Rustup

book/src/development/common_tools_writing_lints.md

@@ -66,7 +66,7 @@ Starting with an `expr`, you can check whether it is calling a specific method
 impl<'tcx> LateLintPass<'tcx> for MyStructLint {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
         // Check our expr is calling a method
-        if let hir::ExprKind::MethodCall(path, _, [_self_arg, ..]) = &expr.kind
+        if let hir::ExprKind::MethodCall(path, _, _self_arg, ..) = &expr.kind
             // Check the name of this method is `some_method`
             && path.ident.name == sym!(some_method)
             // Optionally, check the type of the self argument.

clippy_dev/src/lib.rs

@@ -1,3 +1,4 @@
+#![feature(let_chains)]
 #![feature(let_else)]
 #![feature(once_cell)]
 #![feature(rustc_private)]

clippy_lints/src/assertions_on_result_states.rs

@@ -43,7 +43,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
             && matches!(cx.tcx.get_diagnostic_name(macro_call.def_id), Some(sym::assert_macro))
             && let Some((condition, panic_expn)) = find_assert_args(cx, e, macro_call.expn)
             && matches!(panic_expn, PanicExpn::Empty)
-            && let ExprKind::MethodCall(method_segment, [recv], _) = condition.kind
+            && let ExprKind::MethodCall(method_segment, recv, [], _) = condition.kind
             && let result_type_with_refs = cx.typeck_results().expr_ty(recv)
             && let result_type = result_type_with_refs.peel_refs()
             && is_type_diagnostic_item(cx, result_type, sym::Result)

clippy_lints/src/async_yields_async.rs

@@ -54,7 +54,7 @@ impl<'tcx> LateLintPass<'tcx> for AsyncYieldsAsync {
                     hir_id: body.value.hir_id,
                 };
                 let typeck_results = cx.tcx.typeck_body(body_id);
-                let expr_ty = typeck_results.expr_ty(&body.value);
+                let expr_ty = typeck_results.expr_ty(body.value);
 
                 if implements_trait(cx, expr_ty, future_trait_def_id, &[]) {
                     let return_expr_span = match &body.value.kind {

clippy_lints/src/attrs.rs

@@ -475,15 +475,15 @@ fn check_lint_reason(cx: &LateContext<'_>, name: Symbol, items: &[NestedMetaItem
 
 fn is_relevant_item(cx: &LateContext<'_>, item: &Item<'_>) -> bool {
     if let ItemKind::Fn(_, _, eid) = item.kind {
-        is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value)
+        is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value)
     } else {
         true
     }
 }
 
 fn is_relevant_impl(cx: &LateContext<'_>, item: &ImplItem<'_>) -> bool {
     match item.kind {
-        ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value),
+        ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value),
         _ => false,
     }
 }
@@ -492,7 +492,7 @@ fn is_relevant_trait(cx: &LateContext<'_>, item: &TraitItem<'_>) -> bool {
     match item.kind {
         TraitItemKind::Fn(_, TraitFn::Required(_)) => true,
         TraitItemKind::Fn(_, TraitFn::Provided(eid)) => {
-            is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value)
+            is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value)
         },
         _ => false,
     }

clippy_lints/src/blocks_in_if_conditions.rs

@@ -55,7 +55,7 @@ impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
             // do not lint if the closure is called using an iterator (see #1141)
             if_chain! {
                 if let Some(parent) = get_parent_expr(self.cx, expr);
-                if let ExprKind::MethodCall(_, [self_arg, ..], _) = &parent.kind;
+                if let ExprKind::MethodCall(_, self_arg, ..) = &parent.kind;
                 let caller = self.cx.typeck_results().expr_ty(self_arg);
                 if let Some(iter_id) = self.cx.tcx.get_diagnostic_item(sym::Iterator);
                 if implements_trait(self.cx, caller, iter_id, &[]);

clippy_lints/src/booleans.rs

@@ -270,8 +270,8 @@ fn simplify_not(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> {
                 ))
             })
         },
-        ExprKind::MethodCall(path, args, _) if args.len() == 1 => {
-            let type_of_receiver = cx.typeck_results().expr_ty(&args[0]);
+        ExprKind::MethodCall(path, receiver, [], _) => {
+            let type_of_receiver = cx.typeck_results().expr_ty(receiver);
             if !is_type_diagnostic_item(cx, type_of_receiver, sym::Option)
                 && !is_type_diagnostic_item(cx, type_of_receiver, sym::Result)
             {
@@ -285,7 +285,7 @@ fn simplify_not(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> {
                     let path: &str = path.ident.name.as_str();
                     a == path
                 })
-                .and_then(|(_, neg_method)| Some(format!("{}.{}()", snippet_opt(cx, args[0].span)?, neg_method)))
+                .and_then(|(_, neg_method)| Some(format!("{}.{}()", snippet_opt(cx, receiver.span)?, neg_method)))
         },
         _ => None,
     }

