal_cfg, clippy::maybe_misused_cfg))]
58+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `#![deny(clippy::non_minimal_cfg, clippy::maybe_misused_cfg)]`
59+
60+
error: aborting due to 8 previous errors
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