Auto merge of #74792 - flip1995:clippyup, r=Manishearth

Update Clippy

Biweekly Clippy Sync

r? @Manishearth

Author: bors

src/tools/clippy/.github/deploy.sh

@@ -19,7 +19,7 @@ fi
 
 if [[ $BETA = "true" ]]; then
   echo "Update documentation for the beta release"
-  cp -r out/master out/beta
+  cp -r out/master/* out/beta
 fi
 
 # Generate version index that is shown as root index page
@@ -33,12 +33,13 @@ cd out
 git config user.name "GHA CI"
 git config user.email "[email protected]"
 
-if git diff --exit-code --quiet; then
-  echo "No changes to the output on this push; exiting."
-  exit 0
-fi
-
 if [[ -n $TAG_NAME ]]; then
+  # track files, so that the following check works
+  git add --intent-to-add "$TAG_NAME"
+  if git diff --exit-code --quiet -- $TAG_NAME/; then
+    echo "No changes to the output on this push; exiting."
+    exit 0
+  fi
   # Add the new dir
   git add "$TAG_NAME"
   # Update the symlink
@@ -47,9 +48,17 @@ if [[ -n $TAG_NAME ]]; then
   git add versions.json
   git commit -m "Add documentation for ${TAG_NAME} release: ${SHA}"
 elif [[ $BETA = "true" ]]; then
+  if git diff --exit-code --quiet -- beta/; then
+    echo "No changes to the output on this push; exiting."
+    exit 0
+  fi
   git add beta
   git commit -m "Automatic deploy to GitHub Pages (beta): ${SHA}"
 else
+  if git diff --exit-code --quiet; then
+    echo "No changes to the output on this push; exiting."
+    exit 0
+  fi
   git add .
   git commit -m "Automatic deploy to GitHub Pages: ${SHA}"
 fi

src/tools/clippy/CHANGELOG.md

@@ -1,16 +1,78 @@
-# Change Log
+# Changelog
 
 All notable changes to this project will be documented in this file.
 See [Changelog Update](doc/changelog_update.md) if you want to update this
 document.
 
