From 17d40c6057c88f4c432b0d7bac88e1b84cb7e67f Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:03:36 +0200
Subject: Adding upstream version 1.65.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/test/ui/let-else/const-fn.rs                   |  19 ++
 src/test/ui/let-else/issue-100103.rs               |  15 ++
 src/test/ui/let-else/issue-102317.rs               |  20 ++
 src/test/ui/let-else/issue-94176.rs                |  10 +
 src/test/ui/let-else/issue-94176.stderr            |  19 ++
 src/test/ui/let-else/issue-99975.rs                |  20 ++
 src/test/ui/let-else/let-else-allow-in-expr.rs     |   2 -
 src/test/ui/let-else/let-else-allow-in-expr.stderr |   6 +-
 src/test/ui/let-else/let-else-allow-unused.rs      |   2 +-
 .../let-else-binding-explicit-mut-annotated.rs     |   2 +-
 .../let-else-binding-explicit-mut-borrow.rs        |   4 +-
 .../let-else/let-else-binding-explicit-mut-pass.rs |   2 +-
 .../ui/let-else/let-else-binding-explicit-mut.rs   |   2 +-
 src/test/ui/let-else/let-else-binding-immutable.rs |   2 +-
 src/test/ui/let-else/let-else-bindings.rs          |   2 +-
 .../ui/let-else/let-else-bool-binop-init.fixed     |   2 +-
 src/test/ui/let-else/let-else-bool-binop-init.rs   |   2 +-
 .../ui/let-else/let-else-brace-before-else.fixed   |   2 +-
 src/test/ui/let-else/let-else-brace-before-else.rs |   2 +-
 src/test/ui/let-else/let-else-check.rs             |   2 -
 src/test/ui/let-else/let-else-check.stderr         |   6 +-
 .../let-else/let-else-deref-coercion-annotated.rs  |   2 +-
 src/test/ui/let-else/let-else-deref-coercion.rs    |   2 +-
 src/test/ui/let-else/let-else-destructuring.rs     |   1 -
 src/test/ui/let-else/let-else-destructuring.stderr |   4 +-
 src/test/ui/let-else/let-else-drop-order.rs        | 270 +++++++++++++++++++++
 .../ui/let-else/let-else-drop-order.run.stdout     |  51 ++++
 src/test/ui/let-else/let-else-if.rs                |   2 -
 src/test/ui/let-else/let-else-if.stderr            |   2 +-
 src/test/ui/let-else/let-else-irrefutable.rs       |   2 +-
 src/test/ui/let-else/let-else-missing-semicolon.rs |   2 -
 .../ui/let-else/let-else-missing-semicolon.stderr  |   4 +-
 src/test/ui/let-else/let-else-no-double-error.rs   |   2 +-
 src/test/ui/let-else/let-else-non-copy.rs          |   2 +-
 src/test/ui/let-else/let-else-non-diverging.rs     |   2 -
 src/test/ui/let-else/let-else-non-diverging.stderr |   6 +-
 src/test/ui/let-else/let-else-ref-bindings-pass.rs |   2 +-
 src/test/ui/let-else/let-else-ref-bindings.rs      |   2 +-
 src/test/ui/let-else/let-else-run-pass.rs          |   2 +-
 src/test/ui/let-else/let-else-scope.rs             |   2 -
 src/test/ui/let-else/let-else-scope.stderr         |   2 +-
 src/test/ui/let-else/let-else-slicing-error.rs     |   2 +-
 .../let-else/let-else-source-expr-nomove-pass.rs   |   2 +-
 src/test/ui/let-else/let-else-temp-borrowck.rs     |   2 +-
 .../ui/let-else/let-else-temporary-lifetime.rs     |  13 +-
 src/test/ui/let-else/let-else-then-diverge.rs      |  19 ++
 src/test/ui/let-else/let-else-then-diverge.stderr  |  14 ++
 src/test/ui/let-else/let-else.rs                   |   8 +
 48 files changed, 515 insertions(+), 52 deletions(-)
 create mode 100644 src/test/ui/let-else/const-fn.rs
 create mode 100644 src/test/ui/let-else/issue-100103.rs
 create mode 100644 src/test/ui/let-else/issue-102317.rs
 create mode 100644 src/test/ui/let-else/issue-94176.rs
 create mode 100644 src/test/ui/let-else/issue-94176.stderr
 create mode 100644 src/test/ui/let-else/issue-99975.rs
 create mode 100644 src/test/ui/let-else/let-else-drop-order.rs
 create mode 100644 src/test/ui/let-else/let-else-drop-order.run.stdout
 create mode 100644 src/test/ui/let-else/let-else-then-diverge.rs
 create mode 100644 src/test/ui/let-else/let-else-then-diverge.stderr
 create mode 100644 src/test/ui/let-else/let-else.rs

