Skip to content

Fix empty_enum_variants_with_brackets misses removing brackets in patterns #16160

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
profetia wants to merge 2 commits into
base: master
Choose a base branch
from
+232 −86
Open

Fix empty_enum_variants_with_brackets misses removing brackets in patterns #16160

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
bd0a5e4
fix: `empty_enum_variants_with_brackets` misses removing brackets in …
profetia Nov 30, 2025
ddd328b
Make `empty_enum_variants_with_brackets` to support empty variant wit…
profetia Dec 1, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
84 changes: 59 additions & 25 deletions clippy_lints/src/empty_with_brackets.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,13 +2,13 @@ use clippy_utils::attrs::span_contains_cfg;
use clippy_utils::diagnostics::{span_lint_and_then, span_lint_hir_and_then};
use rustc_data_structures::fx::FxIndexMap;
use rustc_errors::Applicability;
use rustc_hir::def::CtorOf;
use rustc_hir::def::DefKind::Ctor;
use rustc_hir::def::Res::Def;
use rustc_hir::def::{CtorOf, DefKind};
use rustc_hir::def_id::LocalDefId;
use rustc_hir::{Expr, ExprKind, Item, ItemKind, Node, Path, QPath, Variant, VariantData};
use rustc_hir::{Expr, ExprKind, Item, ItemKind, Node, Pat, PatKind, Path, QPath, Variant, VariantData};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::TyCtxt;
use rustc_middle::ty::{self, TyCtxt};
use rustc_session::impl_lint_pass;
use rustc_span::Span;

Expand Down Expand Up @@ -177,35 +177,24 @@ impl LateLintPass<'_> for EmptyWithBrackets {
if expr.span.from_expansion() {
return;
}
match self.empty_tuple_enum_variants.get_mut(&def_id) {
Some(
&mut (Usage::Unused {
ref mut redundant_use_sites,
}
| Usage::NoDefinition {
ref mut redundant_use_sites,
}),
) => {
redundant_use_sites.push(parentheses_span);
},
None => {
// The variant isn't in the IndexMap which means its definition wasn't encountered yet.
self.empty_tuple_enum_variants.insert(
def_id,
Usage::NoDefinition {
redundant_use_sites: vec![parentheses_span],
},
);
},
_ => {},
}
self.update_enum_variant_usage(def_id, parentheses_span);
} else {
// The parentheses are not redundant.
self.empty_tuple_enum_variants.insert(def_id, Usage::Used);
}
}
}

fn check_pat(&mut self, cx: &LateContext<'_>, pat: &Pat<'_>) {
if let Some((def_id, parentheses_span)) = check_pat_for_enum_as_function(cx, pat) {
if pat.span.from_expansion() {
return;
}

self.update_enum_variant_usage(def_id, parentheses_span);
}
}

fn check_crate_post(&mut self, cx: &LateContext<'_>) {
for (local_def_id, usage) in &self.empty_tuple_enum_variants {
// Ignore all variants with Usage::Used or Usage::NoDefinition
Expand Down Expand Up @@ -252,6 +241,33 @@ impl LateLintPass<'_> for EmptyWithBrackets {
}
}

impl EmptyWithBrackets {
fn update_enum_variant_usage(&mut self, def_id: LocalDefId, parentheses_span: Span) {
match self.empty_tuple_enum_variants.get_mut(&def_id) {
Some(
&mut (Usage::Unused {
ref mut redundant_use_sites,
}
| Usage::NoDefinition {
ref mut redundant_use_sites,
}),
) => {
redundant_use_sites.push(parentheses_span);
},
None => {
// The variant isn't in the IndexMap which means its definition wasn't encountered yet.
self.empty_tuple_enum_variants.insert(
def_id,
Usage::NoDefinition {
redundant_use_sites: vec![parentheses_span],
},
);
},
_ => {},
}
}
}

fn has_brackets(var_data: &VariantData<'_>) -> bool {
!matches!(var_data, VariantData::Unit(..))
}
Expand Down Expand Up @@ -291,3 +307,21 @@ fn check_expr_for_enum_as_function(expr: &Expr<'_>) -> Option<LocalDefId> {
None
}
}

