Merge branch 'master' into return-and-then

Author: aaron-ang

.github/driver.sh

@@ -47,9 +47,9 @@ unset CARGO_MANIFEST_DIR
 
 # Run a lint and make sure it produces the expected output. It's also expected to exit with code 1
 # FIXME: How to match the clippy invocation in compile-test.rs?
-./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/double_neg.rs 2>double_neg.stderr && exit 1
-sed -e "/= help: for/d" double_neg.stderr > normalized.stderr
-diff -u normalized.stderr tests/ui/double_neg.stderr
+./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/string_to_string.rs 2>string_to_string.stderr && exit 1
+sed -e "/= help: for/d" string_to_string.stderr > normalized.stderr
+diff -u normalized.stderr tests/ui/string_to_string.stderr
 
 # make sure "clippy-driver --rustc --arg" and "rustc --arg" behave the same
 SYSROOT=$(rustc --print sysroot)

.github/workflows/clippy_changelog.yml

@@ -26,11 +26,13 @@ jobs:
       run: |
         body=$(curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -s "https://api.github.com/repos/rust-lang/rust-clippy/pulls/$PR_NUMBER" | \
           python -c "import sys, json; print(json.load(sys.stdin)['body'])")
-        output=$(grep "^changelog:\s*\S" <<< "$body" | sed "s/changelog:\s*//g") || {
-          echo "ERROR: pull request message must contain 'changelog: ...'. Please add it."
+        output=$(awk '/^changelog:\s*\S/ && !/changelog: \[.*\]: your change/' <<< "$body" | sed "s/changelog:\s*//g")
+        if [ -z "$output" ]; then
+          echo "ERROR: pull request message must contain 'changelog: ...' with your changelog. Please add it."
           exit 1
-        }
-        echo "changelog: $output"
+        else
+          echo "changelog: $output"
+        fi
       env:
         PYTHONIOENCODING: 'utf-8'
         PR_NUMBER: '${{ github.event.number }}'

.github/workflows/lintcheck.yml

@@ -1,6 +1,12 @@
 name: Lintcheck
 
-on: pull_request
+on:
+  pull_request:
+    paths-ignore:
+      - 'book/**'
+      - 'util/**'
+      - 'tests/**'
+      - '*.md'
 
 env:
   RUST_BACKTRACE: 1

CHANGELOG.md

@@ -5533,6 +5533,7 @@ Released 2018-09-13
 [`doc_link_with_quotes`]: https://rust-lang.github.io/rust-clippy/master/index.html#doc_link_with_quotes
 [`doc_markdown`]: https://rust-lang.github.io/rust-clippy/master/index.html#doc_markdown
 [`doc_nested_refdefs`]: https://rust-lang.github.io/rust-clippy/master/index.html#doc_nested_refdefs
+[`doc_overindented_list_items`]: https://rust-lang.github.io/rust-clippy/master/index.html#doc_overindented_list_items
 [`double_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_comparisons
 [`double_ended_iterator_last`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_ended_iterator_last
 [`double_must_use`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_must_use
@@ -5906,6 +5907,7 @@ Released 2018-09-13
 [`non_minimal_cfg`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_minimal_cfg
 [`non_octal_unix_permissions`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_octal_unix_permissions
 [`non_send_fields_in_send_ty`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_send_fields_in_send_ty
+[`non_std_lazy_statics`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_std_lazy_statics
 [`non_zero_suggestions`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_zero_suggestions
 [`nonminimal_bool`]: https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
 [`nonsensical_open_options`]: https://rust-lang.github.io/rust-clippy/master/index.html#nonsensical_open_options
@@ -6066,6 +6068,7 @@ Released 2018-09-13
 [`size_of_in_element_count`]: https://rust-lang.github.io/rust-clippy/master/index.html#size_of_in_element_count
 [`size_of_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#size_of_ref
 [`skip_while_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#skip_while_next
+[`sliced_string_as_bytes`]: https://rust-lang.github.io/rust-clippy/master/index.html#sliced_string_as_bytes
 [`slow_vector_initialization`]: https://rust-lang.github.io/rust-clippy/master/index.html#slow_vector_initialization
 [`stable_sort_primitive`]: https://rust-lang.github.io/rust-clippy/master/index.html#stable_sort_primitive
 [`std_instead_of_alloc`]: https://rust-lang.github.io/rust-clippy/master/index.html#std_instead_of_alloc

README.md

@@ -159,11 +159,11 @@ line. (You can swap `clippy::all` with the specific lint category you are target
 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)]`).
-    Note that `rustc` has additional [lint groups](https://doc.rust-lang.org/rustc/lints/groups.html).
+  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
-    lints prone to false positives.
+  `#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive
+  lints prone to false positives.
 
