From 478555d468d54105a0202220b7632b08a992b9be Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 30 Apr 2023 13:16:04 +0100
Subject: [PATCH 1/9] wip
---
clippy_lints/src/trait_bounds.rs | 45 +++++++++++++++++++++++--
tests/ui/trait_duplication_in_bounds.rs | 8 +++++
2 files changed, 50 insertions(+), 3 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index b5f11b4acae..13651c978e9 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -9,7 +9,7 @@ use rustc_data_structures::unhash::UnhashMap;
use rustc_errors::Applicability;
use rustc_hir::def::Res;
use rustc_hir::{
- GenericArg, GenericBound, Generics, Item, ItemKind, Node, Path, PathSegment, PredicateOrigin, QPath,
+ GenericArg, GenericBound, Generics, Item, ItemKind, MutTy, Node, Path, PathSegment, PredicateOrigin, QPath,
TraitBoundModifier, TraitItem, TraitRef, Ty, TyKind, WherePredicate,
};
use rustc_lint::{LateContext, LateLintPass};
@@ -37,12 +37,12 @@ declare_clippy_lint! {
#[clippy::version = "1.38.0"]
pub TYPE_REPETITION_IN_BOUNDS,
nursery,
- "types are repeated unnecessary in trait bounds use `+` instead of using `T: _, T: _`"
+ "types are repeated unnecessarily in trait bounds, use `+` instead of using `T: _, T: _`"
}
declare_clippy_lint! {
/// ### What it does
- /// Checks for cases where generics are being used and multiple
+ /// Checks for cases where generics or trait objects are being used and multiple
/// syntax specifications for trait bounds are used simultaneously.
///
/// ### Why is this bad?
@@ -167,6 +167,45 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
}
}
}
+
+ fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
+ let TyKind::Ref(
+ ..,
+ MutTy {
+ ty: Ty {
+ kind: TyKind::TraitObject(
+ bounds,
+ ..
+ ),
+ ..
+ },
+ ..
+ }
+ ) = ty.kind else { return; };
+
+ if bounds.len() < 2 {
+ return;
+ }
+
+ let mut seen_def_ids = FxHashSet::default();
+
+ for bound in bounds.iter() {
+ let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
+
+ let already_seen = !seen_def_ids.insert(def_id);
+
+ if already_seen {
+ span_lint_and_help(
+ cx,
+ TRAIT_DUPLICATION_IN_BOUNDS,
+ bound.span,
+ "this trait bound is already specified in trait declaration",
+ None,
+ "consider removing this trait bound",
+ );
+ }
+ }
+ }
}
impl TraitBounds {
diff --git a/tests/ui/trait_duplication_in_bounds.rs b/tests/ui/trait_duplication_in_bounds.rs
index a7a1caf2880..f4f4a9fcb08 100644
--- a/tests/ui/trait_duplication_in_bounds.rs
+++ b/tests/ui/trait_duplication_in_bounds.rs
@@ -109,4 +109,12 @@ fn qualified_path<T: std::clone::Clone + Clone + foo::Clone>(arg0: T) {
unimplemented!();
}
+fn good_trait_object(arg0: &(dyn Any + Send)) {
+ unimplemented!();
+}
+
+fn bad_trait_object(arg0: &(dyn Any + Send + Send)) {
+ unimplemented!();
+}
+
fn main() {}
From 1eff408ca44ae15ffd6592714487f168a5549bcc Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 30 Apr 2023 13:45:45 +0100
Subject: [PATCH 2/9] WIP
---
clippy_lints/src/trait_bounds.rs | 5 +++--
tests/ui/trait_duplication_in_bounds.fixed | 10 +++++++++
tests/ui/trait_duplication_in_bounds.rs | 2 ++
tests/ui/trait_duplication_in_bounds.stderr | 25 +++++++++++++--------
4 files changed, 31 insertions(+), 11 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 13651c978e9..1af2c594243 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -195,13 +195,14 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
let already_seen = !seen_def_ids.insert(def_id);
if already_seen {
- span_lint_and_help(
+ span_lint_and_sugg(
cx,
TRAIT_DUPLICATION_IN_BOUNDS,
bound.span,
"this trait bound is already specified in trait declaration",
- None,
"consider removing this trait bound",
+ "".to_string(),
+ Applicability::MaybeIncorrect,
);
}
}
diff --git a/tests/ui/trait_duplication_in_bounds.fixed b/tests/ui/trait_duplication_in_bounds.fixed
index eef8024b131..fdac0e4cb1e 100644
--- a/tests/ui/trait_duplication_in_bounds.fixed
+++ b/tests/ui/trait_duplication_in_bounds.fixed
@@ -2,6 +2,8 @@
#![deny(clippy::trait_duplication_in_bounds)]
#![allow(unused)]
