Remove let_chains feature

7 files changed, 304 insertions, 351 deletions

diff --git a/tests/ui/drop/drop-order-comparisons-let-chains.rs b/tests/ui/drop/drop-order-comparisons-let-chains.rs
new file mode 100644
index 00000000000..5dea5e1a580
--- /dev/null
+++ b/tests/ui/drop/drop-order-comparisons-let-chains.rs
@@ -0,0 +1,145 @@
+// See drop-order-comparisons.rs
+
+//@ edition: 2024
+//@ run-pass
+
+#![feature(if_let_guard)]
+
+fn t_if_let_chains_then() {
+    let e = Events::new();
+    _ = if e.ok(1).is_ok()
+        && let true = e.ok(9).is_ok()
+        && let Ok(_v) = e.ok(8)
+        && let Ok(_) = e.ok(7)
+        && let Ok(_) = e.ok(6).as_ref()
+        && e.ok(2).is_ok()
+        && let Ok(_v) = e.ok(5)
+        && let Ok(_) = e.ok(4).as_ref() {
+            e.mark(3);
+        };
+    e.assert(9);
+}
+
+fn t_guard_if_let_chains_then() {
+    let e = Events::new();
+    _ = match () {
+        () if e.ok(1).is_ok()
+            && let true = e.ok(9).is_ok()
+            && let Ok(_v) = e.ok(8)
+            && let Ok(_) = e.ok(7)
+            && let Ok(_) = e.ok(6).as_ref()
+            && e.ok(2).is_ok()
+            && let Ok(_v) = e.ok(5)
+            && let Ok(_) = e.ok(4).as_ref() => {
+                e.mark(3);
+            }
+        _ => {}
+    };
+    e.assert(9);
+}
+
+fn t_if_let_chains_then_else() {
+    let e = Events::new();
+    _ = if e.ok(1).is_ok()
+        && let true = e.ok(8).is_ok()
+        && let Ok(_v) = e.ok(7)
+        && let Ok(_) = e.ok(6)
+        && let Ok(_) = e.ok(5).as_ref()
+        && e.ok(2).is_ok()
+        && let Ok(_v) = e.ok(4)
+        && let Ok(_) = e.err(3) {} else {
+            e.mark(9);
+        };
+    e.assert(9);
+}
+
+fn t_guard_if_let_chains_then_else() {
+    let e = Events::new();
+    _ = match () {
+       () if e.ok(1).is_ok()
+            && let true = e.ok(8).is_ok()
+            && let Ok(_v) = e.ok(7)
+            && let Ok(_) = e.ok(6)
+            && let Ok(_) = e.ok(5).as_ref()
+            && e.ok(2).is_ok()
+            && let Ok(_v) = e.ok(4)
+            && let Ok(_) = e.err(3) => {}
+        _ => {
+            e.mark(9);
+        }
+    };
+    e.assert(9);
+}
+
+fn main() {
+    t_if_let_chains_then();
+    t_guard_if_let_chains_then();
+    t_if_let_chains_then_else();
+    t_guard_if_let_chains_then_else();
+}
+
+// # Test scaffolding
+
+use core::cell::RefCell;
+use std::collections::HashSet;
+
+/// A buffer to track the order of events.
+///
+/// First, numbered events are logged into this buffer.
+///
+/// Then, `assert` is called to verify that the correct number of
+/// events were logged, and that they were logged in the expected
+/// order.
+struct Events(RefCell<Option<Vec<u64>>>);
+
+impl Events {
+    const fn new() -> Self {
+        Self(RefCell::new(Some(Vec::new())))
+    }
+    #[track_caller]
+    fn assert(&self, max: u64) {
+        let buf = &self.0;
+        let v1 = buf.borrow().as_ref().unwrap().clone();
+        let mut v2 = buf.borrow().as_ref().unwrap().clone();
+        *buf.borrow_mut() = None;
+        v2.sort();
+        let uniq_len = v2.iter().collect::<HashSet<_>>().len();
+        // Check that the sequence is sorted.
+        assert_eq!(v1, v2);
+        // Check that there are no duplicates.
+        assert_eq!(v2.len(), uniq_len);
+        // Check that the length is the expected one.
+        assert_eq!(max, uniq_len as u64);
+        // Check that the last marker is the expected one.
+        assert_eq!(v2.last().unwrap(), &max);
+    }
+    /// Return an `Ok` value that logs its drop.
+    fn ok(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> {
+        Ok(LogDrop(self, m))
+    }
+    /// Return an `Err` value that logs its drop.
+    fn err(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> {
+        Err(LogDrop(self, m))
+    }
+    /// Log an event.
+    fn mark(&self, m: u64) {
+        self.0.borrow_mut().as_mut().unwrap().push(m);
+    }
+}
+
+impl Drop for Events {
+    fn drop(&mut self) {
+        if self.0.borrow().is_some() {
+            panic!("failed to call `Events::assert()`");
+        }
+    }
+}
+
+/// A type that logs its drop events.
+struct LogDrop<'b>(&'b Events, u64);
+
+impl<'b> Drop for LogDrop<'b> {
+    fn drop(&mut self) {
+        self.0.mark(self.1);
+    }
+}
diff --git a/tests/ui/drop/drop-order-comparisons.e2021.fixed b/tests/ui/drop/drop-order-comparisons.e2021.fixed
index 42f805923ec..b0f6eb93f70 100644
--- a/tests/ui/drop/drop-order-comparisons.e2021.fixed
+++ b/tests/ui/drop/drop-order-comparisons.e2021.fixed
@@ -1,3 +1,6 @@
+// N.B. drop-order-comparisons-let-chains.rs is part of this test.
+// It is separate because let chains cannot be parsed before Rust 2024.
+//
 // This tests various aspects of the drop order with a focus on:
 //
 // - The lifetime of temporaries with the `if let` construct (and with
@@ -25,7 +28,6 @@
 //@ run-pass
 
