Auto merge of #79228 - flip1995:clippyup, r=oli-obk

Update Clippy

Biweekly Clippy update

r? `@Manishearth`

Author: bors

src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md

@@ -1,8 +1,8 @@
 Thank you for making Clippy better!
 
 We're collecting our changelog from pull request descriptions.
-If your PR only updates to the latest nightly, you can leave the
-`changelog` entry as `none`. Otherwise, please write a short comment
+If your PR only includes internal changes, you can just write
+`changelog: none`. Otherwise, please write a short comment
 explaining your change.
 
 If your PR fixes an issue, you can add "fixes #issue_number" into this
@@ -28,5 +28,5 @@ Delete this line and everything above before opening your PR.
 
 ---
 
-*Please keep the line below*
-changelog: none
+*Please write a short comment explaining your change (or "none" for internal only changes)*
+changelog:

src/tools/clippy/CHANGELOG.md

@@ -6,11 +6,117 @@ document.
 
 ## Unreleased / In Rust Nightly
 
-[e636b88...master](https://github.com/rust-lang/rust-clippy/compare/e636b88...master)
+[b20d4c1...master](https://github.com/rust-lang/rust-clippy/compare/b20d4c1...master)
+
+## Rust 1.49
+
+Current beta, release 2020-12-31
+
+[e636b88...b20d4c1](https://github.com/rust-lang/rust-clippy/compare/e636b88...b20d4c1)
+
+### New Lints
+
+* [`field_reassign_with_default`] [#5911](https://github.com/rust-lang/rust-clippy/pull/5911)
+* [`await_holding_refcell_ref`] [#6029](https://github.com/rust-lang/rust-clippy/pull/6029)
+* [`disallowed_method`] [#6081](https://github.com/rust-lang/rust-clippy/pull/6081)
+* [`inline_asm_x86_att_syntax`] [#6092](https://github.com/rust-lang/rust-clippy/pull/6092)
+* [`inline_asm_x86_intel_syntax`] [#6092](https://github.com/rust-lang/rust-clippy/pull/6092)
+* [`from_iter_instead_of_collect`] [#6101](https://github.com/rust-lang/rust-clippy/pull/6101)
+* [`mut_mutex_lock`] [#6103](https://github.com/rust-lang/rust-clippy/pull/6103)
+* [`single_element_loop`] [#6109](https://github.com/rust-lang/rust-clippy/pull/6109)
+* [`manual_unwrap_or`] [#6123](https://github.com/rust-lang/rust-clippy/pull/6123)
+* [`large_types_passed_by_value`] [#6135](https://github.com/rust-lang/rust-clippy/pull/6135)
+* [`result_unit_err`] [#6157](https://github.com/rust-lang/rust-clippy/pull/6157)
+* [`ref_option_ref`] [#6165](https://github.com/rust-lang/rust-clippy/pull/6165)
+* [`manual_range_contains`] [#6177](https://github.com/rust-lang/rust-clippy/pull/6177)
+* [`unusual_byte_groupings`] [#6183](https://github.com/rust-lang/rust-clippy/pull/6183)
+* [`comparison_to_empty`] [#6226](https://github.com/rust-lang/rust-clippy/pull/6226)
+* [`map_collect_result_unit`] [#6227](https://github.com/rust-lang/rust-clippy/pull/6227)
+* [`manual_ok_or`] [#6233](https://github.com/rust-lang/rust-clippy/pull/6233)
+
+### Moves and Deprecations
+
+* Rename `single_char_push_str` to [`single_char_add_str`]
+  [#6037](https://github.com/rust-lang/rust-clippy/pull/6037)
+* Rename `zero_width_space` to [`invisible_characters`]
+  [#6105](https://github.com/rust-lang/rust-clippy/pull/6105)
+* Deprecate [`drop_bounds`] (uplifted)
+  [#6111](https://github.com/rust-lang/rust-clippy/pull/6111)
+* Move [`string_lit_as_bytes`] to `nursery`
+  [#6117](https://github.com/rust-lang/rust-clippy/pull/6117)
+* Move [`rc_buffer`] to `restriction`
+  [#6128](https://github.com/rust-lang/rust-clippy/pull/6128)
+
+### Enhancements
+
+* [`manual_memcpy`]: Also lint when there are loop counters (and produce a
+  reliable suggestion)