(limited to 'src/test/ui/let-else')

diff --git a/src/test/ui/let-else/const-fn.rs b/src/test/ui/let-else/const-fn.rs
new file mode 100644
index 000000000..336b0b4b7
--- /dev/null
+++ b/src/test/ui/let-else/const-fn.rs
@@ -0,0 +1,19 @@
+// run-pass
+// issue #101932
+
+#![cfg_attr(bootstrap, feature(let_else))]
+
+const fn foo(a: Option<i32>) -> i32 {
+    let Some(a) = a else {
+        return 42
+    };
+
+    a + 1
+}
+
+fn main() {
+    const A: i32 = foo(None);
+    const B: i32 = foo(Some(1));
+
+    println!("{} {}", A, B);
+}
diff --git a/src/test/ui/let-else/issue-100103.rs b/src/test/ui/let-else/issue-100103.rs
new file mode 100644
index 000000000..f5f9b2f5f
--- /dev/null
+++ b/src/test/ui/let-else/issue-100103.rs
@@ -0,0 +1,15 @@
+// edition:2021
+// check-pass
+
+#![feature(try_blocks)]
+
+
+fn main() {
+    let _: Result<i32, i32> = try {
+        let Some(x) = Some(0) else {
+            Err(1)?
+        };
+
+        x
+    };
+}
diff --git a/src/test/ui/let-else/issue-102317.rs b/src/test/ui/let-else/issue-102317.rs
new file mode 100644
index 000000000..7369b4938
--- /dev/null
+++ b/src/test/ui/let-else/issue-102317.rs
@@ -0,0 +1,20 @@
+// issue #102317
+// build-pass
+// compile-flags: --edition 2021 -C opt-level=3 -Zvalidate-mir
+
+struct SegmentJob;
+
+impl Drop for SegmentJob {
+    fn drop(&mut self) {}
+}
+
+pub async fn run() -> Result<(), ()> {
+    let jobs = Vec::<SegmentJob>::new();
+    let Some(_job) = jobs.into_iter().next() else {
+        return Ok(())
+    };
+
+    Ok(())
+}
+
+fn main() {}
diff --git a/src/test/ui/let-else/issue-94176.rs b/src/test/ui/let-else/issue-94176.rs
new file mode 100644
index 000000000..f76dfc15b
--- /dev/null
+++ b/src/test/ui/let-else/issue-94176.rs
@@ -0,0 +1,10 @@
+// Issue #94176: wrong span for the error message of a mismatched type error,
+// if the function uses a `let else` construct.
+
+
+pub fn test(a: Option<u32>) -> Option<u32> { //~ ERROR mismatched types
+    let Some(_) = a else { return None; };
+    println!("Foo");
+}
+
+fn main() {}
diff --git a/src/test/ui/let-else/issue-94176.stderr b/src/test/ui/let-else/issue-94176.stderr
new file mode 100644
index 000000000..0cb97acee
--- /dev/null
+++ b/src/test/ui/let-else/issue-94176.stderr
@@ -0,0 +1,19 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-94176.rs:5:32
+   |
+LL | pub fn test(a: Option<u32>) -> Option<u32> {
+   |        ----                    ^^^^^^^^^^^ expected enum `Option`, found `()`
+   |        |
+   |        implicitly returns `()` as its body has no tail or `return` expression
+   |
+   = note:   expected enum `Option<u32>`
+           found unit type `()`
+help: consider returning the local binding `a`
+   |
+LL ~     println!("Foo");
+LL +     a
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/let-else/issue-99975.rs b/src/test/ui/let-else/issue-99975.rs
new file mode 100644
index 000000000..5b164f347
--- /dev/null
+++ b/src/test/ui/let-else/issue-99975.rs
@@ -0,0 +1,20 @@
+// run-pass
+// compile-flags: -C opt-level=3 -Zvalidate-mir
+
+
+
+fn return_result() -> Option<String> {
+    Some("ok".to_string())
+}
+
+fn start() -> String {
+    let Some(content) = return_result() else {
+        return "none".to_string()
+    };
+
+    content
+}
+
+fn main() {
+    start();
+}
diff --git a/src/test/ui/let-else/let-else-allow-in-expr.rs b/src/test/ui/let-else/let-else-allow-in-expr.rs
index 39f4c9060..33acb6c6a 100644
--- a/src/test/ui/let-else/let-else-allow-in-expr.rs
+++ b/src/test/ui/let-else/let-else-allow-in-expr.rs
@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 #![deny(unused_variables)]
 
 fn main() {
diff --git a/src/test/ui/let-else/let-else-allow-in-expr.stderr b/src/test/ui/let-else/let-else-allow-in-expr.stderr
index e86bcbc85..3b2b9066c 100644
--- a/src/test/ui/let-else/let-else-allow-in-expr.stderr
+++ b/src/test/ui/let-else/let-else-allow-in-expr.stderr
@@ -1,17 +1,17 @@
 error: unused variable: `x`
-  --> $DIR/let-else-allow-in-expr.rs:7:13
+  --> $DIR/let-else-allow-in-expr.rs:5:13
    |
 LL |         let x = 1;
    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
-  --> $DIR/let-else-allow-in-expr.rs:3:9
+  --> $DIR/let-else-allow-in-expr.rs:1:9
    |
 LL | #![deny(unused_variables)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unused variable: `x`
-  --> $DIR/let-else-allow-in-expr.rs:29:9
+  --> $DIR/let-else-allow-in-expr.rs:27:9
    |
 LL |     let x = 1;
    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
diff --git a/src/test/ui/let-else/let-else-allow-unused.rs b/src/test/ui/let-else/let-else-allow-unused.rs
index 86ebacfa7..bbb1c7bea 100644
--- a/src/test/ui/let-else/let-else-allow-unused.rs
+++ b/src/test/ui/let-else/let-else-allow-unused.rs
@@ -1,6 +1,6 @@
 // issue #89807
 