 #![feature(if_let_guard)]
-#![cfg_attr(e2021, feature(let_chains))]
 #![cfg_attr(e2021, warn(rust_2024_compatibility))]
 
 fn t_bindings() {
@@ -313,59 +315,6 @@ fn t_let_else_chained_then() {
 
 #[cfg(e2021)]
 #[rustfmt::skip]
-fn t_if_let_chains_then() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(9).is_ok()
-        && let Ok(_v) = e.ok(5)
-        && let Ok(_) = e.ok(8)
-        && let Ok(_) = e.ok(7).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(4)
-        && let Ok(_) = e.ok(6).as_ref() {
-            e.mark(3);
-        };
-    e.assert(9);
-}
-
-#[cfg(e2024)]
-#[rustfmt::skip]
-fn t_if_let_chains_then() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(9).is_ok()
-        && let Ok(_v) = e.ok(8)
-        && let Ok(_) = e.ok(7)
-        && let Ok(_) = e.ok(6).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(5)
-        && let Ok(_) = e.ok(4).as_ref() {
-            e.mark(3);
-        };
-    e.assert(9);
-}
-
-#[rustfmt::skip]
-fn t_guard_if_let_chains_then() {
-    let e = Events::new();
-    _ = match () {
-        () if e.ok(1).is_ok()
-            && let true = e.ok(9).is_ok()
-            && let Ok(_v) = e.ok(8)
-            && let Ok(_) = e.ok(7)
-            && let Ok(_) = e.ok(6).as_ref()
-            && e.ok(2).is_ok()
-            && let Ok(_v) = e.ok(5)
-            && let Ok(_) = e.ok(4).as_ref() => {
-                e.mark(3);
-            }
-        _ => {}
-    };
-    e.assert(9);
-}
-
-#[cfg(e2021)]
-#[rustfmt::skip]
 fn t_if_let_nested_else() {
     let e = Events::new();
     _ = if e.err(1).is_ok() {} else {
@@ -470,59 +419,6 @@ fn t_let_else_chained_then_else() {
     e.assert(9);
 }
 