+  [#5727](https://github.com/rust-lang/rust-clippy/pull/5727)
+* [`single_char_add_str`]: Also lint on `String::insert_str`
+  [#6037](https://github.com/rust-lang/rust-clippy/pull/6037)
+* [`invisible_characters`]: Also lint the characters `\u{AD}` and `\u{2060}`
+  [#6105](https://github.com/rust-lang/rust-clippy/pull/6105)
+* [`eq_op`]: Also lint on the `assert_*!` macro family
+  [#6167](https://github.com/rust-lang/rust-clippy/pull/6167)
+* [`items_after_statements`]: Also lint in local macro expansions
+  [#6176](https://github.com/rust-lang/rust-clippy/pull/6176)
+* [`unnecessary_cast`]: Also lint casts on integer and float literals
+  [#6187](https://github.com/rust-lang/rust-clippy/pull/6187)
+* [`manual_unwrap_or`]: Also lint `Result::unwrap_or`
+  [#6190](https://github.com/rust-lang/rust-clippy/pull/6190)
+* [`match_like_matches_macro`]: Also lint when `match` has more than two arms
+  [#6216](https://github.com/rust-lang/rust-clippy/pull/6216)
+* [`integer_arithmetic`]: Better handle `/` an `%` operators
+  [#6229](https://github.com/rust-lang/rust-clippy/pull/6229)
+
+### False Positive Fixes
+
+* [`needless_lifetimes`]: Bail out if the function has a `where` clause with the
+  lifetime [#5978](https://github.com/rust-lang/rust-clippy/pull/5978)
+* [`explicit_counter_loop`]: No longer lints, when loop counter is used after it
+  is incremented [#6076](https://github.com/rust-lang/rust-clippy/pull/6076)
+* [`or_fun_call`]: Revert changes addressing the handling of `const fn`
+  [#6077](https://github.com/rust-lang/rust-clippy/pull/6077)
+* [`needless_range_loop`]: No longer lints, when the iterable is used in the
+  range [#6102](https://github.com/rust-lang/rust-clippy/pull/6102)
+* [`inconsistent_digit_grouping`]: Fix bug when using floating point exponent
+  [#6104](https://github.com/rust-lang/rust-clippy/pull/6104)
+* [`mistyped_literal_suffixes`]: No longer lints on the fractional part of a
+  float (e.g. `713.32_64`)
+  [#6114](https://github.com/rust-lang/rust-clippy/pull/6114)
+* [`invalid_regex`]: No longer lint on unicode characters within `bytes::Regex`
+  [#6132](https://github.com/rust-lang/rust-clippy/pull/6132)
+* [`boxed_local`]: No longer lints on `extern fn` arguments
+  [#6133](https://github.com/rust-lang/rust-clippy/pull/6133)
+* [`needless_lifetimes`]: Fix regression, where lifetime is used in `where`
+  clause [#6198](https://github.com/rust-lang/rust-clippy/pull/6198)
+
+### Suggestion Fixes/Improvements
+
+* [`unnecessary_sort_by`]: Avoid dereferencing the suggested closure parameter
+  [#6078](https://github.com/rust-lang/rust-clippy/pull/6078)
+* [`needless_arbitrary_self_type`]: Correctly handle expanded code
+  [#6093](https://github.com/rust-lang/rust-clippy/pull/6093)
+* [`useless_format`]: Preserve raw strings in suggestion
+  [#6151](https://github.com/rust-lang/rust-clippy/pull/6151)
+* [`empty_loop`]: Suggest alternatives
+  [#6162](https://github.com/rust-lang/rust-clippy/pull/6162)
+* [`borrowed_box`]: Correctly add parentheses in suggestion
+  [#6200](https://github.com/rust-lang/rust-clippy/pull/6200)
+* [`unused_unit`]: Improve suggestion formatting
+  [#6247](https://github.com/rust-lang/rust-clippy/pull/6247)
+
+### Documentation Improvements
+
+* Some doc improvements:
+    * [`rc_buffer`] [#6090](https://github.com/rust-lang/rust-clippy/pull/6090)
+    * [`empty_loop`] [#6162](https://github.com/rust-lang/rust-clippy/pull/6162)
+* [`doc_markdown`]: Document problematic link text style
+  [#6107](https://github.com/rust-lang/rust-clippy/pull/6107)
 
