Auto merge of #82911 - m-ou-se:rollup-rjomgja, r=m-ou-se

Rollup of 11 pull requests

Successful merges:

 - #82711 (Add documentation for string->Cow conversions)
 - #82767 (Update minifier dependency version)
 - #82800 (Move rustdoc UI tests into a subdirectory)
 - #82810 (Typo fix in Unstable book: `cargo cov` -> `cargo profdata`)
 - #82829 (Handle negative literals in cast overflow warning)
 - #82854 (Account for `if (let pat = expr) {}`)
 - #82870 (Add note about the `#[doc(no-inline)]` usage)
 - #82874 (Add codegen tests for some issues closed by LLVM 12)
 - #82881 (diagnostics: Be clear about "crate root" and `::foo` paths in resolve diagnostics)
 - #82888 (Grammar Fixes)
 - #82897 ([.mailmap] Add entry for Ramkumar Ramachandra)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

38 files changed, 365 insertions, 233 deletions

diff --git a/src/doc/unstable-book/src/compiler-flags/source-based-code-coverage.md b/src/doc/unstable-book/src/compiler-flags/source-based-code-coverage.md
index 8aca0052147..0d05b80e211 100644
--- a/src/doc/unstable-book/src/compiler-flags/source-based-code-coverage.md
+++ b/src/doc/unstable-book/src/compiler-flags/source-based-code-coverage.md
@@ -128,7 +128,7 @@ $ cargo profdata -- --help  # note the additional "--" preceding the tool-specif
 
 ## Creating coverage reports
 
-Raw profiles have to be indexed before they can be used to generate coverage reports. This is done using [`llvm-profdata merge`] (or `cargo cov -- merge`), which can combine multiple raw profiles and index them at the same time:
+Raw profiles have to be indexed before they can be used to generate coverage reports. This is done using [`llvm-profdata merge`] (or `cargo profdata -- merge`), which can combine multiple raw profiles and index them at the same time:
 
 ```shell
 $ llvm-profdata merge -sparse formatjson5.profraw -o formatjson5.profdata
diff --git a/src/librustdoc/Cargo.toml b/src/librustdoc/Cargo.toml
index 44c2c3b1786..9084a1713cb 100644
--- a/src/librustdoc/Cargo.toml
+++ b/src/librustdoc/Cargo.toml
@@ -10,7 +10,7 @@ path = "lib.rs"
 [dependencies]
 arrayvec = { version = "0.5.1", default-features = false }
 pulldown-cmark = { version = "0.8", default-features = false }
-minifier = "0.0.33"
+minifier = "0.0.39"
 rayon = { version = "0.3.0", package = "rustc-rayon" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
diff --git a/src/test/codegen/issue-73031.rs b/src/test/codegen/issue-73031.rs
new file mode 100644
index 00000000000..6ba4d707f42
--- /dev/null
+++ b/src/test/codegen/issue-73031.rs
@@ -0,0 +1,27 @@
+// min-llvm-version: 12.0.0
+// compile-flags: -O
+#![crate_type = "lib"]
+
+// Test that LLVM can eliminate the unreachable `All::None` branch.
+
+pub enum All {
+    None,
+    Foo,
+    Bar,
+}
+
+// CHECK-LABEL: @issue_73031
+#[no_mangle]
+pub fn issue_73031(a: &mut All, q: i32) -> i32 {
+    *a = if q == 5 {
+        All::Foo
+    } else {
+        All::Bar
+    };
+    match *a {
+        // CHECK-NOT: panic
+        All::None => panic!(),
+        All::Foo => 1,
+        All::Bar => 2,
+    }
+}
diff --git a/src/test/codegen/issue-75546.rs b/src/test/codegen/issue-75546.rs
new file mode 100644
index 00000000000..49e4d4c7ec5
--- /dev/null
+++ b/src/test/codegen/issue-75546.rs
@@ -0,0 +1,16 @@
+// min-llvm-version: 12.0.0
+// compile-flags: -O
+#![crate_type = "lib"]
+
+// Test that LLVM can eliminate the impossible `i == 0` check.
+
+// CHECK-LABEL: @issue_75546
+#[no_mangle]
+pub fn issue_75546() {
+    let mut i = 1u32;
+    while i < u32::MAX {
+        // CHECK-NOT: panic
+        if i == 0 { panic!(); }
+        i += 1;
+    }
+}
diff --git a/src/test/codegen/issue-77812.rs b/src/test/codegen/issue-77812.rs
new file mode 100644
index 00000000000..95042579adb
--- /dev/null
+++ b/src/test/codegen/issue-77812.rs
@@ -0,0 +1,33 @@
+// min-llvm-version: 12.0.0
+// compile-flags: -O
+#![crate_type = "lib"]
+
+// Test that LLVM can eliminate the unreachable `Variant::Zero` branch.
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub enum Variant {
+    Zero,
+    One,
+    Two,
+}
+
+extern {
+    fn exf1();
+    fn exf2();
+}
+
+pub static mut GLOBAL: Variant = Variant::Zero;
+
+// CHECK-LABEL: @issue_77812
+#[no_mangle]
+pub unsafe fn issue_77812() {
+    let g = GLOBAL;
+    if g != Variant::Zero {
+        match g {
+            Variant::One => exf1(),
+            Variant::Two => exf2(),
+            // CHECK-NOT: panic
+            Variant::Zero => panic!(),
+        }
+    }
+}
diff --git a/src/test/ui/editions-crate-root-2015.rs b/src/test/ui/editions-crate-root-2015.rs
new file mode 100644
index 00000000000..4c890e3ae69
--- /dev/null
+++ b/src/test/ui/editions-crate-root-2015.rs
@@ -0,0 +1,21 @@
+// edition:2015
+
+mod inner {
+    fn global_inner(_: ::nonexistant::Foo) {
+        //~^ ERROR failed to resolve: maybe a missing crate `nonexistant`?