clippy_lints/src/casts/cast_abs_to_unsigned.rs

@@ -20,7 +20,7 @@ pub(super) fn check(
     if meets_msrv(msrv, msrvs::UNSIGNED_ABS)
         && let ty::Int(from) = cast_from.kind()
         && let ty::Uint(to) = cast_to.kind()
-        && let ExprKind::MethodCall(method_path, args, _) = cast_expr.kind
+        && let ExprKind::MethodCall(method_path, receiver, ..) = cast_expr.kind
         && method_path.ident.name.as_str() == "abs"
     {
         let span = if from.bit_width() == to.bit_width() {
@@ -37,7 +37,7 @@ pub(super) fn check(
             span,
             &format!("casting the result of `{cast_from}::abs()` to {cast_to}"),
             "replace with",
-            format!("{}.unsigned_abs()", Sugg::hir(cx, &args[0], "..").maybe_par()),
+            format!("{}.unsigned_abs()", Sugg::hir(cx, receiver, "..").maybe_par()),
             Applicability::MachineApplicable,
         );
     }

clippy_lints/src/casts/cast_possible_truncation.rs

@@ -44,7 +44,7 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b
                 .saturating_sub(constant_int(cx, right).map_or(0, |s| u64::try_from(s).expect("shift too high"))),
             _ => nbits,
         },
-        ExprKind::MethodCall(method, [left, right], _) => {
+        ExprKind::MethodCall(method, left, [right], _) => {
             if signed {
                 return nbits;
             }
@@ -55,7 +55,7 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b
             };
             apply_reductions(cx, nbits, left, signed).min(max_bits.unwrap_or(u64::max_value()))
         },
-        ExprKind::MethodCall(method, [_, lo, hi], _) => {
+        ExprKind::MethodCall(method, _, [lo, hi], _) => {
             if method.ident.as_str() == "clamp" {
                 //FIXME: make this a diagnostic item
                 if let (Some(lo_bits), Some(hi_bits)) = (get_constant_bits(cx, lo), get_constant_bits(cx, hi)) {
@@ -64,7 +64,7 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b
             }
             nbits
         },
-        ExprKind::MethodCall(method, [_value], _) => {
+        ExprKind::MethodCall(method, _value, [], _) => {
             if method.ident.name.as_str() == "signum" {
                 0 // do not lint if cast comes from a `signum` function
             } else {

clippy_lints/src/casts/cast_ptr_alignment.rs

@@ -18,7 +18,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
             cx.typeck_results().expr_ty(expr),
         );
         lint_cast_ptr_alignment(cx, expr, cast_from, cast_to);
-    } else if let ExprKind::MethodCall(method_path, [self_arg, ..], _) = &expr.kind {
+    } else if let ExprKind::MethodCall(method_path, self_arg, ..) = &expr.kind {
         if method_path.ident.name == sym!(cast)
             && let Some(generic_args) = method_path.args
             && let [GenericArg::Type(cast_to)] = generic_args.args
@@ -64,7 +64,7 @@ fn is_used_as_unaligned(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
         return false;
     };
     match parent.kind {
-        ExprKind::MethodCall(name, [self_arg, ..], _) if self_arg.hir_id == e.hir_id => {
+        ExprKind::MethodCall(name, self_arg, ..) if self_arg.hir_id == e.hir_id => {
             if matches!(name.ident.as_str(), "read_unaligned" | "write_unaligned")
                 && let Some(def_id) = cx.typeck_results().type_dependent_def_id(parent.hir_id)
                 && let Some(def_id) = cx.tcx.impl_of_method(def_id)

clippy_lints/src/casts/cast_sign_loss.rs

@@ -41,14 +41,14 @@ fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast
             }
 
             // Don't lint for the result of methods that always return non-negative values.
-            if let ExprKind::MethodCall(path, _, _) = cast_op.kind {
+            if let ExprKind::MethodCall(path, ..) = cast_op.kind {
                 let mut method_name = path.ident.name.as_str();
                 let allowed_methods = ["abs", "checked_abs", "rem_euclid", "checked_rem_euclid"];
 
                 if_chain! {
                     if method_name == "unwrap";
                     if let Some(arglist) = method_chain_args(cast_op, &["unwrap"]);
-                    if let ExprKind::MethodCall(inner_path, _, _) = &arglist[0][0].kind;
+                    if let ExprKind::MethodCall(inner_path, ..) = &arglist[0].0.kind;
                     then {
                         method_name = inner_path.ident.name.as_str();
                     }

clippy_lints/src/default_numeric_fallback.rs

@@ -131,10 +131,10 @@ impl<'a, 'tcx> Visitor<'tcx> for NumericFallbackVisitor<'a, 'tcx> {
                 }
             },
 