 ## Unreleased / In Rust Nightly
 
-[7ea7cd1...master](https://github.com/rust-lang/rust-clippy/compare/7ea7cd1...master)
+[c2c07fa...master](https://github.com/rust-lang/rust-clippy/compare/7ea7cd1...master)
+
+## Rust 1.46
+
+Current beta, release 2020-08-27
+
+[7ea7cd1...c2c07fa](https://github.com/rust-lang/rust-clippy/compare/7ea7cd1...master)
+
+### New lints
+
+* [`unnested_or_patterns`] [#5378](https://github.com/rust-lang/rust-clippy/pull/5378)
+* [`iter_next_slice`] [#5597](https://github.com/rust-lang/rust-clippy/pull/5597)
+* [`unnecessary_sort_by`] [#5623](https://github.com/rust-lang/rust-clippy/pull/5623)
+* [`vec_resize_to_zero`] [#5637](https://github.com/rust-lang/rust-clippy/pull/5637)
+
+### Moves and Deprecations
+
+* Move [`cast_ptr_alignment`] to pedantic [#5667](https://github.com/rust-lang/rust-clippy/pull/5667)
+
+### Enhancements
+
+* Improve [`mem_replace_with_uninit`] lint [#5695](https://github.com/rust-lang/rust-clippy/pull/5695)
+
+### False Positive Fixes
+
+* [`len_zero`]: Avoid linting ranges when the `range_is_empty` feature is not enabled
+  [#5656](https://github.com/rust-lang/rust-clippy/pull/5656)
+* [`let_and_return`]: Don't lint if a temporary borrow is involved
+  [#5680](https://github.com/rust-lang/rust-clippy/pull/5680)
+* [`reversed_empty_ranges`]: Avoid linting `N..N` in for loop arguments in
+  [#5692](https://github.com/rust-lang/rust-clippy/pull/5692)
+* [`if_same_then_else`]: Don't assume multiplication is always commutative
+  [#5702](https://github.com/rust-lang/rust-clippy/pull/5702)
+* [`blacklisted_name`]: Remove `bar` from the default configuration
+  [#5712](https://github.com/rust-lang/rust-clippy/pull/5712)
+* [`redundant_pattern_matching`]: Avoid suggesting non-`const fn` calls in const contexts
+  [#5724](https://github.com/rust-lang/rust-clippy/pull/5724)
+
+### Suggestion Fixes/Improvements
+
+* Fix suggestion of [`unit_arg`] lint, so that it suggest semantic equivalent code
+  [#4455](https://github.com/rust-lang/rust-clippy/pull/4455)
+* Add auto applicable suggestion to [`macro_use_imports`]
+  [#5279](https://github.com/rust-lang/rust-clippy/pull/5279)
+
+### ICE Fixes
+
+* Fix ICE in the `consts` module of Clippy [#5709](https://github.com/rust-lang/rust-clippy/pull/5709)
+
+### Documentation Improvements
+
+* Improve code examples across multiple lints [#5664](https://github.com/rust-lang/rust-clippy/pull/5664)
+
+### Others
+
+* Introduce a `--rustc` flag to `clippy-driver`, which turns `clippy-driver`
+  into `rustc` and passes all the given arguments to `rustc`. This is especially
+  useful for tools that need the `rustc` version Clippy was compiled with,
+  instead of the Clippy version. E.g. `clippy-driver --rustc --version` will
+  print the output of `rustc --version`.
+  [#5178](https://github.com/rust-lang/rust-clippy/pull/5178)
+* New issue templates now make it easier to complain if Clippy is too annoying
+  or not annoying enough! [#5735](https://github.com/rust-lang/rust-clippy/pull/5735)
 
 ## Rust 1.45
 
-Current beta, release 2020-07-16
+Current stable, released 2020-07-16
 
 [891e1a8...7ea7cd1](https://github.com/rust-lang/rust-clippy/compare/891e1a8...7ea7cd1)
 
@@ -87,7 +149,7 @@ and [`similar_names`]. [#5651](https://github.com/rust-lang/rust-clippy/pull/565
 
 ## Rust 1.44
 
-Current stable, released 2020-06-04
+Released 2020-06-04
 
 [204bb9b...891e1a8](https://github.com/rust-lang/rust-clippy/compare/204bb9b...891e1a8)
 
@@ -1679,6 +1741,7 @@ Released 2018-09-13
 [`uninit_assumed_init`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_assumed_init
 [`unit_arg`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_arg
 [`unit_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_cmp
+[`unit_return_expecting_ord`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_return_expecting_ord
 [`unknown_clippy_lints`]: https://rust-lang.github.io/rust-clippy/master/index.html#unknown_clippy_lints
 [`unnecessary_cast`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
 [`unnecessary_filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_filter_map

src/tools/clippy/README.md

@@ -42,10 +42,8 @@ Table of contents:
 
 ## Usage
 
-Since this is a tool for helping the developer of a library or application
-write better code, it is recommended not to include Clippy as a hard dependency.
-Options include using it as an optional dependency, as a cargo subcommand, or
-as an included feature during build. These options are detailed below.
+Below are instructions on how to use Clippy as a subcommand, compiled from source
+or in Travis CI.
 