-#![feature(let_else)]
+
 
 #[deny(unused_variables)]
 
diff --git a/src/test/ui/let-else/let-else-binding-explicit-mut-annotated.rs b/src/test/ui/let-else/let-else-binding-explicit-mut-annotated.rs
index b65fa13c1..955f33ee1 100644
--- a/src/test/ui/let-else/let-else-binding-explicit-mut-annotated.rs
+++ b/src/test/ui/let-else/let-else-binding-explicit-mut-annotated.rs
@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 // Verify the binding mode shifts - only when no `&` are auto-dereferenced is the
 // final default binding mode mutable.
diff --git a/src/test/ui/let-else/let-else-binding-explicit-mut-borrow.rs b/src/test/ui/let-else/let-else-binding-explicit-mut-borrow.rs
index 63b35df76..1524d0102 100644
--- a/src/test/ui/let-else/let-else-binding-explicit-mut-borrow.rs
+++ b/src/test/ui/let-else/let-else-binding-explicit-mut-borrow.rs
@@ -1,8 +1,8 @@
-#![feature(let_else)]
-
 // Slightly different from explicit-mut-annotated -- this won't show an error until borrowck.
 // Should it show a type error instead?
 
+
+
 fn main() {
     let Some(n): &mut Option<i32> = &mut &Some(5i32) else {
         //~^ ERROR cannot borrow data in a `&` reference as mutable
diff --git a/src/test/ui/let-else/let-else-binding-explicit-mut-pass.rs b/src/test/ui/let-else/let-else-binding-explicit-mut-pass.rs
index 305be9221..b0a6264a1 100644
--- a/src/test/ui/let-else/let-else-binding-explicit-mut-pass.rs
+++ b/src/test/ui/let-else/let-else-binding-explicit-mut-pass.rs
@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(let_else)]
+
 
 fn main() {
     let Some(n) = &mut &mut Some(5i32) else { return; };
diff --git a/src/test/ui/let-else/let-else-binding-explicit-mut.rs b/src/test/ui/let-else/let-else-binding-explicit-mut.rs
index dbe4715b1..a153b3af0 100644
--- a/src/test/ui/let-else/let-else-binding-explicit-mut.rs
+++ b/src/test/ui/let-else/let-else-binding-explicit-mut.rs
@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 // Verify the binding mode shifts - only when no `&` are auto-dereferenced is the
 // final default binding mode mutable.
diff --git a/src/test/ui/let-else/let-else-binding-immutable.rs b/src/test/ui/let-else/let-else-binding-immutable.rs
index 96de0ffe2..ff2d9f240 100644
--- a/src/test/ui/let-else/let-else-binding-immutable.rs
+++ b/src/test/ui/let-else/let-else-binding-immutable.rs
@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 pub fn main() {
     let Some(x) = &Some(3) else {
diff --git a/src/test/ui/let-else/let-else-bindings.rs b/src/test/ui/let-else/let-else-bindings.rs
index d5121e744..7d2cad978 100644
--- a/src/test/ui/let-else/let-else-bindings.rs
+++ b/src/test/ui/let-else/let-else-bindings.rs
@@ -1,6 +1,6 @@
 // run-pass
 // adapted from src/test/ui/binding/if-let.rs
-#![feature(let_else)]
+
 #![allow(dead_code)]
 
 fn none() -> bool {
diff --git a/src/test/ui/let-else/let-else-bool-binop-init.fixed b/src/test/ui/let-else/let-else-bool-binop-init.fixed
index e47f7f23d..20e558ca9 100644
--- a/src/test/ui/let-else/let-else-bool-binop-init.fixed
+++ b/src/test/ui/let-else/let-else-bool-binop-init.fixed
@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let true = (true && false) else { return }; //~ ERROR a `&&` expression cannot be directly assigned in `let...else`
diff --git a/src/test/ui/let-else/let-else-bool-binop-init.rs b/src/test/ui/let-else/let-else-bool-binop-init.rs
index e443fb0d6..f88179a94 100644
--- a/src/test/ui/let-else/let-else-bool-binop-init.rs
+++ b/src/test/ui/let-else/let-else-bool-binop-init.rs
@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let true = true && false else { return }; //~ ERROR a `&&` expression cannot be directly assigned in `let...else`
diff --git a/src/test/ui/let-else/let-else-brace-before-else.fixed b/src/test/ui/let-else/let-else-brace-before-else.fixed
index fb4fd7779..a75c770dd 100644
--- a/src/test/ui/let-else/let-else-brace-before-else.fixed
+++ b/src/test/ui/let-else/let-else-brace-before-else.fixed
@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let Some(1) = ({ Some(1) }) else {
diff --git a/src/test/ui/let-else/let-else-brace-before-else.rs b/src/test/ui/let-else/let-else-brace-before-else.rs
index c4c5a1ca2..5603b946f 100644
--- a/src/test/ui/let-else/let-else-brace-before-else.rs
+++ b/src/test/ui/let-else/let-else-brace-before-else.rs
@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let Some(1) = { Some(1) } else {
diff --git a/src/test/ui/let-else/let-else-check.rs b/src/test/ui/let-else/let-else-check.rs
index 9e32cbef7..713fd986e 100644
--- a/src/test/ui/let-else/let-else-check.rs
+++ b/src/test/ui/let-else/let-else-check.rs
@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 #![deny(unused_variables)]
 