 ## Rust 1.48
 
-Current beta, release 2020-11-19
+Current stable, released 2020-11-19
 
 [09bd400...e636b88](https://github.com/rust-lang/rust-clippy/compare/09bd400...e636b88)
 
@@ -56,15 +162,15 @@ Current beta, release 2020-11-19
 
 * [`useless_attribute`]: permit allowing [`wildcard_imports`] and [`enum_glob_use`]
   [#5994](https://github.com/rust-lang/rust-clippy/pull/5994)
-* [`transmute_ptr_to_ptr`]: avoid suggesting dereferencing raw pointers in const contexts 
+* [`transmute_ptr_to_ptr`]: avoid suggesting dereferencing raw pointers in const contexts
   [#5999](https://github.com/rust-lang/rust-clippy/pull/5999)
 * [`redundant_closure_call`]: take into account usages of the closure in nested functions and closures
   [#5920](https://github.com/rust-lang/rust-clippy/pull/5920)
 * Fix false positive in [`borrow_interior_mutable_const`] when referencing a field behind a pointer
   [#5949](https://github.com/rust-lang/rust-clippy/pull/5949)
 * [`doc_markdown`]: allow using "GraphQL" without backticks
   [#5996](https://github.com/rust-lang/rust-clippy/pull/5996)
-* [`to_string_in_display`]: avoid linting when calling `to_string()` on anything that is not `self` 
+* [`to_string_in_display`]: avoid linting when calling `to_string()` on anything that is not `self`
   [#5971](https://github.com/rust-lang/rust-clippy/pull/5971)
 * [`indexing_slicing`] and [`out_of_bounds_indexing`] treat references to arrays as arrays
   [#6034](https://github.com/rust-lang/rust-clippy/pull/6034)
@@ -85,27 +191,27 @@ Current beta, release 2020-11-19
   [#5946](https://github.com/rust-lang/rust-clippy/pull/5946)
 * [`useless_conversion`]: show the type in the error message
   [#6035](https://github.com/rust-lang/rust-clippy/pull/6035)
-* [`unnecessary_mut_passed`]: discriminate between functions and methods in the error message 
+* [`unnecessary_mut_passed`]: discriminate between functions and methods in the error message
   [#5892](https://github.com/rust-lang/rust-clippy/pull/5892)
 * [`float_cmp`] and [`float_cmp_const`]: change wording to make margin of error less ambiguous
   [#6043](https://github.com/rust-lang/rust-clippy/pull/6043)
 * [`default_trait_access`]: do not use unnecessary type parameters in the suggestion
   [#5993](https://github.com/rust-lang/rust-clippy/pull/5993)
-* [`collapsible_if`]: don't use expanded code in the suggestion 
+* [`collapsible_if`]: don't use expanded code in the suggestion
   [#5992](https://github.com/rust-lang/rust-clippy/pull/5992)
 * Do not suggest empty format strings in [`print_with_newline`] and [`write_with_newline`]
   [#6042](https://github.com/rust-lang/rust-clippy/pull/6042)
 * [`unit_arg`]: improve the readability of the suggestion
   [#5931](https://github.com/rust-lang/rust-clippy/pull/5931)
-* [`stable_sort_primitive`]: print the type that is being sorted in the lint message 
+* [`stable_sort_primitive`]: print the type that is being sorted in the lint message
   [#5935](https://github.com/rust-lang/rust-clippy/pull/5935)
 * Show line count and max lines in [`too_many_lines`] lint message
   [#6009](https://github.com/rust-lang/rust-clippy/pull/6009)
 * Keep parentheses in the suggestion of [`useless_conversion`] where applicable
   [#5900](https://github.com/rust-lang/rust-clippy/pull/5900)
 * [`option_map_unit_fn`] and [`result_map_unit_fn`]: print the unit type `()` explicitly
   [#6024](https://github.com/rust-lang/rust-clippy/pull/6024)
-* [`redundant_allocation`]: suggest replacing `Rc<Box<T>>` with `Rc<T>` 
+* [`redundant_allocation`]: suggest replacing `Rc<Box<T>>` with `Rc<T>`
   [#5899](https://github.com/rust-lang/rust-clippy/pull/5899)
 * Make lint messages adhere to rustc dev guide conventions
   [#5893](https://github.com/rust-lang/rust-clippy/pull/5893)
@@ -128,7 +234,7 @@ Current beta, release 2020-11-19
 
