Update Clippy

src/tools/clippy/.github/ISSUE_TEMPLATE/new_lint.md

@@ -12,7 +12,7 @@ labels: L-lint
 
 - Kind: *See <https://github.com/rust-lang/rust-clippy/blob/master/README.md#clippy> for list of lint kinds*
 
-*What benefit of this lint over old code?*
+*What is the advantage of the recommended code over the original code*
 
 For example:
 - Remove bounce checking inserted by ...

src/tools/clippy/.github/workflows/clippy_bors.yml

@@ -240,7 +240,8 @@ jobs:
         - 'Geal/nom'
         - 'rust-lang/stdarch'
         - 'serde-rs/serde'
-        - 'chronotope/chrono'
+        # FIXME: chrono currently cannot be compiled with `--all-targets`
+        # - 'chronotope/chrono'
         - 'hyperium/hyper'
         - 'rust-random/rand'
         - 'rust-lang/futures-rs'

src/tools/clippy/CHANGELOG.md

@@ -1352,6 +1352,7 @@ Released 2018-09-13
 [`bad_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#bad_bit_mask
 [`bind_instead_of_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#bind_instead_of_map
 [`blacklisted_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#blacklisted_name
+[`blanket_clippy_restriction_lints`]: https://rust-lang.github.io/rust-clippy/master/index.html#blanket_clippy_restriction_lints
 [`blocks_in_if_conditions`]: https://rust-lang.github.io/rust-clippy/master/index.html#blocks_in_if_conditions
 [`bool_comparison`]: https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
 [`borrow_interior_mutable_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrow_interior_mutable_const
@@ -1508,9 +1509,11 @@ Released 2018-09-13
 [`map_clone`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_clone
 [`map_entry`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_entry
 [`map_flatten`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten
+[`map_identity`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_identity
 [`map_unwrap_or`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_unwrap_or
 [`match_as_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_as_ref
 [`match_bool`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_bool
+[`match_like_matches_macro`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro
 [`match_on_vec_items`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_on_vec_items
 [`match_overlapping_arm`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_overlapping_arm
 [`match_ref_pats`]: https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
@@ -1575,6 +1578,7 @@ Released 2018-09-13
 [`op_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#op_ref
 [`option_as_ref_deref`]: https://rust-lang.github.io/rust-clippy/master/index.html#option_as_ref_deref
 [`option_env_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#option_env_unwrap
+[`option_if_let_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#option_if_let_else
 [`option_map_or_none`]: https://rust-lang.github.io/rust-clippy/master/index.html#option_map_or_none
 [`option_map_unit_fn`]: https://rust-lang.github.io/rust-clippy/master/index.html#option_map_unit_fn
 [`option_option`]: https://rust-lang.github.io/rust-clippy/master/index.html#option_option
@@ -1586,6 +1590,7 @@ Released 2018-09-13
 [`panicking_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#panicking_unwrap
 [`partialeq_ne_impl`]: https://rust-lang.github.io/rust-clippy/master/index.html#partialeq_ne_impl
 [`path_buf_push_overwrite`]: https://rust-lang.github.io/rust-clippy/master/index.html#path_buf_push_overwrite
+[`pattern_type_mismatch`]: https://rust-lang.github.io/rust-clippy/master/index.html#pattern_type_mismatch
 [`possible_missing_comma`]: https://rust-lang.github.io/rust-clippy/master/index.html#possible_missing_comma
 [`precedence`]: https://rust-lang.github.io/rust-clippy/master/index.html#precedence
 [`print_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#print_literal
@@ -1612,6 +1617,7 @@ Released 2018-09-13
 [`redundant_static_lifetimes`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_static_lifetimes
 [`ref_in_deref`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_in_deref
 [`regex_macro`]: https://rust-lang.github.io/rust-clippy/master/index.html#regex_macro
+[`repeat_once`]: https://rust-lang.github.io/rust-clippy/master/index.html#repeat_once
 [`replace_consts`]: https://rust-lang.github.io/rust-clippy/master/index.html#replace_consts
 [`rest_pat_in_fully_bound_structs`]: https://rust-lang.github.io/rust-clippy/master/index.html#rest_pat_in_fully_bound_structs
 [`result_map_or_into_option`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_map_or_into_option

src/tools/clippy/CONTRIBUTING.md

@@ -245,7 +245,7 @@ this to work, you will need the fix of `git subtree` available
 [here][gitgitgadget-pr].
 