 fn main() {
diff --git a/src/test/ui/let-else/let-else-check.stderr b/src/test/ui/let-else/let-else-check.stderr
index 3d647a4c0..bdecbf708 100644
--- a/src/test/ui/let-else/let-else-check.stderr
+++ b/src/test/ui/let-else/let-else-check.stderr
@@ -1,17 +1,17 @@
 error: unused variable: `x`
-  --> $DIR/let-else-check.rs:14:13
+  --> $DIR/let-else-check.rs:12:13
    |
 LL |         let x = 1;
    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
-  --> $DIR/let-else-check.rs:3:9
+  --> $DIR/let-else-check.rs:1:9
    |
 LL | #![deny(unused_variables)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unused variable: `x`
-  --> $DIR/let-else-check.rs:18:9
+  --> $DIR/let-else-check.rs:16:9
    |
 LL |     let x = 1;
    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
diff --git a/src/test/ui/let-else/let-else-deref-coercion-annotated.rs b/src/test/ui/let-else/let-else-deref-coercion-annotated.rs
index 65d88a6d8..60fdf825a 100644
--- a/src/test/ui/let-else/let-else-deref-coercion-annotated.rs
+++ b/src/test/ui/let-else/let-else-deref-coercion-annotated.rs
@@ -6,7 +6,7 @@
 // Deref/DerefMut to Bar. You can do this with an irrefutable binding, so it should work with
 // let-else too.
 
-#![feature(let_else)]
+
 use std::ops::{Deref, DerefMut};
 
 struct Foo(Bar);
diff --git a/src/test/ui/let-else/let-else-deref-coercion.rs b/src/test/ui/let-else/let-else-deref-coercion.rs
index 87489d84b..052a5a8c7 100644
--- a/src/test/ui/let-else/let-else-deref-coercion.rs
+++ b/src/test/ui/let-else/let-else-deref-coercion.rs
@@ -3,7 +3,7 @@
 // We attempt to `let Bar::Present(_) = foo else { ... }` where foo is meant to Deref/DerefMut to
 // Bar. This fails, you must add a type annotation like `let _: &mut Bar = _ else { ... }`
 
-#![feature(let_else)]
+
 use std::ops::{Deref, DerefMut};
 
