-use crate::utils::{in_macro, snippet, snippet_with_applicability, span_lint_and_help, SpanlessHash};
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::source::{snippet, snippet_with_applicability};
+use clippy_utils::{SpanlessEq, SpanlessHash};
+use core::hash::{Hash, Hasher};
use if_chain::if_chain;
use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::unhash::UnhashMap;
use rustc_errors::Applicability;
-use rustc_hir::{def::Res, GenericBound, Generics, ParamName, Path, QPath, TyKind, WherePredicate};
+use rustc_hir::def::Res;
+use rustc_hir::{
+ GenericBound, Generics, Item, ItemKind, Node, ParamName, Path, PathSegment, QPath, TraitItem, Ty, TyKind,
+ WherePredicate,
+};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::Span;
declare_clippy_lint! {
- /// **What it does:** This lint warns about unnecessary type repetitions in trait bounds
+ /// ### What it does
+ /// This lint warns about unnecessary type repetitions in trait bounds
///
- /// **Why is this bad?** Repeating the type for every bound makes the code
+ /// ### Why is this bad?
+ /// Repeating the type for every bound makes the code
/// less readable than combining the bounds
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// pub fn foo<T>(t: T) where T: Copy, T: Clone {}
/// ```
/// ```rust
/// pub fn foo<T>(t: T) where T: Copy + Clone {}
/// ```
+ #[clippy::version = "1.38.0"]
pub TYPE_REPETITION_IN_BOUNDS,
pedantic,
"Types are repeated unnecessary 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
+ /// ### What it does
+ /// Checks for cases where generics are being used and multiple
/// syntax specifications for trait bounds are used simultaneously.
///
- /// **Why is this bad?** Duplicate bounds makes the code
+ /// ### Why is this bad?
+ /// Duplicate bounds makes the code
/// less readable than specifing them only once.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// fn func<T: Clone + Default>(arg: T) where T: Clone + Default {}
/// ```
/// ```rust
/// fn func<T>(arg: T) where T: Clone + Default {}
/// ```
+ #[clippy::version = "1.47.0"]
pub TRAIT_DUPLICATION_IN_BOUNDS,
pedantic,
"Check if the same trait bounds are specified twice during a function declaration"
self.check_type_repetition(cx, gen);
check_trait_bound_duplication(cx, gen);
}
-}
-fn get_trait_res_span_from_bound(bound: &GenericBound<'_>) -> Option<(Res, Span)> {
- if let GenericBound::Trait(t, _) = bound {
- Some((t.trait_ref.path.res, t.span))
- } else {
- None
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'tcx>) {
+ let Generics { where_clause, .. } = &item.generics;
+ let mut self_bounds_map = FxHashMap::default();
+
+ for predicate in where_clause.predicates {
+ if_chain! {
+ if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate;
+ if !bound_predicate.span.from_expansion();
+ if let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind;
+ if let Some(PathSegment { res: Some(Res::SelfTy(Some(def_id), _)), .. }) = segments.first();
+
+ if let Some(
+ Node::Item(
+ Item {
+ kind: ItemKind::Trait(_, _, _, self_bounds, _),
+ .. }
+ )
+ ) = cx.tcx.hir().get_if_local(*def_id);
+ then {
+ if self_bounds_map.is_empty() {
+ for bound in self_bounds.iter() {
+ let Some((self_res, self_segments, _)) = get_trait_info_from_bound(bound) else { continue };
+ self_bounds_map.insert(self_res, self_segments);
+ }
+ }
+
+ bound_predicate
+ .bounds
+ .iter()
+ .filter_map(get_trait_info_from_bound)
+ .for_each(|(trait_item_res, trait_item_segments, span)| {
+ if let Some(self_segments) = self_bounds_map.get(&trait_item_res) {
