Merge commit 'c2c07fa9d095931eb5684a42942a7b573a0c5238' into clippyup

48 files changed, 1077 insertions, 293 deletions

diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE.md b/src/tools/clippy/.github/ISSUE_TEMPLATE.md
deleted file mode 100644
index 15006a07b44..00000000000
--- a/src/tools/clippy/.github/ISSUE_TEMPLATE.md
+++ /dev/null
@@ -1,8 +0,0 @@
-<!--
-Hi there! Whether you've come to make a suggestion for a new lint, an improvement to an existing lint or to report a bug or a false positive in Clippy, you've come to the right place.
-
-For bug reports and false positives, please include the output of `cargo clippy -V` in the report.
-
-Thank you for using Clippy!
-
-Write your comment below this line: -->
diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE/blank_issue.md b/src/tools/clippy/.github/ISSUE_TEMPLATE/blank_issue.md
new file mode 100644
index 00000000000..9aef3ebe637
--- /dev/null
+++ b/src/tools/clippy/.github/ISSUE_TEMPLATE/blank_issue.md
@@ -0,0 +1,4 @@
+---
+name: Blank Issue
+about: Create a blank issue.
+---
diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE/bug_report.md b/src/tools/clippy/.github/ISSUE_TEMPLATE/bug_report.md
new file mode 100644
index 00000000000..d8f0c44148c
--- /dev/null
+++ b/src/tools/clippy/.github/ISSUE_TEMPLATE/bug_report.md
@@ -0,0 +1,47 @@
+---
+name: Bug Report
+about: Create a bug report for Clippy
+labels: L-bug
+---
+<!--
+Thank you for filing a bug report! 🐛 Please provide a short summary of the bug,
+along with any information you feel relevant to replicating the bug.
+-->
+
+I tried this code:
+
+```rust
+<code>
+```
+
+I expected to see this happen: *explanation*
+
+Instead, this happened: *explanation*
+
+### Meta
+
+- `cargo clippy -V`: e.g. clippy 0.0.212 (f455e46 2020-06-20)
+- `rustc -Vv`:
+  ```
+  rustc 1.46.0-nightly (f455e46ea 2020-06-20)
+  binary: rustc
+  commit-hash: f455e46eae1a227d735091091144601b467e1565
+  commit-date: 2020-06-20
+  host: x86_64-unknown-linux-gnu
+  release: 1.46.0-nightly
+  LLVM version: 10.0
+  ```
+
+<!--
+Include a backtrace in the code block by setting `RUST_BACKTRACE=1` in your
+environment. E.g. `RUST_BACKTRACE=1 cargo clippy`.
+-->
+<details><summary>Backtrace</summary>
+  <p>
+  
+  ```
+  <backtrace>
+  ```
+  
+  </p>
+</details>
diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE/config.yml b/src/tools/clippy/.github/ISSUE_TEMPLATE/config.yml
new file mode 100644
index 00000000000..bd7dc0ac95c
--- /dev/null
+++ b/src/tools/clippy/.github/ISSUE_TEMPLATE/config.yml
@@ -0,0 +1,5 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Rust Programming Language Forum
+    url: https://users.rust-lang.org
+    about: Please ask and answer questions about Rust here.
diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE/ice.md b/src/tools/clippy/.github/ISSUE_TEMPLATE/ice.md
new file mode 100644
index 00000000000..3abe76bf2c4
--- /dev/null
+++ b/src/tools/clippy/.github/ISSUE_TEMPLATE/ice.md
@@ -0,0 +1,53 @@
+---
+name: Internal Compiler Error
+about: Create a report for an internal compiler error in Clippy.
+labels: L-bug, L-crash
+---
+<!--
+Thank you for finding an Internal Compiler Error! 🧊  If possible, try to provide
+a minimal verifiable example. You can read "Rust Bug Minimization Patterns" for
+how to create smaller examples.
+
+http://blog.pnkfx.org/blog/2019/11/18/rust-bug-minimization-patterns/
+
+-->
+
+### Code
+
+```rust
+<code>
+```
+
+### Meta
+
+- `cargo clippy -V`: e.g. clippy 0.0.212 (f455e46 2020-06-20)
+- `rustc -Vv`:
+  ```
+  rustc 1.46.0-nightly (f455e46ea 2020-06-20)
+  binary: rustc
+  commit-hash: f455e46eae1a227d735091091144601b467e1565
+  commit-date: 2020-06-20
+  host: x86_64-unknown-linux-gnu
+  release: 1.46.0-nightly
+  LLVM version: 10.0
+  ```
+
+### Error output
+
+```
+<output>
+```
+
+<!--
+Include a backtrace in the code block by setting `RUST_BACKTRACE=1` in your
+environment. E.g. `RUST_BACKTRACE=1 cargo clippy`.
+-->
+<details><summary>Backtrace</summary>
+  <p>
+  
+  ```
+  <backtrace>
+  ```
+  
+  </p>
+</details>
diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE/new_lint.md b/src/tools/clippy/.github/ISSUE_TEMPLATE/new_lint.md
new file mode 100644
index 00000000000..70445d7ef25
--- /dev/null
+++ b/src/tools/clippy/.github/ISSUE_TEMPLATE/new_lint.md
@@ -0,0 +1,35 @@
+---
+name: New lint suggestion
+about: Suggest a new Clippy lint.
+labels: L-lint
+---
+
+### What it does
+
+*What does this lint do?*
+
+### Categories (optional)
+
+- 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?*
+
+For example:
+- Remove bounce checking inserted by ...
+- Remove the need to duplicating/storing/typo ...
+
+### Drawbacks
+
+None.
+
+### Example
+
+```rust
+<code>
+```
+
+Could be written as:
+
+```rust
+<code>
+```
diff --git a/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md b/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md
index 97aa220afea..137a7363094 100644
--- a/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md
+++ b/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md
@@ -28,4 +28,5 @@ Delete this line and everything above before opening your PR.
 
 ---
 
+*Please keep the line below*
 changelog: none
diff --git a/src/tools/clippy/.github/driver.sh b/src/tools/clippy/.github/driver.sh
index a2e87f5eb37..2c17c4203ae 100644
--- a/src/tools/clippy/.github/driver.sh
+++ b/src/tools/clippy/.github/driver.sh
@@ -26,4 +26,16 @@ unset CARGO_MANIFEST_DIR
 sed -e "s,tests/ui,\$DIR," -e "/= help/d" cstring.stderr > normalized.stderr
 diff normalized.stderr tests/ui/cstring.stderr
 
+
+# make sure "clippy-driver --rustc --arg" and "rustc --arg" behave the same
+SYSROOT=`rustc --print sysroot`
+diff <(LD_LIBRARY_PATH=${SYSROOT}/lib ./target/debug/clippy-driver --rustc --version --verbose) <(rustc --version --verbose)
+
+
+echo "fn main() {}" > target/driver_test.rs
+# we can't run 2 rustcs on the same file at the same time
+CLIPPY=`LD_LIBRARY_PATH=${SYSROOT}/lib ./target/debug/clippy-driver ./target/driver_test.rs --rustc`
+RUSTC=`rustc ./target/driver_test.rs`
+diff <($CLIPPY) <($RUSTC)
+
 # TODO: CLIPPY_CONF_DIR / CARGO_MANIFEST_DIR
diff --git a/src/tools/clippy/clippy_lints/src/consts.rs b/src/tools/clippy/clippy_lints/src/consts.rs
index 22c5acca064..550752396c7 100644
--- a/src/tools/clippy/clippy_lints/src/consts.rs
+++ b/src/tools/clippy/clippy_lints/src/consts.rs
@@ -396,7 +396,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
         let l = self.expr(left)?;
         let r = self.expr(right);
         match (l, r) {
-            (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty(left).kind {
+            (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty_opt(left)?.kind {
                 ty::Int(ity) => {
                     let l = sext(self.lcx.tcx, l, ity);
                     let r = sext(self.lcx.tcx, r, ity);
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
index 59af475af17..77e90eeac49 100644
--- a/src/tools/clippy/clippy_lints/src/escape.rs
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -6,7 +6,7 @@ use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 use rustc_target::abi::LayoutOf;
-use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceWithHirId, PlaceBase};
+use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 
 use crate::utils::span_lint;
 
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index 13e85fda8ff..7838e8e8ab7 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -211,7 +211,8 @@ fn check_impl_items(cx: &LateContext<'_, '_>, item: &Item<'_>, impl_items: &[Imp
 }
 
 fn check_cmp(cx: &LateContext<'_, '_>, span: Span, method: &Expr<'_>, lit: &Expr<'_>, op: &str, compare_to: u32) {
-    if let (&ExprKind::MethodCall(ref method_path, _, ref args, _), &ExprKind::Lit(ref lit)) = (&method.kind, &lit.kind) {
+    if let (&ExprKind::MethodCall(ref method_path, _, ref args, _), &ExprKind::Lit(ref lit)) = (&method.kind, &lit.kind)
+    {
         // check if we are in an is_empty() method
         if let Some(name) = get_item_name(cx, method) {
             if name.as_str() == "is_empty" {
diff --git a/src/tools/clippy/clippy_lints/src/let_underscore.rs b/src/tools/clippy/clippy_lints/src/let_underscore.rs
index 710dec8d33f..acd628bbaca 100644
--- a/src/tools/clippy/clippy_lints/src/let_underscore.rs
+++ b/src/tools/clippy/clippy_lints/src/let_underscore.rs
@@ -35,7 +35,7 @@ declare_clippy_lint! {
     /// **What it does:** Checks for `let _ = sync_lock`
     ///
     /// **Why is this bad?** This statement immediately drops the lock instead of
-    /// extending it's lifetime to the end of the scope, which is often not intended.
+    /// extending its lifetime to the end of the scope, which is often not intended.
     /// To extend lock lifetime to the end of the scope, use an underscore-prefixed
     /// name instead (i.e. _lock). If you want to explicitly drop the lock,
     /// `std::mem::drop` conveys your intention better and is less error-prone.
diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs
index cd258c7b506..501220f28e5 100644
--- a/src/tools/clippy/clippy_lints/src/lib.rs
+++ b/src/tools/clippy/clippy_lints/src/lib.rs
@@ -1,63 +1,44 @@
 // error-pattern:cargo-clippy
 
 #![feature(bindings_after_at)]
-#![feature(box_syntax)]
 #![feature(box_patterns)]
+#![feature(box_syntax)]
+#![feature(concat_idents)]
+#![feature(crate_visibility_modifier)]
+#![feature(drain_filter)]
 #![feature(or_patterns)]
 #![feature(rustc_private)]
 #![feature(stmt_expr_attributes)]
-#![allow(clippy::missing_docs_in_private_items, clippy::must_use_candidate)]
 #![recursion_limit = "512"]
-#![warn(rust_2018_idioms, trivial_casts, trivial_numeric_casts)]
-#![deny(rustc::internal)]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
-#![feature(crate_visibility_modifier)]
-#![feature(concat_idents)]
-#![feature(drain_filter)]
+#![allow(clippy::missing_docs_in_private_items, clippy::must_use_candidate)]
+#![warn(trivial_casts, trivial_numeric_casts)]
+// warn on lints, that are included in `rust-lang/rust`s bootstrap
+#![warn(rust_2018_idioms, unused_lifetimes)]
+// warn on rustc internal lints
+#![deny(rustc::internal)]
 