 struct Foo(Bar);
diff --git a/src/test/ui/let-else/let-else-destructuring.rs b/src/test/ui/let-else/let-else-destructuring.rs
index 9a09c414a..d1f1a69bf 100644
--- a/src/test/ui/let-else/let-else-destructuring.rs
+++ b/src/test/ui/let-else/let-else-destructuring.rs
@@ -1,4 +1,3 @@
-#![feature(let_else)]
 #[derive(Debug)]
 enum Foo {
     Done,
diff --git a/src/test/ui/let-else/let-else-destructuring.stderr b/src/test/ui/let-else/let-else-destructuring.stderr
index 95efb7116..7d6cb2386 100644
--- a/src/test/ui/let-else/let-else-destructuring.stderr
+++ b/src/test/ui/let-else/let-else-destructuring.stderr
@@ -1,11 +1,11 @@
 error: <assignment> ... else { ... } is not allowed
-  --> $DIR/let-else-destructuring.rs:11:9
+  --> $DIR/let-else-destructuring.rs:10:9
    |
 LL |         &Foo::Nested(Some(value)) = value else { break };
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0070]: invalid left-hand side of assignment
-  --> $DIR/let-else-destructuring.rs:11:35
+  --> $DIR/let-else-destructuring.rs:10:35
    |
 LL |         &Foo::Nested(Some(value)) = value else { break };
    |         ------------------------- ^
diff --git a/src/test/ui/let-else/let-else-drop-order.rs b/src/test/ui/let-else/let-else-drop-order.rs
new file mode 100644
index 000000000..e91e5de84
--- /dev/null
+++ b/src/test/ui/let-else/let-else-drop-order.rs
@@ -0,0 +1,270 @@
+// run-pass
+// edition:2021
+// check-run-results
+//
+// Drop order tests for let else
+//
+// Mostly this ensures two things:
+// 1. That let and let else temporary drop order is the same.
+//    This is a specific design request: https://github.com/rust-lang/rust/pull/93628#issuecomment-1047140316
+// 2. That the else block truly only runs after the
+//    temporaries have dropped.
+//
+// We also print some nice tables for an overview by humans.
+// Changes in those tables are considered breakages, but the
+// important properties 1 and 2 are also enforced by the code.
+// This is important as it's easy to update the stdout file
+// with a --bless and miss the impact of that change.
+
+
+#![allow(irrefutable_let_patterns)]
+
+use std::cell::RefCell;
+use std::rc::Rc;
+
+#[derive(Clone)]
+struct DropAccountant(Rc<RefCell<Vec<Vec<String>>>>);
+
+impl DropAccountant {
+    fn new() -> Self {
+        Self(Default::default())
+    }
+    fn build_droppy(&self, v: u32) -> Droppy<u32> {
+        Droppy(self.clone(), v)
+    }
+    fn build_droppy_enum_none(&self, _v: u32) -> ((), DroppyEnum<u32>) {
+        ((), DroppyEnum::None(self.clone()))
+    }
+    fn new_list(&self, s: impl ToString) {
+        self.0.borrow_mut().push(vec![s.to_string()]);
+    }
+    fn push(&self, s: impl ToString) {
+        let s = s.to_string();
+        let mut accounts = self.0.borrow_mut();
+        accounts.last_mut().unwrap().push(s);
+    }
+    fn print_table(&self) {
+        println!();
+
+        let accounts = self.0.borrow();
+        let before_last = &accounts[accounts.len() - 2];
+        let last = &accounts[accounts.len() - 1];
+        let before_last = get_comma_list(before_last);
+        let last = get_comma_list(last);
+        const LINES: &[&str] = &[
+            "vanilla",
+            "&",
+            "&mut",
+            "move",
+            "fn(this)",
+            "tuple",
+            "array",
+            "ref &",
+            "ref mut &mut",
+        ];
+        let max_len = LINES.iter().map(|v| v.len()).max().unwrap();
+        let max_len_before = before_last.iter().map(|v| v.len()).max().unwrap();
+        let max_len_last = last.iter().map(|v| v.len()).max().unwrap();
+
+        println!(
+            "| {: <max_len$} | {: <max_len_before$} | {: <max_len_last$} |",
+            "construct", before_last[0], last[0]
+        );
+        println!("| {:-<max_len$} | {:-<max_len_before$} | {:-<max_len_last$} |", "", "", "");
+
+        for ((l, l_before), l_last) in
+            LINES.iter().zip(before_last[1..].iter()).zip(last[1..].iter())
+        {
+            println!(
+                "| {: <max_len$} | {: <max_len_before$} | {: <max_len_last$} |",
+                l, l_before, l_last,
+            );
+        }
+    }
+    #[track_caller]
+    fn assert_all_equal_to(&self, st: &str) {
+        let accounts = self.0.borrow();
+        let last = &accounts[accounts.len() - 1];
+        let last = get_comma_list(last);
+        for line in last[1..].iter() {
+            assert_eq!(line.trim(), st.trim());
+        }
+    }
+    #[track_caller]
+    fn assert_equality_last_two_lists(&self) {
+        let accounts = self.0.borrow();
+        let last = &accounts[accounts.len() - 1];
+        let before_last = &accounts[accounts.len() - 2];
+        for (l, b) in last[1..].iter().zip(before_last[1..].iter()) {
+            if !(l == b || l == "n/a" || b == "n/a") {
+                panic!("not equal: '{last:?}' != '{before_last:?}'");
+            }
+        }
+    }
+}
+
+fn get_comma_list(sl: &[String]) -> Vec<String> {
+    std::iter::once(sl[0].clone())
+        .chain(sl[1..].chunks(2).map(|c| c.join(",")))
+        .collect::<Vec<String>>()
+}
+
+struct Droppy<T>(DropAccountant, T);
+
+impl<T> Drop for Droppy<T> {
+    fn drop(&mut self) {
+        self.0.push("drop");
+    }
+}
+
+#[allow(dead_code)]
+enum DroppyEnum<T> {
+    Some(DropAccountant, T),
+    None(DropAccountant),
+}
+
+impl<T> Drop for DroppyEnum<T> {
+    fn drop(&mut self) {
+        match self {
+            DroppyEnum::Some(acc, _inner) => acc,
+            DroppyEnum::None(acc) => acc,
+        }
+        .push("drop");
+    }
+}
+
+macro_rules! nestings_with {
+    ($construct:ident, $binding:pat, $exp:expr) => {
+        // vanilla:
+        $construct!($binding, $exp.1);
+
+        // &:
+        $construct!(&$binding, &$exp.1);
+
+        // &mut:
+        $construct!(&mut $binding, &mut ($exp.1));
+
+        {
+            // move:
+            let w = $exp;
+            $construct!(
+                $binding,
+                {
+                    let w = w;
+                    w
+                }
+                .1
+            );
+        }
+
+        // fn(this):
+        $construct!($binding, std::convert::identity($exp).1);
+    };
+}
+
+macro_rules! nestings {
+    ($construct:ident, $binding:pat, $exp:expr) => {
+        nestings_with!($construct, $binding, $exp);
+
+        // tuple:
+        $construct!(($binding, 77), ($exp.1, 77));
+
+        // array:
+        $construct!([$binding], [$exp.1]);
+    };
+}
+
+macro_rules! let_else {