-#[cfg(e2021)]
-#[rustfmt::skip]
-fn t_if_let_chains_then_else() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(9).is_ok()
-        && let Ok(_v) = e.ok(4)
-        && let Ok(_) = e.ok(8)
-        && let Ok(_) = e.ok(7).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(3)
-        && let Ok(_) = e.err(6) {} else {
-            e.mark(5);
-        };
-    e.assert(9);
-}
-
-#[cfg(e2024)]
-#[rustfmt::skip]
-fn t_if_let_chains_then_else() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(8).is_ok()
-        && let Ok(_v) = e.ok(7)
-        && let Ok(_) = e.ok(6)
-        && let Ok(_) = e.ok(5).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(4)
-        && let Ok(_) = e.err(3) {} else {
-            e.mark(9);
-        };
-    e.assert(9);
-}
-
-#[rustfmt::skip]
-fn t_guard_if_let_chains_then_else() {
-    let e = Events::new();
-    _ = match () {
-       () if e.ok(1).is_ok()
-            && let true = e.ok(8).is_ok()
-            && let Ok(_v) = e.ok(7)
-            && let Ok(_) = e.ok(6)
-            && let Ok(_) = e.ok(5).as_ref()
-            && e.ok(2).is_ok()
-            && let Ok(_v) = e.ok(4)
-            && let Ok(_) = e.err(3) => {}
-        _ => {
-            e.mark(9);
-        }
-    };
-    e.assert(9);
-}
-
 fn main() {
     t_bindings();
     t_tuples();
@@ -540,13 +436,9 @@ fn main() {
     t_if_let_else_tailexpr();
     t_if_let_nested_then();
     t_let_else_chained_then();
-    t_if_let_chains_then();
-    t_guard_if_let_chains_then();
     t_if_let_nested_else();
     t_if_let_nested_then_else();
     t_let_else_chained_then_else();
-    t_if_let_chains_then_else();
-    t_guard_if_let_chains_then_else();
 }
 
 // # Test scaffolding
diff --git a/tests/ui/drop/drop-order-comparisons.e2021.stderr b/tests/ui/drop/drop-order-comparisons.e2021.stderr
index 8b93376cc0d..15a3f274514 100644
--- a/tests/ui/drop/drop-order-comparisons.e2021.stderr
+++ b/tests/ui/drop/drop-order-comparisons.e2021.stderr
@@ -1,5 +1,5 @@
 warning: relative drop order changing in Rust 2024
-  --> $DIR/drop-order-comparisons.rs:77:9
+  --> $DIR/drop-order-comparisons.rs:79:9
    |
 LL |       _ = ({
    |  _________-
@@ -29,35 +29,35 @@ LL | |     }, e.mark(3), e.ok(4));
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-tail-expr-scope.html>
 note: `#3` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `#1` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `_v` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `#2` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 note: the lint level is defined here
-  --> $DIR/drop-order-comparisons.rs:29:25
+  --> $DIR/drop-order-comparisons.rs:31:25
    |
 LL | #![cfg_attr(e2021, warn(rust_2024_compatibility))]
    |                         ^^^^^^^^^^^^^^^^^^^^^^^
    = note: `#[warn(tail_expr_drop_order)]` implied by `#[warn(rust_2024_compatibility)]`
 