 [gitgitgadget-pr]: https://github.com/gitgitgadget/git/pull/493
-[subtree]: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#external-dependencies-subtree
+[subtree]: https://rustc-dev-guide.rust-lang.org/contributing.html#external-dependencies-subtree
 [`rust-lang/rust`]: https://github.com/rust-lang/rust
 
 ## Issue and PR triage

src/tools/clippy/clippy_lints/src/attrs.rs

@@ -2,8 +2,8 @@
 
 use crate::reexport::Name;
 use crate::utils::{
-    first_line_of_span, is_present_in_source, match_def_path, paths, snippet_opt, span_lint, span_lint_and_sugg,
-    span_lint_and_then, without_block_comments,
+    first_line_of_span, is_present_in_source, match_def_path, paths, snippet_opt, span_lint, span_lint_and_help,
+    span_lint_and_sugg, span_lint_and_then, without_block_comments,
 };
 use if_chain::if_chain;
 use rustc_ast::ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
@@ -17,7 +17,7 @@ use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
-use rustc_span::symbol::Symbol;
+use rustc_span::symbol::{Symbol, SymbolStr};
 use semver::Version;
 
 static UNIX_SYSTEMS: &[&str] = &[
@@ -182,6 +182,29 @@ declare_clippy_lint! {
     "unknown_lints for scoped Clippy lints"
 }
 
+declare_clippy_lint! {
+    /// **What it does:** Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category.
+    ///
+    /// **Why is this bad?** Restriction lints sometimes are in contrast with other lints or even go against idiomatic rust.
+    /// These lints should only be enabled on a lint-by-lint basis and with careful consideration.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// Bad:
+    /// ```rust
+    /// #![deny(clippy::restriction)]
+    /// ```
+    ///
+    /// Good:
+    /// ```rust
+    /// #![deny(clippy::as_conversions)]
+    /// ```
+    pub BLANKET_CLIPPY_RESTRICTION_LINTS,
+    style,
+    "enabling the complete restriction group"
+}
+
 declare_clippy_lint! {
     /// **What it does:** Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it
     /// with `#[rustfmt::skip]`.
@@ -249,15 +272,17 @@ declare_lint_pass!(Attributes => [
     DEPRECATED_SEMVER,
     USELESS_ATTRIBUTE,
     UNKNOWN_CLIPPY_LINTS,
+    BLANKET_CLIPPY_RESTRICTION_LINTS,
 ]);
 
 impl<'tcx> LateLintPass<'tcx> for Attributes {
     fn check_attribute(&mut self, cx: &LateContext<'tcx>, attr: &'tcx Attribute) {
         if let Some(items) = &attr.meta_item_list() {
             if let Some(ident) = attr.ident() {
-                match &*ident.as_str() {
+                let ident = &*ident.as_str();
+                match ident {
                     "allow" | "warn" | "deny" | "forbid" => {
-                        check_clippy_lint_names(cx, items);
+                        check_clippy_lint_names(cx, ident, items);
                     },
                     _ => {},
                 }
@@ -363,38 +388,43 @@ impl<'tcx> LateLintPass<'tcx> for Attributes {
     }
 }
 
-#[allow(clippy::single_match_else)]
-fn check_clippy_lint_names(cx: &LateContext<'_>, items: &[NestedMetaItem]) {
-    let lint_store = cx.lints();
-    for lint in items {
+fn check_clippy_lint_names(cx: &LateContext<'_>, ident: &str, items: &[NestedMetaItem]) {
+    fn extract_name(lint: &NestedMetaItem) -> Option<SymbolStr> {
         if_chain! {
             if let Some(meta_item) = lint.meta_item();
             if meta_item.path.segments.len() > 1;
             if let tool_name = meta_item.path.segments[0].ident;
             if tool_name.as_str() == "clippy";
-            let name = meta_item.path.segments.last().unwrap().ident.name;
-            if let CheckLintNameResult::Tool(Err((None, _))) = lint_store.check_lint_name(
-                &name.as_str(),
-                Some(tool_name.name),
-            );
+            let lint_name = meta_item.path.segments.last().unwrap().ident.name;
             then {
+                return Some(lint_name.as_str());
+            }
+        }
+        None
+    }
+
+    let lint_store = cx.lints();
+    for lint in items {
+        if let Some(lint_name) = extract_name(lint) {
+            if let CheckLintNameResult::Tool(Err((None, _))) =
+                lint_store.check_lint_name(&lint_name, Some(sym!(clippy)))
+            {
                 span_lint_and_then(
                     cx,
                     UNKNOWN_CLIPPY_LINTS,
                     lint.span(),
-                    &format!("unknown clippy lint: clippy::{}", name),
+                    &format!("unknown clippy lint: clippy::{}", lint_name),
                     |diag| {
-                        let name_lower = name.as_str().to_lowercase();
-                        let symbols = lint_store.get_lints().iter().map(
-                            |l| Symbol::intern(&l.name_lower())
-                        ).collect::<Vec<_>>();
-                        let sugg = find_best_match_for_name(
-                            symbols.iter(),
-                            &format!("clippy::{}", name_lower),
-                            None,
-                        );
-                        if name.as_str().chars().any(char::is_uppercase)
-                            && lint_store.find_lints(&format!("clippy::{}", name_lower)).is_ok() {
+                        let name_lower = lint_name.to_lowercase();
+                        let symbols = lint_store
+                            .get_lints()
+                            .iter()
+                            .map(|l| Symbol::intern(&l.name_lower()))
+                            .collect::<Vec<_>>();
+                        let sugg = find_best_match_for_name(symbols.iter(), &format!("clippy::{}", name_lower), None);
+                        if lint_name.chars().any(char::is_uppercase)
+                            && lint_store.find_lints(&format!("clippy::{}", name_lower)).is_ok()
+                        {
                             diag.span_suggestion(
                                 lint.span(),
                                 "lowercase the lint name",
@@ -409,10 +439,19 @@ fn check_clippy_lint_names(cx: &LateContext<'_>, items: &[NestedMetaItem]) {
                                 Applicability::MachineApplicable,
                             );
                         }
-                    }
+                    },
+                );
+            } else if lint_name == "restriction" && ident != "allow" {
+                span_lint_and_help(
+                    cx,
+                    BLANKET_CLIPPY_RESTRICTION_LINTS,
+                    lint.span(),
+                    "restriction lints are not meant to be all enabled",
+                    None,
+                    "try enabling only the lints you really need",
                 );
             }
-        };
+        }
     }
 }
 