 * only some lints (`#![deny(clippy::single_match, clippy::box_vec)]`, etc.)
 

book/src/lint_configuration.md

@@ -750,6 +750,7 @@ The minimum rust version that the project supports. Defaults to the `rust-versio
 * [`manual_pattern_char_comparison`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_pattern_char_comparison)
 * [`manual_range_contains`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains)
 * [`manual_rem_euclid`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_rem_euclid)
+* [`manual_repeat_n`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_repeat_n)
 * [`manual_retain`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_retain)
 * [`manual_split_once`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_split_once)
 * [`manual_str_repeat`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_str_repeat)
@@ -762,11 +763,13 @@ The minimum rust version that the project supports. Defaults to the `rust-versio
 * [`mem_replace_with_default`](https://rust-lang.github.io/rust-clippy/master/index.html#mem_replace_with_default)
 * [`missing_const_for_fn`](https://rust-lang.github.io/rust-clippy/master/index.html#missing_const_for_fn)
 * [`needless_borrow`](https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow)
+* [`non_std_lazy_statics`](https://rust-lang.github.io/rust-clippy/master/index.html#non_std_lazy_statics)
 * [`option_as_ref_deref`](https://rust-lang.github.io/rust-clippy/master/index.html#option_as_ref_deref)
 * [`option_map_unwrap_or`](https://rust-lang.github.io/rust-clippy/master/index.html#option_map_unwrap_or)
 * [`ptr_as_ptr`](https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr)
 * [`redundant_field_names`](https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names)
 * [`redundant_static_lifetimes`](https://rust-lang.github.io/rust-clippy/master/index.html#redundant_static_lifetimes)
+* [`same_item_push`](https://rust-lang.github.io/rust-clippy/master/index.html#same_item_push)
 * [`seek_from_current`](https://rust-lang.github.io/rust-clippy/master/index.html#seek_from_current)
 * [`seek_rewind`](https://rust-lang.github.io/rust-clippy/master/index.html#seek_rewind)
 * [`transmute_ptr_to_ref`](https://rust-lang.github.io/rust-clippy/master/index.html#transmute_ptr_to_ref)

book/src/usage.md

@@ -33,7 +33,7 @@ You can configure lint levels on the command line by adding
 `-A/W/D clippy::lint_name` like this:
 
 ```bash
-cargo clippy -- -Aclippy::style -Wclippy::double_neg -Dclippy::perf
+cargo clippy -- -Aclippy::style -Wclippy::box_default -Dclippy::perf
 ```
 
 For [CI] all warnings can be elevated to errors which will in turn fail
@@ -101,11 +101,10 @@ You can configure lint levels in source code the same way you can configure
 ```rust,ignore
 #![allow(clippy::style)]
 
-#[warn(clippy::double_neg)]
+#[warn(clippy::box_default)]
 fn main() {
-    let x = 1;
-    let y = --x;
-    //      ^^ warning: double negation
+    let _ = Box::<String>::new(Default::default());
+    // ^ warning: `Box::new(_)` of default value
 }
 ```
 

clippy_config/src/conf.rs

@@ -619,6 +619,7 @@ define_Conf! {
         manual_pattern_char_comparison,
         manual_range_contains,
         manual_rem_euclid,
+        manual_repeat_n,
         manual_retain,
         manual_split_once,
         manual_str_repeat,
@@ -631,11 +632,13 @@ define_Conf! {
         mem_replace_with_default,
         missing_const_for_fn,
         needless_borrow,
+        non_std_lazy_statics,
         option_as_ref_deref,
         option_map_unwrap_or,
         ptr_as_ptr,
         redundant_field_names,
         redundant_static_lifetimes,
+        same_item_push,
         seek_from_current,
         seek_rewind,
         transmute_ptr_to_ref,

clippy_dev/src/new_lint.rs

@@ -255,8 +255,9 @@ fn get_lint_file_contents(lint: &LintData<'_>, enable_msrv: bool) -> String {
     let name_camel = to_camel_case(lint.name);
     let name_upper = lint_name.to_uppercase();
 