 warning: relative drop order changing in Rust 2024
-  --> $DIR/drop-order-comparisons.rs:101:45
+  --> $DIR/drop-order-comparisons.rs:103:45
    |
 LL |       _ = ({
    |  _________-
@@ -77,19 +77,19 @@ LL | |     }, e.mark(1), e.ok(4));
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-tail-expr-scope.html>
 note: `#2` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `#1` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 
 warning: relative drop order changing in Rust 2024
-  --> $DIR/drop-order-comparisons.rs:101:19
+  --> $DIR/drop-order-comparisons.rs:103:19
    |
 LL |       _ = ({
    |  _________-
@@ -109,19 +109,19 @@ LL | |     }, e.mark(1), e.ok(4));
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-tail-expr-scope.html>
 note: `#2` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `#1` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 
 warning: relative drop order changing in Rust 2024
-  --> $DIR/drop-order-comparisons.rs:222:24
+  --> $DIR/drop-order-comparisons.rs:224:24
    |
 LL |       _ = ({
    |  _________-
@@ -141,19 +141,19 @@ LL | |     }, e.mark(2), e.ok(3));
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-tail-expr-scope.html>
 note: `#2` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `#1` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 
 warning: relative drop order changing in Rust 2024
-  --> $DIR/drop-order-comparisons.rs:248:24
+  --> $DIR/drop-order-comparisons.rs:250:24
    |
 LL |       _ = ({
    |  _________-
@@ -173,19 +173,19 @@ LL | |     }, e.mark(2), e.ok(3));
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-tail-expr-scope.html>
 note: `#2` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `#1` invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:124:13
+  --> $DIR/drop-order-comparisons.rs:126:13
    |
 LL |     _ = (if let Ok(_) = e.ok(4).as_ref() {
    |             ^^^^^^^^^^^^-------^^^^^^^^^
@@ -195,12 +195,12 @@ LL |     _ = (if let Ok(_) = e.ok(4).as_ref() {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:128:5
+  --> $DIR/drop-order-comparisons.rs:130:5
    |
 LL |     }, e.mark(2), e.ok(3));
    |     ^
@@ -215,7 +215,7 @@ LL ~     } _ => {}}, e.mark(2), e.ok(3));
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:146:13
+  --> $DIR/drop-order-comparisons.rs:148:13
    |
 LL |     _ = (if let Ok(_) = e.err(4).as_ref() {} else {
    |             ^^^^^^^^^^^^--------^^^^^^^^^
@@ -225,12 +225,12 @@ LL |     _ = (if let Ok(_) = e.err(4).as_ref() {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:146:44
+  --> $DIR/drop-order-comparisons.rs:148:44
    |
 LL |     _ = (if let Ok(_) = e.err(4).as_ref() {} else {
    |                                            ^
@@ -244,7 +244,7 @@ LL ~     }}, e.mark(2), e.ok(3));
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:248:12
+  --> $DIR/drop-order-comparisons.rs:250:12
    |
 LL |         if let Ok(_) = e.err(4).as_ref() {} else {
    |            ^^^^^^^^^^^^--------^^^^^^^^^
@@ -254,12 +254,12 @@ LL |         if let Ok(_) = e.err(4).as_ref() {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:248:43
+  --> $DIR/drop-order-comparisons.rs:250:43
    |
 LL |         if let Ok(_) = e.err(4).as_ref() {} else {
    |                                           ^
@@ -273,7 +273,7 @@ LL ~         }}
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:372:12
+  --> $DIR/drop-order-comparisons.rs:321:12
    |
 LL |         if let true = e.err(9).is_ok() {} else {
    |            ^^^^^^^^^^^--------^^^^^^^^
@@ -283,12 +283,12 @@ LL |         if let true = e.err(9).is_ok() {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:372:41
+  --> $DIR/drop-order-comparisons.rs:321:41
    |
 LL |         if let true = e.err(9).is_ok() {} else {
    |                                         ^
@@ -302,7 +302,7 @@ LL ~         }}}}}}}}};
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:375:12
+  --> $DIR/drop-order-comparisons.rs:324:12
    |
 LL |         if let Ok(_v) = e.err(8) {} else {
    |            ^^^^^^^^^^^^^--------
@@ -312,12 +312,12 @@ LL |         if let Ok(_v) = e.err(8) {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:375:35
+  --> $DIR/drop-order-comparisons.rs:324:35
    |
 LL |         if let Ok(_v) = e.err(8) {} else {
    |                                   ^
@@ -331,7 +331,7 @@ LL ~         }}}}}}}}};
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:378:12
+  --> $DIR/drop-order-comparisons.rs:327:12
    |
 LL |         if let Ok(_) = e.err(7) {} else {
    |            ^^^^^^^^^^^^--------
@@ -341,12 +341,12 @@ LL |         if let Ok(_) = e.err(7) {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:378:34
+  --> $DIR/drop-order-comparisons.rs:327:34
    |
 LL |         if let Ok(_) = e.err(7) {} else {
    |                                  ^
@@ -360,7 +360,7 @@ LL ~         }}}}}}}}};
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:381:12
+  --> $DIR/drop-order-comparisons.rs:330:12
    |
 LL |         if let Ok(_) = e.err(6).as_ref() {} else {
    |            ^^^^^^^^^^^^--------^^^^^^^^^
@@ -370,12 +370,12 @@ LL |         if let Ok(_) = e.err(6).as_ref() {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:381:43
+  --> $DIR/drop-order-comparisons.rs:330:43
    |
 LL |         if let Ok(_) = e.err(6).as_ref() {} else {
    |                                           ^
@@ -389,7 +389,7 @@ LL ~         }}}}}}}}};
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:385:12
+  --> $DIR/drop-order-comparisons.rs:334:12
    |
 LL |         if let Ok(_v) = e.err(5) {} else {
    |            ^^^^^^^^^^^^^--------
@@ -399,12 +399,12 @@ LL |         if let Ok(_v) = e.err(5) {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:385:35
+  --> $DIR/drop-order-comparisons.rs:334:35
    |
 LL |         if let Ok(_v) = e.err(5) {} else {
    |                                   ^
@@ -418,7 +418,7 @@ LL ~         }}}}}}}}};
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:388:12
+  --> $DIR/drop-order-comparisons.rs:337:12
    |
 LL |         if let Ok(_) = e.err(4) {} else {
    |            ^^^^^^^^^^^^--------
@@ -428,12 +428,12 @@ LL |         if let Ok(_) = e.err(4) {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:388:34
+  --> $DIR/drop-order-comparisons.rs:337:34
    |
 LL |         if let Ok(_) = e.err(4) {} else {
    |                                  ^
@@ -447,7 +447,7 @@ LL ~         }}}}}}}}};
    |
 