 // FIXME: switch to something more ergonomic here, once available.
 // (Currently there is no way to opt into sysroot crates without `extern crate`.)
-#[allow(unused_extern_crates)]
 extern crate rustc_ast;
-#[allow(unused_extern_crates)]
 extern crate rustc_ast_pretty;
-#[allow(unused_extern_crates)]
 extern crate rustc_attr;
-#[allow(unused_extern_crates)]
 extern crate rustc_data_structures;
-#[allow(unused_extern_crates)]
-extern crate rustc_driver;
-#[allow(unused_extern_crates)]
 extern crate rustc_errors;
-#[allow(unused_extern_crates)]
 extern crate rustc_hir;
-#[allow(unused_extern_crates)]
 extern crate rustc_hir_pretty;
-#[allow(unused_extern_crates)]
 extern crate rustc_index;
-#[allow(unused_extern_crates)]
 extern crate rustc_infer;
-#[allow(unused_extern_crates)]
 extern crate rustc_lexer;
-#[allow(unused_extern_crates)]
 extern crate rustc_lint;
-#[allow(unused_extern_crates)]
 extern crate rustc_middle;
-#[allow(unused_extern_crates)]
 extern crate rustc_mir;
-#[allow(unused_extern_crates)]
 extern crate rustc_parse;
-#[allow(unused_extern_crates)]
 extern crate rustc_parse_format;
-#[allow(unused_extern_crates)]
 extern crate rustc_session;
-#[allow(unused_extern_crates)]
 extern crate rustc_span;
-#[allow(unused_extern_crates)]
 extern crate rustc_target;
-#[allow(unused_extern_crates)]
 extern crate rustc_trait_selection;
-#[allow(unused_extern_crates)]
 extern crate rustc_typeck;
 
 use rustc_data_structures::fx::FxHashSet;
@@ -82,14 +63,10 @@ use rustc_session::Session;
 /// # Example
 ///
 /// ```
-/// # #![feature(rustc_private)]
-/// # #[allow(unused_extern_crates)]
-/// # extern crate rustc_middle;
-/// # #[allow(unused_extern_crates)]
-/// # extern crate rustc_session;
-/// # #[macro_use]
-/// # use clippy_lints::declare_clippy_lint;
+/// #![feature(rustc_private)]
+/// extern crate rustc_session;
 /// use rustc_session::declare_tool_lint;
+/// use clippy_lints::declare_clippy_lint;
 ///
 /// declare_clippy_lint! {
 ///     /// **What it does:** Checks for ... (describe what the lint matches).
@@ -1062,7 +1039,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_early_pass(|| box option_env_unwrap::OptionEnvUnwrap);
     let warn_on_all_wildcard_imports = conf.warn_on_all_wildcard_imports;
     store.register_late_pass(move || box wildcard_imports::WildcardImports::new(warn_on_all_wildcard_imports));
-    store.register_early_pass(|| box macro_use::MacroUseImports);
     store.register_late_pass(|| box verbose_file_reads::VerboseFileReads);
     store.register_late_pass(|| box redundant_pub_crate::RedundantPubCrate::default());
     store.register_late_pass(|| box unnamed_address::UnnamedAddress);
@@ -1080,6 +1056,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         single_char_binding_names_threshold,
     });
     store.register_early_pass(|| box unnested_or_patterns::UnnestedOrPatterns);
+    store.register_late_pass(|| box macro_use::MacroUseImports::default());
 
     store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
         LintId::of(&arithmetic::FLOAT_ARITHMETIC),
@@ -1187,6 +1164,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&types::OPTION_OPTION),
         LintId::of(&unicode::NON_ASCII_LITERAL),
         LintId::of(&unicode::UNICODE_NOT_NFC),
+        LintId::of(&unnested_or_patterns::UNNESTED_OR_PATTERNS),
         LintId::of(&unused_self::UNUSED_SELF),
         LintId::of(&wildcard_imports::ENUM_GLOB_USE),
         LintId::of(&wildcard_imports::WILDCARD_IMPORTS),
@@ -1440,7 +1418,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
         LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
         LintId::of(&unnecessary_sort_by::UNNECESSARY_SORT_BY),
-        LintId::of(&unnested_or_patterns::UNNESTED_OR_PATTERNS),
         LintId::of(&unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
         LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT),
         LintId::of(&unwrap::PANICKING_UNWRAP),
@@ -1624,7 +1601,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&types::UNNECESSARY_CAST),
         LintId::of(&types::VEC_BOX),
         LintId::of(&unnecessary_sort_by::UNNECESSARY_SORT_BY),
-        LintId::of(&unnested_or_patterns::UNNESTED_OR_PATTERNS),
         LintId::of(&unwrap::UNNECESSARY_UNWRAP),
         LintId::of(&useless_conversion::USELESS_CONVERSION),
         LintId::of(&zero_div_zero::ZERO_DIVIDED_BY_ZERO),
diff --git a/src/tools/clippy/clippy_lints/src/loops.rs b/src/tools/clippy/clippy_lints/src/loops.rs
index 83093ec51bd..9c8e8d8fabf 100644
--- a/src/tools/clippy/clippy_lints/src/loops.rs
+++ b/src/tools/clippy/clippy_lints/src/loops.rs
@@ -28,7 +28,7 @@ use rustc_middle::ty::{self, Ty, TyS};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 use rustc_span::symbol::Symbol;
-use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceWithHirId, PlaceBase};
+use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 use std::iter::{once, Iterator};
 use std::mem;
 
@@ -1497,7 +1497,7 @@ struct MutatePairDelegate<'a, 'tcx> {
     span_high: Option<Span>,
 }
 
-impl<'a, 'tcx> Delegate<'tcx> for MutatePairDelegate<'a, 'tcx> {
+impl<'tcx> Delegate<'tcx> for MutatePairDelegate<'_, 'tcx> {
     fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: ConsumeMode) {}
 
     fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, bk: ty::BorrowKind) {
@@ -1525,7 +1525,7 @@ impl<'a, 'tcx> Delegate<'tcx> for MutatePairDelegate<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> MutatePairDelegate<'a, 'tcx> {
+impl MutatePairDelegate<'_, '_> {
     fn mutation_span(&self) -> (Option<Span>, Option<Span>) {
         (self.span_low, self.span_high)
     }
@@ -1580,13 +1580,13 @@ fn check_for_mutability(cx: &LateContext<'_, '_>, bound: &Expr<'_>) -> Option<Hi
     None
 }
 
-fn check_for_mutation<'a, 'tcx> (
+fn check_for_mutation<'a, 'tcx>(
     cx: &LateContext<'a, 'tcx>,
     body: &Expr<'_>,
     bound_ids: &[Option<HirId>],
 ) -> (Option<Span>, Option<Span>) {
     let mut delegate = MutatePairDelegate {
-        cx: cx,
+        cx,
         hir_id_low: bound_ids[0],
         hir_id_high: bound_ids[1],
         span_low: None,
@@ -2042,7 +2042,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InitializeVisitor<'a, 'tcx> {
         if self.state == VarState::DontWarn {
             return;
         }
-        if SpanlessEq::new(self.cx).eq_expr(&expr, self.end_expr) {
+        if expr.hir_id == self.end_expr.hir_id {
             self.past_loop = true;
             return;
         }
@@ -2292,7 +2292,7 @@ struct HasBreakOrReturnVisitor {
     has_break_or_return: bool,
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for HasBreakOrReturnVisitor {
+impl<'tcx> Visitor<'tcx> for HasBreakOrReturnVisitor {
     type Map = Map<'tcx>;
 
     fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
diff --git a/src/tools/clippy/clippy_lints/src/macro_use.rs b/src/tools/clippy/clippy_lints/src/macro_use.rs
index b1345d0b751..b845b20d2c0 100644
--- a/src/tools/clippy/clippy_lints/src/macro_use.rs
+++ b/src/tools/clippy/clippy_lints/src/macro_use.rs
@@ -1,10 +1,13 @@
-use crate::utils::{snippet, span_lint_and_sugg};
+use crate::utils::{in_macro, snippet, span_lint_and_sugg};
+use hir::def::{DefKind, Res};
 use if_chain::if_chain;
 use rustc_ast::ast;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::Applicability;
-use rustc_lint::{EarlyContext, EarlyLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::edition::Edition;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{edition::Edition, Span};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for `#[macro_use] use...`.
@@ -12,7 +15,7 @@ declare_clippy_lint! {
     /// **Why is this bad?** Since the Rust 2018 edition you can import
     /// macro's directly, this is considered idiomatic.
     ///
-    /// **Known problems:** This lint does not generate an auto-applicable suggestion.
+    /// **Known problems:** None.
     ///
     /// **Example:**
     /// ```rust
@@ -24,29 +27,205 @@ declare_clippy_lint! {
     "#[macro_use] is no longer needed"
 }
 
-declare_lint_pass!(MacroUseImports => [MACRO_USE_IMPORTS]);
+const BRACKETS: &[char] = &['<', '>'];
 