+    }
+    fn crate_inner(_: crate::nonexistant::Foo) {
+        //~^ ERROR failed to resolve: maybe a missing crate `nonexistant`?
+    }
+
+    fn bare_global(_: ::nonexistant) {
+        //~^ ERROR cannot find type `nonexistant` in the crate root
+    }
+    fn bare_crate(_: crate::nonexistant) {
+        //~^ ERROR cannot find type `nonexistant` in the crate root
+    }
+}
+
+fn main() {
+
+}
diff --git a/src/test/ui/editions-crate-root-2015.stderr b/src/test/ui/editions-crate-root-2015.stderr
new file mode 100644
index 00000000000..f8d65fec3d1
--- /dev/null
+++ b/src/test/ui/editions-crate-root-2015.stderr
@@ -0,0 +1,28 @@
+error[E0433]: failed to resolve: maybe a missing crate `nonexistant`?
+  --> $DIR/editions-crate-root-2015.rs:4:26
+   |
+LL |     fn global_inner(_: ::nonexistant::Foo) {
+   |                          ^^^^^^^^^^^ maybe a missing crate `nonexistant`?
+
+error[E0433]: failed to resolve: maybe a missing crate `nonexistant`?
+  --> $DIR/editions-crate-root-2015.rs:7:30
+   |
+LL |     fn crate_inner(_: crate::nonexistant::Foo) {
+   |                              ^^^^^^^^^^^ maybe a missing crate `nonexistant`?
+
+error[E0412]: cannot find type `nonexistant` in the crate root
+  --> $DIR/editions-crate-root-2015.rs:11:25
+   |
+LL |     fn bare_global(_: ::nonexistant) {
+   |                         ^^^^^^^^^^^ not found in the crate root
+
+error[E0412]: cannot find type `nonexistant` in the crate root
+  --> $DIR/editions-crate-root-2015.rs:14:29
+   |
+LL |     fn bare_crate(_: crate::nonexistant) {
+   |                             ^^^^^^^^^^^ not found in the crate root
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0412, E0433.
+For more information about an error, try `rustc --explain E0412`.
diff --git a/src/test/ui/editions-crate-root-2018.rs b/src/test/ui/editions-crate-root-2018.rs
new file mode 100644
index 00000000000..61e4329bbb3
--- /dev/null
+++ b/src/test/ui/editions-crate-root-2018.rs
@@ -0,0 +1,21 @@
+// edition:2018
+
+mod inner {
+    fn global_inner(_: ::nonexistant::Foo) {
+        //~^ ERROR failed to resolve: could not find `nonexistant` in the list of imported crates
+    }
+    fn crate_inner(_: crate::nonexistant::Foo) {
+        //~^ ERROR failed to resolve: could not find `nonexistant` in the crate root
+    }
+
+    fn bare_global(_: ::nonexistant) {
+        //~^ ERROR cannot find crate `nonexistant` in the list of imported crates
+    }
+    fn bare_crate(_: crate::nonexistant) {
+        //~^ ERROR cannot find type `nonexistant` in the crate root
+    }
+}
+
+fn main() {
+
+}
diff --git a/src/test/ui/editions-crate-root-2018.stderr b/src/test/ui/editions-crate-root-2018.stderr
new file mode 100644
index 00000000000..967a5a2fca1
--- /dev/null
+++ b/src/test/ui/editions-crate-root-2018.stderr
@@ -0,0 +1,28 @@
+error[E0433]: failed to resolve: could not find `nonexistant` in the list of imported crates
+  --> $DIR/editions-crate-root-2018.rs:4:26
+   |
+LL |     fn global_inner(_: ::nonexistant::Foo) {
+   |                          ^^^^^^^^^^^ could not find `nonexistant` in the list of imported crates
+
+error[E0433]: failed to resolve: could not find `nonexistant` in the crate root
+  --> $DIR/editions-crate-root-2018.rs:7:30
+   |
+LL |     fn crate_inner(_: crate::nonexistant::Foo) {
+   |                              ^^^^^^^^^^^ could not find `nonexistant` in the crate root
+
+error[E0412]: cannot find crate `nonexistant` in the list of imported crates
+  --> $DIR/editions-crate-root-2018.rs:11:25
+   |
+LL |     fn bare_global(_: ::nonexistant) {
+   |                         ^^^^^^^^^^^ not found in the list of imported crates
+
+error[E0412]: cannot find type `nonexistant` in the crate root
+  --> $DIR/editions-crate-root-2018.rs:14:29
+   |
+LL |     fn bare_crate(_: crate::nonexistant) {
+   |                             ^^^^^^^^^^^ not found in the crate root
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0412, E0433.