+    ($acc:expr, $v:expr, $binding:pat, $build:ident) => {
+        let acc = $acc;
+        let v = $v;
+
+        macro_rules! let_else_construct {
+            ($arg:pat, $exp:expr) => {
+                loop {
+                    let $arg = $exp else {
+                        acc.push("else");
+                        break;
+                    };
+                    acc.push("body");
+                    break;
+                }
+            };
+        }
+        nestings!(let_else_construct, $binding, acc.$build(v));
+        // ref &:
+        let_else_construct!($binding, &acc.$build(v).1);
+
+        // ref mut &mut:
+        let_else_construct!($binding, &mut acc.$build(v).1);
+    };
+}
+
+macro_rules! let_ {
+    ($acc:expr, $binding:tt) => {
+        let acc = $acc;
+
+        macro_rules! let_construct {
+            ($arg:pat, $exp:expr) => {{
+                let $arg = $exp;
+                acc.push("body");
+            }};
+        }
+        let v = 0;
+        {
+            nestings_with!(let_construct, $binding, acc.build_droppy(v));
+        }
+        acc.push("n/a");
+        acc.push("n/a");
+        acc.push("n/a");
+        acc.push("n/a");
+
+        // ref &:
+        let_construct!($binding, &acc.build_droppy(v).1);
+
+        // ref mut &mut:
+        let_construct!($binding, &mut acc.build_droppy(v).1);
+    };
+}
+
+fn main() {
+    let acc = DropAccountant::new();
+
+    println!(" --- matching cases ---");
+
+    // Ensure that let and let else have the same behaviour
+    acc.new_list("let _");
+    let_!(&acc, _);
+    acc.new_list("let else _");
+    let_else!(&acc, 0, _, build_droppy);
+    acc.assert_equality_last_two_lists();
+    acc.print_table();
+
+    // Ensure that let and let else have the same behaviour
+    acc.new_list("let _v");
+    let_!(&acc, _v);
+    acc.new_list("let else _v");
+    let_else!(&acc, 0, _v, build_droppy);
+    acc.assert_equality_last_two_lists();
+    acc.print_table();
+
+    println!();
+
+    println!(" --- mismatching cases ---");
+
+    acc.new_list("let else _ mismatch");
+    let_else!(&acc, 1, DroppyEnum::Some(_, _), build_droppy_enum_none);
+    acc.new_list("let else _v mismatch");
+    let_else!(&acc, 1, DroppyEnum::Some(_, _v), build_droppy_enum_none);
+    acc.print_table();
+    // This ensures that we always drop before visiting the else case
+    acc.assert_all_equal_to("drop,else");
+
+    acc.new_list("let else 0 mismatch");
+    let_else!(&acc, 1, 0, build_droppy);
+    acc.new_list("let else 0 mismatch");
+    let_else!(&acc, 1, 0, build_droppy);
+    acc.print_table();
+    // This ensures that we always drop before visiting the else case
+    acc.assert_all_equal_to("drop,else");
+}
diff --git a/src/test/ui/let-else/let-else-drop-order.run.stdout b/src/test/ui/let-else/let-else-drop-order.run.stdout
new file mode 100644
index 000000000..01cf2f73e
--- /dev/null
+++ b/src/test/ui/let-else/let-else-drop-order.run.stdout
@@ -0,0 +1,51 @@
+ --- matching cases ---
+
+| construct    | let _     | let else _ |
+| ------------ | --------- | ---------- |
+| vanilla      | drop,body | drop,body  |
+| &            | body,drop | body,drop  |
+| &mut         | body,drop | body,drop  |
+| move         | drop,body | drop,body  |
+| fn(this)     | drop,body | drop,body  |
+| tuple        | n/a,n/a   | drop,body  |
+| array        | n/a,n/a   | drop,body  |
+| ref &        | body,drop | body,drop  |
+| ref mut &mut | body,drop | body,drop  |
+
+| construct    | let _v    | let else _v |
+| ------------ | --------- | ----------- |
+| vanilla      | drop,body | drop,body   |
+| &            | body,drop | body,drop   |
+| &mut         | body,drop | body,drop   |
+| move         | drop,body | drop,body   |
+| fn(this)     | drop,body | drop,body   |
+| tuple        | n/a,n/a   | drop,body   |
+| array        | n/a,n/a   | drop,body   |
+| ref &        | body,drop | body,drop   |
+| ref mut &mut | body,drop | body,drop   |
+
+ --- mismatching cases ---
+
+| construct    | let else _ mismatch | let else _v mismatch |
+| ------------ | ------------------- | -------------------- |
+| vanilla      | drop,else           | drop,else            |
+| &            | drop,else           | drop,else            |
+| &mut         | drop,else           | drop,else            |
+| move         | drop,else           | drop,else            |
+| fn(this)     | drop,else           | drop,else            |
+| tuple        | drop,else           | drop,else            |
+| array        | drop,else           | drop,else            |
+| ref &        | drop,else           | drop,else            |
+| ref mut &mut | drop,else           | drop,else            |
+
+| construct    | let else 0 mismatch | let else 0 mismatch |
+| ------------ | ------------------- | ------------------- |
+| vanilla      | drop,else           | drop,else           |
+| &            | drop,else           | drop,else           |
+| &mut         | drop,else           | drop,else           |
+| move         | drop,else           | drop,else           |
+| fn(this)     | drop,else           | drop,else           |
+| tuple        | drop,else           | drop,else           |
+| array        | drop,else           | drop,else           |
+| ref &        | drop,else           | drop,else           |
+| ref mut &mut | drop,else           | drop,else           |
diff --git a/src/test/ui/let-else/let-else-if.rs b/src/test/ui/let-else/let-else-if.rs
index c3a17330d..e8c54ca7a 100644
--- a/src/test/ui/let-else/let-else-if.rs
+++ b/src/test/ui/let-else/let-else-if.rs
@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(_) = Some(()) else if true {
         //~^ ERROR conditional `else if` is not supported for `let...else`
diff --git a/src/test/ui/let-else/let-else-if.stderr b/src/test/ui/let-else/let-else-if.stderr
index 746738bbd..c63fd61c5 100644
--- a/src/test/ui/let-else/let-else-if.stderr
+++ b/src/test/ui/let-else/let-else-if.stderr
@@ -1,5 +1,5 @@
 error: conditional `else if` is not supported for `let...else`
-  --> $DIR/let-else-if.rs:4:33
+  --> $DIR/let-else-if.rs:2:33
    |
 LL |     let Some(_) = Some(()) else if true {
    |                                 ^^ expected `{`
diff --git a/src/test/ui/let-else/let-else-irrefutable.rs b/src/test/ui/let-else/let-else-irrefutable.rs
index b1e09a124..1cb68ecb8 100644
--- a/src/test/ui/let-else/let-else-irrefutable.rs
+++ b/src/test/ui/let-else/let-else-irrefutable.rs
@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(let_else)]
+
 