-impl EarlyLintPass for MacroUseImports {
-    fn check_item(&mut self, ecx: &EarlyContext<'_>, item: &ast::Item) {
+#[derive(Clone, Debug, PartialEq, Eq)]
+struct PathAndSpan {
+    path: String,
+    span: Span,
+}
+
+/// `MacroRefData` includes the name of the macro
+/// and the path from `SourceMap::span_to_filename`.
+#[derive(Debug, Clone)]
+pub struct MacroRefData {
+    name: String,
+    path: String,
+}
+
+impl MacroRefData {
+    pub fn new(name: String, callee: Span, cx: &LateContext<'_, '_>) -> Self {
+        let mut path = cx.sess().source_map().span_to_filename(callee).to_string();
+
+        // std lib paths are <::std::module::file type>
+        // so remove brackets, space and type.
+        if path.contains('<') {
+            path = path.replace(BRACKETS, "");
+        }
+        if path.contains(' ') {
+            path = path.split(' ').next().unwrap().to_string();
+        }
+        Self { name, path }
+    }
+}
+
+#[derive(Default)]
+#[allow(clippy::module_name_repetitions)]
+pub struct MacroUseImports {
+    /// the actual import path used and the span of the attribute above it.
+    imports: Vec<(String, Span)>,
+    /// the span of the macro reference, kept to ensure only one reference is used per macro call.
+    collected: FxHashSet<Span>,
+    mac_refs: Vec<MacroRefData>,
+}
+
+impl_lint_pass!(MacroUseImports => [MACRO_USE_IMPORTS]);
+
+impl MacroUseImports {
+    fn push_unique_macro(&mut self, cx: &LateContext<'_, '_>, span: Span) {
+        let call_site = span.source_callsite();
+        let name = snippet(cx, cx.sess().source_map().span_until_char(call_site, '!'), "_");
+        if let Some(callee) = span.source_callee() {
+            if !self.collected.contains(&call_site) {
+                let name = if name.contains("::") {
+                    name.split("::").last().unwrap().to_string()
+                } else {
+                    name.to_string()
+                };
+
+                self.mac_refs.push(MacroRefData::new(name, callee.def_site, cx));
+                self.collected.insert(call_site);
+            }
+        }
+    }
+
+    fn push_unique_macro_pat_ty(&mut self, cx: &LateContext<'_, '_>, span: Span) {
+        let call_site = span.source_callsite();
+        let name = snippet(cx, cx.sess().source_map().span_until_char(call_site, '!'), "_");
+        if let Some(callee) = span.source_callee() {
+            if !self.collected.contains(&call_site) {
+                self.mac_refs
+                    .push(MacroRefData::new(name.to_string(), callee.def_site, cx));
+                self.collected.insert(call_site);
+            }
+        }
+    }
+}
+
+impl<'l, 'txc> LateLintPass<'l, 'txc> for MacroUseImports {
+    fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::Item<'_>) {
         if_chain! {
-            if ecx.sess.opts.edition == Edition::Edition2018;
-            if let ast::ItemKind::Use(use_tree) = &item.kind;
+            if cx.sess().opts.edition == Edition::Edition2018;
+            if let hir::ItemKind::Use(path, _kind) = &item.kind;
             if let Some(mac_attr) = item
                 .attrs
                 .iter()
                 .find(|attr| attr.ident().map(|s| s.to_string()) == Some("macro_use".to_string()));
+            if let Res::Def(DefKind::Mod, id) = path.res;
             then {
-                let msg = "`macro_use` attributes are no longer needed in the Rust 2018 edition";
-                let help = format!("use {}::<macro name>", snippet(ecx, use_tree.span, "_"));
+                for kid in cx.tcx.item_children(id).iter() {
+                    if let Res::Def(DefKind::Macro(_mac_type), mac_id) = kid.res {
+                        let span = mac_attr.span;
+                        let def_path = cx.tcx.def_path_str(mac_id);
+                        self.imports.push((def_path, span));
+                    }
+                }
+            } else {
+                if in_macro(item.span) {
+                    self.push_unique_macro_pat_ty(cx, item.span);
+                }
+            }
+        }
+    }
+    fn check_attribute(&mut self, cx: &LateContext<'_, '_>, attr: &ast::Attribute) {
+        if in_macro(attr.span) {
+            self.push_unique_macro(cx, attr.span);
+        }
+    }
+    fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>) {
+        if in_macro(expr.span) {
+            self.push_unique_macro(cx, expr.span);
+        }
+    }
+    fn check_stmt(&mut self, cx: &LateContext<'_, '_>, stmt: &hir::Stmt<'_>) {
+        if in_macro(stmt.span) {
+            self.push_unique_macro(cx, stmt.span);
+        }
+    }
+    fn check_pat(&mut self, cx: &LateContext<'_, '_>, pat: &hir::Pat<'_>) {
+        if in_macro(pat.span) {
+            self.push_unique_macro_pat_ty(cx, pat.span);
+        }
+    }
+    fn check_ty(&mut self, cx: &LateContext<'_, '_>, ty: &hir::Ty<'_>) {
+        if in_macro(ty.span) {
+            self.push_unique_macro_pat_ty(cx, ty.span);
+        }
+    }
+    #[allow(clippy::too_many_lines)]
+    fn check_crate_post(&mut self, cx: &LateContext<'_, '_>, _krate: &hir::Crate<'_>) {
+        let mut used = FxHashMap::default();
+        let mut check_dup = vec![];
+        for (import, span) in &self.imports {
+            let found_idx = self.mac_refs.iter().position(|mac| import.ends_with(&mac.name));
+
+            if let Some(idx) = found_idx {
+                let _ = self.mac_refs.remove(idx);
+                let seg = import.split("::").collect::<Vec<_>>();
+
+                match seg.as_slice() {
+                    // an empty path is impossible
+                    // a path should always consist of 2 or more segments
+                    [] | [_] => return,
+                    [root, item] => {
+                        if !check_dup.contains(&(*item).to_string()) {
+                            used.entry(((*root).to_string(), span))
+                                .or_insert_with(Vec::new)
+                                .push((*item).to_string());
+                            check_dup.push((*item).to_string());
+                        }
+                    },
+                    [root, rest @ ..] => {
+                        if rest.iter().all(|item| !check_dup.contains(&(*item).to_string())) {
+                            let filtered = rest
+                                .iter()
+                                .filter_map(|item| {
+                                    if check_dup.contains(&(*item).to_string()) {
+                                        None
+                                    } else {
+                                        Some((*item).to_string())
+                                    }
+                                })
+                                .collect::<Vec<_>>();
+                            used.entry(((*root).to_string(), span))
+                                .or_insert_with(Vec::new)
+                                .push(filtered.join("::"));
+                            check_dup.extend(filtered);
+                        } else {
+                            let rest = rest.to_vec();
+                            used.entry(((*root).to_string(), span))
+                                .or_insert_with(Vec::new)
+                                .push(rest.join("::"));
+                            check_dup.extend(rest.iter().map(ToString::to_string));
+                        }
+                    },
+                }
+            }
+        }
+
+        let mut suggestions = vec![];
+        for ((root, span), path) in used {
+            if path.len() == 1 {
+                suggestions.push((span, format!("{}::{}", root, path[0])))
+            } else {
+                suggestions.push((span, format!("{}::{{{}}}", root, path.join(", "))))
+            }
+        }
+
+        // If mac_refs is not empty we have encountered an import we could not handle
+        // such as `std::prelude::v1::foo` or some other macro that expands to an import.
+        if self.mac_refs.is_empty() {
+            for (span, import) in suggestions {
+                let help = format!("use {};", import);
                 span_lint_and_sugg(
-                    ecx,
+                    cx,
                     MACRO_USE_IMPORTS,
-                    mac_attr.span,
-                    msg,
+                    *span,
+                    "`macro_use` attributes are no longer needed in the Rust 2018 edition",
                     "remove the attribute and import the macro directly, try",
                     help,
-                    Applicability::HasPlaceholders,
-                );
+                    Applicability::MaybeIncorrect,
+                )
             }
         }
     }
diff --git a/src/tools/clippy/clippy_lints/src/mem_replace.rs b/src/tools/clippy/clippy_lints/src/mem_replace.rs
index ab6865bf0f3..e2672e02b36 100644
--- a/src/tools/clippy/clippy_lints/src/mem_replace.rs
+++ b/src/tools/clippy/clippy_lints/src/mem_replace.rs
@@ -135,33 +135,59 @@ fn check_replace_option_with_none(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest
     }
 }
 
-fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, expr_span: Span) {
-    if let ExprKind::Call(ref repl_func, ref repl_args) = src.kind {
-        if_chain! {
-            if repl_args.is_empty();
-            if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
-            if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
-            then {
-                if cx.tcx.is_diagnostic_item(sym::mem_uninitialized, repl_def_id) {
-                    span_lint_and_help(
-                        cx,
-                        MEM_REPLACE_WITH_UNINIT,
-                        expr_span,
-                        "replacing with `mem::uninitialized()`",
-                        None,
-                        "consider using the `take_mut` crate instead",
-                    );
-                } else if cx.tcx.is_diagnostic_item(sym::mem_zeroed, repl_def_id) &&
-                        !cx.tables.expr_ty(src).is_primitive() {
-                    span_lint_and_help(
-                        cx,
-                        MEM_REPLACE_WITH_UNINIT,
-                        expr_span,
-                        "replacing with `mem::zeroed()`",
-                        None,
-                        "consider using a default value or the `take_mut` crate instead",
-                    );
-                }
+fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
+    if_chain! {
+        // check if replacement is mem::MaybeUninit::uninit().assume_init()
+        if let Some(method_def_id) = cx.tables.type_dependent_def_id(src.hir_id);
+        if cx.tcx.is_diagnostic_item(sym::assume_init, method_def_id);
+        then {
+            let mut applicability = Applicability::MachineApplicable;
+            span_lint_and_sugg(
+                cx,
+                MEM_REPLACE_WITH_UNINIT,
+                expr_span,
+                "replacing with `mem::MaybeUninit::uninit().assume_init()`",
+                "consider using",
+                format!(
+                    "std::ptr::read({})",
+                    snippet_with_applicability(cx, dest.span, "", &mut applicability)
+                ),
+                applicability,
+            );
+            return;
+        }
+    }
+
+    if_chain! {
+        if let ExprKind::Call(ref repl_func, ref repl_args) = src.kind;
+        if repl_args.is_empty();
+        if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
+        if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
+        then {
+            if cx.tcx.is_diagnostic_item(sym::mem_uninitialized, repl_def_id) {
+                let mut applicability = Applicability::MachineApplicable;
+                span_lint_and_sugg(
+                    cx,
+                    MEM_REPLACE_WITH_UNINIT,
+                    expr_span,
+                    "replacing with `mem::uninitialized()`",
+                    "consider using",
+                    format!(
+                        "std::ptr::read({})",
+                        snippet_with_applicability(cx, dest.span, "", &mut applicability)
+                    ),
+                    applicability,
+                );
+            } else if cx.tcx.is_diagnostic_item(sym::mem_zeroed, repl_def_id) &&
+                    !cx.tables.expr_ty(src).is_primitive() {
+                span_lint_and_help(
+                    cx,
+                    MEM_REPLACE_WITH_UNINIT,
+                    expr_span,
+                    "replacing with `mem::zeroed()`",
+                    None,
+                    "consider using a default value or the `take_mut` crate instead",
+                );
             }
         }
     }
@@ -209,7 +235,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MemReplace {
             if let [dest, src] = &**func_args;
             then {
                 check_replace_option_with_none(cx, src, dest, expr.span);
-                check_replace_with_uninit(cx, src, expr.span);
+                check_replace_with_uninit(cx, src, dest, expr.span);
                 check_replace_with_default(cx, src, dest, expr.span);
             }
         }
diff --git a/src/tools/clippy/clippy_lints/src/new_without_default.rs b/src/tools/clippy/clippy_lints/src/new_without_default.rs
index dd236535c18..42200385932 100644
--- a/src/tools/clippy/clippy_lints/src/new_without_default.rs
+++ b/src/tools/clippy/clippy_lints/src/new_without_default.rs
@@ -33,7 +33,7 @@ declare_clippy_lint! {
     /// }
     /// ```
     ///
-    /// To fix the lint, and a `Default` implementation that delegates to `new`:
+    /// To fix the lint, add a `Default` implementation that delegates to `new`:
     ///
     /// ```ignore
     /// struct Foo(Bar);
diff --git a/src/tools/clippy/clippy_lints/src/redundant_pattern_matching.rs b/src/tools/clippy/clippy_lints/src/redundant_pattern_matching.rs
index f16b916441a..3c528a295b0 100644
--- a/src/tools/clippy/clippy_lints/src/redundant_pattern_matching.rs
+++ b/src/tools/clippy/clippy_lints/src/redundant_pattern_matching.rs
@@ -1,10 +1,13 @@
-use crate::utils::{match_qpath, match_trait_method, paths, snippet, span_lint_and_then};
+use crate::utils::{in_constant, match_qpath, match_trait_method, paths, snippet, span_lint_and_then};
 use if_chain::if_chain;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
-use rustc_hir::{Arm, Expr, ExprKind, MatchSource, PatKind, QPath};
+use rustc_hir::{Arm, Expr, ExprKind, HirId, MatchSource, PatKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_mir::const_eval::is_const_fn;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Symbol;
 
 declare_clippy_lint! {
     /// **What it does:** Lint for redundant pattern matching over `Result` or
@@ -64,26 +67,37 @@ fn find_sugg_for_if_let<'a, 'tcx>(
     arms: &[Arm<'_>],
     keyword: &'static str,
 ) {
+    fn find_suggestion(cx: &LateContext<'_, '_>, hir_id: HirId, path: &QPath<'_>) -> Option<&'static str> {
+        if match_qpath(path, &paths::RESULT_OK) && can_suggest(cx, hir_id, sym!(result_type), "is_ok") {
+            return Some("is_ok()");
+        }
+        if match_qpath(path, &paths::RESULT_ERR) && can_suggest(cx, hir_id, sym!(result_type), "is_err") {
+            return Some("is_err()");
+        }
+        if match_qpath(path, &paths::OPTION_SOME) && can_suggest(cx, hir_id, sym!(option_type), "is_some") {
+            return Some("is_some()");
+        }
+        if match_qpath(path, &paths::OPTION_NONE) && can_suggest(cx, hir_id, sym!(option_type), "is_none") {
+            return Some("is_none()");
+        }
+        None
+    }
+
+    let hir_id = expr.hir_id;
     let good_method = match arms[0].pat.kind {
         PatKind::TupleStruct(ref path, ref patterns, _) if patterns.len() == 1 => {
             if let PatKind::Wild = patterns[0].kind {
-                if match_qpath(path, &paths::RESULT_OK) {
-                    "is_ok()"
-                } else if match_qpath(path, &paths::RESULT_ERR) {
-                    "is_err()"
-                } else if match_qpath(path, &paths::OPTION_SOME) {
-                    "is_some()"
-                } else {
-                    return;
-                }
+                find_suggestion(cx, hir_id, path)
             } else {
-                return;
+                None
             }
         },
-
-        PatKind::Path(ref path) if match_qpath(path, &paths::OPTION_NONE) => "is_none()",
-
-        _ => return,
+        PatKind::Path(ref path) => find_suggestion(cx, hir_id, path),
+        _ => None,
+    };
+    let good_method = match good_method {
+        Some(method) => method,
+        None => return,
     };
 
     // check that `while_let_on_iterator` lint does not trigger
@@ -128,6 +142,7 @@ fn find_sugg_for_match<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_
     if arms.len() == 2 {
         let node_pair = (&arms[0].pat.kind, &arms[1].pat.kind);
 
+        let hir_id = expr.hir_id;
         let found_good_method = match node_pair {
             (
                 PatKind::TupleStruct(ref path_left, ref patterns_left, _),
@@ -142,6 +157,8 @@ fn find_sugg_for_match<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_
                         &paths::RESULT_ERR,
                         "is_ok()",
                         "is_err()",
+                        || can_suggest(cx, hir_id, sym!(result_type), "is_ok"),
+                        || can_suggest(cx, hir_id, sym!(result_type), "is_err"),
                     )
                 } else {
                     None
@@ -160,6 +177,8 @@ fn find_sugg_for_match<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_
                         &paths::OPTION_NONE,
                         "is_some()",
                         "is_none()",
+                        || can_suggest(cx, hir_id, sym!(option_type), "is_some"),
+                        || can_suggest(cx, hir_id, sym!(option_type), "is_none"),
                     )
                 } else {
                     None
@@ -188,6 +207,7 @@ fn find_sugg_for_match<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_
     }
 }
 
+#[allow(clippy::too_many_arguments)]
 fn find_good_method_for_match<'a>(
     arms: &[Arm<'_>],
     path_left: &QPath<'_>,
@@ -196,6 +216,8 @@ fn find_good_method_for_match<'a>(
     expected_right: &[&str],
     should_be_left: &'a str,
     should_be_right: &'a str,
+    can_suggest_left: impl Fn() -> bool,
+    can_suggest_right: impl Fn() -> bool,
 ) -> Option<&'a str> {
     let body_node_pair = if match_qpath(path_left, expected_left) && match_qpath(path_right, expected_right) {
         (&(*arms[0].body).kind, &(*arms[1].body).kind)
@@ -207,10 +229,32 @@ fn find_good_method_for_match<'a>(
 
     match body_node_pair {
         (ExprKind::Lit(ref lit_left), ExprKind::Lit(ref lit_right)) => match (&lit_left.node, &lit_right.node) {
-            (LitKind::Bool(true), LitKind::Bool(false)) => Some(should_be_left),
-            (LitKind::Bool(false), LitKind::Bool(true)) => Some(should_be_right),
+            (LitKind::Bool(true), LitKind::Bool(false)) if can_suggest_left() => Some(should_be_left),
+            (LitKind::Bool(false), LitKind::Bool(true)) if can_suggest_right() => Some(should_be_right),
             _ => None,
         },
         _ => None,
     }
 }
+
+fn can_suggest(cx: &LateContext<'_, '_>, hir_id: HirId, diag_item: Symbol, name: &str) -> bool {
+    if !in_constant(cx, hir_id) {
+        return true;
+    }
+
+    // Avoid suggesting calls to non-`const fn`s in const contexts, see #5697.
+    cx.tcx
+        .get_diagnostic_item(diag_item)
+        .and_then(|def_id| {
+            cx.tcx.inherent_impls(def_id).iter().find_map(|imp| {
+                cx.tcx
+                    .associated_items(*imp)
+                    .in_definition_order()
+                    .find_map(|item| match item.kind {
+                        ty::AssocKind::Fn if item.ident.name.as_str() == name => Some(item.def_id),
+                        _ => None,
+                    })
+            })
+        })
+        .map_or(false, |def_id| is_const_fn(cx.tcx, def_id))
+}
diff --git a/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs b/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs
index a9e6fa329c0..cf71c3144a2 100644
--- a/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs
@@ -184,7 +184,7 @@ struct BinaryExprVisitor {
     in_binary_expr: bool,
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for BinaryExprVisitor {
+impl<'tcx> Visitor<'tcx> for BinaryExprVisitor {
     type Map = Map<'tcx>;
 
     fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
diff --git a/src/tools/clippy/clippy_lints/src/trivially_copy_pass_by_ref.rs b/src/tools/clippy/clippy_lints/src/trivially_copy_pass_by_ref.rs
index 8e0cb94317a..146ac4b09d5 100644
--- a/src/tools/clippy/clippy_lints/src/trivially_copy_pass_by_ref.rs
+++ b/src/tools/clippy/clippy_lints/src/trivially_copy_pass_by_ref.rs
@@ -58,7 +58,7 @@ pub struct TriviallyCopyPassByRef {
     limit: u64,
 }
 
-impl<'a, 'tcx> TriviallyCopyPassByRef {
+impl<'tcx> TriviallyCopyPassByRef {
     pub fn new(limit: Option<u64>, target: &SessionConfig) -> Self {
         let limit = limit.unwrap_or_else(|| {
             let bit_width = u64::from(target.ptr_width);
diff --git a/src/tools/clippy/clippy_lints/src/types.rs b/src/tools/clippy/clippy_lints/src/types.rs
index d59a2f1bae0..98de08f79f3 100644
--- a/src/tools/clippy/clippy_lints/src/types.rs
+++ b/src/tools/clippy/clippy_lints/src/types.rs
@@ -1945,16 +1945,12 @@ fn detect_extreme_expr<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_
 
     let which = match (&ty.kind, cv) {
         (&ty::Bool, Constant::Bool(false)) | (&ty::Uint(_), Constant::Int(0)) => Minimum,
-        (&ty::Int(ity), Constant::Int(i))
-            if i == unsext(cx.tcx, i128::MIN >> (128 - int_bits(cx.tcx, ity)), ity) =>
-        {
+        (&ty::Int(ity), Constant::Int(i)) if i == unsext(cx.tcx, i128::MIN >> (128 - int_bits(cx.tcx, ity)), ity) => {
             Minimum
         },
 
         (&ty::Bool, Constant::Bool(true)) => Maximum,
-        (&ty::Int(ity), Constant::Int(i))
-            if i == unsext(cx.tcx, i128::MAX >> (128 - int_bits(cx.tcx, ity)), ity) =>
-        {
+        (&ty::Int(ity), Constant::Int(i)) if i == unsext(cx.tcx, i128::MAX >> (128 - int_bits(cx.tcx, ity)), ity) => {
             Maximum
         },
         (&ty::Uint(uty), Constant::Int(i)) if clip(cx.tcx, u128::MAX, uty) == i => Maximum,
@@ -2083,50 +2079,20 @@ fn numeric_cast_precast_bounds<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr<'_>)
         }
         match pre_cast_ty.kind {
             ty::Int(int_ty) => Some(match int_ty {
-                IntTy::I8 => (
-                    FullInt::S(i128::from(i8::MIN)),
-                    FullInt::S(i128::from(i8::MAX)),
-                ),
-                IntTy::I16 => (
-                    FullInt::S(i128::from(i16::MIN)),
-                    FullInt::S(i128::from(i16::MAX)),
-                ),
-                IntTy::I32 => (
-                    FullInt::S(i128::from(i32::MIN)),
-                    FullInt::S(i128::from(i32::MAX)),
-                ),
-                IntTy::I64 => (
-                    FullInt::S(i128::from(i64::MIN)),
-                    FullInt::S(i128::from(i64::MAX)),
-                ),
+                IntTy::I8 => (FullInt::S(i128::from(i8::MIN)), FullInt::S(i128::from(i8::MAX))),
+                IntTy::I16 => (FullInt::S(i128::from(i16::MIN)), FullInt::S(i128::from(i16::MAX))),
+                IntTy::I32 => (FullInt::S(i128::from(i32::MIN)), FullInt::S(i128::from(i32::MAX))),
+                IntTy::I64 => (FullInt::S(i128::from(i64::MIN)), FullInt::S(i128::from(i64::MAX))),
                 IntTy::I128 => (FullInt::S(i128::MIN), FullInt::S(i128::MAX)),
-                IntTy::Isize => (
-                    FullInt::S(isize::MIN as i128),
-                    FullInt::S(isize::MAX as i128),
-                ),
+                IntTy::Isize => (FullInt::S(isize::MIN as i128), FullInt::S(isize::MAX as i128)),
             }),
             ty::Uint(uint_ty) => Some(match uint_ty {
-                UintTy::U8 => (
-                    FullInt::U(u128::from(u8::MIN)),
-                    FullInt::U(u128::from(u8::MAX)),
-                ),
-                UintTy::U16 => (
-                    FullInt::U(u128::from(u16::MIN)),
-                    FullInt::U(u128::from(u16::MAX)),
-                ),
-                UintTy::U32 => (
-                    FullInt::U(u128::from(u32::MIN)),
-                    FullInt::U(u128::from(u32::MAX)),
-                ),
-                UintTy::U64 => (
-                    FullInt::U(u128::from(u64::MIN)),
-                    FullInt::U(u128::from(u64::MAX)),
-                ),
+                UintTy::U8 => (FullInt::U(u128::from(u8::MIN)), FullInt::U(u128::from(u8::MAX))),
+                UintTy::U16 => (FullInt::U(u128::from(u16::MIN)), FullInt::U(u128::from(u16::MAX))),
+                UintTy::U32 => (FullInt::U(u128::from(u32::MIN)), FullInt::U(u128::from(u32::MAX))),
+                UintTy::U64 => (FullInt::U(u128::from(u64::MIN)), FullInt::U(u128::from(u64::MAX))),
                 UintTy::U128 => (FullInt::U(u128::MIN), FullInt::U(u128::MAX)),
-                UintTy::Usize => (
-                    FullInt::U(usize::MIN as u128),
-                    FullInt::U(usize::MAX as u128),
-                ),
+                UintTy::Usize => (FullInt::U(usize::MIN as u128), FullInt::U(usize::MAX as u128)),
             }),
             _ => None,
         }
diff --git a/src/tools/clippy/clippy_lints/src/unnecessary_sort_by.rs b/src/tools/clippy/clippy_lints/src/unnecessary_sort_by.rs
index e94eebb88e4..6ac6a12529c 100644
--- a/src/tools/clippy/clippy_lints/src/unnecessary_sort_by.rs
+++ b/src/tools/clippy/clippy_lints/src/unnecessary_sort_by.rs
@@ -95,7 +95,10 @@ fn mirrored_exprs(
         // The two exprs are method calls.
         // Check to see that the function is the same and the arguments are mirrored
         // This is enough because the receiver of the method is listed in the arguments
-        (ExprKind::MethodCall(left_segment, _, left_args, _), ExprKind::MethodCall(right_segment, _, right_args, _)) => {
+        (
+            ExprKind::MethodCall(left_segment, _, left_args, _),
+            ExprKind::MethodCall(right_segment, _, right_args, _),
+        ) => {
             left_segment.ident == right_segment.ident
                 && left_args
                     .iter()
diff --git a/src/tools/clippy/clippy_lints/src/unnested_or_patterns.rs b/src/tools/clippy/clippy_lints/src/unnested_or_patterns.rs
index 8c281126c32..4d3682263f1 100644
--- a/src/tools/clippy/clippy_lints/src/unnested_or_patterns.rs
+++ b/src/tools/clippy/clippy_lints/src/unnested_or_patterns.rs
@@ -45,7 +45,7 @@ declare_clippy_lint! {
     /// }
     /// ```
     pub UNNESTED_OR_PATTERNS,
-    complexity,
+    pedantic,
     "unnested or-patterns, e.g., `Foo(Bar) | Foo(Baz) instead of `Foo(Bar | Baz)`"
 }
 
diff --git a/src/tools/clippy/clippy_lints/src/utils/author.rs b/src/tools/clippy/clippy_lints/src/utils/author.rs
index 8b58bbb5e65..910b665ccb7 100644
--- a/src/tools/clippy/clippy_lints/src/utils/author.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/author.rs
@@ -251,7 +251,10 @@ impl<'tcx> Visitor<'tcx> for PrintVisitor {
                 }
             },
             ExprKind::MethodCall(ref _method_name, ref _generics, ref _args, ref _fn_span) => {
-                println!("MethodCall(ref method_name, ref generics, ref args, ref fn_span) = {};", current);
+                println!(
+                    "MethodCall(ref method_name, ref generics, ref args, ref fn_span) = {};",
+                    current
+                );
                 println!("    // unimplemented: `ExprKind::MethodCall` is not further destructured at the moment");
             },
             ExprKind::Tup(ref elements) => {
diff --git a/src/tools/clippy/clippy_lints/src/utils/conf.rs b/src/tools/clippy/clippy_lints/src/utils/conf.rs
index 9e8e0ff30ec..c41befbf147 100644
--- a/src/tools/clippy/clippy_lints/src/utils/conf.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/conf.rs
@@ -106,8 +106,8 @@ macro_rules! define_Conf {
 
 pub use self::helpers::Conf;
 define_Conf! {
-    /// Lint: BLACKLISTED_NAME. The list of blacklisted names to lint about
-    (blacklisted_names, "blacklisted_names": Vec<String>, ["foo", "bar", "baz", "quux"].iter().map(ToString::to_string).collect()),
+    /// Lint: BLACKLISTED_NAME. The list of blacklisted names to lint about. NB: `bar` is not here since it has legitimate uses
+    (blacklisted_names, "blacklisted_names": Vec<String>, ["foo", "baz", "quux"].iter().map(ToString::to_string).collect()),
     /// Lint: COGNITIVE_COMPLEXITY. The maximum cognitive complexity a function can have
     (cognitive_complexity_threshold, "cognitive_complexity_threshold": u64, 25),
     /// DEPRECATED LINT: CYCLOMATIC_COMPLEXITY. Use the Cognitive Complexity lint instead.
diff --git a/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs b/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs
index 7a84f1c986a..9a9aa3f94eb 100644
--- a/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs
@@ -309,18 +309,15 @@ fn swap_binop<'a>(
     rhs: &'a Expr<'a>,
 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
     match binop {
-        BinOpKind::Add
-        | BinOpKind::Mul
-        | BinOpKind::Eq
-        | BinOpKind::Ne
-        | BinOpKind::BitAnd
-        | BinOpKind::BitXor
-        | BinOpKind::BitOr => Some((binop, rhs, lhs)),
+        BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
+            Some((binop, rhs, lhs))
+        },
         BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
         BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
         BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
         BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
-        BinOpKind::Shl
+        BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
+        | BinOpKind::Shl
         | BinOpKind::Shr
         | BinOpKind::Rem
         | BinOpKind::Sub
diff --git a/src/tools/clippy/clippy_lints/src/utils/sugg.rs b/src/tools/clippy/clippy_lints/src/utils/sugg.rs
index 73758b7eeb7..e919b1522d8 100644
--- a/src/tools/clippy/clippy_lints/src/utils/sugg.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/sugg.rs
@@ -509,7 +509,7 @@ fn indentation<T: LintContext>(cx: &T, span: Span) -> Option<String> {
 }
 
 /// Convenience extension trait for `DiagnosticBuilder`.
-pub trait DiagnosticBuilderExt<'a, T: LintContext> {
+pub trait DiagnosticBuilderExt<T: LintContext> {
     /// Suggests to add an attribute to an item.
     ///
     /// Correctly handles indentation of the attribute and item.
@@ -556,7 +556,7 @@ pub trait DiagnosticBuilderExt<'a, T: LintContext> {
     fn suggest_remove_item(&mut self, cx: &T, item: Span, msg: &str, applicability: Applicability);
 }
 
-impl<'a, 'b, 'c, T: LintContext> DiagnosticBuilderExt<'c, T> for rustc_errors::DiagnosticBuilder<'b> {
+impl<T: LintContext> DiagnosticBuilderExt<T> for rustc_errors::DiagnosticBuilder<'_> {
     fn suggest_item_with_attr<D: Display + ?Sized>(
         &mut self,
         cx: &T,
diff --git a/src/tools/clippy/clippy_lints/src/utils/usage.rs b/src/tools/clippy/clippy_lints/src/utils/usage.rs
index 6a7a1f1ceaa..0492878fc27 100644
--- a/src/tools/clippy/clippy_lints/src/utils/usage.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/usage.rs
@@ -8,7 +8,7 @@ use rustc_lint::LateContext;
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty;
 use rustc_span::symbol::{Ident, Symbol};
-use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceWithHirId, PlaceBase};
+use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 
 /// Returns a set of mutated local variable IDs, or `None` if mutations could not be determined.
 pub fn mutated_variables<'a, 'tcx>(expr: &'tcx Expr<'_>, cx: &'a LateContext<'a, 'tcx>) -> Option<FxHashSet<HirId>> {
diff --git a/src/tools/clippy/clippy_lints/src/wildcard_imports.rs b/src/tools/clippy/clippy_lints/src/wildcard_imports.rs
index b637253bd02..79f7705e281 100644
--- a/src/tools/clippy/clippy_lints/src/wildcard_imports.rs
+++ b/src/tools/clippy/clippy_lints/src/wildcard_imports.rs
@@ -36,7 +36,7 @@ declare_clippy_lint! {
 declare_clippy_lint! {
     /// **What it does:** Checks for wildcard imports `use _::*`.
     ///
-    /// **Why is this bad?** wildcard imports can polute the namespace. This is especially bad if
+    /// **Why is this bad?** wildcard imports can pollute the namespace. This is especially bad if
     /// you try to import something through a wildcard, that already has been imported by name from
     /// a different source:
     ///
diff --git a/src/tools/clippy/src/driver.rs b/src/tools/clippy/src/driver.rs
index 4453ae5ce44..decd3a79cce 100644
--- a/src/tools/clippy/src/driver.rs
+++ b/src/tools/clippy/src/driver.rs
@@ -1,15 +1,16 @@
-#![cfg_attr(feature = "deny-warnings", deny(warnings))]
 #![feature(rustc_private)]
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+// warn on lints, that are included in `rust-lang/rust`s bootstrap
+#![warn(rust_2018_idioms, unused_lifetimes)]
+// warn on rustc internal lints
+#![deny(rustc::internal)]
 
 // FIXME: switch to something more ergonomic here, once available.
 // (Currently there is no way to opt into sysroot crates without `extern crate`.)
-#[allow(unused_extern_crates)]
+extern crate rustc_data_structures;
 extern crate rustc_driver;
-#[allow(unused_extern_crates)]
 extern crate rustc_errors;
-#[allow(unused_extern_crates)]
 extern crate rustc_interface;
-#[allow(unused_extern_crates)]
 extern crate rustc_middle;
 
 use rustc_interface::interface;
@@ -93,7 +94,7 @@ impl rustc_driver::Callbacks for ClippyCallbacks {
 #[allow(clippy::find_map, clippy::filter_map)]
 fn describe_lints() {
     use lintlist::{Level, Lint, ALL_LINTS, LINT_LEVELS};
-    use std::collections::HashSet;
+    use rustc_data_structures::fx::FxHashSet;
 
     println!(
         "
@@ -137,7 +138,7 @@ Available lint options:
 
     let scoped = |x: &str| format!("clippy::{}", x);
 
-    let lint_groups: HashSet<_> = lints.iter().map(|lint| lint.group).collect();
+    let lint_groups: FxHashSet<_> = lints.iter().map(|lint| lint.group).collect();
 
     println!("Lint checks provided by clippy:\n");
     println!("    {}  {:7.7}  meaning", padded("name"), "default");
@@ -207,6 +208,7 @@ Usage:
 
 Common options:
     -h, --help               Print this message
+        --rustc              Pass all args to rustc
     -V, --version            Print version info and exit
 
 Other options are the same as `cargo check`.
@@ -297,12 +299,6 @@ pub fn main() {
     exit(rustc_driver::catch_with_exit_code(move || {
         let mut orig_args: Vec<String> = env::args().collect();
 
-        if orig_args.iter().any(|a| a == "--version" || a == "-V") {
-            let version_info = rustc_tools_util::get_version_info!();
-            println!("{}", version_info);
-            exit(0);
-        }
-
         // Get the sysroot, looking from most specific to this invocation to the least:
         // - command line
         // - runtime environment
@@ -348,6 +344,28 @@ pub fn main() {
             .map(|pb| pb.to_string_lossy().to_string())
             .expect("need to specify SYSROOT env var during clippy compilation, or use rustup or multirust");
 
+        // make "clippy-driver --rustc" work like a subcommand that passes further args to "rustc"
+        // for example `clippy-driver --rustc --version` will print the rustc version that clippy-driver
+        // uses
+        if let Some(pos) = orig_args.iter().position(|arg| arg == "--rustc") {
+            orig_args.remove(pos);
+            orig_args[0] = "rustc".to_string();
+
+            // if we call "rustc", we need to pass --sysroot here as well
+            let mut args: Vec<String> = orig_args.clone();
+            if !have_sys_root_arg {
+                args.extend(vec!["--sysroot".into(), sys_root]);
+            };
+
+            return rustc_driver::run_compiler(&args, &mut DefaultCallbacks, None, None);
+        }
+
+        if orig_args.iter().any(|a| a == "--version" || a == "-V") {
+            let version_info = rustc_tools_util::get_version_info!();
+            println!("{}", version_info);
+            exit(0);
+        }
+
         // Setting RUSTC_WRAPPER causes Cargo to pass 'rustc' as the first argument.
         // We're invoking the compiler programmatically, so we ignore this/
         let wrapper_mode = orig_args.get(1).map(Path::new).and_then(Path::file_stem) == Some("rustc".as_ref());
diff --git a/src/tools/clippy/src/lintlist/mod.rs b/src/tools/clippy/src/lintlist/mod.rs
index cac3cc6bdb3..edceb755180 100644
--- a/src/tools/clippy/src/lintlist/mod.rs
+++ b/src/tools/clippy/src/lintlist/mod.rs
@@ -2329,7 +2329,7 @@ pub static ref ALL_LINTS: Vec<Lint> = vec![
     },
     Lint {
         name: "unnested_or_patterns",
-        group: "complexity",
+        group: "pedantic",
         desc: "unnested or-patterns, e.g., `Foo(Bar) | Foo(Baz) instead of `Foo(Bar | Baz)`",
         deprecation: None,
         module: "unnested_or_patterns",
diff --git a/src/tools/clippy/src/main.rs b/src/tools/clippy/src/main.rs
index bc43a34ed5d..6739a4cf224 100644
--- a/src/tools/clippy/src/main.rs
+++ b/src/tools/clippy/src/main.rs
@@ -1,4 +1,6 @@
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
+// warn on lints, that are included in `rust-lang/rust`s bootstrap
+#![warn(rust_2018_idioms, unused_lifetimes)]
 
 use rustc_tools_util::VersionInfo;
 use std::env;
diff --git a/src/tools/clippy/tests/ui/auxiliary/macro_use_helper.rs b/src/tools/clippy/tests/ui/auxiliary/macro_use_helper.rs
new file mode 100644
index 00000000000..ecb55d8cb48
--- /dev/null
+++ b/src/tools/clippy/tests/ui/auxiliary/macro_use_helper.rs
@@ -0,0 +1,60 @@
+extern crate macro_rules;
+
+// STMT
+#[macro_export]
+macro_rules! pub_macro {
+    () => {
+        let _ = "hello Mr. Vonnegut";
+    };
+}
+
+pub mod inner {
+    pub use super::*;
+
+    // RE-EXPORT
+    // this will stick in `inner` module
+    pub use macro_rules::foofoo;
+    pub use macro_rules::try_err;
+
+    pub mod nested {
+        pub use macro_rules::string_add;
+    }
+
+    // ITEM
+    #[macro_export]
+    macro_rules! inner_mod_macro {
+        () => {
+            #[allow(dead_code)]
+            pub struct Tardis;
+        };
+    }
+}
+
+// EXPR
+#[macro_export]
+macro_rules! function_macro {
+    () => {
+        if true {
+        } else {
+        }
+    };
+}
+
+// TYPE
+#[macro_export]
+macro_rules! ty_macro {
+    () => {
+        Vec<u8>
+    };
+}
+
+mod extern_exports {
+    pub(super) mod private_inner {
+        #[macro_export]
+        macro_rules! pub_in_private_macro {
+            ($name:ident) => {
+                let $name = String::from("secrets and lies");
+            };
+        }
+    }
+}
diff --git a/src/tools/clippy/tests/ui/blacklisted_name.rs b/src/tools/clippy/tests/ui/blacklisted_name.rs
index ca9d8d16b78..cb15bdd2f1b 100644
--- a/src/tools/clippy/tests/ui/blacklisted_name.rs
+++ b/src/tools/clippy/tests/ui/blacklisted_name.rs
@@ -12,29 +12,34 @@ fn test(foo: ()) {}
 
 fn main() {
     let foo = 42;
-    let bar = 42;
     let baz = 42;
+    let quux = 42;
+    // Unlike these others, `bar` is actually considered an acceptable name.
+    // Among many other legitimate uses, bar commonly refers to a period of time in music.
+    // See https://github.com/rust-lang/rust-clippy/issues/5225.
+    let bar = 42;
 
-    let barb = 42;
-    let barbaric = 42;
+    let food = 42;
+    let foodstuffs = 42;
+    let bazaar = 42;
 
     match (42, Some(1337), Some(0)) {
-        (foo, Some(bar), baz @ Some(_)) => (),
+        (foo, Some(baz), quux @ Some(_)) => (),
         _ => (),
     }
 }
 
 fn issue_1647(mut foo: u8) {
-    let mut bar = 0;
-    if let Some(mut baz) = Some(42) {}
+    let mut baz = 0;
+    if let Some(mut quux) = Some(42) {}
 }
 
 fn issue_1647_ref() {
-    let ref bar = 0;
-    if let Some(ref baz) = Some(42) {}
+    let ref baz = 0;
+    if let Some(ref quux) = Some(42) {}
 }
 
 fn issue_1647_ref_mut() {
-    let ref mut bar = 0;
-    if let Some(ref mut baz) = Some(42) {}
+    let ref mut baz = 0;
+    if let Some(ref mut quux) = Some(42) {}
 }
diff --git a/src/tools/clippy/tests/ui/blacklisted_name.stderr b/src/tools/clippy/tests/ui/blacklisted_name.stderr
index 44123829fb0..70dbdaece8b 100644
--- a/src/tools/clippy/tests/ui/blacklisted_name.stderr
+++ b/src/tools/clippy/tests/ui/blacklisted_name.stderr
@@ -12,77 +12,77 @@ error: use of a blacklisted/placeholder name `foo`
 LL |     let foo = 42;
    |         ^^^
 
-error: use of a blacklisted/placeholder name `bar`
+error: use of a blacklisted/placeholder name `baz`
   --> $DIR/blacklisted_name.rs:15:9
    |
-LL |     let bar = 42;
+LL |     let baz = 42;
    |         ^^^
 
-error: use of a blacklisted/placeholder name `baz`
+error: use of a blacklisted/placeholder name `quux`
   --> $DIR/blacklisted_name.rs:16:9
    |
-LL |     let baz = 42;
-   |         ^^^
+LL |     let quux = 42;
+   |         ^^^^
 
 error: use of a blacklisted/placeholder name `foo`
-  --> $DIR/blacklisted_name.rs:22:10
+  --> $DIR/blacklisted_name.rs:27:10
    |
-LL |         (foo, Some(bar), baz @ Some(_)) => (),
+LL |         (foo, Some(baz), quux @ Some(_)) => (),
    |          ^^^
 
-error: use of a blacklisted/placeholder name `bar`
-  --> $DIR/blacklisted_name.rs:22:20
+error: use of a blacklisted/placeholder name `baz`
+  --> $DIR/blacklisted_name.rs:27:20
    |
-LL |         (foo, Some(bar), baz @ Some(_)) => (),
+LL |         (foo, Some(baz), quux @ Some(_)) => (),
    |                    ^^^
 
-error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:22:26
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:27:26
    |
-LL |         (foo, Some(bar), baz @ Some(_)) => (),
-   |                          ^^^
+LL |         (foo, Some(baz), quux @ Some(_)) => (),
+   |                          ^^^^
 
 error: use of a blacklisted/placeholder name `foo`
-  --> $DIR/blacklisted_name.rs:27:19
+  --> $DIR/blacklisted_name.rs:32:19
    |
 LL | fn issue_1647(mut foo: u8) {
    |                   ^^^
 
-error: use of a blacklisted/placeholder name `bar`
-  --> $DIR/blacklisted_name.rs:28:13
+error: use of a blacklisted/placeholder name `baz`
+  --> $DIR/blacklisted_name.rs:33:13
    |
-LL |     let mut bar = 0;
+LL |     let mut baz = 0;
    |             ^^^
 
-error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:29:21
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:34:21
    |
-LL |     if let Some(mut baz) = Some(42) {}
-   |                     ^^^
+LL |     if let Some(mut quux) = Some(42) {}
+   |                     ^^^^
 
-error: use of a blacklisted/placeholder name `bar`
-  --> $DIR/blacklisted_name.rs:33:13
+error: use of a blacklisted/placeholder name `baz`
+  --> $DIR/blacklisted_name.rs:38:13
    |
-LL |     let ref bar = 0;
+LL |     let ref baz = 0;
    |             ^^^
 
-error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:34:21
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:39:21
    |
-LL |     if let Some(ref baz) = Some(42) {}
-   |                     ^^^
+LL |     if let Some(ref quux) = Some(42) {}
+   |                     ^^^^
 
-error: use of a blacklisted/placeholder name `bar`
-  --> $DIR/blacklisted_name.rs:38:17
+error: use of a blacklisted/placeholder name `baz`
+  --> $DIR/blacklisted_name.rs:43:17
    |
-LL |     let ref mut bar = 0;
+LL |     let ref mut baz = 0;
    |                 ^^^
 
-error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:39:25
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:44:25
    |
-LL |     if let Some(ref mut baz) = Some(42) {}
-   |                         ^^^
+LL |     if let Some(ref mut quux) = Some(42) {}
+   |                         ^^^^
 
 error: aborting due to 14 previous errors
 
diff --git a/src/tools/clippy/tests/ui/crashes/ice-5389.rs b/src/tools/clippy/tests/ui/crashes/ice-5389.rs
new file mode 100644
index 00000000000..de262199004
--- /dev/null
+++ b/src/tools/clippy/tests/ui/crashes/ice-5389.rs
@@ -0,0 +1,13 @@
+#![allow(clippy::explicit_counter_loop)]
+
+fn main() {
+    let v = vec![1, 2, 3];
+    let mut i = 0;
+    let max_storage_size = [0; 128 * 1024];
+    for item in &v {
+        bar(i, *item);
+        i += 1;
+    }
+}
+
+fn bar(_: usize, _: u32) {}
diff --git a/src/tools/clippy/tests/ui/if_same_then_else.rs b/src/tools/clippy/tests/ui/if_same_then_else.rs
index 6bbf79edfcf..9c5fe02f751 100644
--- a/src/tools/clippy/tests/ui/if_same_then_else.rs
+++ b/src/tools/clippy/tests/ui/if_same_then_else.rs
@@ -142,4 +142,16 @@ fn func() {
 
 fn f(val: &[u8]) {}
 
+mod issue_5698 {
+    fn mul_not_always_commutative(x: i32, y: i32) -> i32 {
+        if x == 42 {
+            x * y
+        } else if x == 21 {
+            y * x
+        } else {
+            0
+        }
+    }
+}
+
 fn main() {}
diff --git a/src/tools/clippy/tests/ui/macro_use_imports.fixed b/src/tools/clippy/tests/ui/macro_use_imports.fixed
new file mode 100644
index 00000000000..91e34c62160
--- /dev/null
+++ b/src/tools/clippy/tests/ui/macro_use_imports.fixed
@@ -0,0 +1,43 @@
+// compile-flags: --edition 2018
+// aux-build:macro_rules.rs
+// aux-build:macro_use_helper.rs
+// run-rustfix
+// ignore-32bit
+
+#![allow(unused_imports, unreachable_code, unused_variables, dead_code)]
+#![allow(clippy::single_component_path_imports)]
+#![warn(clippy::macro_use_imports)]
+
+#[macro_use]
+extern crate macro_use_helper as mac;
+
+#[macro_use]
+extern crate clippy_mini_macro_test as mini_mac;
+
+mod a {
+    use mac::{pub_macro, inner_mod_macro, function_macro, ty_macro, pub_in_private_macro};
+    use mac;
+    use mini_mac::ClippyMiniMacroTest;
+    use mini_mac;
+    use mac::{inner::foofoo, inner::try_err};
+    use mac::inner;
+    use mac::inner::nested::string_add;
+    use mac::inner::nested;
+
+    #[derive(ClippyMiniMacroTest)]
+    struct Test;
+
+    fn test() {
+        pub_macro!();
+        inner_mod_macro!();
+        pub_in_private_macro!(_var);
+        function_macro!();
+        let v: ty_macro!() = Vec::default();
+
+        inner::try_err!();
+        inner::foofoo!();
+        nested::string_add!();
+    }
+}
+
+fn main() {}
diff --git a/src/tools/clippy/tests/ui/macro_use_imports.rs b/src/tools/clippy/tests/ui/macro_use_imports.rs
index 60c64ee8146..9c3c50c5d49 100644
--- a/src/tools/clippy/tests/ui/macro_use_imports.rs
+++ b/src/tools/clippy/tests/ui/macro_use_imports.rs
@@ -1,11 +1,43 @@
-// edition:2018
+// compile-flags: --edition 2018
+// aux-build:macro_rules.rs
+// aux-build:macro_use_helper.rs
+// run-rustfix
+// ignore-32bit
+
+#![allow(unused_imports, unreachable_code, unused_variables, dead_code)]
+#![allow(clippy::single_component_path_imports)]
 #![warn(clippy::macro_use_imports)]
 
-use std::collections::HashMap;
 #[macro_use]
-use std::prelude;
+extern crate macro_use_helper as mac;
+
+#[macro_use]
+extern crate clippy_mini_macro_test as mini_mac;
+
+mod a {
+    #[macro_use]
+    use mac;
+    #[macro_use]
+    use mini_mac;
+    #[macro_use]
+    use mac::inner;
+    #[macro_use]
+    use mac::inner::nested;
 
-fn main() {
-    let _ = HashMap::<u8, u8>::new();
-    println!();
+    #[derive(ClippyMiniMacroTest)]
+    struct Test;
+
+    fn test() {
+        pub_macro!();
+        inner_mod_macro!();
+        pub_in_private_macro!(_var);
+        function_macro!();
+        let v: ty_macro!() = Vec::default();
+
+        inner::try_err!();
+        inner::foofoo!();
+        nested::string_add!();
+    }
 }
+
+fn main() {}
diff --git a/src/tools/clippy/tests/ui/macro_use_imports.stderr b/src/tools/clippy/tests/ui/macro_use_imports.stderr
index b5e3dbec572..f8c86c8d917 100644
--- a/src/tools/clippy/tests/ui/macro_use_imports.stderr
+++ b/src/tools/clippy/tests/ui/macro_use_imports.stderr
@@ -1,10 +1,28 @@
 error: `macro_use` attributes are no longer needed in the Rust 2018 edition
-  --> $DIR/macro_use_imports.rs:5:1
+  --> $DIR/macro_use_imports.rs:18:5
    |
-LL | #[macro_use]
-   | ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use std::prelude::<macro name>`
+LL |     #[macro_use]
+   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::{pub_macro, inner_mod_macro, function_macro, ty_macro, pub_in_private_macro};`
    |
    = note: `-D clippy::macro-use-imports` implied by `-D warnings`
 
-error: aborting due to previous error
+error: `macro_use` attributes are no longer needed in the Rust 2018 edition
+  --> $DIR/macro_use_imports.rs:20:5
+   |
+LL |     #[macro_use]
+   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mini_mac::ClippyMiniMacroTest;`
+
+error: `macro_use` attributes are no longer needed in the Rust 2018 edition
+  --> $DIR/macro_use_imports.rs:22:5
+   |
+LL |     #[macro_use]
+   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::{inner::foofoo, inner::try_err};`
+
+error: `macro_use` attributes are no longer needed in the Rust 2018 edition
+  --> $DIR/macro_use_imports.rs:24:5
+   |
+LL |     #[macro_use]
+   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::inner::nested::string_add;`
+
+error: aborting due to 4 previous errors
 
diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching.fixed b/src/tools/clippy/tests/ui/redundant_pattern_matching.fixed
index fc8cb0e747c..6ba5cfb1d71 100644
--- a/src/tools/clippy/tests/ui/redundant_pattern_matching.fixed
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching.fixed
@@ -1,5 +1,7 @@
 // run-rustfix
 
+#![feature(const_if_match)]
+#![feature(const_loop)]
 #![warn(clippy::all)]
 #![warn(clippy::redundant_pattern_matching)]
 #![allow(clippy::unit_arg, unused_must_use, clippy::needless_bool, deprecated)]
@@ -67,6 +69,7 @@ fn main() {
     takes_bool(x);
 
     issue5504();
+    issue5697();
 
     let _ = if gen_opt().is_some() {
         1
@@ -117,3 +120,42 @@ fn issue5504() {
     if m!().is_some() {}
     while m!().is_some() {}
 }
+
+// None of these should be linted because none of the suggested methods
+// are `const fn` without toggling a feature.
+const fn issue5697() {
+    if let Ok(_) = Ok::<i32, i32>(42) {}
+
+    if let Err(_) = Err::<i32, i32>(42) {}
+
+    if let Some(_) = Some(42) {}
+
+    if let None = None::<()> {}
+
+    while let Ok(_) = Ok::<i32, i32>(10) {}
+
+    while let Err(_) = Ok::<i32, i32>(10) {}
+
+    while let Some(_) = Some(42) {}
+
+    while let None = None::<()> {}
+
+    match Ok::<i32, i32>(42) {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+
+    match Err::<i32, i32>(42) {
+        Ok(_) => false,
+        Err(_) => true,
+    };
+    match Some(42) {
+        Some(_) => true,
+        None => false,
+    };
+
+    match None::<()> {
+        Some(_) => false,
+        None => true,
+    };
+}
diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching.rs b/src/tools/clippy/tests/ui/redundant_pattern_matching.rs
index 51912dade03..17de66f9ad0 100644
--- a/src/tools/clippy/tests/ui/redundant_pattern_matching.rs
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching.rs
@@ -1,5 +1,7 @@
 // run-rustfix
 
+#![feature(const_if_match)]
+#![feature(const_loop)]
 #![warn(clippy::all)]
 #![warn(clippy::redundant_pattern_matching)]
 #![allow(clippy::unit_arg, unused_must_use, clippy::needless_bool, deprecated)]
@@ -88,6 +90,7 @@ fn main() {
     takes_bool(x);
 
     issue5504();
+    issue5697();
 
     let _ = if let Some(_) = gen_opt() {
         1
@@ -138,3 +141,42 @@ fn issue5504() {
     if let Some(_) = m!() {}
     while let Some(_) = m!() {}
 }
+
+// None of these should be linted because none of the suggested methods
+// are `const fn` without toggling a feature.
+const fn issue5697() {
+    if let Ok(_) = Ok::<i32, i32>(42) {}
+
+    if let Err(_) = Err::<i32, i32>(42) {}
+
+    if let Some(_) = Some(42) {}
+
+    if let None = None::<()> {}
+
+    while let Ok(_) = Ok::<i32, i32>(10) {}
+
+    while let Err(_) = Ok::<i32, i32>(10) {}
+
+    while let Some(_) = Some(42) {}
+
+    while let None = None::<()> {}
+
+    match Ok::<i32, i32>(42) {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+
+    match Err::<i32, i32>(42) {
+        Ok(_) => false,
+        Err(_) => true,
+    };
+    match Some(42) {
+        Some(_) => true,
+        None => false,
+    };
+
+    match None::<()> {
+        Some(_) => false,
+        None => true,
+    };
+}
diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching.stderr b/src/tools/clippy/tests/ui/redundant_pattern_matching.stderr
index b58deb7954e..1b9a4b40a2f 100644
--- a/src/tools/clippy/tests/ui/redundant_pattern_matching.stderr
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching.stderr
@@ -1,5 +1,5 @@
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:8:12
+  --> $DIR/redundant_pattern_matching.rs:10:12
    |
 LL |     if let Ok(_) = Ok::<i32, i32>(42) {}
    |     -------^^^^^--------------------- help: try this: `if Ok::<i32, i32>(42).is_ok()`
@@ -7,67 +7,67 @@ LL |     if let Ok(_) = Ok::<i32, i32>(42) {}
    = note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:10:12
+  --> $DIR/redundant_pattern_matching.rs:12:12
    |
 LL |     if let Err(_) = Err::<i32, i32>(42) {}
    |     -------^^^^^^---------------------- help: try this: `if Err::<i32, i32>(42).is_err()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:12:12
+  --> $DIR/redundant_pattern_matching.rs:14:12
    |
 LL |     if let None = None::<()> {}
    |     -------^^^^------------- help: try this: `if None::<()>.is_none()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:14:12
+  --> $DIR/redundant_pattern_matching.rs:16:12
    |
 LL |     if let Some(_) = Some(42) {}
    |     -------^^^^^^^----------- help: try this: `if Some(42).is_some()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:16:12
+  --> $DIR/redundant_pattern_matching.rs:18:12
    |
 LL |     if let Some(_) = Some(42) {
    |     -------^^^^^^^----------- help: try this: `if Some(42).is_some()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:22:15
+  --> $DIR/redundant_pattern_matching.rs:24:15
    |
 LL |     while let Some(_) = Some(42) {}
    |     ----------^^^^^^^----------- help: try this: `while Some(42).is_some()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:24:15
+  --> $DIR/redundant_pattern_matching.rs:26:15
    |
 LL |     while let None = Some(42) {}
    |     ----------^^^^----------- help: try this: `while Some(42).is_none()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:26:15
+  --> $DIR/redundant_pattern_matching.rs:28:15
    |
 LL |     while let None = None::<()> {}
    |     ----------^^^^------------- help: try this: `while None::<()>.is_none()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:28:15
+  --> $DIR/redundant_pattern_matching.rs:30:15
    |
 LL |     while let Ok(_) = Ok::<i32, i32>(10) {}
    |     ----------^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_ok()`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:30:15
+  --> $DIR/redundant_pattern_matching.rs:32:15
    |
 LL |     while let Err(_) = Ok::<i32, i32>(10) {}
    |     ----------^^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_err()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:33:15
+  --> $DIR/redundant_pattern_matching.rs:35:15
    |
 LL |     while let Some(_) = v.pop() {
    |     ----------^^^^^^^---------- help: try this: `while v.pop().is_some()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:49:5
+  --> $DIR/redundant_pattern_matching.rs:51:5
    |
 LL | /     match Ok::<i32, i32>(42) {
 LL | |         Ok(_) => true,
@@ -76,7 +76,7 @@ LL | |     };
    | |_____^ help: try this: `Ok::<i32, i32>(42).is_ok()`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:54:5
+  --> $DIR/redundant_pattern_matching.rs:56:5
    |
 LL | /     match Ok::<i32, i32>(42) {
 LL | |         Ok(_) => false,
@@ -85,7 +85,7 @@ LL | |     };
    | |_____^ help: try this: `Ok::<i32, i32>(42).is_err()`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:59:5
+  --> $DIR/redundant_pattern_matching.rs:61:5
    |
 LL | /     match Err::<i32, i32>(42) {
 LL | |         Ok(_) => false,
@@ -94,7 +94,7 @@ LL | |     };
    | |_____^ help: try this: `Err::<i32, i32>(42).is_err()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:64:5
+  --> $DIR/redundant_pattern_matching.rs:66:5
    |
 LL | /     match Err::<i32, i32>(42) {
 LL | |         Ok(_) => true,
@@ -103,7 +103,7 @@ LL | |     };
    | |_____^ help: try this: `Err::<i32, i32>(42).is_ok()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:69:5
+  --> $DIR/redundant_pattern_matching.rs:71:5
    |
 LL | /     match Some(42) {
 LL | |         Some(_) => true,
@@ -112,7 +112,7 @@ LL | |     };
    | |_____^ help: try this: `Some(42).is_some()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:74:5
+  --> $DIR/redundant_pattern_matching.rs:76:5
    |
 LL | /     match None::<()> {
 LL | |         Some(_) => false,
@@ -121,7 +121,7 @@ LL | |     };
    | |_____^ help: try this: `None::<()>.is_none()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:79:13
+  --> $DIR/redundant_pattern_matching.rs:81:13
    |
 LL |       let _ = match None::<()> {
    |  _____________^
@@ -131,61 +131,61 @@ LL | |     };
    | |_____^ help: try this: `None::<()>.is_none()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:84:20
+  --> $DIR/redundant_pattern_matching.rs:86:20
    |
 LL |     let _ = if let Ok(_) = Ok::<usize, ()>(4) { true } else { false };
    |             -------^^^^^--------------------- help: try this: `if Ok::<usize, ()>(4).is_ok()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:87:20
+  --> $DIR/redundant_pattern_matching.rs:89:20
    |
 LL |     let x = if let Some(_) = opt { true } else { false };
    |             -------^^^^^^^------ help: try this: `if opt.is_some()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:92:20
+  --> $DIR/redundant_pattern_matching.rs:95:20
    |
 LL |     let _ = if let Some(_) = gen_opt() {
    |             -------^^^^^^^------------ help: try this: `if gen_opt().is_some()`
 
 error: redundant pattern matching, consider using `is_none()`
-  --> $DIR/redundant_pattern_matching.rs:94:19
+  --> $DIR/redundant_pattern_matching.rs:97:19
    |
 LL |     } else if let None = gen_opt() {
    |            -------^^^^------------ help: try this: `if gen_opt().is_none()`
 
 error: redundant pattern matching, consider using `is_ok()`
-  --> $DIR/redundant_pattern_matching.rs:96:19
+  --> $DIR/redundant_pattern_matching.rs:99:19
    |
 LL |     } else if let Ok(_) = gen_res() {
    |            -------^^^^^------------ help: try this: `if gen_res().is_ok()`
 
 error: redundant pattern matching, consider using `is_err()`
-  --> $DIR/redundant_pattern_matching.rs:98:19
+  --> $DIR/redundant_pattern_matching.rs:101:19
    |
 LL |     } else if let Err(_) = gen_res() {
    |            -------^^^^^^------------ help: try this: `if gen_res().is_err()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:131:19
+  --> $DIR/redundant_pattern_matching.rs:134:19
    |
 LL |         while let Some(_) = r#try!(result_opt()) {}
    |         ----------^^^^^^^----------------------- help: try this: `while r#try!(result_opt()).is_some()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:132:16
+  --> $DIR/redundant_pattern_matching.rs:135:16
    |
 LL |         if let Some(_) = r#try!(result_opt()) {}
    |         -------^^^^^^^----------------------- help: try this: `if r#try!(result_opt()).is_some()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:138:12
+  --> $DIR/redundant_pattern_matching.rs:141:12
    |
 LL |     if let Some(_) = m!() {}
    |     -------^^^^^^^------- help: try this: `if m!().is_some()`
 
 error: redundant pattern matching, consider using `is_some()`
-  --> $DIR/redundant_pattern_matching.rs:139:15
+  --> $DIR/redundant_pattern_matching.rs:142:15
    |
 LL |     while let Some(_) = m!() {}
    |     ----------^^^^^^^------- help: try this: `while m!().is_some()`
diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.fixed b/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.fixed
new file mode 100644
index 00000000000..c8bc5458067
--- /dev/null
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.fixed
@@ -0,0 +1,46 @@
+// run-rustfix
+
+#![feature(const_if_match)]
+#![feature(const_loop)]
+#![feature(const_result)]
+#![warn(clippy::redundant_pattern_matching)]
+#![allow(unused)]
+
+// Test that results are linted with the feature enabled.
+
+const fn issue_5697() {
+    if Ok::<i32, i32>(42).is_ok() {}
+
+    if Err::<i32, i32>(42).is_err() {}
+
+    while Ok::<i32, i32>(10).is_ok() {}
+
+    while Ok::<i32, i32>(10).is_err() {}
+
+    Ok::<i32, i32>(42).is_ok();
+
+    Err::<i32, i32>(42).is_err();
+
+    // These should not be linted until `const_option` is implemented.
+    // See https://github.com/rust-lang/rust/issues/67441
+
+    if let Some(_) = Some(42) {}
+
+    if let None = None::<()> {}
+
+    while let Some(_) = Some(42) {}
+
+    while let None = None::<()> {}
+
+    match Some(42) {
+        Some(_) => true,
+        None => false,
+    };
+
+    match None::<()> {
+        Some(_) => false,
+        None => true,
+    };
+}
+
+fn main() {}
diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.rs b/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.rs
new file mode 100644
index 00000000000..75f37ec15c6
--- /dev/null
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.rs
@@ -0,0 +1,52 @@
+// run-rustfix
+
+#![feature(const_if_match)]
+#![feature(const_loop)]
+#![feature(const_result)]
+#![warn(clippy::redundant_pattern_matching)]
+#![allow(unused)]
+
+// Test that results are linted with the feature enabled.
+
+const fn issue_5697() {
+    if let Ok(_) = Ok::<i32, i32>(42) {}
+
+    if let Err(_) = Err::<i32, i32>(42) {}
+
+    while let Ok(_) = Ok::<i32, i32>(10) {}
+
+    while let Err(_) = Ok::<i32, i32>(10) {}
+
+    match Ok::<i32, i32>(42) {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+
+    match Err::<i32, i32>(42) {
+        Ok(_) => false,
+        Err(_) => true,
+    };
+
+    // These should not be linted until `const_option` is implemented.
+    // See https://github.com/rust-lang/rust/issues/67441
+
+    if let Some(_) = Some(42) {}
+
+    if let None = None::<()> {}
+
+    while let Some(_) = Some(42) {}
+
+    while let None = None::<()> {}
+
+    match Some(42) {
+        Some(_) => true,
+        None => false,
+    };
+
+    match None::<()> {
+        Some(_) => false,
+        None => true,
+    };
+}
+
+fn main() {}
diff --git a/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.stderr b/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.stderr
new file mode 100644
index 00000000000..c32292f0eee
--- /dev/null
+++ b/src/tools/clippy/tests/ui/redundant_pattern_matching_const_result.stderr
@@ -0,0 +1,46 @@
+error: redundant pattern matching, consider using `is_ok()`
+  --> $DIR/redundant_pattern_matching_const_result.rs:12:12
+   |
+LL |     if let Ok(_) = Ok::<i32, i32>(42) {}
+   |     -------^^^^^--------------------- help: try this: `if Ok::<i32, i32>(42).is_ok()`
+   |
+   = note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
+
+error: redundant pattern matching, consider using `is_err()`
+  --> $DIR/redundant_pattern_matching_const_result.rs:14:12
+   |
+LL |     if let Err(_) = Err::<i32, i32>(42) {}
+   |     -------^^^^^^---------------------- help: try this: `if Err::<i32, i32>(42).is_err()`
+
+error: redundant pattern matching, consider using `is_ok()`
+  --> $DIR/redundant_pattern_matching_const_result.rs:16:15
+   |
+LL |     while let Ok(_) = Ok::<i32, i32>(10) {}
+   |     ----------^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_ok()`
+
+error: redundant pattern matching, consider using `is_err()`
+  --> $DIR/redundant_pattern_matching_const_result.rs:18:15
+   |
+LL |     while let Err(_) = Ok::<i32, i32>(10) {}
+   |     ----------^^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_err()`
+
+error: redundant pattern matching, consider using `is_ok()`
+  --> $DIR/redundant_pattern_matching_const_result.rs:20:5
+   |
+LL | /     match Ok::<i32, i32>(42) {
+LL | |         Ok(_) => true,
+LL | |         Err(_) => false,
+LL | |     };
+   | |_____^ help: try this: `Ok::<i32, i32>(42).is_ok()`
+
+error: redundant pattern matching, consider using `is_err()`
+  --> $DIR/redundant_pattern_matching_const_result.rs:25:5
+   |
+LL | /     match Err::<i32, i32>(42) {
+LL | |         Ok(_) => false,
+LL | |         Err(_) => true,
+LL | |     };
+   | |_____^ help: try this: `Err::<i32, i32>(42).is_err()`
+
+error: aborting due to 6 previous errors
+
diff --git a/src/tools/clippy/tests/ui/repl_uninit.rs b/src/tools/clippy/tests/ui/repl_uninit.rs
index 346972b7bb4..ad5b8e4857d 100644
--- a/src/tools/clippy/tests/ui/repl_uninit.rs
+++ b/src/tools/clippy/tests/ui/repl_uninit.rs
@@ -18,6 +18,12 @@ fn main() {
     }
 
     unsafe {
+        let taken_v = mem::replace(&mut v, mem::MaybeUninit::uninit().assume_init());
+        let new_v = might_panic(taken_v);
+        std::mem::forget(mem::replace(&mut v, new_v));
+    }
+
+    unsafe {
         let taken_v = mem::replace(&mut v, mem::zeroed());
         let new_v = might_panic(taken_v);
         std::mem::forget(mem::replace(&mut v, new_v));
diff --git a/src/tools/clippy/tests/ui/repl_uninit.stderr b/src/tools/clippy/tests/ui/repl_uninit.stderr
index c1f55d7601e..09468eeaea4 100644
--- a/src/tools/clippy/tests/ui/repl_uninit.stderr
+++ b/src/tools/clippy/tests/ui/repl_uninit.stderr
@@ -2,26 +2,29 @@ error: replacing with `mem::uninitialized()`
   --> $DIR/repl_uninit.rs:15:23
    |
 LL |         let taken_v = mem::replace(&mut v, mem::uninitialized());
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::ptr::read(&mut v)`
    |
    = note: `-D clippy::mem-replace-with-uninit` implied by `-D warnings`
-   = help: consider using the `take_mut` crate instead
 
-error: replacing with `mem::zeroed()`
+error: replacing with `mem::MaybeUninit::uninit().assume_init()`
   --> $DIR/repl_uninit.rs:21:23
    |
+LL |         let taken_v = mem::replace(&mut v, mem::MaybeUninit::uninit().assume_init());
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::ptr::read(&mut v)`
+
+error: replacing with `mem::zeroed()`
+  --> $DIR/repl_uninit.rs:27:23
+   |
 LL |         let taken_v = mem::replace(&mut v, mem::zeroed());
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider using a default value or the `take_mut` crate instead
 
 error: replacing with `mem::uninitialized()`
-  --> $DIR/repl_uninit.rs:33:28
+  --> $DIR/repl_uninit.rs:39:28
    |
 LL |     let taken_u = unsafe { mem::replace(uref, mem::uninitialized()) };
-   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider using the `take_mut` crate instead
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::ptr::read(uref)`
 
-error: aborting due to 3 previous errors
+error: aborting due to 4 previous errors