 warning: `if let` assigns a shorter lifetime since Edition 2024
-  --> $DIR/drop-order-comparisons.rs:424:12
+  --> $DIR/drop-order-comparisons.rs:373:12
    |
 LL |         if let Ok(_) = e.err(4).as_ref() {} else {
    |            ^^^^^^^^^^^^--------^^^^^^^^^
@@ -457,12 +457,12 @@ LL |         if let Ok(_) = e.err(4).as_ref() {} else {
    = warning: this changes meaning in Rust 2024
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/temporary-if-let-scope.html>
 note: value invokes this custom destructor
-  --> $DIR/drop-order-comparisons.rs:612:1
+  --> $DIR/drop-order-comparisons.rs:504:1
    |
 LL | impl<'b> Drop for LogDrop<'b> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: the value is now dropped here in Edition 2024
-  --> $DIR/drop-order-comparisons.rs:424:43
+  --> $DIR/drop-order-comparisons.rs:373:43
    |
 LL |         if let Ok(_) = e.err(4).as_ref() {} else {
    |                                           ^
diff --git a/tests/ui/drop/drop-order-comparisons.rs b/tests/ui/drop/drop-order-comparisons.rs
index e7425159aa2..257c0c14ecf 100644
--- a/tests/ui/drop/drop-order-comparisons.rs
+++ b/tests/ui/drop/drop-order-comparisons.rs
@@ -1,3 +1,6 @@
+// N.B. drop-order-comparisons-let-chains.rs is part of this test.
+// It is separate because let chains cannot be parsed before Rust 2024.
+//
 // This tests various aspects of the drop order with a focus on:
 //
 // - The lifetime of temporaries with the `if let` construct (and with
@@ -25,7 +28,6 @@
 //@ run-pass
 