@@ -442,15 +481,14 @@ fn is_relevant_trait(cx: &LateContext<'_>, item: &TraitItem<'_>) -> bool {
 }
 
 fn is_relevant_block(cx: &LateContext<'_>, tables: &ty::TypeckTables<'_>, block: &Block<'_>) -> bool {
-    if let Some(stmt) = block.stmts.first() {
-        match &stmt.kind {
+    block.stmts.first().map_or(
+        block.expr.as_ref().map_or(false, |e| is_relevant_expr(cx, tables, e)),
+        |stmt| match &stmt.kind {
             StmtKind::Local(_) => true,
             StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, tables, expr),
             _ => false,
-        }
-    } else {
-        block.expr.as_ref().map_or(false, |e| is_relevant_expr(cx, tables, e))
-    }
+        },
+    )
 }
 
 fn is_relevant_expr(cx: &LateContext<'_>, tables: &ty::TypeckTables<'_>, expr: &Expr<'_>) -> bool {
@@ -460,11 +498,10 @@ fn is_relevant_expr(cx: &LateContext<'_>, tables: &ty::TypeckTables<'_>, expr: &
         ExprKind::Ret(None) | ExprKind::Break(_, None) => false,
         ExprKind::Call(path_expr, _) => {
             if let ExprKind::Path(qpath) = &path_expr.kind {
-                if let Some(fun_id) = tables.qpath_res(qpath, path_expr.hir_id).opt_def_id() {
-                    !match_def_path(cx, fun_id, &paths::BEGIN_PANIC)
-                } else {
-                    true
-                }
+                tables
+                    .qpath_res(qpath, path_expr.hir_id)
+                    .opt_def_id()
+                    .map_or(true, |fun_id| !match_def_path(cx, fun_id, &paths::BEGIN_PANIC))
             } else {
                 true
             }

src/tools/clippy/clippy_lints/src/await_holding_lock.rs

@@ -11,7 +11,7 @@ declare_clippy_lint! {
     /// non-async-aware MutexGuard.
     ///
     /// **Why is this bad?** The Mutex types found in syd::sync and parking_lot
-    /// are not designed to operator in an async context across await points.
+    /// are not designed to operate in an async context across await points.
     ///
     /// There are two potential solutions. One is to use an asynx-aware Mutex
     /// type. Many asynchronous foundation crates provide such a Mutex type. The

src/tools/clippy/clippy_lints/src/collapsible_if.rs

@@ -115,7 +115,7 @@ fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) {
                 COLLAPSIBLE_IF,
                 block.span,
                 "this `else { if .. }` block can be collapsed",
-                "try",
+                "collapse nested if block",
                 snippet_block_with_applicability(cx, else_.span, "..", Some(block.span), &mut applicability).into_owned(),
                 applicability,
             );
@@ -142,7 +142,7 @@ fn check_collapsible_no_if_let(cx: &EarlyContext<'_>, expr: &ast::Expr, check: &
                 let rhs = Sugg::ast(cx, check_inner, "..");
                 diag.span_suggestion(
                     expr.span,
-                    "try",
+                    "collapse nested if block",
                     format!(
                         "if {} {}",
                         lhs.and(&rhs),