+For more information about an error, try `rustc --explain E0412`.
diff --git a/src/test/ui/editions/edition-imports-virtual-2015-gated.stderr b/src/test/ui/editions/edition-imports-virtual-2015-gated.stderr
index 06605c6f208..1cde0f72140 100644
--- a/src/test/ui/editions/edition-imports-virtual-2015-gated.stderr
+++ b/src/test/ui/editions/edition-imports-virtual-2015-gated.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `E`
   --> $DIR/edition-imports-virtual-2015-gated.rs:8:5
    |
 LL |     gen_gated!();
-   |     ^^^^^^^^^^^^^ could not find `E` in crate root
+   |     ^^^^^^^^^^^^^ could not find `E` in the list of imported crates
    |
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/src/test/ui/lint/type-overflow.stderr b/src/test/ui/lint/type-overflow.stderr
index 521223e3256..8a31fd44746 100644
--- a/src/test/ui/lint/type-overflow.stderr
+++ b/src/test/ui/lint/type-overflow.stderr
@@ -60,7 +60,8 @@ warning: literal out of range for `i8`
 LL |     let fail = -0b1111_1111i8;
    |                 ^^^^^^^^^^^^^ help: consider using the type `i16` instead: `0b1111_1111i16`
    |
-   = note: the literal `0b1111_1111i8` (decimal `255`) does not fit into the type `i8` and will become `-1i8`
+   = note: the literal `0b1111_1111i8` (decimal `255`) does not fit into the type `i8`
+   = note: and the value `-0b1111_1111i8` will become `1i8`
 
 warning: 7 warnings emitted
 
diff --git a/src/test/ui/lex-bare-cr-nondoc-comment.rs b/src/test/ui/parser/lex-bare-cr-nondoc-comment.rs
index 5b528d6e1e1..5b528d6e1e1 100644
--- a/src/test/ui/lex-bare-cr-nondoc-comment.rs
+++ b/src/test/ui/parser/lex-bare-cr-nondoc-comment.rs
diff --git a/src/test/ui/lexer-crlf-line-endings-string-literal-doc-comment.rs b/src/test/ui/parser/lexer-crlf-line-endings-string-literal-doc-comment.rs
index 802be7f5afb..802be7f5afb 100644
--- a/src/test/ui/lexer-crlf-line-endings-string-literal-doc-comment.rs
+++ b/src/test/ui/parser/lexer-crlf-line-endings-string-literal-doc-comment.rs
diff --git a/src/test/ui/pattern/issue-82290.stderr b/src/test/ui/pattern/issue-82290.stderr
index 65ef018dc97..666b1e785bf 100644
--- a/src/test/ui/pattern/issue-82290.stderr
+++ b/src/test/ui/pattern/issue-82290.stderr
@@ -4,8 +4,7 @@ error: `let` expressions are not supported here
 LL |     if true && let x = 1 {
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 warning: the feature `let_chains` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/issue-82290.rs:1:12
diff --git a/src/test/ui/resolve/raw-ident-in-path.rs b/src/test/ui/resolve/raw-ident-in-path.rs
index 1bcbef59437..7f1163bebde 100644
--- a/src/test/ui/resolve/raw-ident-in-path.rs
+++ b/src/test/ui/resolve/raw-ident-in-path.rs
@@ -1,5 +1,5 @@
 // Regression test for issue #63882.
 
-type A = crate::r#break; //~ ERROR cannot find type `r#break` in module `crate`
+type A = crate::r#break; //~ ERROR cannot find type `r#break` in the crate root
 
 fn main() {}
diff --git a/src/test/ui/resolve/raw-ident-in-path.stderr b/src/test/ui/resolve/raw-ident-in-path.stderr
index f2efcbc8e85..771dacbbb20 100644
--- a/src/test/ui/resolve/raw-ident-in-path.stderr
+++ b/src/test/ui/resolve/raw-ident-in-path.stderr
@@ -1,8 +1,8 @@
-error[E0412]: cannot find type `r#break` in module `crate`
+error[E0412]: cannot find type `r#break` in the crate root
   --> $DIR/raw-ident-in-path.rs:3:17
    |
 LL | type A = crate::r#break;
-   |                 ^^^^^^^ not found in `crate`
+   |                 ^^^^^^^ not found in the crate root
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs
index 61212f299be..def60feb5a6 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs
@@ -2,5 +2,5 @@
 
 fn main() {
     let s = ::xcrate::S;
-    //~^ ERROR failed to resolve: could not find `xcrate` in crate root
+    //~^ ERROR failed to resolve: could not find `xcrate` in the list of imported crates
 }
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr
index 8b2a6933f37..7df4f06d1c7 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve: could not find `xcrate` in crate root
+error[E0433]: failed to resolve: could not find `xcrate` in the list of imported crates
   --> $DIR/non-existent-2.rs:4:15
    |
 LL |     let s = ::xcrate::S;
-   |               ^^^^^^ could not find `xcrate` in crate root
+   |               ^^^^^^ could not find `xcrate` in the list of imported crates
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2294-if-let-guard/feature-gate.stderr b/src/test/ui/rfc-2294-if-let-guard/feature-gate.stderr
index 113870c19f5..00811fe3044 100644
--- a/src/test/ui/rfc-2294-if-let-guard/feature-gate.stderr
+++ b/src/test/ui/rfc-2294-if-let-guard/feature-gate.stderr
@@ -15,6 +15,7 @@ LL |         () if let 0 = 1 => {}
    |
    = note: see issue #51114 <https://github.com/rust-lang/rust/issues/51114> for more information
    = help: add `#![feature(if_let_guard)]` to the crate attributes to enable
+   = help: you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`
 
 error[E0658]: `if let` guards are experimental
   --> $DIR/feature-gate.rs:76:12
@@ -24,6 +25,7 @@ LL |         () if let 0 = 1 => {}
    |
    = note: see issue #51114 <https://github.com/rust-lang/rust/issues/51114> for more information
    = help: add `#![feature(if_let_guard)]` to the crate attributes to enable
+   = help: you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:10:16
@@ -33,6 +35,7 @@ LL |         () if (let 0 = 1) => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:14:18
@@ -42,6 +45,7 @@ LL |         () if (((let 0 = 1))) => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:18:23
@@ -51,6 +55,7 @@ LL |         () if true && let 0 = 1 => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:22:15
@@ -60,6 +65,7 @@ LL |         () if let 0 = 1 && true => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:26:16
@@ -69,6 +75,7 @@ LL |         () if (let 0 = 1) && true => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:30:24
@@ -78,6 +85,7 @@ LL |         () if true && (let 0 = 1) => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:34:16
@@ -87,6 +95,7 @@ LL |         () if (let 0 = 1) && (let 0 = 1) => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:34:31
@@ -96,6 +105,7 @@ LL |         () if (let 0 = 1) && (let 0 = 1) => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:40:15
@@ -105,6 +115,7 @@ LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 =
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:40:28
@@ -114,6 +125,7 @@ LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 =
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:40:42
@@ -123,6 +135,7 @@ LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 =
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:40:55
@@ -132,6 +145,7 @@ LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 =