+use std::any::Any;
+
fn bad_foo<T: Clone + Copy, U: Clone + Copy>(arg0: T, argo1: U) {
unimplemented!();
}
@@ -109,4 +111,12 @@ fn qualified_path<T: std::clone::Clone + foo::Clone>(arg0: T) {
unimplemented!();
}
+fn good_trait_object(arg0: &(dyn Any + Send)) {
+ unimplemented!();
+}
+
+fn bad_trait_object(arg0: &(dyn Any + Send)) {
+ unimplemented!();
+}
+
fn main() {}
diff --git a/tests/ui/trait_duplication_in_bounds.rs b/tests/ui/trait_duplication_in_bounds.rs
index f4f4a9fcb08..a0300da5555 100644
--- a/tests/ui/trait_duplication_in_bounds.rs
+++ b/tests/ui/trait_duplication_in_bounds.rs
@@ -2,6 +2,8 @@
#![deny(clippy::trait_duplication_in_bounds)]
#![allow(unused)]
+use std::any::Any;
+
fn bad_foo<T: Clone + Clone + Clone + Copy, U: Clone + Copy>(arg0: T, argo1: U) {
unimplemented!();
}
diff --git a/tests/ui/trait_duplication_in_bounds.stderr b/tests/ui/trait_duplication_in_bounds.stderr
index af800ba7888..a6508eb86f3 100644
--- a/tests/ui/trait_duplication_in_bounds.stderr
+++ b/tests/ui/trait_duplication_in_bounds.stderr
@@ -1,5 +1,5 @@
error: these bounds contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:5:15
+ --> $DIR/trait_duplication_in_bounds.rs:7:15
|
LL | fn bad_foo<T: Clone + Clone + Clone + Copy, U: Clone + Copy>(arg0: T, argo1: U) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
@@ -11,46 +11,53 @@ LL | #![deny(clippy::trait_duplication_in_bounds)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: these where clauses contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:11:8
+ --> $DIR/trait_duplication_in_bounds.rs:13:8
|
LL | T: Clone + Clone + Clone + Copy,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
error: these bounds contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:39:26
+ --> $DIR/trait_duplication_in_bounds.rs:41:26
|
LL | trait BadSelfTraitBound: Clone + Clone + Clone {
| ^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone`
error: these where clauses contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:46:15
+ --> $DIR/trait_duplication_in_bounds.rs:48:15
|
LL | Self: Clone + Clone + Clone;
| ^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone`
error: these bounds contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:60:24
+ --> $DIR/trait_duplication_in_bounds.rs:62:24
|
LL | trait BadTraitBound<T: Clone + Clone + Clone + Copy, U: Clone + Copy> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
error: these where clauses contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:67:12
+ --> $DIR/trait_duplication_in_bounds.rs:69:12
|
LL | T: Clone + Clone + Clone + Copy,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
error: these bounds contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:100:19
+ --> $DIR/trait_duplication_in_bounds.rs:102:19
|
LL | fn bad_generic<T: GenericTrait<u64> + GenericTrait<u32> + GenericTrait<u64>>(arg0: T) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `GenericTrait<u64> + GenericTrait<u32>`
error: these bounds contain repeated elements
- --> $DIR/trait_duplication_in_bounds.rs:108:22
+ --> $DIR/trait_duplication_in_bounds.rs:110:22
|
LL | fn qualified_path<T: std::clone::Clone + Clone + foo::Clone>(arg0: T) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::clone::Clone + foo::Clone`
-error: aborting due to 8 previous errors
+error: this trait bound is already specified in trait declaration
+ --> $DIR/trait_duplication_in_bounds.rs:118:46
+ |
+LL | fn bad_trait_object(arg0: &(dyn Any + Send + Send)) {
+ | ^^^^ help: consider removing this trait bound
+ |
+
+error: aborting due to 9 previous errors
From 0fb3f3b25667c2e9c56a7fd83019cafec7ada1cf Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 30 Apr 2023 14:10:26 +0100
Subject: [PATCH 3/9] WIP
---
clippy_lints/src/trait_bounds.rs | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 1af2c594243..4c70bae7529 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -177,6 +177,7 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
bounds,
..
),
+ span,
..
},
..
@@ -189,6 +190,12 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
let mut seen_def_ids = FxHashSet::default();
+ let traits = bounds
+ .iter()
+ .filter_map(|b| snippet_opt(cx, b.span))
+ .collect::<Vec<_>>();
+ let traits = traits.join(" + ");
+
for bound in bounds.iter() {
let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
@@ -198,10 +205,10 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
span_lint_and_sugg(
cx,
TRAIT_DUPLICATION_IN_BOUNDS,
- bound.span,
+ *span,
"this trait bound is already specified in trait declaration",
"consider removing this trait bound",
- "".to_string(),
+ traits.clone(),
Applicability::MaybeIncorrect,
);
}
From 8db21e9a9c63496271b5db11af665ada036fac4d Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 30 Apr 2023 14:14:47 +0100
Subject: [PATCH 4/9] WIP
---
clippy_lints/src/trait_bounds.rs | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 4c70bae7529..2c1c63e808b 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -177,7 +177,6 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
bounds,
..
),
- span,
..
},
..
@@ -188,6 +187,12 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
return;
}
+ let mut bounds_span = Span::default();
+
+ for bound in bounds.iter() {
+ bounds_span = bounds_span.to(bound.span);
+ }
+
let mut seen_def_ids = FxHashSet::default();
let traits = bounds
@@ -205,7 +210,7 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
span_lint_and_sugg(
cx,
TRAIT_DUPLICATION_IN_BOUNDS,
- *span,
+ bounds_span,
"this trait bound is already specified in trait declaration",
"consider removing this trait bound",
traits.clone(),
From b9788fef298815c2b8366a42ef0c8113170d11ed Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 30 Apr 2023 14:34:46 +0100
Subject: [PATCH 5/9] Working
---
clippy_lints/src/trait_bounds.rs | 43 ++++++++++++---------
tests/ui/trait_duplication_in_bounds.stderr | 5 +--
2 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 2c1c63e808b..8de0f92109b 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -187,37 +187,42 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
return;
}
- let mut bounds_span = Span::default();
+ let mut bounds_span = bounds[0].span;
- for bound in bounds.iter() {
+ for bound in bounds.iter().skip(1) {
bounds_span = bounds_span.to(bound.span);
}
let mut seen_def_ids = FxHashSet::default();
-
- let traits = bounds
- .iter()
- .filter_map(|b| snippet_opt(cx, b.span))
- .collect::<Vec<_>>();
- let traits = traits.join(" + ");
+ let mut fixed_traits = Vec::new();
for bound in bounds.iter() {
let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
- let already_seen = !seen_def_ids.insert(def_id);
+ let new_trait = seen_def_ids.insert(def_id);
- if already_seen {
- span_lint_and_sugg(
- cx,
- TRAIT_DUPLICATION_IN_BOUNDS,
- bounds_span,
- "this trait bound is already specified in trait declaration",
- "consider removing this trait bound",
- traits.clone(),
- Applicability::MaybeIncorrect,
- );
+ if new_trait {
+ fixed_traits.push(bound);
}
}
+
+ let fixed_trait_snippet = fixed_traits
+ .iter()
+ .filter_map(|b| snippet_opt(cx, b.span))
+ .collect::<Vec<_>>()
+ .join(" + ");
+
+ if bounds.len() != fixed_traits.len() {
+ span_lint_and_sugg(
+ cx,
+ TRAIT_DUPLICATION_IN_BOUNDS,
+ bounds_span,
+ "this trait bound is already specified in trait declaration",
+ "try",
+ fixed_trait_snippet,
+ Applicability::MaybeIncorrect,
+ );
+ }
}
}
diff --git a/tests/ui/trait_duplication_in_bounds.stderr b/tests/ui/trait_duplication_in_bounds.stderr
index a6508eb86f3..539b6114ca3 100644
--- a/tests/ui/trait_duplication_in_bounds.stderr
+++ b/tests/ui/trait_duplication_in_bounds.stderr
@@ -53,11 +53,10 @@ LL | fn qualified_path<T: std::clone::Clone + Clone + foo::Clone>(arg0: T) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::clone::Clone + foo::Clone`
error: this trait bound is already specified in trait declaration
- --> $DIR/trait_duplication_in_bounds.rs:118:46
+ --> $DIR/trait_duplication_in_bounds.rs:118:33
|
LL | fn bad_trait_object(arg0: &(dyn Any + Send + Send)) {
- | ^^^^ help: consider removing this trait bound
- |
+ | ^^^^^^^^^^^^^^^^^ help: try: `Any + Send`
error: aborting due to 9 previous errors
From cbd0135bd2d2e546ca4c2c2147798d1f7c547128 Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Tue, 2 May 2023 18:15:02 +0100
Subject: [PATCH 6/9] Update trait_bounds.rs
---
clippy_lints/src/trait_bounds.rs | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 8de0f92109b..ac61fb157b4 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -206,13 +206,13 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
}
}
- let fixed_trait_snippet = fixed_traits
- .iter()
- .filter_map(|b| snippet_opt(cx, b.span))
- .collect::<Vec<_>>()
- .join(" + ");
-
if bounds.len() != fixed_traits.len() {
+ let fixed_trait_snippet = fixed_traits
+ .iter()
+ .filter_map(|b| snippet_opt(cx, b.span))
+ .collect::<Vec<_>>()
+ .join(" + ");
+
span_lint_and_sugg(
cx,
TRAIT_DUPLICATION_IN_BOUNDS,
From 122793b4947c2691efcb2ab6450c251a25311aaf Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Tue, 2 May 2023 18:21:23 +0100
Subject: [PATCH 7/9] Update trait_bounds.rs
---
clippy_lints/src/trait_bounds.rs | 95 ++++++++++++++------------------
1 file changed, 42 insertions(+), 53 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index ac61fb157b4..5acd44dccaf 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -9,7 +9,7 @@ use rustc_data_structures::unhash::UnhashMap;
use rustc_errors::Applicability;
use rustc_hir::def::Res;
use rustc_hir::{
- GenericArg, GenericBound, Generics, Item, ItemKind, MutTy, Node, Path, PathSegment, PredicateOrigin, QPath,
+ GenericArg, GenericBound, Generics, Item, ItemKind, Node, Path, PathSegment, PredicateOrigin, QPath,
TraitBoundModifier, TraitItem, TraitRef, Ty, TyKind, WherePredicate,
};
use rustc_lint::{LateContext, LateLintPass};
@@ -169,59 +169,48 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
}
fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
- let TyKind::Ref(
- ..,
- MutTy {
- ty: Ty {
- kind: TyKind::TraitObject(
- bounds,
- ..
- ),
- ..
- },
- ..