src/tools/clippy/clippy_lints/src/comparison_chain.rs

@@ -122,8 +122,5 @@ impl<'tcx> LateLintPass<'tcx> for ComparisonChain {
 }
 
 fn kind_is_cmp(kind: BinOpKind) -> bool {
-    match kind {
-        BinOpKind::Lt | BinOpKind::Gt | BinOpKind::Eq => true,
-        _ => false,
-    }
+    matches!(kind, BinOpKind::Lt | BinOpKind::Gt | BinOpKind::Eq)
 }

src/tools/clippy/clippy_lints/src/deprecated_lints.rs

@@ -153,5 +153,13 @@ declare_deprecated_lint! {
     ///
     /// **Deprecation reason:** Associated-constants are now preferred.
     pub REPLACE_CONSTS,
-    "associated-constants `MIN`/`MAX` of integers are prefer to `{min,max}_value()` and module constants"
+    "associated-constants `MIN`/`MAX` of integers are prefered to `{min,max}_value()` and module constants"
+}
+
+declare_deprecated_lint! {
+    /// **What it does:** Nothing. This lint has been deprecated.
+    ///
+    /// **Deprecation reason:** The regex! macro does not exist anymore.
+    pub REGEX_MACRO,
+    "the regex! macro has been removed from the regex crate in 2018"
 }

src/tools/clippy/clippy_lints/src/dereference.rs

@@ -73,9 +73,10 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing {
 fn lint_deref(cx: &LateContext<'_>, method_name: &str, call_expr: &Expr<'_>, var_span: Span, expr_span: Span) {
     match method_name {
         "deref" => {
-            if cx.tcx.lang_items().deref_trait().map_or(false, |id| {
+            let impls_deref_trait = cx.tcx.lang_items().deref_trait().map_or(false, |id| {
                 implements_trait(cx, cx.tables().expr_ty(&call_expr), id, &[])
-            }) {
+            });
+            if impls_deref_trait {
                 span_lint_and_sugg(
                     cx,
                     EXPLICIT_DEREF_METHODS,
@@ -88,9 +89,10 @@ fn lint_deref(cx: &LateContext<'_>, method_name: &str, call_expr: &Expr<'_>, var
             }
         },
         "deref_mut" => {
-            if cx.tcx.lang_items().deref_mut_trait().map_or(false, |id| {
+            let impls_deref_mut_trait = cx.tcx.lang_items().deref_mut_trait().map_or(false, |id| {
                 implements_trait(cx, cx.tables().expr_ty(&call_expr), id, &[])
-            }) {
+            });
+            if impls_deref_mut_trait {
                 span_lint_and_sugg(
                     cx,
                     EXPLICIT_DEREF_METHODS,

src/tools/clippy/clippy_lints/src/eq_op.rs

@@ -214,20 +214,20 @@ impl<'tcx> LateLintPass<'tcx> for EqOp {
 }
 
 fn is_valid_operator(op: BinOp) -> bool {
-    match op.node {
+    matches!(
+        op.node,
         BinOpKind::Sub
-        | BinOpKind::Div
-        | BinOpKind::Eq
-        | BinOpKind::Lt
-        | BinOpKind::Le
-        | BinOpKind::Gt
-        | BinOpKind::Ge
-        | BinOpKind::Ne
-        | BinOpKind::And
-        | BinOpKind::Or
-        | BinOpKind::BitXor
-        | BinOpKind::BitAnd
-        | BinOpKind::BitOr => true,
-        _ => false,
-    }
+            | BinOpKind::Div
+            | BinOpKind::Eq
+            | BinOpKind::Lt
+            | BinOpKind::Le
+            | BinOpKind::Gt
+            | BinOpKind::Ge
+            | BinOpKind::Ne
+            | BinOpKind::And
+            | BinOpKind::Or
+            | BinOpKind::BitXor
+            | BinOpKind::BitAnd
+            | BinOpKind::BitOr
+    )
 }

src/tools/clippy/clippy_lints/src/escape.rs

@@ -105,10 +105,7 @@ fn is_argument(map: rustc_middle::hir::map::Map<'_>, id: HirId) -> bool {
         _ => return false,
     }
 
-    match map.find(map.get_parent_node(id)) {
-        Some(Node::Param(_)) => true,
-        _ => false,
-    }
+    matches!(map.find(map.get_parent_node(id)), Some(Node::Param(_)))
 }
 
 impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {