Auto merge of #5741 - flip1995:rollup-8chbwhy, r=flip1995

Rollup of 9 pull requests

Successful merges:

 - #5178 (clippy-driver: pass all args to rustc if --rustc is present)
 - #5705 (Downgrade unnested_or_patterns to pedantic)
 - #5709 (Fix ICE in consts::binop)
 - #5710 (typo)
 - #5712 (Remove `bar` from blacklisted names)
 - #5713 (Use lints in Clippy that are enabled in rustc bootstrap)
 - #5716 (Fix typo in wildcard_imports)
 - #5724 (redundant_pattern_matching: avoid non-`const fn` calls in const contexts)
 - #5726 (Fix typo)

Failed merges:

r? @ghost

changelog: rollup

.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

clippy_lints/src/consts.rs

@@ -396,7 +396,7 @@ fn binop(&mut self, op: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> Option<Cons
         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);

clippy_lints/src/let_underscore.rs

@@ -35,7 +35,7 @@
     /// **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.

clippy_lints/src/lib.rs

@@ -1,19 +1,22 @@
 // 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`.)
@@ -1187,6 +1190,7 @@ 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 +1444,6 @@ 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 +1627,6 @@ 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),

clippy_lints/src/loops.rs

@@ -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 @@ fn mutate(&mut self, cmt: &PlaceWithHirId<'tcx>) {
     }
 }
 
-impl<'a, 'tcx> MutatePairDelegate<'a, 'tcx> {
+impl MutatePairDelegate<'_, '_> {
     fn mutation_span(&self) -> (Option<Span>, Option<Span>) {
         (self.span_low, self.span_high)
     }
@@ -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<'_>) {

clippy_lints/src/new_without_default.rs

@@ -33,7 +33,7 @@
     /// }
     /// ```
     ///
-    /// 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);

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))
+}

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<'_>) {

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);

clippy_lints/src/unnested_or_patterns.rs

@@ -45,7 +45,7 @@
     /// }
     /// ```
     pub UNNESTED_OR_PATTERNS,
-    complexity,
+    pedantic,
     "unnested or-patterns, e.g., `Foo(Bar) | Foo(Baz) instead of `Foo(Bar | Baz)`"
 }
 

clippy_lints/src/utils/conf.rs

@@ -106,8 +106,8 @@ fn $config() -> $Ty {
 
 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.

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 @@ fn suggest_item_with_attr<D: Display + ?Sized>(
     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,

clippy_lints/src/wildcard_imports.rs

@@ -36,7 +36,7 @@
 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:
     ///

src/driver.rs

@@ -1,9 +1,15 @@
-#![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;
+#[allow(unused_extern_crates)]
 extern crate rustc_driver;
 #[allow(unused_extern_crates)]
 extern crate rustc_errors;
@@ -93,7 +99,7 @@ fn config(&mut self, config: &mut interface::Config) {
 #[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 +143,7 @@ fn describe_lints() {
 
     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 +213,7 @@ fn display_help() {
 
 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 +304,6 @@ 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 +349,28 @@ 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());

src/lintlist/mod.rs

@@ -2329,7 +2329,7 @@
     },
     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",

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;

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) {}
 }

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`
-  --> $DIR/blacklisted_name.rs:15:9
-   |
-LL |     let bar = 42;
-   |         ^^^
-
 error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:16:9
+  --> $DIR/blacklisted_name.rs:15:9
    |
 LL |     let baz = 42;
    |         ^^^
 
-error: use of a blacklisted/placeholder name `foo`
-  --> $DIR/blacklisted_name.rs:22:10
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:16:9
    |
-LL |         (foo, Some(bar), baz @ Some(_)) => (),
+LL |     let quux = 42;
+   |         ^^^^
+
+error: use of a blacklisted/placeholder name `foo`
+  --> $DIR/blacklisted_name.rs:27:10
+   |
+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
-   |
-LL |     let mut bar = 0;
-   |             ^^^
-
 error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:29:21
-   |
-LL |     if let Some(mut baz) = Some(42) {}
-   |                     ^^^
-
-error: use of a blacklisted/placeholder name `bar`
   --> $DIR/blacklisted_name.rs:33:13
    |
-LL |     let ref bar = 0;
+LL |     let mut baz = 0;
    |             ^^^
 
-error: use of a blacklisted/placeholder name `baz`
+error: use of a blacklisted/placeholder name `quux`
   --> $DIR/blacklisted_name.rs:34:21
    |
-LL |     if let Some(ref baz) = Some(42) {}
-   |                     ^^^
-
-error: use of a blacklisted/placeholder name `bar`
-  --> $DIR/blacklisted_name.rs:38:17
-   |
-LL |     let ref mut bar = 0;
-   |                 ^^^
+LL |     if let Some(mut quux) = Some(42) {}
+   |                     ^^^^
 
 error: use of a blacklisted/placeholder name `baz`
-  --> $DIR/blacklisted_name.rs:39:25
+  --> $DIR/blacklisted_name.rs:38:13
    |
-LL |     if let Some(ref mut baz) = Some(42) {}
-   |                         ^^^
+LL |     let ref baz = 0;
+   |             ^^^
+
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:39:21
+   |
+LL |     if let Some(ref quux) = Some(42) {}
+   |                     ^^^^
+
+error: use of a blacklisted/placeholder name `baz`
+  --> $DIR/blacklisted_name.rs:43:17
+   |
+LL |     let ref mut baz = 0;
+   |                 ^^^
+
+error: use of a blacklisted/placeholder name `quux`
+  --> $DIR/blacklisted_name.rs:44:25
+   |
+LL |     if let Some(ref mut quux) = Some(42) {}
+   |                         ^^^^
 
 error: aborting due to 14 previous errors
 

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) {}

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,
+    };
+}

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 try_result_opt() -> Result<i32, i32> {
     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,
+    };
+}

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()`

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() {}

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() {}

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
+