 #![feature(if_let_guard)]
-#![cfg_attr(e2021, feature(let_chains))]
 #![cfg_attr(e2021, warn(rust_2024_compatibility))]
 
 fn t_bindings() {
@@ -313,59 +315,6 @@ fn t_let_else_chained_then() {
 
 #[cfg(e2021)]
 #[rustfmt::skip]
-fn t_if_let_chains_then() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(9).is_ok()
-        && let Ok(_v) = e.ok(5)
-        && let Ok(_) = e.ok(8)
-        && let Ok(_) = e.ok(7).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(4)
-        && let Ok(_) = e.ok(6).as_ref() {
-            e.mark(3);
-        };
-    e.assert(9);
-}
-
-#[cfg(e2024)]
-#[rustfmt::skip]
-fn t_if_let_chains_then() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(9).is_ok()
-        && let Ok(_v) = e.ok(8)
-        && let Ok(_) = e.ok(7)
-        && let Ok(_) = e.ok(6).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(5)
-        && let Ok(_) = e.ok(4).as_ref() {
-            e.mark(3);
-        };
-    e.assert(9);
-}
-
-#[rustfmt::skip]
-fn t_guard_if_let_chains_then() {
-    let e = Events::new();
-    _ = match () {
-        () if e.ok(1).is_ok()
-            && let true = e.ok(9).is_ok()
-            && let Ok(_v) = e.ok(8)
-            && let Ok(_) = e.ok(7)
-            && let Ok(_) = e.ok(6).as_ref()
-            && e.ok(2).is_ok()
-            && let Ok(_v) = e.ok(5)
-            && let Ok(_) = e.ok(4).as_ref() => {
-                e.mark(3);
-            }
-        _ => {}
-    };
-    e.assert(9);
-}
-
-#[cfg(e2021)]
-#[rustfmt::skip]
 fn t_if_let_nested_else() {
     let e = Events::new();
     _ = if e.err(1).is_ok() {} else {
@@ -470,59 +419,6 @@ fn t_let_else_chained_then_else() {
     e.assert(9);
 }
 
-#[cfg(e2021)]
-#[rustfmt::skip]
-fn t_if_let_chains_then_else() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(9).is_ok()
-        && let Ok(_v) = e.ok(4)
-        && let Ok(_) = e.ok(8)
-        && let Ok(_) = e.ok(7).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(3)
-        && let Ok(_) = e.err(6) {} else {
-            e.mark(5);
-        };
-    e.assert(9);
-}
-
-#[cfg(e2024)]
-#[rustfmt::skip]
-fn t_if_let_chains_then_else() {
-    let e = Events::new();
-    _ = if e.ok(1).is_ok()
-        && let true = e.ok(8).is_ok()
-        && let Ok(_v) = e.ok(7)
-        && let Ok(_) = e.ok(6)
-        && let Ok(_) = e.ok(5).as_ref()
-        && e.ok(2).is_ok()
-        && let Ok(_v) = e.ok(4)
-        && let Ok(_) = e.err(3) {} else {
-            e.mark(9);
-        };
-    e.assert(9);
-}
-
-#[rustfmt::skip]
-fn t_guard_if_let_chains_then_else() {
-    let e = Events::new();
-    _ = match () {
-       () if e.ok(1).is_ok()
-            && let true = e.ok(8).is_ok()
-            && let Ok(_v) = e.ok(7)
-            && let Ok(_) = e.ok(6)
-            && let Ok(_) = e.ok(5).as_ref()
-            && e.ok(2).is_ok()
-            && let Ok(_v) = e.ok(4)
-            && let Ok(_) = e.err(3) => {}
-        _ => {
-            e.mark(9);
-        }
-    };
-    e.assert(9);
-}
-
 fn main() {
     t_bindings();
     t_tuples();
@@ -540,13 +436,9 @@ fn main() {
     t_if_let_else_tailexpr();
     t_if_let_nested_then();
     t_let_else_chained_then();
-    t_if_let_chains_then();
-    t_guard_if_let_chains_then();
     t_if_let_nested_else();
     t_if_let_nested_then_else();
     t_let_else_chained_then_else();
-    t_if_let_chains_then_else();
-    t_guard_if_let_chains_then_else();
 }
 
