Auto merge of rust-lang#92036 - flip1995:clippyup, r=Manishearth

Update Clippy

Only one day delayed! 😅

r? `@Manishearth`

Author: bors

src/tools/clippy/.gitignore

@@ -27,9 +27,11 @@ out
 # Generated by dogfood
 /target_recur/
 
+# Generated by lintcheck
+/lintcheck-logs
+
 # gh pages docs
 util/gh-pages/lints.json
-**/metadata_collection.json
 
 # rustfmt backups
 *.rs.bk

src/tools/clippy/CHANGELOG.md

@@ -3118,6 +3118,7 @@ Released 2018-09-13
 [`result_map_or_into_option`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_map_or_into_option
 [`result_map_unit_fn`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_map_unit_fn
 [`result_unit_err`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_unit_err
+[`return_self_not_must_use`]: https://rust-lang.github.io/rust-clippy/master/index.html#return_self_not_must_use
 [`reversed_empty_ranges`]: https://rust-lang.github.io/rust-clippy/master/index.html#reversed_empty_ranges
 [`same_functions_in_if_condition`]: https://rust-lang.github.io/rust-clippy/master/index.html#same_functions_in_if_condition
 [`same_item_push`]: https://rust-lang.github.io/rust-clippy/master/index.html#same_item_push
@@ -3209,6 +3210,7 @@ Released 2018-09-13
 [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation
 [`unnecessary_self_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_self_imports
 [`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by
+[`unnecessary_to_owned`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_to_owned
 [`unnecessary_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap
 [`unnecessary_wraps`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_wraps
 [`unneeded_field_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_field_pattern

src/tools/clippy/README.md

@@ -162,7 +162,8 @@ define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable.
 
 You can add options to your code to `allow`/`warn`/`deny` Clippy lints:
 
-*   the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`)
+*   the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`).
+    Note that `rustc` has additional [lint groups](https://doc.rust-lang.org/rustc/lints/groups.html).
 
 *   all lints using both the `clippy` and `clippy::pedantic` lint groups (`#![deny(clippy::all)]`,
     `#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive

src/tools/clippy/clippy_lints/src/asm_syntax.rs

@@ -65,13 +65,15 @@ declare_clippy_lint! {
     /// ```rust,no_run
     /// # #![feature(asm)]
     /// # unsafe { let ptr = "".as_ptr();
+    /// # use std::arch::asm;
     /// asm!("lea {}, [{}]", lateout(reg) _, in(reg) ptr);
     /// # }
     /// ```
     /// Use instead:
     /// ```rust,no_run
     /// # #![feature(asm)]
     /// # unsafe { let ptr = "".as_ptr();
+    /// # use std::arch::asm;
     /// asm!("lea ({}), {}", in(reg) ptr, lateout(reg) _, options(att_syntax));
     /// # }
     /// ```
@@ -102,13 +104,15 @@ declare_clippy_lint! {
     /// ```rust,no_run
     /// # #![feature(asm)]
     /// # unsafe { let ptr = "".as_ptr();
+    /// # use std::arch::asm;
     /// asm!("lea ({}), {}", in(reg) ptr, lateout(reg) _, options(att_syntax));
     /// # }
     /// ```
     /// Use instead:
     /// ```rust,no_run
     /// # #![feature(asm)]
     /// # unsafe { let ptr = "".as_ptr();
+    /// # use std::arch::asm;
     /// asm!("lea {}, [{}]", lateout(reg) _, in(reg) ptr);
     /// # }
     /// ```

src/tools/clippy/clippy_lints/src/assertions_on_constants.rs

@@ -2,7 +2,7 @@ use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::higher;
 use clippy_utils::source::snippet_opt;
-use clippy_utils::{is_direct_expn_of, is_expn_of, match_panic_call};
+use clippy_utils::{is_direct_expn_of, is_expn_of, match_panic_call, peel_blocks};
 use if_chain::if_chain;
 use rustc_hir::{Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
@@ -122,15 +122,7 @@ fn match_assert_with_message<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>)
         if let ExprKind::Unary(UnOp::Not, expr) = cond.kind;
         // bind the first argument of the `assert!` macro
         if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), expr);
-        // block
-        if let ExprKind::Block(block, _) = then.kind;
-        if block.stmts.is_empty();
-        if let Some(block_expr) = &block.expr;
-        // inner block is optional. unwrap it if it exists, or use the expression as is otherwise.
-        if let Some(begin_panic_call) = match block_expr.kind {
-            ExprKind::Block(inner_block, _) => &inner_block.expr,
-            _ => &block.expr,
-        };
+        let begin_panic_call = peel_blocks(then);
         // function call
         if let Some(arg) = match_panic_call(cx, begin_panic_call);
         // bind the second argument of the `assert!` macro if it exists

src/tools/clippy/clippy_lints/src/blocks_in_if_conditions.rs

@@ -73,9 +73,11 @@ impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
 
             let body = self.cx.tcx.hir().body(eid);
             let ex = &body.value;
-            if matches!(ex.kind, ExprKind::Block(_, _)) && !body.value.span.from_expansion() {
-                self.found_block = Some(ex);
-                return;
+            if let ExprKind::Block(block, _) = ex.kind {
+                if !body.value.span.from_expansion() && !block.stmts.is_empty() {
+                    self.found_block = Some(ex);
+                    return;
+                }
             }
         }
         walk_expr(self, expr);

src/tools/clippy/clippy_lints/src/bytecount.rs

@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::ty::match_type;
 use clippy_utils::visitors::is_local_used;
-use clippy_utils::{path_to_local_id, paths, peel_ref_operators, remove_blocks, strip_pat_refs};
+use clippy_utils::{path_to_local_id, paths, peel_blocks, peel_ref_operators, strip_pat_refs};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind, PatKind};
@@ -42,7 +42,7 @@ impl<'tcx> LateLintPass<'tcx> for ByteCount {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
         if_chain! {
             if let ExprKind::MethodCall(count, _, [count_recv], _) = expr.kind;
-            if count.ident.name == sym!(count);
+            if count.ident.name == sym::count;
             if let ExprKind::MethodCall(filter, _, [filter_recv, filter_arg], _) = count_recv.kind;
             if filter.ident.name == sym!(filter);
             if let ExprKind::Closure(_, _, body_id, _, _) = filter_arg.kind;
@@ -55,7 +55,7 @@ impl<'tcx> LateLintPass<'tcx> for ByteCount {
                        cx.typeck_results().expr_ty(filter_recv).peel_refs(),
                        &paths::SLICE_ITER);
             let operand_is_arg = |expr| {
-                let expr = peel_ref_operators(cx, remove_blocks(expr));
+                let expr = peel_ref_operators(cx, peel_blocks(expr));
                 path_to_local_id(expr, arg_id)
             };
             let needle = if operand_is_arg(l) {

src/tools/clippy/clippy_lints/src/collapsible_match.rs

@@ -1,10 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::higher::IfLetOrMatch;
 use clippy_utils::visitors::is_local_used;
-use clippy_utils::{is_lang_ctor, is_unit_expr, path_to_local, peel_ref_operators, SpanlessEq};
+use clippy_utils::{is_lang_ctor, is_unit_expr, path_to_local, peel_blocks_with_stmt, peel_ref_operators, SpanlessEq};
 use if_chain::if_chain;
 use rustc_hir::LangItem::OptionNone;
-use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind, StmtKind};
+use rustc_hir::{Arm, Expr, Guard, HirId, Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{MultiSpan, Span};
@@ -75,7 +75,7 @@ fn check_arm<'tcx>(
     outer_guard: Option<&'tcx Guard<'tcx>>,
     outer_else_body: Option<&'tcx Expr<'tcx>>,
 ) {
-    let inner_expr = strip_singleton_blocks(outer_then_body);
+    let inner_expr = peel_blocks_with_stmt(outer_then_body);
     if_chain! {
         if let Some(inner) = IfLetOrMatch::parse(cx, inner_expr);
         if let Some((inner_scrutinee, inner_then_pat, inner_else_body)) = match inner {
@@ -138,20 +138,6 @@ fn check_arm<'tcx>(
     }
 }
 
-fn strip_singleton_blocks<'hir>(mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> {
-    while let ExprKind::Block(block, _) = expr.kind {
-        match (block.stmts, block.expr) {
-            ([stmt], None) => match stmt.kind {
-                StmtKind::Expr(e) | StmtKind::Semi(e) => expr = e,
-                _ => break,
-            },
-            ([], Some(e)) => expr = e,
-            _ => break,
-        }
-    }
-    expr
-}
-
 /// A "wild-like" arm has a wild (`_`) or `None` pattern and no guard. Such arms can be "collapsed"
 /// into a single wild arm without any significant loss in semantics or readability.
 fn arm_is_wild_like(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {

src/tools/clippy/clippy_lints/src/derivable_impls.rs

@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use clippy_utils::{is_automatically_derived, is_default_equivalent, remove_blocks};
+use clippy_utils::{is_automatically_derived, is_default_equivalent, peel_blocks};
 use rustc_hir::{
     def::{DefKind, Res},
     Body, Expr, ExprKind, GenericArg, Impl, ImplItemKind, Item, ItemKind, Node, PathSegment, QPath, TyKind,
@@ -95,7 +95,7 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
                         }
                     }
                 }
-                let should_emit = match remove_blocks(func_expr).kind {
+                let should_emit = match peel_blocks(func_expr).kind {
                     ExprKind::Tup(fields) => fields.iter().all(|e| is_default_equivalent(cx, e)),
                     ExprKind::Call(callee, args)
                         if is_path_self(callee) => args.iter().all(|e| is_default_equivalent(cx, e)),

src/tools/clippy/clippy_lints/src/floating_point_arithmetic.rs

@@ -4,7 +4,7 @@ use clippy_utils::consts::{
 };
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::higher;
-use clippy_utils::{eq_expr_value, get_parent_expr, in_constant, numeric_literal, sugg};
+use clippy_utils::{eq_expr_value, get_parent_expr, in_constant, numeric_literal, peel_blocks, sugg};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind, PathSegment, UnOp};
@@ -546,13 +546,9 @@ fn are_negated<'a>(cx: &LateContext<'_>, expr1: &'a Expr<'a>, expr2: &'a Expr<'a
 
 fn check_custom_abs(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if_chain! {
-        if let Some(higher::If { cond, then, r#else }) = higher::If::hir(expr);
-        if let ExprKind::Block(block, _) = then.kind;
-        if block.stmts.is_empty();
-        if let Some(if_body_expr) = block.expr;
-        if let Some(ExprKind::Block(else_block, _)) = r#else.map(|el| &el.kind);
-        if else_block.stmts.is_empty();
-        if let Some(else_body_expr) = else_block.expr;
+        if let Some(higher::If { cond, then, r#else: Some(r#else) }) = higher::If::hir(expr);
+        let if_body_expr = peel_blocks(then);
+        let else_body_expr = peel_blocks(r#else);
         if let Some((if_expr_positive, body)) = are_negated(cx, if_body_expr, else_body_expr);
         then {
             let positive_abs_sugg = (