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:40:68
@@ -141,6 +155,7 @@ LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 =
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:52:15
@@ -150,6 +165,7 @@ LL |         () if let Range { start: _, end: _ } = (true..true) && false => {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:68:16
@@ -159,6 +175,7 @@ LL |     use_expr!((let 0 = 1 && 0 == 0));
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:71:16
@@ -168,6 +185,7 @@ LL |     use_expr!((let 0 = 1));
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:10:16
@@ -175,8 +193,7 @@ error: `let` expressions are not supported here
 LL |         () if (let 0 = 1) => {}
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:14:18
@@ -184,8 +201,7 @@ error: `let` expressions are not supported here
 LL |         () if (((let 0 = 1))) => {}
    |                  ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:18:23
@@ -193,8 +209,7 @@ error: `let` expressions are not supported here
 LL |         () if true && let 0 = 1 => {}
    |                       ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:22:15
@@ -202,8 +217,7 @@ error: `let` expressions are not supported here
 LL |         () if let 0 = 1 && true => {}
    |               ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:26:16
@@ -211,8 +225,7 @@ error: `let` expressions are not supported here
 LL |         () if (let 0 = 1) && true => {}
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:30:24
@@ -220,8 +233,7 @@ error: `let` expressions are not supported here
 LL |         () if true && (let 0 = 1) => {}
    |                        ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:34:16
@@ -229,8 +241,7 @@ error: `let` expressions are not supported here
 LL |         () if (let 0 = 1) && (let 0 = 1) => {}
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:34:31
@@ -238,8 +249,7 @@ error: `let` expressions are not supported here
 LL |         () if (let 0 = 1) && (let 0 = 1) => {}
    |                               ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:40:15
@@ -247,8 +257,7 @@ error: `let` expressions are not supported here
 LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) => {}
    |               ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:40:28
@@ -256,8 +265,7 @@ error: `let` expressions are not supported here
 LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) => {}
    |                            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:40:42
@@ -265,8 +273,7 @@ error: `let` expressions are not supported here
 LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) => {}
    |                                          ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:40:55
@@ -274,8 +281,7 @@ error: `let` expressions are not supported here
 LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) => {}
    |                                                       ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:40:68
@@ -283,8 +289,7 @@ error: `let` expressions are not supported here
 LL |         () if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) => {}
    |                                                                    ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:52:15
@@ -292,8 +297,7 @@ error: `let` expressions are not supported here
 LL |         () if let Range { start: _, end: _ } = (true..true) && false => {}
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:68:16
@@ -301,8 +305,7 @@ error: `let` expressions are not supported here
 LL |     use_expr!((let 0 = 1 && 0 == 0));
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:71:16
@@ -310,8 +313,7 @@ error: `let` expressions are not supported here
 LL |     use_expr!((let 0 = 1));
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: aborting due to 35 previous errors
 
diff --git a/src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr b/src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr
index 861a4a80ad6..1adce5e0150 100644
--- a/src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr
+++ b/src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr
@@ -15,8 +15,7 @@ error: `let` expressions are not supported here
 LL |     if &let 0 = 0 {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:35:9
@@ -24,8 +23,7 @@ error: `let` expressions are not supported here
 LL |     if !let 0 = 0 {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:36:9
@@ -33,8 +31,7 @@ error: `let` expressions are not supported here
 LL |     if *let 0 = 0 {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:38:9
@@ -42,8 +39,7 @@ error: `let` expressions are not supported here
 LL |     if -let 0 = 0 {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:46:9
@@ -51,8 +47,7 @@ error: `let` expressions are not supported here
 LL |     if (let 0 = 0)? {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:50:16
@@ -60,8 +55,7 @@ error: `let` expressions are not supported here
 LL |     if true || let 0 = 0 {}
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:51:17
@@ -69,8 +63,7 @@ error: `let` expressions are not supported here
 LL |     if (true || let 0 = 0) {}
    |                 ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:52:25
@@ -78,8 +71,7 @@ error: `let` expressions are not supported here
 LL |     if true && (true || let 0 = 0) {}
    |                         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:53:25
@@ -87,8 +79,7 @@ error: `let` expressions are not supported here
 LL |     if true || (true && let 0 = 0) {}
    |                         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:56:12
@@ -96,8 +87,7 @@ error: `let` expressions are not supported here
 LL |     if x = let 0 = 0 {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:59:15
@@ -105,8 +95,7 @@ error: `let` expressions are not supported here
 LL |     if true..(let 0 = 0) {}
    |               ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:61:11
@@ -114,8 +103,7 @@ error: `let` expressions are not supported here
 LL |     if ..(let 0 = 0) {}
    |           ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:63:9
@@ -123,8 +111,7 @@ error: `let` expressions are not supported here
 LL |     if (let 0 = 0).. {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:67:8
@@ -132,8 +119,7 @@ error: `let` expressions are not supported here
 LL |     if let Range { start: _, end: _ } = true..true && false {}
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:71:8
@@ -141,8 +127,7 @@ error: `let` expressions are not supported here
 LL |     if let Range { start: _, end: _ } = true..true || false {}
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:78:8
@@ -150,8 +135,7 @@ error: `let` expressions are not supported here