 // # Test scaffolding
diff --git a/tests/ui/drop/drop_order.rs b/tests/ui/drop/drop_order.rs
index 34b1a0e8f75..ead498a21c3 100644
--- a/tests/ui/drop/drop_order.rs
+++ b/tests/ui/drop/drop_order.rs
@@ -5,8 +5,6 @@
 //@ [edition2024] compile-flags: -Z lint-mir
 //@ [edition2024] edition: 2024
 
-#![cfg_attr(edition2021, feature(let_chains))]
-
 use std::cell::RefCell;
 use std::convert::TryInto;
 
@@ -210,68 +208,6 @@ impl DropOrderCollector {
         }
     }
 
-    fn let_chain(&self) {
-        // take the "then" branch
-        if self.option_loud_drop(1).is_some() // 1
-            && self.option_loud_drop(2).is_some() // 2
-            && let Some(_d) = self.option_loud_drop(4) { // 4
-            self.print(3); // 3
-        }
-
-        #[cfg(edition2021)]
-        // take the "else" branch
-        if self.option_loud_drop(5).is_some() // 1
-            && self.option_loud_drop(6).is_some() // 2
-            && let None = self.option_loud_drop(8) { // 4
-            unreachable!();
-        } else {
-            self.print(7); // 3
-        }
-        #[cfg(edition2024)]
-        // take the "else" branch
-        if self.option_loud_drop(5).is_some() // 1
-            && self.option_loud_drop(6).is_some() // 2
-            && let None = self.option_loud_drop(7) { // 4
-            unreachable!();
-        } else {
-            self.print(8); // 3
-        }
-
-        // let exprs interspersed
-        if self.option_loud_drop(9).is_some() // 1
-            && let Some(_d) = self.option_loud_drop(13) // 5
-            && self.option_loud_drop(10).is_some() // 2
-            && let Some(_e) = self.option_loud_drop(12) { // 4
-            self.print(11); // 3
-        }
-
-        // let exprs first
-        if let Some(_d) = self.option_loud_drop(18) // 5
-            && let Some(_e) = self.option_loud_drop(17) // 4
-            && self.option_loud_drop(14).is_some() // 1
-            && self.option_loud_drop(15).is_some() { // 2
-                self.print(16); // 3
-            }
-
-        // let exprs last
-        if self.option_loud_drop(19).is_some() // 1
-            && self.option_loud_drop(20).is_some() // 2
-            && let Some(_d) = self.option_loud_drop(23) // 5
-            && let Some(_e) = self.option_loud_drop(22) { // 4
-                self.print(21); // 3
-        }
-    }
-
-    fn while_(&self) {
-        let mut v = self.option_loud_drop(4);
-        while let Some(_d) = v
-            && self.option_loud_drop(1).is_some()
-            && self.option_loud_drop(2).is_some() {
-            self.print(3);
-            v = None;
-        }
-    }
-
     fn assert_sorted(self) {
         assert!(
             self.0
@@ -313,14 +249,4 @@ fn main() {
     let collector = DropOrderCollector::default();
     collector.match_();
     collector.assert_sorted();
-
-    println!("-- let chain --");
-    let collector = DropOrderCollector::default();
-    collector.let_chain();
-    collector.assert_sorted();
-
-    println!("-- while --");
-    let collector = DropOrderCollector::default();
-    collector.while_();
-    collector.assert_sorted();
 }
diff --git a/tests/ui/drop/drop_order_let_chain.rs b/tests/ui/drop/drop_order_let_chain.rs
new file mode 100644
index 00000000000..8d1b71c4dab
--- /dev/null
+++ b/tests/ui/drop/drop_order_let_chain.rs
@@ -0,0 +1,103 @@
+//@ run-pass
+//@ compile-flags: -Z validate-mir
+//@ edition: 2024
+
+use std::cell::RefCell;
+use std::convert::TryInto;
+