-    result.push_str(&if enable_msrv {
-        formatdoc!(
+    if enable_msrv {
+        let _: fmt::Result = writedoc!(
+            result,
             r"
             use clippy_utils::msrvs::{{self, Msrv}};
             use clippy_config::Conf;
@@ -265,22 +266,24 @@ fn get_lint_file_contents(lint: &LintData<'_>, enable_msrv: bool) -> String {
             use rustc_session::impl_lint_pass;
 
         "
-        )
+        );
     } else {
-        formatdoc!(
+        let _: fmt::Result = writedoc!(
+            result,
             r"
             {pass_import}
             use rustc_lint::{{{context_import}, {pass_type}}};
             use rustc_session::declare_lint_pass;
 
         "
-        )
-    });
+        );
+    }
 
     let _: fmt::Result = writeln!(result, "{}", get_lint_declaration(&name_upper, category));
 
-    result.push_str(&if enable_msrv {
-        formatdoc!(
+    if enable_msrv {
+        let _: fmt::Result = writedoc!(
+            result,
             r"
             pub struct {name_camel} {{
                 msrv: Msrv,
@@ -301,16 +304,17 @@ fn get_lint_file_contents(lint: &LintData<'_>, enable_msrv: bool) -> String {
             // TODO: Add MSRV level to `clippy_config/src/msrvs.rs` if needed.
             // TODO: Update msrv config comment in `clippy_config/src/conf.rs`
         "
-        )
+        );
     } else {
-        formatdoc!(
+        let _: fmt::Result = writedoc!(
+            result,
             r"
             declare_lint_pass!({name_camel} => [{name_upper}]);
 
             impl {pass_type}{pass_lifetimes} for {name_camel} {{}}
         "
-        )
-    });
+        );
+    }
 
     result
 }

clippy_lints/src/box_default.rs

@@ -4,12 +4,12 @@ use clippy_utils::ty::expr_sig;
 use clippy_utils::{is_default_equivalent, path_def_id};
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
-use rustc_hir::intravisit::{Visitor, walk_ty};
-use rustc_hir::{Block, Expr, ExprKind, LetStmt, Node, QPath, Ty, TyKind};
+use rustc_hir::intravisit::{InferKind, Visitor, VisitorExt, walk_ty};
+use rustc_hir::{AmbigArg, Block, Expr, ExprKind, HirId, LetStmt, Node, QPath, Ty, TyKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::declare_lint_pass;
-use rustc_span::sym;
+use rustc_span::{Span, sym};
 
 declare_clippy_lint! {
     /// ### What it does
@@ -92,8 +92,13 @@ fn is_local_vec_expn(cx: &LateContext<'_>, expr: &Expr<'_>, ref_expr: &Expr<'_>)
 struct InferVisitor(bool);
 
 impl Visitor<'_> for InferVisitor {
-    fn visit_ty(&mut self, t: &Ty<'_>) {
-        self.0 |= matches!(t.kind, TyKind::Infer | TyKind::OpaqueDef(..) | TyKind::TraitObject(..));
+    fn visit_infer(&mut self, inf_id: HirId, _inf_span: Span, _kind: InferKind<'_>) -> Self::Result {
+        self.0 = true;
+        self.visit_id(inf_id);
+    }
+
+    fn visit_ty(&mut self, t: &Ty<'_, AmbigArg>) {
+        self.0 |= matches!(t.kind, TyKind::OpaqueDef(..) | TyKind::TraitObject(..));
         if !self.0 {
             walk_ty(self, t);
         }
@@ -104,7 +109,7 @@ fn given_type(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     match cx.tcx.parent_hir_node(expr.hir_id) {
         Node::LetStmt(LetStmt { ty: Some(ty), .. }) => {
             let mut v = InferVisitor::default();
-            v.visit_ty(ty);
+            v.visit_ty_unambig(ty);
             !v.0
         },
         Node::Expr(Expr {