 LL |     if let Range { start: F, end } = F..|| true {}
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:86:8
@@ -159,8 +143,7 @@ error: `let` expressions are not supported here
 LL |     if let Range { start: true, end } = t..&&false {}
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:92:19
@@ -168,8 +151,7 @@ error: `let` expressions are not supported here
 LL |     if let true = let true = true {}
    |                   ^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:96:12
@@ -177,8 +159,7 @@ error: `let` expressions are not supported here
 LL |     while &let 0 = 0 {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:99:12
@@ -186,8 +167,7 @@ error: `let` expressions are not supported here
 LL |     while !let 0 = 0 {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:100:12
@@ -195,8 +175,7 @@ error: `let` expressions are not supported here
 LL |     while *let 0 = 0 {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:102:12
@@ -204,8 +183,7 @@ error: `let` expressions are not supported here
 LL |     while -let 0 = 0 {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:110:12
@@ -213,8 +191,7 @@ error: `let` expressions are not supported here
 LL |     while (let 0 = 0)? {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:114:19
@@ -222,8 +199,7 @@ error: `let` expressions are not supported here
 LL |     while true || let 0 = 0 {}
    |                   ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:115:20
@@ -231,8 +207,7 @@ error: `let` expressions are not supported here
 LL |     while (true || let 0 = 0) {}
    |                    ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:116:28
@@ -240,8 +215,7 @@ error: `let` expressions are not supported here
 LL |     while true && (true || let 0 = 0) {}
    |                            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:117:28
@@ -249,8 +223,7 @@ error: `let` expressions are not supported here
 LL |     while true || (true && let 0 = 0) {}
    |                            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:120:15
@@ -258,8 +231,7 @@ error: `let` expressions are not supported here
 LL |     while x = let 0 = 0 {}
    |               ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:123:18
@@ -267,8 +239,7 @@ error: `let` expressions are not supported here
 LL |     while true..(let 0 = 0) {}
    |                  ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:125:14
@@ -276,8 +247,7 @@ error: `let` expressions are not supported here
 LL |     while ..(let 0 = 0) {}
    |              ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:127:12
@@ -285,8 +255,7 @@ error: `let` expressions are not supported here
 LL |     while (let 0 = 0).. {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:131:11
@@ -294,8 +263,7 @@ error: `let` expressions are not supported here
 LL |     while let Range { start: _, end: _ } = true..true && false {}
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:135:11
@@ -303,8 +271,7 @@ error: `let` expressions are not supported here
 LL |     while let Range { start: _, end: _ } = true..true || false {}
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:142:11
@@ -312,8 +279,7 @@ error: `let` expressions are not supported here
 LL |     while let Range { start: F, end } = F..|| true {}
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:150:11
@@ -321,8 +287,7 @@ error: `let` expressions are not supported here
 LL |     while let Range { start: true, end } = t..&&false {}
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:156:22
@@ -330,8 +295,7 @@ error: `let` expressions are not supported here
 LL |     while let true = let true = true {}
    |                      ^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:170:6
@@ -339,8 +303,7 @@ error: `let` expressions are not supported here
 LL |     &let 0 = 0;
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:172:6
@@ -348,8 +311,7 @@ error: `let` expressions are not supported here
 LL |     !let 0 = 0;
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:173:6
@@ -357,8 +319,7 @@ error: `let` expressions are not supported here
 LL |     *let 0 = 0;
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:175:6
@@ -366,8 +327,7 @@ error: `let` expressions are not supported here
 LL |     -let 0 = 0;
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:183:6
@@ -375,8 +335,7 @@ error: `let` expressions are not supported here
 LL |     (let 0 = 0)?;
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:187:13
@@ -384,8 +343,7 @@ error: `let` expressions are not supported here
 LL |     true || let 0 = 0;
    |             ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:188:14
@@ -393,8 +351,7 @@ error: `let` expressions are not supported here
 LL |     (true || let 0 = 0);
    |              ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:189:22
@@ -402,8 +359,7 @@ error: `let` expressions are not supported here
 LL |     true && (true || let 0 = 0);
    |                      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:192:9
@@ -411,8 +367,7 @@ error: `let` expressions are not supported here
 LL |     x = let 0 = 0;
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:194:12
@@ -420,8 +375,7 @@ error: `let` expressions are not supported here
 LL |     true..(let 0 = 0);
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:195:8
@@ -429,8 +383,7 @@ error: `let` expressions are not supported here
 LL |     ..(let 0 = 0);
    |        ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:196:6
@@ -438,8 +391,7 @@ error: `let` expressions are not supported here
 LL |     (let 0 = 0)..;
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:198:6
@@ -447,8 +399,7 @@ error: `let` expressions are not supported here
 LL |     (let Range { start: _, end: _ } = true..true || false);
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:202:6
@@ -456,8 +407,7 @@ error: `let` expressions are not supported here
 LL |     (let true = let true = true);
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:202:17
@@ -465,8 +415,7 @@ error: `let` expressions are not supported here
 LL |     (let true = let true = true);
    |                 ^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:207:6
@@ -474,8 +423,7 @@ error: `let` expressions are not supported here
 LL |     &let 0 = 0
    |      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:218:17
@@ -483,8 +431,7 @@ error: `let` expressions are not supported here
 LL |         true && let 1 = 1
    |                 ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:222:17
@@ -492,8 +439,7 @@ error: `let` expressions are not supported here
 LL |         true && let 1 = 1
    |                 ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:226:17