 ### As a cargo subcommand (`cargo clippy`)
 

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

@@ -153,7 +153,7 @@ declare_deprecated_lint! {
     ///
     /// **Deprecation reason:** Associated-constants are now preferred.
     pub REPLACE_CONSTS,
-    "associated-constants `MIN`/`MAX` of integers are prefered to `{min,max}_value()` and module constants"
+    "associated-constants `MIN`/`MAX` of integers are preferred to `{min,max}_value()` and module constants"
 }
 
 declare_deprecated_lint! {

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

@@ -10,7 +10,7 @@ use rustc_span::source_map::Span;
 declare_clippy_lint! {
     /// **What it does:** Checks for explicit `deref()` or `deref_mut()` method calls.
     ///
-    /// **Why is this bad?** Derefencing by `&*x` or `&mut *x` is clearer and more concise,
+    /// **Why is this bad?** Dereferencing by `&*x` or `&mut *x` is clearer and more concise,
     /// when not part of a method chain.
     ///
     /// **Example:**

src/tools/clippy/clippy_lints/src/inherent_impl.rs

@@ -55,7 +55,7 @@ impl<'tcx> LateLintPass<'tcx> for MultipleInherentImpl {
             ..
         } = item.kind
         {
-            // Remember for each inherent implementation encoutered its span and generics
+            // Remember for each inherent implementation encountered its span and generics
             // but filter out implementations that have generic params (type or lifetime)
             // or are derived from a macro
             if !in_macro(item.span) && generics.params.is_empty() {