+ if SpanlessEq::new(cx).eq_path_segments(self_segments, trait_item_segments) {
+ span_lint_and_help(
+ cx,
+ TRAIT_DUPLICATION_IN_BOUNDS,
+ span,
+ "this trait bound is already specified in trait declaration",
+ None,
+ "consider removing this trait bound",
+ );
+ }
+ }
+ });
+ }
+ }
+ }
}
}
impl TraitBounds {
- fn check_type_repetition(self, cx: &LateContext<'_>, gen: &'_ Generics<'_>) {
- if in_macro(gen.span) {
+ fn check_type_repetition<'tcx>(self, cx: &LateContext<'tcx>, gen: &'tcx Generics<'_>) {
+ struct SpanlessTy<'cx, 'tcx> {
+ ty: &'tcx Ty<'tcx>,
+ cx: &'cx LateContext<'tcx>,
+ }
+ impl PartialEq for SpanlessTy<'_, '_> {
+ fn eq(&self, other: &Self) -> bool {
+ let mut eq = SpanlessEq::new(self.cx);
+ eq.inter_expr().eq_ty(self.ty, other.ty)
+ }
+ }
+ impl Hash for SpanlessTy<'_, '_> {
+ fn hash<H: Hasher>(&self, h: &mut H) {
+ let mut t = SpanlessHash::new(self.cx);
+ t.hash_ty(self.ty);
+ h.write_u64(t.finish());
+ }
+ }
+ impl Eq for SpanlessTy<'_, '_> {}
+
+ if gen.span.from_expansion() {
return;
}
- let hash = |ty| -> u64 {
- let mut hasher = SpanlessHash::new(cx);
- hasher.hash_ty(ty);
- hasher.finish()
- };
- let mut map = FxHashMap::default();
+ let mut map: UnhashMap<SpanlessTy<'_, '_>, Vec<&GenericBound<'_>>> = UnhashMap::default();
let mut applicability = Applicability::MaybeIncorrect;
for bound in gen.where_clause.predicates {
if_chain! {
if let WherePredicate::BoundPredicate(ref p) = bound;
if p.bounds.len() as u64 <= self.max_trait_bounds;
- if !in_macro(p.span);
- let h = hash(&p.bounded_ty);
- if let Some(ref v) = map.insert(h, p.bounds.iter().collect::<Vec<_>>());
+ if !p.span.from_expansion();
+ if let Some(ref v) = map.insert(
+ SpanlessTy { ty: p.bounded_ty, cx },
+ p.bounds.iter().collect::<Vec<_>>()
+ );
then {
let mut hint_string = format!(
}
fn check_trait_bound_duplication(cx: &LateContext<'_>, gen: &'_ Generics<'_>) {
- if in_macro(gen.span) || gen.params.is_empty() || gen.where_clause.predicates.is_empty() {
+ if gen.span.from_expansion() || gen.params.is_empty() || gen.where_clause.predicates.is_empty() {
return;
}
let res = param
.bounds
.iter()
- .filter_map(get_trait_res_span_from_bound)
+ .filter_map(get_trait_info_from_bound)
.collect::<Vec<_>>();
map.insert(*ident, res);
}
for predicate in gen.where_clause.predicates {
if_chain! {
if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate;
- if !in_macro(bound_predicate.span);
- if let TyKind::Path(ref path) = bound_predicate.bounded_ty.kind;
- if let QPath::Resolved(_, Path { ref segments, .. }) = path;
+ if !bound_predicate.span.from_expansion();
+ if let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind;
if let Some(segment) = segments.first();
if let Some(trait_resolutions_direct) = map.get(&segment.ident);
then {
- for (res_where, _) in bound_predicate.bounds.iter().filter_map(get_trait_res_span_from_bound) {
- if let Some((_, span_direct)) = trait_resolutions_direct
+ for (res_where, _, _) in bound_predicate.bounds.iter().filter_map(get_trait_info_from_bound) {
+ if let Some((_, _, span_direct)) = trait_resolutions_direct
.iter()
- .find(|(res_direct, _)| *res_direct == res_where) {
+ .find(|(res_direct, _, _)| *res_direct == res_where) {
span_lint_and_help(
cx,
TRAIT_DUPLICATION_IN_BOUNDS,
}
}
}
+
+fn get_trait_info_from_bound<'a>(bound: &'a GenericBound<'_>) -> Option<(Res, &'a [PathSegment<'a>], Span)> {
+ if let GenericBound::Trait(t, _) = bound {
+ Some((t.trait_ref.path.res, t.trait_ref.path.segments, t.span))
+ } else {
+ None
+ }
+}
projects / rust.git / blobdiff