 ## Rust 1.47
 
-Current stable, released 2020-10-08
+Released 2020-10-08
 
 [c2c07fa...09bd400](https://github.com/rust-lang/rust-clippy/compare/c2c07fa...09bd400)
 
@@ -1787,6 +1893,7 @@ Released 2018-09-13
 [`len_without_is_empty`]: https://rust-lang.github.io/rust-clippy/master/index.html#len_without_is_empty
 [`len_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
 [`let_and_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return
+[`let_underscore_drop`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_underscore_drop
 [`let_underscore_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_underscore_lock
 [`let_underscore_must_use`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_underscore_must_use
 [`let_unit_value`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_unit_value
@@ -1956,6 +2063,7 @@ Released 2018-09-13
 [`string_add`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_add
 [`string_add_assign`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_add_assign
 [`string_extend_chars`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_extend_chars
+[`string_from_utf8_as_bytes`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_from_utf8_as_bytes
 [`string_lit_as_bytes`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_lit_as_bytes
 [`string_to_string`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_to_string
 [`struct_excessive_bools`]: https://rust-lang.github.io/rust-clippy/master/index.html#struct_excessive_bools
@@ -2006,6 +2114,7 @@ Released 2018-09-13
 [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation
 [`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by
 [`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
 [`unneeded_wildcard_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_wildcard_pattern
 [`unnested_or_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnested_or_patterns

src/tools/clippy/README.md

@@ -7,28 +7,22 @@ A collection of lints to catch common mistakes and improve your [Rust](https://g
 
 [There are over 400 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
 
-We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:
-
-* `clippy::all` (everything that is on by default: all the categories below except for `nursery`, `pedantic`, and `cargo`)
-* `clippy::correctness` (code that is just **outright wrong** or **very very useless**, causes hard errors by default)
-* `clippy::style` (code that should be written in a more idiomatic way)
-* `clippy::complexity` (code that does something simple but in a complex way)
-* `clippy::perf` (code that can be written in a faster way)
-* `clippy::pedantic` (lints which are rather strict, off by default)
-* `clippy::nursery` (new lints that aren't quite ready yet, off by default)
-* `clippy::cargo` (checks against the cargo manifest, off by default)
+Lints are divided into categories, each with a default [lint level](https://doc.rust-lang.org/rustc/lints/levels.html).
+You can choose how much Clippy is supposed to ~~annoy~~ help you by changing the lint level by category.
+
+Category | Description | Default level
+-- | -- | --
+`clippy::all` | all lints that are on by default (correctness, style, complexity, perf) | **warn/deny**
+`clippy::correctness` | code that is outright wrong or very useless | **deny**
+`clippy::style` | code that should be written in a more idiomatic way | **warn**
+`clippy::complexity` | code that does something simple but in a complex way | **warn**
+`clippy::perf` | code that can be written to run faster | **warn**
+`clippy::pedantic` | lints which are rather strict or might have false positives | allow
+`clippy::nursery` | new lints that are still under development | allow
+`clippy::cargo` | lints for the cargo manifest | allow
 
 More to come, please [file an issue](https://github.com/rust-lang/rust-clippy/issues) if you have ideas!
 