@@ -501,8 +447,7 @@ error: `let` expressions are not supported here
 LL |         true && let 1 = 1
    |                 ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/disallowed-positions.rs:236:17
@@ -510,8 +455,7 @@ error: `let` expressions are not supported here
 LL |         true && let 1 = 1
    |                 ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 warning: the feature `const_generics` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/disallowed-positions.rs:20:12
diff --git a/src/test/ui/rfc-2497-if-let-chains/feature-gate.rs b/src/test/ui/rfc-2497-if-let-chains/feature-gate.rs
index f5cb1860d47..0b38b5f47ef 100644
--- a/src/test/ui/rfc-2497-if-let-chains/feature-gate.rs
+++ b/src/test/ui/rfc-2497-if-let-chains/feature-gate.rs
@@ -13,11 +13,11 @@ fn _if() {
 
     if (let 0 = 1) {}
     //~^ ERROR `let` expressions in this position are experimental [E0658]
-    //~| ERROR `let` expressions are not supported here
+    //~| ERROR invalid parentheses around `let` expression in `if let`
 
     if (((let 0 = 1))) {}
     //~^ ERROR `let` expressions in this position are experimental [E0658]
-    //~| ERROR `let` expressions are not supported here
+    //~| ERROR invalid parentheses around `let` expression in `if let`
 
     if true && let 0 = 1 {}
     //~^ ERROR `let` expressions in this position are experimental [E0658]
@@ -126,7 +126,7 @@ fn _macros() {
     //~| ERROR `let` expressions are not supported here
     use_expr!((let 0 = 1));
     //~^ ERROR `let` expressions in this position are experimental [E0658]
-    //~| ERROR `let` expressions are not supported here
+    //~| ERROR invalid parentheses around `let` expression in `if let`
     //~| ERROR `let` expressions are not supported here
     #[cfg(FALSE)] (let 0 = 1);
     //~^ ERROR `let` expressions in this position are experimental [E0658]
diff --git a/src/test/ui/rfc-2497-if-let-chains/feature-gate.stderr b/src/test/ui/rfc-2497-if-let-chains/feature-gate.stderr
index 178e8627287..7364f62c922 100644
--- a/src/test/ui/rfc-2497-if-let-chains/feature-gate.stderr
+++ b/src/test/ui/rfc-2497-if-let-chains/feature-gate.stderr
@@ -15,6 +15,7 @@ LL |     if (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:18:11
@@ -24,6 +25,7 @@ LL |     if (((let 0 = 1))) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:22:16
@@ -33,6 +35,7 @@ LL |     if true && let 0 = 1 {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:26:8
@@ -42,6 +45,7 @@ LL |     if let 0 = 1 && true {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:30:9
@@ -51,6 +55,7 @@ LL |     if (let 0 = 1) && true {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:34:17
@@ -60,6 +65,7 @@ LL |     if true && (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:38:9
@@ -69,6 +75,7 @@ LL |     if (let 0 = 1) && (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:38:24
@@ -78,6 +85,7 @@ LL |     if (let 0 = 1) && (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:44:8
@@ -87,6 +95,7 @@ LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:44:21
@@ -96,6 +105,7 @@ LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:44:35
@@ -105,6 +115,7 @@ LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:44:48
@@ -114,6 +125,7 @@ LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:44:61
@@ -123,6 +135,7 @@ LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:56:8
@@ -132,6 +145,7 @@ LL |     if let Range { start: _, end: _ } = (true..true) && false {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:64:12
@@ -141,6 +155,7 @@ LL |     while (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:68:14
@@ -150,6 +165,7 @@ LL |     while (((let 0 = 1))) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:72:19
@@ -159,6 +175,7 @@ LL |     while true && let 0 = 1 {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:76:11
@@ -168,6 +185,7 @@ LL |     while let 0 = 1 && true {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:80:12
@@ -177,6 +195,7 @@ LL |     while (let 0 = 1) && true {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:84:20
@@ -186,6 +205,7 @@ LL |     while true && (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:88:12
@@ -195,6 +215,7 @@ LL |     while (let 0 = 1) && (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:88:27
@@ -204,6 +225,7 @@ LL |     while (let 0 = 1) && (let 0 = 1) {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:94:11
@@ -213,6 +235,7 @@ LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:94:24
@@ -222,6 +245,7 @@ LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:94:38
@@ -231,6 +255,7 @@ LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:94:51
@@ -240,6 +265,7 @@ LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:94:64
@@ -249,6 +275,7 @@ LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:106:11
@@ -258,6 +285,7 @@ LL |     while let Range { start: _, end: _ } = (true..true) && false {}
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:131:20
@@ -267,6 +295,7 @@ LL |     #[cfg(FALSE)] (let 0 = 1);
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:114:17
@@ -276,6 +305,7 @@ LL |     noop_expr!((let 0 = 1));
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:123:16
@@ -285,6 +315,7 @@ LL |     use_expr!((let 0 = 1 && 0 == 0));
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
 error[E0658]: `let` expressions in this position are experimental
   --> $DIR/feature-gate.rs:127:16
@@ -294,24 +325,29 @@ LL |     use_expr!((let 0 = 1));
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
    = help: add `#![feature(let_chains)]` to the crate attributes to enable
+   = help: you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`
 
-error: `let` expressions are not supported here
-  --> $DIR/feature-gate.rs:14:9
+error: invalid parentheses around `let` expression in `if let`
+  --> $DIR/feature-gate.rs:14:8
    |
 LL |     if (let 0 = 1) {}
-   |         ^^^^^^^^^
+   |        ^         ^
+   |
+help: `if let` needs to be written without parentheses
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+LL |     if let 0 = 1 {}
+   |       --       --
 
-error: `let` expressions are not supported here
-  --> $DIR/feature-gate.rs:18:11
+error: invalid parentheses around `let` expression in `if let`
+  --> $DIR/feature-gate.rs:18:8
    |
 LL |     if (((let 0 = 1))) {}
-   |           ^^^^^^^^^
+   |        ^^^         ^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+help: `if let` needs to be written without parentheses
+   |
+LL |     if let 0 = 1 {}
+   |       --       --
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:22:16
@@ -319,8 +355,7 @@ error: `let` expressions are not supported here
 LL |     if true && let 0 = 1 {}
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:26:8