src/tools/clippy/clippy_lints/src/lib.rs

@@ -276,6 +276,7 @@ mod ptr_offset_with_cast;
 mod question_mark;
 mod ranges;
 mod redundant_clone;
+mod redundant_closure_call;
 mod redundant_field_names;
 mod redundant_pub_crate;
 mod redundant_static_lifetimes;
@@ -300,6 +301,7 @@ mod trivially_copy_pass_by_ref;
 mod try_err;
 mod types;
 mod unicode;
+mod unit_return_expecting_ord;
 mod unnamed_address;
 mod unnecessary_sort_by;
 mod unnested_or_patterns;
@@ -462,7 +464,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     );
     store.register_removed(
         "clippy::replace_consts",
-        "associated-constants `MIN`/`MAX` of integers are prefered to `{min,max}_value()` and module constants",
+        "associated-constants `MIN`/`MAX` of integers are preferred to `{min,max}_value()` and module constants",
     );
     store.register_removed(
         "clippy::regex_macro",
@@ -701,7 +703,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &misc_early::DOUBLE_NEG,
         &misc_early::DUPLICATE_UNDERSCORE_ARGUMENT,
         &misc_early::MIXED_CASE_HEX_LITERALS,
-        &misc_early::REDUNDANT_CLOSURE_CALL,
         &misc_early::REDUNDANT_PATTERN,
         &misc_early::UNNEEDED_FIELD_PATTERN,
         &misc_early::UNNEEDED_WILDCARD_PATTERN,
@@ -758,6 +759,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &ranges::RANGE_ZIP_WITH_LEN,
         &ranges::REVERSED_EMPTY_RANGES,
         &redundant_clone::REDUNDANT_CLONE,
+        &redundant_closure_call::REDUNDANT_CLOSURE_CALL,
         &redundant_field_names::REDUNDANT_FIELD_NAMES,
         &redundant_pub_crate::REDUNDANT_PUB_CRATE,
         &redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES,
@@ -826,6 +828,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &unicode::NON_ASCII_LITERAL,
         &unicode::UNICODE_NOT_NFC,
         &unicode::ZERO_WIDTH_SPACE,
+        &unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD,
         &unnamed_address::FN_ADDRESS_COMPARISONS,
         &unnamed_address::VTABLE_ADDRESS_COMPARISONS,
         &unnecessary_sort_by::UNNECESSARY_SORT_BY,
@@ -891,6 +894,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|| box attrs::Attributes);
     store.register_late_pass(|| box blocks_in_if_conditions::BlocksInIfConditions);
     store.register_late_pass(|| box unicode::Unicode);
+    store.register_late_pass(|| box unit_return_expecting_ord::UnitReturnExpectingOrd);
     store.register_late_pass(|| box strings::StringAdd);
     store.register_late_pass(|| box implicit_return::ImplicitReturn);
     store.register_late_pass(|| box implicit_saturating_sub::ImplicitSaturatingSub);
@@ -1015,6 +1019,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_early_pass(|| box int_plus_one::IntPlusOne);
     store.register_early_pass(|| box formatting::Formatting);
     store.register_early_pass(|| box misc_early::MiscEarlyLints);
+    store.register_early_pass(|| box redundant_closure_call::RedundantClosureCall);
+    store.register_late_pass(|| box redundant_closure_call::RedundantClosureCall);
     store.register_early_pass(|| box returns::Return);
     store.register_late_pass(|| box let_and_return::LetReturn);
     store.register_early_pass(|| box collapsible_if::CollapsibleIf);
@@ -1356,7 +1362,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&misc_early::DOUBLE_NEG),
         LintId::of(&misc_early::DUPLICATE_UNDERSCORE_ARGUMENT),
         LintId::of(&misc_early::MIXED_CASE_HEX_LITERALS),
-        LintId::of(&misc_early::REDUNDANT_CLOSURE_CALL),
         LintId::of(&misc_early::REDUNDANT_PATTERN),
         LintId::of(&misc_early::UNNEEDED_WILDCARD_PATTERN),
         LintId::of(&misc_early::ZERO_PREFIXED_LITERAL),
@@ -1390,6 +1395,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&ranges::RANGE_ZIP_WITH_LEN),
         LintId::of(&ranges::REVERSED_EMPTY_RANGES),
         LintId::of(&redundant_clone::REDUNDANT_CLONE),
+        LintId::of(&redundant_closure_call::REDUNDANT_CLOSURE_CALL),
         LintId::of(&redundant_field_names::REDUNDANT_FIELD_NAMES),
         LintId::of(&redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES),
         LintId::of(&reference::DEREF_ADDROF),
@@ -1436,6 +1442,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&types::UNNECESSARY_CAST),
         LintId::of(&types::VEC_BOX),
         LintId::of(&unicode::ZERO_WIDTH_SPACE),
+        LintId::of(&unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD),
         LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
         LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
         LintId::of(&unnecessary_sort_by::UNNECESSARY_SORT_BY),
@@ -1589,7 +1596,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::UNNECESSARY_FILTER_MAP),
         LintId::of(&methods::USELESS_ASREF),
         LintId::of(&misc::SHORT_CIRCUIT_STATEMENT),
-        LintId::of(&misc_early::REDUNDANT_CLOSURE_CALL),
         LintId::of(&misc_early::UNNEEDED_WILDCARD_PATTERN),
         LintId::of(&misc_early::ZERO_PREFIXED_LITERAL),
         LintId::of(&needless_bool::BOOL_COMPARISON),
@@ -1604,6 +1610,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&precedence::PRECEDENCE),
         LintId::of(&ptr_offset_with_cast::PTR_OFFSET_WITH_CAST),
         LintId::of(&ranges::RANGE_ZIP_WITH_LEN),
+        LintId::of(&redundant_closure_call::REDUNDANT_CLOSURE_CALL),
         LintId::of(&reference::DEREF_ADDROF),
         LintId::of(&reference::REF_IN_DEREF),
         LintId::of(&repeat_once::REPEAT_ONCE),
@@ -1692,6 +1699,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&types::CAST_REF_TO_MUT),
         LintId::of(&types::UNIT_CMP),
         LintId::of(&unicode::ZERO_WIDTH_SPACE),
+        LintId::of(&unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD),
         LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
         LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
         LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT),

src/tools/clippy/clippy_lints/src/matches.rs

@@ -1512,6 +1512,10 @@ mod redundant_pattern_match {
             }
         }
 
+        let result_expr = match &op.kind {
+            ExprKind::AddrOf(_, _, borrowed) => borrowed,
+            _ => op,
+        };
         span_lint_and_then(
             cx,
             REDUNDANT_PATTERN_MATCHING,
@@ -1524,7 +1528,7 @@ mod redundant_pattern_match {
 