-Only the following of those categories are enabled by default:
-
-* `clippy::style`
-* `clippy::correctness`
-* `clippy::complexity`
-* `clippy::perf`
-
-Other categories need to be enabled in order for their lints to be executed.
-
 The [lint list](https://rust-lang.github.io/rust-clippy/master/index.html) also contains "restriction lints", which are
 for things which are usually not considered "bad", but may be useful to turn on in specific cases. These should be used
 very selectively, if at all.

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

@@ -129,7 +129,7 @@ fn match_assert_with_message<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>)
         if let ExprKind::Block(ref block, _) = arms[0].body.kind;
         if block.stmts.is_empty();
         if let Some(block_expr) = &block.expr;
-        // inner block is optional. unwarp it if it exists, or use the expression as is otherwise.
+        // 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(ref inner_block, _) => &inner_block.expr,
             _ => &block.expr,

src/tools/clippy/clippy_lints/src/await_holding_invalid.rs

@@ -45,7 +45,7 @@ declare_clippy_lint! {
     /// }
     /// ```
     pub AWAIT_HOLDING_LOCK,
-    correctness,
+    pedantic,
     "Inside an async function, holding a MutexGuard while calling await"
 }
 
@@ -65,8 +65,8 @@ declare_clippy_lint! {
     /// use std::cell::RefCell;
     ///
     /// async fn foo(x: &RefCell<u32>) {
-    ///   let b = x.borrow_mut()();
-    ///   *ref += 1;
+    ///   let mut y = x.borrow_mut();
+    ///   *y += 1;
     ///   bar.await;
     /// }
     /// ```
@@ -77,14 +77,14 @@ declare_clippy_lint! {
     ///
     /// async fn foo(x: &RefCell<u32>) {
     ///   {
-    ///     let b = x.borrow_mut();
-    ///     *ref += 1;
+    ///      let mut y = x.borrow_mut();
+    ///      *y += 1;
     ///   }
     ///   bar.await;
     /// }
     /// ```
     pub AWAIT_HOLDING_REFCELL_REF,
-    correctness,
+    pedantic,
     "Inside an async function, holding a RefCell ref while calling await"
 }
 

src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs

@@ -23,6 +23,21 @@ declare_clippy_lint! {
     /// [package]
     /// name = "clippy"
     /// version = "0.0.212"
+    /// description = "A bunch of helpful lints to avoid common pitfalls in Rust"
+    /// repository = "https://github.com/rust-lang/rust-clippy"
+    /// readme = "README.md"
+    /// license = "MIT OR Apache-2.0"
+    /// keywords = ["clippy", "lint", "plugin"]
+    /// categories = ["development-tools", "development-tools::cargo-plugins"]
+    /// ```
+    ///
+    /// Should include an authors field like:
+    ///
+    /// ```toml
+    /// # This `Cargo.toml` includes all common metadata
+    /// [package]
+    /// name = "clippy"
+    /// version = "0.0.212"
     /// authors = ["Someone <[email protected]>"]
     /// description = "A bunch of helpful lints to avoid common pitfalls in Rust"
     /// repository = "https://github.com/rust-lang/rust-clippy"

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

@@ -181,3 +181,8 @@ declare_deprecated_lint! {
     pub TEMPORARY_CSTRING_AS_PTR,
     "this lint has been uplifted to rustc and is now called `temporary_cstring_as_ptr`"
 }
+
+declare_deprecated_lint! {
+    pub PANIC_PARAMS,
+    "this lint has been uplifted to rustc and is now called `panic_fmt`"
+}

src/tools/clippy/clippy_lints/src/len_zero.rs

@@ -69,7 +69,7 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for comparing to an empty slice such as "" or [],`
+    /// **What it does:** Checks for comparing to an empty slice such as `""` or `[]`,
     /// and suggests using `.is_empty()` where applicable.
     ///
     /// **Why is this bad?** Some structures can answer `.is_empty()` much faster