-            ExprKind::MethodCall(_, args, _) => {
+            ExprKind::MethodCall(_, receiver, args, _) => {
                 if let Some(def_id) = self.cx.typeck_results().type_dependent_def_id(expr.hir_id) {
                     let fn_sig = self.cx.tcx.fn_sig(def_id).skip_binder();
-                    for (expr, bound) in iter::zip(*args, fn_sig.inputs()) {
+                    for (expr, bound) in iter::zip(std::iter::once(*receiver).chain(args.iter()), fn_sig.inputs()) {
                         self.ty_bounds.push(TyBound::Ty(*bound));
                         self.visit_expr(expr);
                         self.ty_bounds.pop();

clippy_lints/src/dereference.rs

@@ -503,7 +503,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing {
     }
 
     fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
-        if let PatKind::Binding(BindingAnnotation::Ref, id, name, _) = pat.kind {
+        if let PatKind::Binding(BindingAnnotation::REF, id, name, _) = pat.kind {
             if let Some(opt_prev_pat) = self.ref_locals.get_mut(&id) {
                 // This binding id has been seen before. Add this pattern to the list of changes.
                 if let Some(prev_pat) = opt_prev_pat {
@@ -581,7 +581,7 @@ fn try_parse_ref_op<'tcx>(
     expr: &'tcx Expr<'_>,
 ) -> Option<(RefOp, &'tcx Expr<'tcx>)> {
     let (def_id, arg) = match expr.kind {
-        ExprKind::MethodCall(_, [arg], _) => (typeck.type_dependent_def_id(expr.hir_id)?, arg),
+        ExprKind::MethodCall(_, arg, [], _) => (typeck.type_dependent_def_id(expr.hir_id)?, arg),
         ExprKind::Call(
             Expr {
                 kind: ExprKind::Path(path),
@@ -796,56 +796,54 @@ fn walk_parents<'tcx>(
                             },
                         })
                     }),
-                ExprKind::MethodCall(_, args, _) => {
+                ExprKind::MethodCall(_, receiver, args, _) => {
                     let id = cx.typeck_results().type_dependent_def_id(parent.hir_id).unwrap();
-                    args.iter().position(|arg| arg.hir_id == child_id).map(|i| {
-                        if i == 0 {
-                            // Check for calls to trait methods where the trait is implemented on a reference.
-                            // Two cases need to be handled:
-                            // * `self` methods on `&T` will never have auto-borrow
-                            // * `&self` methods on `&T` can have auto-borrow, but `&self` methods on `T` will take
-                            //   priority.
-                            if e.hir_id != child_id {
-                                Position::ReborrowStable(precedence)
-                            } else if let Some(trait_id) = cx.tcx.trait_of_item(id)
-                                && let arg_ty = cx.tcx.erase_regions(cx.typeck_results().expr_ty_adjusted(e))
-                                && let ty::Ref(_, sub_ty, _) = *arg_ty.kind()
-                                && let subs = match cx
-                                    .typeck_results()
-                                    .node_substs_opt(parent.hir_id)
-                                    .and_then(|subs| subs.get(1..))
-                                {
-                                    Some(subs) => cx.tcx.mk_substs(subs.iter().copied()),
-                                    None => cx.tcx.mk_substs(std::iter::empty::<ty::subst::GenericArg<'_>>()),
-                                } && let impl_ty = if cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref() {
-                                    // Trait methods taking `&self`
-                                    sub_ty
-                                } else {
-                                    // Trait methods taking `self`
-                                    arg_ty
-                                } && impl_ty.is_ref()
-                                && cx.tcx.infer_ctxt().enter(|infcx|
-                                    infcx
-                                        .type_implements_trait(trait_id, impl_ty, subs, cx.param_env)
-                                        .must_apply_modulo_regions()
-                                )
+                    if receiver.hir_id == child_id {
+                        // Check for calls to trait methods where the trait is implemented on a reference.
+                        // Two cases need to be handled:
+                        // * `self` methods on `&T` will never have auto-borrow
+                        // * `&self` methods on `&T` can have auto-borrow, but `&self` methods on `T` will take
+                        //   priority.
+                        if e.hir_id != child_id {
+                            return Some(Position::ReborrowStable(precedence))
+                        } else if let Some(trait_id) = cx.tcx.trait_of_item(id)
+                            && let arg_ty = cx.tcx.erase_regions(cx.typeck_results().expr_ty_adjusted(e))
+                            && let ty::Ref(_, sub_ty, _) = *arg_ty.kind()
+                            && let subs = match cx
+                                .typeck_results()
+                                .node_substs_opt(parent.hir_id)
+                                .and_then(|subs| subs.get(1..))
                             {
-                                Position::MethodReceiverRefImpl
+                                Some(subs) => cx.tcx.mk_substs(subs.iter().copied()),
+                                None => cx.tcx.mk_substs(std::iter::empty::<ty::subst::GenericArg<'_>>()),
+                            } && let impl_ty = if cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref() {
+                                // Trait methods taking `&self`
+                                sub_ty
                             } else {
-                                Position::MethodReceiver
-                            }
+                                // Trait methods taking `self`
+                                arg_ty
+                            } && impl_ty.is_ref()
+                            && cx.tcx.infer_ctxt().enter(|infcx|
+                                infcx
+                                    .type_implements_trait(trait_id, impl_ty, subs, cx.param_env)
+                                    .must_apply_modulo_regions()
+                            )
+                        {
+                            return Some(Position::MethodReceiverRefImpl)
+                        }
+                        return Some(Position::MethodReceiver);
+                    }
+                    args.iter().position(|arg| arg.hir_id == child_id).map(|i| {
+                        let ty = cx.tcx.fn_sig(id).skip_binder().inputs()[i + 1];
+                        if let ty::Param(param_ty) = ty.kind() {
+                            needless_borrow_impl_arg_position(cx, parent, i + 1, *param_ty, e, precedence, msrv)
                         } else {
-                            let ty = cx.tcx.fn_sig(id).skip_binder().inputs()[i];
-                            if let ty::Param(param_ty) = ty.kind() {
-                                needless_borrow_impl_arg_position(cx, parent, i, *param_ty, e, precedence, msrv)
-                            } else {
-                                ty_auto_deref_stability(
-                                    cx,
-                                    cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).input(i)),
-                                    precedence,
-                                )
-                                .position_for_arg()
-                            }
+                            ty_auto_deref_stability(
+                                cx,
+                                cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).input(i + 1)),
+                                precedence,
+                            )
+                            .position_for_arg()
                         }
                     })
                 },
@@ -1174,7 +1172,7 @@ fn replace_types<'tcx>(
         if replaced.insert(param_ty.index) {
             for projection_predicate in projection_predicates {
                 if projection_predicate.projection_ty.self_ty() == param_ty.to_ty(cx.tcx)
-                    && let ty::Term::Ty(term_ty) = projection_predicate.term
+                    && let Some(term_ty) = projection_predicate.term.ty()
                     && let ty::Param(term_param_ty) = term_ty.kind()
                 {
                     let item_def_id = projection_predicate.projection_ty.item_def_id;