+ if_chain! {
+ if let TyKind::Ref(.., mut_ty) = &ty.kind;
+ if let TyKind::TraitObject(bounds, ..) = mut_ty.ty.kind;
+ if bounds.len() > 2;
+ then {
+ let mut bounds_span = bounds[0].span;
+
+ for bound in bounds.iter().skip(1) {
+ bounds_span = bounds_span.to(bound.span);
+ }
+
+ let mut seen_def_ids = FxHashSet::default();
+ let mut fixed_traits = Vec::new();
+
+ for bound in bounds.iter() {
+ let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
+
+ let new_trait = seen_def_ids.insert(def_id);
+
+ if new_trait {
+ fixed_traits.push(bound);
+ }
+ }
+
+ if bounds.len() != fixed_traits.len() {
+ let fixed_trait_snippet = fixed_traits
+ .iter()
+ .filter_map(|b| snippet_opt(cx, b.span))
+ .collect::<Vec<_>>()
+ .join(" + ");
+
+ span_lint_and_sugg(
+ cx,
+ TRAIT_DUPLICATION_IN_BOUNDS,
+ bounds_span,
+ "this trait bound is already specified in trait declaration",
+ "try",
+ fixed_trait_snippet,
+ Applicability::MaybeIncorrect,
+ );
+ }
}
- ) = ty.kind else { return; };
-
- if bounds.len() < 2 {
- return;
- }
-
- let mut bounds_span = bounds[0].span;
-
- for bound in bounds.iter().skip(1) {
- bounds_span = bounds_span.to(bound.span);
- }
-
- let mut seen_def_ids = FxHashSet::default();
- let mut fixed_traits = Vec::new();
-
- for bound in bounds.iter() {
- let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
-
- let new_trait = seen_def_ids.insert(def_id);
-
- if new_trait {
- fixed_traits.push(bound);
- }
- }
-
- if bounds.len() != fixed_traits.len() {
- let fixed_trait_snippet = fixed_traits
- .iter()
- .filter_map(|b| snippet_opt(cx, b.span))
- .collect::<Vec<_>>()
- .join(" + ");
-
- span_lint_and_sugg(
- cx,
- TRAIT_DUPLICATION_IN_BOUNDS,
- bounds_span,
- "this trait bound is already specified in trait declaration",
- "try",
- fixed_trait_snippet,
- Applicability::MaybeIncorrect,
- );
}
}
}
From 5c8a00923bc435cec37820c32768871b9e8a9ca1 Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 7 May 2023 10:10:44 +0100
Subject: [PATCH 8/9] Comments
---
clippy_lints/src/trait_bounds.rs | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 5acd44dccaf..c4e4410e9fd 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -174,15 +174,11 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
if let TyKind::TraitObject(bounds, ..) = mut_ty.ty.kind;
if bounds.len() > 2;
then {
- let mut bounds_span = bounds[0].span;
-
- for bound in bounds.iter().skip(1) {
- bounds_span = bounds_span.to(bound.span);
- }
-
let mut seen_def_ids = FxHashSet::default();
let mut fixed_traits = Vec::new();
+ // Iterate the bounds and add them to our seen hash
+ // If we haven't yet seen it, add it to the fixed traits
for bound in bounds.iter() {
let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
@@ -193,7 +189,15 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
}
}
+ // If the number added to fixed (which are not duplicates) isn't the same as the number found,
+ // there must be 1 or more duplicates
if bounds.len() != fixed_traits.len() {
+ let mut bounds_span = bounds[0].span;
+
+ for bound in bounds.iter().skip(1) {
+ bounds_span = bounds_span.to(bound.span);
+ }
+
let fixed_trait_snippet = fixed_traits
.iter()
.filter_map(|b| snippet_opt(cx, b.span))
From b169bdb732c1a0751a32c4ede1c16a3bba3ffb09 Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Tue, 9 May 2023 10:06:38 +0100
Subject: [PATCH 9/9] Comments
---
clippy_lints/src/trait_bounds.rs | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index c4e4410e9fd..4ccda15068b 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -174,8 +174,13 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
if let TyKind::TraitObject(bounds, ..) = mut_ty.ty.kind;
if bounds.len() > 2;
then {
+
+ // Build up a hash of every trait we've seen
+ // When we see a trait for the first time, add it to unique_traits
+ // so we can later use it to build a string of all traits exactly once, without duplicates
+
let mut seen_def_ids = FxHashSet::default();
- let mut fixed_traits = Vec::new();
+ let mut unique_traits = Vec::new();
// Iterate the bounds and add them to our seen hash
// If we haven't yet seen it, add it to the fixed traits
@@ -185,20 +190,20 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
let new_trait = seen_def_ids.insert(def_id);
if new_trait {
- fixed_traits.push(bound);
+ unique_traits.push(bound);
}
}
- // If the number added to fixed (which are not duplicates) isn't the same as the number found,
+ // If the number of unique traits isn't the same as the number of traits in the bounds,
// there must be 1 or more duplicates
- if bounds.len() != fixed_traits.len() {
+ if bounds.len() != unique_traits.len() {
let mut bounds_span = bounds[0].span;
for bound in bounds.iter().skip(1) {
bounds_span = bounds_span.to(bound.span);
}
- let fixed_trait_snippet = fixed_traits
+ let fixed_trait_snippet = unique_traits
.iter()
.filter_map(|b| snippet_opt(cx, b.span))
.collect::<Vec<_>>()