fn check_pat_for_enum_as_function(cx: &LateContext<'_>, pat: &Pat<'_>) -> Option<(LocalDefId, Span)> {
match pat.kind {
PatKind::TupleStruct(qpath, ..)
if let Def(Ctor(CtorOf::Variant, _), def_id) = cx.typeck_results().qpath_res(&qpath, pat.hir_id) =>
{
def_id.as_local().map(|id| (id, qpath.span().with_lo(pat.span.hi())))
},
PatKind::Struct(qpath, ..)
if let Def(DefKind::Variant, def_id) = cx.typeck_results().qpath_res(&qpath, pat.hir_id)
&& let ty = cx.tcx.type_of(def_id).instantiate_identity()
&& let ty::FnDef(def_id, _) = ty.kind() =>
{
def_id.as_local().map(|id| (id, qpath.span().with_lo(pat.span.hi())))
},
_ => None,
}
}
13 changes: 13 additions & 0 deletions tests/ui/empty_enum_variants_with_brackets.fixed
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
#![warn(clippy::empty_enum_variants_with_brackets)]
#![allow(dead_code)]
#![feature(more_qualified_paths)]

pub enum PublicTestEnum {
NonEmptyBraces { x: i32, y: i32 }, // No error
Expand Down Expand Up @@ -102,4 +103,16 @@ pub enum PubFoo {
Variant3(),
}

fn issue16157() {
enum E {
V,
//~^ empty_enum_variants_with_brackets
}

let E::V = E::V;

<E>::V = E::V;
<E>::V = E::V;
}

fn main() {}
13 changes: 13 additions & 0 deletions tests/ui/empty_enum_variants_with_brackets.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
#![warn(clippy::empty_enum_variants_with_brackets)]
#![allow(dead_code)]
#![feature(more_qualified_paths)]

pub enum PublicTestEnum {
NonEmptyBraces { x: i32, y: i32 }, // No error
Expand Down Expand Up @@ -102,4 +103,16 @@ pub enum PubFoo {
Variant3(),
}

fn issue16157() {
enum E {
V(),
//~^ empty_enum_variants_with_brackets
}

let E::V() = E::V();

<E>::V() = E::V();
<E>::V {} = E::V();
}

fn main() {}
36 changes: 27 additions & 9 deletions tests/ui/empty_enum_variants_with_brackets.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:7:16
--> tests/ui/empty_enum_variants_with_brackets.rs:8:16
|
LL | EmptyBraces {},
| ^^^
Expand All @@ -9,39 +9,39 @@ LL | EmptyBraces {},
= help: remove the brackets

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:15:16
--> tests/ui/empty_enum_variants_with_brackets.rs:16:16
|
LL | EmptyBraces {},
| ^^^
|
= help: remove the brackets

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:17:21
--> tests/ui/empty_enum_variants_with_brackets.rs:18:21
|
LL | EmptyParentheses(),
| ^^
|
= help: remove the brackets

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:28:16
--> tests/ui/empty_enum_variants_with_brackets.rs:29:16
|
LL | Unknown(),
| ^^
|
= help: remove the brackets

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:47:16
--> tests/ui/empty_enum_variants_with_brackets.rs:48:16
|
LL | Unknown(),
| ^^
|
= help: remove the brackets

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:53:20
--> tests/ui/empty_enum_variants_with_brackets.rs:54:20
|
LL | Parentheses(),
| ^^
Expand All @@ -56,7 +56,7 @@ LL ~ RedundantParenthesesFunctionCall::Parentheses;
|

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:76:20
--> tests/ui/empty_enum_variants_with_brackets.rs:77:20
|
LL | Parentheses(),
| ^^
Expand All @@ -71,12 +71,30 @@ LL ~ Parentheses,
|

error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:95:13
--> tests/ui/empty_enum_variants_with_brackets.rs:96:13
|
LL | Variant3(),
| ^^
|
= help: remove the brackets

error: aborting due to 8 previous errors
error: enum variant has empty brackets
--> tests/ui/empty_enum_variants_with_brackets.rs:108:10
|
LL | V(),
| ^^
|
help: remove the brackets
|
LL ~ V,
LL |
LL | }
LL |
LL ~ let E::V = E::V;
LL |
LL ~ <E>::V = E::V;
LL ~ <E>::V = E::V;
|

error: aborting due to 9 previous errors

Loading