clippy_lints/src/doc.rs

@@ -236,7 +236,7 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
                         typeck_results: cx.tcx.typeck(item.def_id),
                         panic_span: None,
                     };
-                    fpu.visit_expr(&body.value);
+                    fpu.visit_expr(body.value);
                     lint_for_missing_headers(cx, item.def_id, item.span, sig, headers, Some(body_id), fpu.panic_span);
                 }
             },
@@ -286,7 +286,7 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
                 typeck_results: cx.tcx.typeck(item.def_id),
                 panic_span: None,
             };
-            fpu.visit_expr(&body.value);
+            fpu.visit_expr(body.value);
             lint_for_missing_headers(cx, item.def_id, item.span, sig, headers, Some(body_id), fpu.panic_span);
         }
     }
@@ -348,7 +348,7 @@ fn lint_for_missing_headers<'tcx>(
                 if let Some(future) = cx.tcx.lang_items().future_trait();
                 let typeck = cx.tcx.typeck_body(body_id);
                 let body = cx.tcx.hir().body(body_id);
-                let ret_ty = typeck.expr_ty(&body.value);
+                let ret_ty = typeck.expr_ty(body.value);
                 if implements_trait(cx, ret_ty, future, &[]);
                 if let ty::Opaque(_, subs) = ret_ty.kind();
                 if let Some(gen) = subs.types().next();
@@ -828,7 +828,7 @@ impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
 
         // check for `unwrap`
         if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
-            let receiver_ty = self.typeck_results.expr_ty(&arglists[0][0]).peel_refs();
+            let receiver_ty = self.typeck_results.expr_ty(arglists[0].0).peel_refs();
             if is_type_diagnostic_item(self.cx, receiver_ty, sym::Option)
                 || is_type_diagnostic_item(self.cx, receiver_ty, sym::Result)
             {