use if_chain::if_chain;
use rustc_ast::ast::Attribute;
use rustc_data_structures::fx::FxHashSet;
-use rustc_errors::{Applicability, DiagnosticBuilder};
+use rustc_errors::{Applicability, Diagnostic};
use rustc_hir::intravisit::FnKind;
-use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, Impl, ItemKind, Node, PatKind, QPath, TyKind};
+use rustc_hir::{
+ BindingAnnotation, Body, FnDecl, GenericArg, HirId, Impl, ItemKind, Mutability, Node, PatKind, QPath, TyKind,
+};
use rustc_hir::{HirIdMap, HirIdSet};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::mir::FakeReadCause;
-use rustc_middle::ty::{self, TypeFoldable};
+use rustc_middle::ty::{self, TypeVisitable};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::symbol::kw;
use rustc_span::{sym, Span};
use std::borrow::Cow;
declare_clippy_lint! {
- /// **What it does:** Checks for functions taking arguments by value, but not
+ /// ### What it does
+ /// Checks for functions taking arguments by value, but not
/// consuming them in its
/// body.
///
- /// **Why is this bad?** Taking arguments by reference is more flexible and can
+ /// ### Why is this bad?
+ /// Taking arguments by reference is more flexible and can
/// sometimes avoid
/// unnecessary allocations.
///
- /// **Known problems:**
+ /// ### Known problems
/// * This lint suggests taking an argument by reference,
/// however sometimes it is better to let users decide the argument type
/// (by using `Borrow` trait, for example), depending on how the function is used.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// fn foo(v: Vec<i32>) {
/// assert_eq!(v.len(), 42);
/// assert_eq!(v.len(), 42);
/// }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub NEEDLESS_PASS_BY_VALUE,
pedantic,
"functions taking arguments by value, but not consuming them in its body"
}
impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
- #[allow(clippy::too_many_lines)]
+ #[expect(clippy::too_many_lines)]
fn check_fn(
&mut self,
cx: &LateContext<'tcx>,
}
match kind {
- FnKind::ItemFn(.., header, _) => {
+ FnKind::ItemFn(.., header) => {
let attrs = cx.tcx.hir().attrs(hir_id);
if header.abi != Abi::Rust || requires_exact_signature(attrs) {
return;
}
// Allow `Borrow` or functions to be taken by value
- let borrow_trait = need!(get_trait_def_id(cx, &paths::BORROW_TRAIT));
let allowed_traits = [
need!(cx.tcx.lang_items().fn_trait()),
need!(cx.tcx.lang_items().fn_once_trait()),
.filter_map(|obligation| {
// Note that we do not want to deal with qualified predicates here.
match obligation.predicate.kind().no_bound_vars() {
- Some(ty::PredicateKind::Trait(pred, _)) if pred.def_id() != sized_trait => Some(pred),
+ Some(ty::PredicateKind::Trait(pred)) if pred.def_id() != sized_trait => Some(pred),
_ => None,
}
})
let preds = preds.iter().filter(|t| t.self_ty() == ty).collect::<Vec<_>>();
(
- preds.iter().any(|t| t.def_id() == borrow_trait),
+ preds.iter().any(|t| cx.tcx.is_diagnostic_item(sym::Borrow, t.def_id())),
!preds.is_empty() && {
- let ty_empty_region = cx.tcx.mk_imm_ref(cx.tcx.lifetimes.re_root_empty, ty);
+ let ty_empty_region = cx.tcx.mk_imm_ref(cx.tcx.lifetimes.re_erased, ty);
preds.iter().all(|t| {
let ty_params = t.trait_ref.substs.iter().skip(1).collect::<Vec<_>>();
implements_trait(cx, ty_empty_region, t.def_id(), &ty_params)
if !implements_borrow_trait;
if !all_borrowable_trait;
- if let PatKind::Binding(mode, canonical_id, ..) = arg.pat.kind;
+ if let PatKind::Binding(BindingAnnotation(_, Mutability::Not), canonical_id, ..) = arg.pat.kind;
if !moved_vars.contains(&canonical_id);
then {
- if mode == BindingAnnotation::Mutable || mode == BindingAnnotation::RefMut {
- continue;
- }
-
// Dereference suggestion
- let sugg = |diag: &mut DiagnosticBuilder<'_>| {
+ let sugg = |diag: &mut Diagnostic| {
if let ty::Adt(def, ..) = ty.kind() {
- if let Some(span) = cx.tcx.hir().span_if_local(def.did) {
- if can_type_implement_copy(cx.tcx, cx.param_env, ty).is_ok() {
+ if let Some(span) = cx.tcx.hir().span_if_local(def.did()) {
+ if can_type_implement_copy(
+ cx.tcx,
+ cx.param_env,
+ ty,
+ traits::ObligationCause::dummy_with_span(span),
+ ).is_ok() {
diag.span_help(span, "consider marking this type as `Copy`");
}
}
let deref_span = spans_need_deref.get(&canonical_id);
if_chain! {
- if is_type_diagnostic_item(cx, ty, sym::vec_type);
+ if is_type_diagnostic_item(cx, ty, sym::Vec);
if let Some(clone_spans) =
get_spans(cx, Some(body.id()), idx, &[("clone", ".to_owned()")]);
if let TyKind::Path(QPath::Resolved(_, path)) = input.kind;
for (span, suggestion) in clone_spans {
diag.span_suggestion(
span,
- &snippet_opt(cx, span)
+ snippet_opt(cx, span)
.map_or(
"change the call to".into(),
|x| Cow::from(format!("change `{}` to", x)),
- ),
- suggestion.into(),
+ )
+ .as_ref(),
+ suggestion,
Applicability::Unspecified,
);
}
}
}
- if is_type_diagnostic_item(cx, ty, sym::string_type) {
+ if is_type_diagnostic_item(cx, ty, sym::String) {
if let Some(clone_spans) =
get_spans(cx, Some(body.id()), idx, &[("clone", ".to_string()"), ("as_str", "")]) {
diag.span_suggestion(
input.span,
"consider changing the type to",
- "&str".to_string(),
+ "&str",
Applicability::Unspecified,
);
for (span, suggestion) in clone_spans {
diag.span_suggestion(
span,
- &snippet_opt(cx, span)
+ snippet_opt(cx, span)
.map_or(
"change the call to".into(),
|x| Cow::from(format!("change `{}` to", x))
- ),
- suggestion.into(),
+ )
+ .as_ref(),
+ suggestion,
Applicability::Unspecified,
);
}
fn mutate(&mut self, _: &euv::PlaceWithHirId<'tcx>, _: HirId) {}
- fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
}
projects / rust.git / blobdiff