+#[derive(Default)]
+struct DropOrderCollector(RefCell<Vec<u32>>);
+
+struct LoudDrop<'a>(&'a DropOrderCollector, u32);
+
+impl Drop for LoudDrop<'_> {
+    fn drop(&mut self) {
+        println!("{}", self.1);
+        self.0.0.borrow_mut().push(self.1);
+    }
+}
+
+impl DropOrderCollector {
+    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop<'_>> {
+        Some(LoudDrop(self, n))
+    }
+
+    fn print(&self, n: u32) {
+        println!("{}", n);
+        self.0.borrow_mut().push(n)
+    }
+
+    fn let_chain(&self) {
+        // take the "then" branch
+        if self.option_loud_drop(1).is_some() // 1
+            && self.option_loud_drop(2).is_some() // 2
+            && let Some(_d) = self.option_loud_drop(4) { // 4
+            self.print(3); // 3
+        }
+
+        // take the "else" branch
+        if self.option_loud_drop(5).is_some() // 1
+            && self.option_loud_drop(6).is_some() // 2
+            && let None = self.option_loud_drop(7) { // 4
+            unreachable!();
+        } else {
+            self.print(8); // 3
+        }
+
+        // let exprs interspersed
+        if self.option_loud_drop(9).is_some() // 1
+            && let Some(_d) = self.option_loud_drop(13) // 5
+            && self.option_loud_drop(10).is_some() // 2
+            && let Some(_e) = self.option_loud_drop(12) { // 4
+            self.print(11); // 3
+        }
+
+        // let exprs first
+        if let Some(_d) = self.option_loud_drop(18) // 5
+            && let Some(_e) = self.option_loud_drop(17) // 4
+            && self.option_loud_drop(14).is_some() // 1
+            && self.option_loud_drop(15).is_some() { // 2
+                self.print(16); // 3
+            }
+
+        // let exprs last
+        if self.option_loud_drop(19).is_some() // 1
+            && self.option_loud_drop(20).is_some() // 2
+            && let Some(_d) = self.option_loud_drop(23) // 5
+            && let Some(_e) = self.option_loud_drop(22) { // 4
+                self.print(21); // 3
+        }
+    }
+
+    fn while_(&self) {
+        let mut v = self.option_loud_drop(4);
+        while let Some(_d) = v
+            && self.option_loud_drop(1).is_some()
+            && self.option_loud_drop(2).is_some() {
+            self.print(3);
+            v = None;
+        }
+    }
+
+    fn assert_sorted(self) {
+        assert!(
+            self.0
+                .into_inner()
+                .into_iter()
+                .enumerate()
+                .all(|(idx, item)| idx + 1 == item.try_into().unwrap())
+        );
+    }
+}
+
+fn main() {
+    println!("-- let chain --");
+    let collector = DropOrderCollector::default();
+    collector.let_chain();
+    collector.assert_sorted();
+
+    println!("-- while --");
+    let collector = DropOrderCollector::default();
+    collector.while_();
+    collector.assert_sorted();
+}
diff --git a/tests/ui/drop/issue-100276.rs b/tests/ui/drop/issue-100276.rs
index 5d212b3a0a9..c8e25e48b15 100644
--- a/tests/ui/drop/issue-100276.rs
+++ b/tests/ui/drop/issue-100276.rs
@@ -1,11 +1,6 @@
 //@ check-pass
-//@ compile-flags: -Z validate-mir
-//@ revisions: edition2021 edition2024
-//@ [edition2021] edition: 2021
-//@ [edition2024] compile-flags: -Z lint-mir
-//@ [edition2024] edition: 2024
-
-#![cfg_attr(edition2021, feature(let_chains))]
+//@ compile-flags: -Z lint-mir -Z validate-mir
+//@ edition: 2024
 
 fn let_chains(entry: std::io::Result<std::fs::DirEntry>) {
     if let Ok(entry) = entry