@@ -328,8 +363,7 @@ error: `let` expressions are not supported here
 LL |     if let 0 = 1 && true {}
    |        ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:30:9
@@ -337,8 +371,7 @@ error: `let` expressions are not supported here
 LL |     if (let 0 = 1) && true {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:34:17
@@ -346,8 +379,7 @@ error: `let` expressions are not supported here
 LL |     if true && (let 0 = 1) {}
    |                 ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:38:9
@@ -355,8 +387,7 @@ error: `let` expressions are not supported here
 LL |     if (let 0 = 1) && (let 0 = 1) {}
    |         ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:38:24
@@ -364,8 +395,7 @@ error: `let` expressions are not supported here
 LL |     if (let 0 = 1) && (let 0 = 1) {}
    |                        ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:44:8
@@ -373,8 +403,7 @@ error: `let` expressions are not supported here
 LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |        ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:44:21
@@ -382,8 +411,7 @@ error: `let` expressions are not supported here
 LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                     ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:44:35
@@ -391,8 +419,7 @@ error: `let` expressions are not supported here
 LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                                   ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:44:48
@@ -400,8 +427,7 @@ error: `let` expressions are not supported here
 LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                                                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:44:61
@@ -409,8 +435,7 @@ error: `let` expressions are not supported here
 LL |     if let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                                                             ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:56:8
@@ -418,8 +443,7 @@ error: `let` expressions are not supported here
 LL |     if let Range { start: _, end: _ } = (true..true) && false {}
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:64:12
@@ -427,8 +451,7 @@ error: `let` expressions are not supported here
 LL |     while (let 0 = 1) {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:68:14
@@ -436,8 +459,7 @@ error: `let` expressions are not supported here
 LL |     while (((let 0 = 1))) {}
    |              ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:72:19
@@ -445,8 +467,7 @@ error: `let` expressions are not supported here
 LL |     while true && let 0 = 1 {}
    |                   ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:76:11
@@ -454,8 +475,7 @@ error: `let` expressions are not supported here
 LL |     while let 0 = 1 && true {}
    |           ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:80:12
@@ -463,8 +483,7 @@ error: `let` expressions are not supported here
 LL |     while (let 0 = 1) && true {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:84:20
@@ -472,8 +491,7 @@ error: `let` expressions are not supported here
 LL |     while true && (let 0 = 1) {}
    |                    ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:88:12
@@ -481,8 +499,7 @@ error: `let` expressions are not supported here
 LL |     while (let 0 = 1) && (let 0 = 1) {}
    |            ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:88:27
@@ -490,8 +507,7 @@ error: `let` expressions are not supported here
 LL |     while (let 0 = 1) && (let 0 = 1) {}
    |                           ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:94:11
@@ -499,8 +515,7 @@ error: `let` expressions are not supported here
 LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |           ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:94:24
@@ -508,8 +523,7 @@ error: `let` expressions are not supported here
 LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                        ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:94:38
@@ -517,8 +531,7 @@ error: `let` expressions are not supported here
 LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                                      ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:94:51
@@ -526,8 +539,7 @@ error: `let` expressions are not supported here
 LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                                                   ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:94:64
@@ -535,8 +547,7 @@ error: `let` expressions are not supported here
 LL |     while let 0 = 1 && let 1 = 2 && (let 2 = 3 && let 3 = 4 && let 4 = 5) {}
    |                                                                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:106:11
@@ -544,8 +555,7 @@ error: `let` expressions are not supported here
 LL |     while let Range { start: _, end: _ } = (true..true) && false {}
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:123:16
@@ -553,8 +563,7 @@ error: `let` expressions are not supported here
 LL |     use_expr!((let 0 = 1 && 0 == 0));
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:123:16
@@ -562,17 +571,18 @@ error: `let` expressions are not supported here
 LL |     use_expr!((let 0 = 1 && 0 == 0));
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
-error: `let` expressions are not supported here
-  --> $DIR/feature-gate.rs:127:16
+error: invalid parentheses around `let` expression in `if let`
+  --> $DIR/feature-gate.rs:127:15
    |
 LL |     use_expr!((let 0 = 1));
-   |                ^^^^^^^^^
+   |               ^         ^
+   |
+help: `if let` needs to be written without parentheses
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+LL |     use_expr!(let 0 = 1);
+   |              --       --
 
 error: `let` expressions are not supported here
   --> $DIR/feature-gate.rs:127:16
@@ -580,8 +590,7 @@ error: `let` expressions are not supported here
 LL |     use_expr!((let 0 = 1));
    |                ^^^^^^^^^
    |
-   = note: only supported directly in conditions of `if`- and `while`-expressions
-   = note: as well as when nested within `&&` and parenthesis in those conditions
+   = note: only supported directly without parentheses in conditions of `if`- and `while`-expressions, as well as in `let` chains within parentheses
 
 error: aborting due to 65 previous errors
 
diff --git a/src/test/ui/rustdoc/README.md b/src/test/ui/rustdoc/README.md
new file mode 100644
index 00000000000..1c98ab038ab
--- /dev/null
+++ b/src/test/ui/rustdoc/README.md
@@ -0,0 +1,3 @@
+This directory is for tests that have to do with rustdoc, but test the behavior
+of rustc. For example, rustc should not warn that an attribute rustdoc uses is
+unknown.
diff --git a/src/test/ui/cfg-rustdoc.rs b/src/test/ui/rustdoc/cfg-rustdoc.rs
index dd8e1ed97c4..dd8e1ed97c4 100644
--- a/src/test/ui/cfg-rustdoc.rs
+++ b/src/test/ui/rustdoc/cfg-rustdoc.rs
diff --git a/src/test/ui/cfg-rustdoc.stderr b/src/test/ui/rustdoc/cfg-rustdoc.stderr
index c687d186989..c687d186989 100644
--- a/src/test/ui/cfg-rustdoc.stderr
+++ b/src/test/ui/rustdoc/cfg-rustdoc.stderr
diff --git a/src/test/ui/check-doc-alias-attr-location.rs b/src/test/ui/rustdoc/check-doc-alias-attr-location.rs
index 007d2ae6506..007d2ae6506 100644
--- a/src/test/ui/check-doc-alias-attr-location.rs
+++ b/src/test/ui/rustdoc/check-doc-alias-attr-location.rs
diff --git a/src/test/ui/check-doc-alias-attr-location.stderr b/src/test/ui/rustdoc/check-doc-alias-attr-location.stderr
index a66e9939eaf..a66e9939eaf 100644
--- a/src/test/ui/check-doc-alias-attr-location.stderr
+++ b/src/test/ui/rustdoc/check-doc-alias-attr-location.stderr
diff --git a/src/test/ui/check-doc-alias-attr.rs b/src/test/ui/rustdoc/check-doc-alias-attr.rs
index 912e35f9165..912e35f9165 100644
--- a/src/test/ui/check-doc-alias-attr.rs
+++ b/src/test/ui/rustdoc/check-doc-alias-attr.rs
diff --git a/src/test/ui/check-doc-alias-attr.stderr b/src/test/ui/rustdoc/check-doc-alias-attr.stderr
index 1c7fc83bb8d..1c7fc83bb8d 100644
--- a/src/test/ui/check-doc-alias-attr.stderr
+++ b/src/test/ui/rustdoc/check-doc-alias-attr.stderr
diff --git a/src/test/ui/doc-alias-crate-level.rs b/src/test/ui/rustdoc/doc-alias-crate-level.rs
index c7783aae5ea..c7783aae5ea 100644
--- a/src/test/ui/doc-alias-crate-level.rs
+++ b/src/test/ui/rustdoc/doc-alias-crate-level.rs
diff --git a/src/test/ui/doc-alias-crate-level.stderr b/src/test/ui/rustdoc/doc-alias-crate-level.stderr
index c0467514ae1..c0467514ae1 100644
--- a/src/test/ui/doc-alias-crate-level.stderr
+++ b/src/test/ui/rustdoc/doc-alias-crate-level.stderr
diff --git a/src/test/ui/doc-alias-same-name.rs b/src/test/ui/rustdoc/doc-alias-same-name.rs
index da97c267618..da97c267618 100644
--- a/src/test/ui/doc-alias-same-name.rs
+++ b/src/test/ui/rustdoc/doc-alias-same-name.rs
diff --git a/src/test/ui/doc-alias-same-name.stderr b/src/test/ui/rustdoc/doc-alias-same-name.stderr
index 5ba09a2eae1..5ba09a2eae1 100644
--- a/src/test/ui/doc-alias-same-name.stderr
+++ b/src/test/ui/rustdoc/doc-alias-same-name.stderr
diff --git a/src/test/ui/doc_keyword.rs b/src/test/ui/rustdoc/doc_keyword.rs
index 4c72e7e9684..4c72e7e9684 100644
--- a/src/test/ui/doc_keyword.rs
+++ b/src/test/ui/rustdoc/doc_keyword.rs
diff --git a/src/test/ui/doc_keyword.stderr b/src/test/ui/rustdoc/doc_keyword.stderr
index d72a876163e..d72a876163e 100644
--- a/src/test/ui/doc_keyword.stderr
+++ b/src/test/ui/rustdoc/doc_keyword.stderr
diff --git a/src/test/ui/unterminated-doc-comment.rs b/src/test/ui/rustdoc/unterminated-doc-comment.rs
index 82546fe73da..82546fe73da 100644
--- a/src/test/ui/unterminated-doc-comment.rs
+++ b/src/test/ui/rustdoc/unterminated-doc-comment.rs
diff --git a/src/test/ui/unterminated-doc-comment.stderr b/src/test/ui/rustdoc/unterminated-doc-comment.stderr
index 2d5e537973e..2d5e537973e 100644
--- a/src/test/ui/unterminated-doc-comment.stderr
+++ b/src/test/ui/rustdoc/unterminated-doc-comment.stderr
diff --git a/src/tools/tidy/src/ui_tests.rs b/src/tools/tidy/src/ui_tests.rs
index c69bdca7611..3374a8c9b73 100644
--- a/src/tools/tidy/src/ui_tests.rs
+++ b/src/tools/tidy/src/ui_tests.rs
@@ -7,7 +7,7 @@ use std::path::Path;
 
 const ENTRY_LIMIT: usize = 1000;
 // FIXME: The following limits should be reduced eventually.
-const ROOT_ENTRY_LIMIT: usize = 1418;
+const ROOT_ENTRY_LIMIT: usize = 1408;
 const ISSUES_ENTRY_LIMIT: usize = 2565;
 
 fn check_entries(path: &Path, bad: &mut bool) {