                 // while let ... = ... { ... }
                 //                 ^^^
-                let op_span = op.span.source_callsite();
+                let op_span = result_expr.span.source_callsite();
 
                 // while let ... = ... { ... }
                 // ^^^^^^^^^^^^^^^^^^^
@@ -1589,17 +1593,21 @@ mod redundant_pattern_match {
             };
 
             if let Some(good_method) = found_good_method {
+                let span = expr.span.to(op.span);
+                let result_expr = match &op.kind {
+                    ExprKind::AddrOf(_, _, borrowed) => borrowed,
+                    _ => op,
+                };
                 span_lint_and_then(
                     cx,
                     REDUNDANT_PATTERN_MATCHING,
                     expr.span,
                     &format!("redundant pattern matching, consider using `{}`", good_method),
                     |diag| {
-                        let span = expr.span.to(op.span);
                         diag.span_suggestion(
                             span,
                             "try this",
-                            format!("{}.{}", snippet(cx, op.span, "_"), good_method),
+                            format!("{}.{}", snippet(cx, result_expr.span, "_"), good_method),
                             Applicability::MaybeIncorrect, // snippet
                         );
                     },

src/tools/clippy/clippy_lints/src/methods/mod.rs

@@ -2354,8 +2354,8 @@ fn lint_iter_nth_zero<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, nth_ar
                 cx,
                 ITER_NTH_ZERO,
                 expr.span,
-                "called `.nth(0)` on a `std::iter::Iterator`",
-                "try calling",
+                "called `.nth(0)` on a `std::iter::Iterator`, when `.next()` is equivalent",
+                "try calling `.next()` instead of `.nth(0)`",
                 format!("{}.next()", snippet_with_applicability(cx, nth_args[0].span, "..", &mut applicability)),
                 applicability,
             );
@@ -3290,7 +3290,12 @@ fn lint_option_as_ref_deref<'tcx>(
                         if let hir::ExprKind::Path(qpath) = &args[0].kind;
                         if let hir::def::Res::Local(local_id) = cx.qpath_res(qpath, args[0].hir_id);
                         if closure_body.params[0].pat.hir_id == local_id;
-                        let adj = cx.typeck_results().expr_adjustments(&args[0]).iter().map(|x| &x.kind).collect::<Box<[_]>>();
+                        let adj = cx
+                            .typeck_results()
+                            .expr_adjustments(&args[0])
+                            .iter()
+                            .map(|x| &x.kind)
+                            .collect::<Box<[_]>>();
                         if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj;
                         then {
                             let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap();

src/tools/clippy/clippy_lints/src/misc.rs

@@ -99,7 +99,9 @@ declare_clippy_lint! {
     /// if y != x {} // where both are floats
     ///
     /// // Good
-    /// let error = 0.01f64; // Use an epsilon for comparison
+    /// let error = f64::EPSILON; // Use an epsilon for comparison
+    /// // Or, if Rust <= 1.42, use `std::f64::EPSILON` constant instead.
+    /// // let error = std::f64::EPSILON;
     /// if (y - 1.23f64).abs() < error { }
     /// if (y - x).abs() > error { }
     /// ```
@@ -237,10 +239,12 @@ declare_clippy_lint! {
     /// const ONE: f64 = 1.00;
     ///
     /// // Bad
-    /// if x == ONE { }  // where both are floats
+    /// if x == ONE { } // where both are floats
     ///
     /// // Good
-    /// let error = 0.1f64; // Use an epsilon for comparison
+    /// let error = f64::EPSILON; // Use an epsilon for comparison
+    /// // Or, if Rust <= 1.42, use `std::f64::EPSILON` constant instead.
+    /// // let error = std::f64::EPSILON;
     /// if (x - ONE).abs() < error { }
     /// ```
     pub FLOAT_CMP_CONST,