 fn main() {
     let x = 1 else { return }; //~ WARN irrefutable `let...else` pattern
diff --git a/src/test/ui/let-else/let-else-missing-semicolon.rs b/src/test/ui/let-else/let-else-missing-semicolon.rs
index ed9d79f1e..d87ac90c1 100644
--- a/src/test/ui/let-else/let-else-missing-semicolon.rs
+++ b/src/test/ui/let-else/let-else-missing-semicolon.rs
@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(x) = Some(1) else {
         return;
diff --git a/src/test/ui/let-else/let-else-missing-semicolon.stderr b/src/test/ui/let-else/let-else-missing-semicolon.stderr
index 1818a0b12..99029ff33 100644
--- a/src/test/ui/let-else/let-else-missing-semicolon.stderr
+++ b/src/test/ui/let-else/let-else-missing-semicolon.stderr
@@ -1,5 +1,5 @@
 error: expected `;`, found keyword `let`
-  --> $DIR/let-else-missing-semicolon.rs:6:6
+  --> $DIR/let-else-missing-semicolon.rs:4:6
    |
 LL |     }
    |      ^ help: add `;` here
@@ -7,7 +7,7 @@ LL |     let _ = "";
    |     --- unexpected token
 
 error: expected `;`, found `}`
-  --> $DIR/let-else-missing-semicolon.rs:10:6
+  --> $DIR/let-else-missing-semicolon.rs:8:6
    |
 LL |     }
    |      ^ help: add `;` here
diff --git a/src/test/ui/let-else/let-else-no-double-error.rs b/src/test/ui/let-else/let-else-no-double-error.rs
index 35dcdd3f6..91fcc5d7e 100644
--- a/src/test/ui/let-else/let-else-no-double-error.rs
+++ b/src/test/ui/let-else/let-else-no-double-error.rs
@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 // Without caching type lookups in FnCtxt.resolve_ty_and_def_ufcs
 // the error below would be reported twice (once when checking
diff --git a/src/test/ui/let-else/let-else-non-copy.rs b/src/test/ui/let-else/let-else-non-copy.rs
index 79ed82dd1..08c07dd1a 100644
--- a/src/test/ui/let-else/let-else-non-copy.rs
+++ b/src/test/ui/let-else/let-else-non-copy.rs
@@ -10,7 +10,7 @@
 //
 // The move was due to mir::Place being Copy, but mir::VarDebugInfoContents not being Copy.
 
-#![feature(let_else)]
+
 
 #[derive(Copy, Clone)]
 struct Copyable;
diff --git a/src/test/ui/let-else/let-else-non-diverging.rs b/src/test/ui/let-else/let-else-non-diverging.rs
index a1cee335a..b5bd91ceb 100644
--- a/src/test/ui/let-else/let-else-non-diverging.rs
+++ b/src/test/ui/let-else/let-else-non-diverging.rs
@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(x) = Some(1) else { //~ ERROR does not diverge
         Some(2)
diff --git a/src/test/ui/let-else/let-else-non-diverging.stderr b/src/test/ui/let-else/let-else-non-diverging.stderr
index 05e45f689..c999a5495 100644
--- a/src/test/ui/let-else/let-else-non-diverging.stderr
+++ b/src/test/ui/let-else/let-else-non-diverging.stderr
@@ -1,5 +1,5 @@
 error[E0308]: `else` clause of `let...else` does not diverge
-  --> $DIR/let-else-non-diverging.rs:4:32
+  --> $DIR/let-else-non-diverging.rs:2:32
    |
 LL |       let Some(x) = Some(1) else {
    |  ________________________________^
@@ -13,7 +13,7 @@ LL | |     };
    = help: ...or use `match` instead of `let...else`
 
 error[E0308]: `else` clause of `let...else` does not diverge
-  --> $DIR/let-else-non-diverging.rs:7:32
+  --> $DIR/let-else-non-diverging.rs:5:32
    |
 LL |       let Some(x) = Some(1) else {
    |  ________________________________^
@@ -29,7 +29,7 @@ LL | |     };
    = help: ...or use `match` instead of `let...else`
 
 error[E0308]: `else` clause of `let...else` does not diverge
-  --> $DIR/let-else-non-diverging.rs:12:32
+  --> $DIR/let-else-non-diverging.rs:10:32
    |
 LL |     let Some(x) = Some(1) else { Some(2) };
    |                                ^^^^^^^^^^^ expected `!`, found enum `Option`
diff --git a/src/test/ui/let-else/let-else-ref-bindings-pass.rs b/src/test/ui/let-else/let-else-ref-bindings-pass.rs
index f4abd6cc2..62fc65731 100644
--- a/src/test/ui/let-else/let-else-ref-bindings-pass.rs
+++ b/src/test/ui/let-else/let-else-ref-bindings-pass.rs
@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(let_else)]
+
 #![allow(unused_variables)]
 
 fn ref_() {
diff --git a/src/test/ui/let-else/let-else-ref-bindings.rs b/src/test/ui/let-else/let-else-ref-bindings.rs
index a4cd8e8c4..687e235d4 100644
--- a/src/test/ui/let-else/let-else-ref-bindings.rs
+++ b/src/test/ui/let-else/let-else-ref-bindings.rs
@@ -1,6 +1,6 @@
-#![feature(let_else)]
 #![allow(unused_variables)]
 
+
 fn ref_() {
     let bytes: Vec<u8> = b"Hello"[..].to_vec();
     let some = Some(bytes);
diff --git a/src/test/ui/let-else/let-else-run-pass.rs b/src/test/ui/let-else/let-else-run-pass.rs
index 5d9662323..a0fb6c683 100644
--- a/src/test/ui/let-else/let-else-run-pass.rs
+++ b/src/test/ui/let-else/let-else-run-pass.rs
@@ -1,6 +1,6 @@
 // run-pass
 
-#![feature(let_else)]
+
 
 fn main() {
     #[allow(dead_code)]
diff --git a/src/test/ui/let-else/let-else-scope.rs b/src/test/ui/let-else/let-else-scope.rs
index f17682db4..78a67769e 100644
--- a/src/test/ui/let-else/let-else-scope.rs
+++ b/src/test/ui/let-else/let-else-scope.rs
@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(x) = Some(2) else {
         panic!("{}", x); //~ ERROR cannot find value `x` in this scope
diff --git a/src/test/ui/let-else/let-else-scope.stderr b/src/test/ui/let-else/let-else-scope.stderr
index 4b3936eac..3b4f09829 100644
--- a/src/test/ui/let-else/let-else-scope.stderr
+++ b/src/test/ui/let-else/let-else-scope.stderr
@@ -1,5 +1,5 @@
 error[E0425]: cannot find value `x` in this scope
-  --> $DIR/let-else-scope.rs:5:22
+  --> $DIR/let-else-scope.rs:3:22
    |
 LL |         panic!("{}", x);
    |                      ^ not found in this scope
diff --git a/src/test/ui/let-else/let-else-slicing-error.rs b/src/test/ui/let-else/let-else-slicing-error.rs
index 4022656a8..25770094b 100644
--- a/src/test/ui/let-else/let-else-slicing-error.rs
+++ b/src/test/ui/let-else/let-else-slicing-error.rs
@@ -1,5 +1,5 @@
 // issue #92069
-#![feature(let_else)]
+
 
 fn main() {
     let nums = vec![5, 4, 3, 2, 1];
diff --git a/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs b/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs
index 2aa17ae8c..ee378abcf 100644
--- a/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs
+++ b/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs
@@ -1,7 +1,7 @@
 // run-pass
 // issue #89688
 
-#![feature(let_else)]
+
 
 fn example_let_else(value: Option<String>) {
     let Some(inner) = value else {
diff --git a/src/test/ui/let-else/let-else-temp-borrowck.rs b/src/test/ui/let-else/let-else-temp-borrowck.rs
index 3910d35e7..6b4642d2f 100644
--- a/src/test/ui/let-else/let-else-temp-borrowck.rs
+++ b/src/test/ui/let-else/let-else-temp-borrowck.rs
@@ -3,7 +3,7 @@
 // from issue #93951, where borrowck complained the temporary that `foo(&x)` was stored in was to
 // be dropped sometime after `x` was. It then suggested adding a semicolon that was already there.
 
-#![feature(let_else)]
+
 use std::fmt::Debug;
 
 fn foo<'a>(x: &'a str) -> Result<impl Debug + 'a, ()> {
diff --git a/src/test/ui/let-else/let-else-temporary-lifetime.rs b/src/test/ui/let-else/let-else-temporary-lifetime.rs
index 9c86901b9..c23eaa997 100644
--- a/src/test/ui/let-else/let-else-temporary-lifetime.rs
+++ b/src/test/ui/let-else/let-else-temporary-lifetime.rs
@@ -1,5 +1,5 @@
 // run-pass
-#![feature(let_else)]
+// compile-flags: -Zvalidate-mir
 
 use std::fmt::Display;
 use std::rc::Rc;
@@ -74,6 +74,17 @@ fn main() {
             };
         }
     }
+    {
+        fn must_pass() {
+            let rc = Rc::new(());
+            let &None = &Some(Rc::clone(&rc)) else {
+                Rc::try_unwrap(rc).unwrap();
+                return;
+            };
+            unreachable!();
+        }
+        must_pass();
+    }
     {
         // test let-else drops temps before else block
         // NOTE: this test has to be the last block in the `main`
diff --git a/src/test/ui/let-else/let-else-then-diverge.rs b/src/test/ui/let-else/let-else-then-diverge.rs
new file mode 100644
index 000000000..1c8f7d758
--- /dev/null
+++ b/src/test/ui/let-else/let-else-then-diverge.rs
@@ -0,0 +1,19 @@
+//
+// popped up in in #94012, where an alternative desugaring was
+// causing unreachable code errors
+
+
+#![deny(unused_variables)]
+#![deny(unreachable_code)]
+
+fn let_else_diverge() -> bool {
+    let Some(_) = Some("test") else {
+        let x = 5; //~ ERROR unused variable: `x`
+        return false;
+    };
+    return true;
+}
+
+fn main() {
+    let_else_diverge();
+}
diff --git a/src/test/ui/let-else/let-else-then-diverge.stderr b/src/test/ui/let-else/let-else-then-diverge.stderr
new file mode 100644
index 000000000..ceb61029d
--- /dev/null
+++ b/src/test/ui/let-else/let-else-then-diverge.stderr
@@ -0,0 +1,14 @@
+error: unused variable: `x`
+  --> $DIR/let-else-then-diverge.rs:11:13
+   |
+LL |         let x = 5;
+   |             ^ help: if this is intentional, prefix it with an underscore: `_x`
+   |
+note: the lint level is defined here
+  --> $DIR/let-else-then-diverge.rs:6:9
+   |
+LL | #![deny(unused_variables)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/let-else/let-else.rs b/src/test/ui/let-else/let-else.rs
new file mode 100644
index 000000000..3505533e6
--- /dev/null
+++ b/src/test/ui/let-else/let-else.rs
@@ -0,0 +1,8 @@
+// run-pass
+
+fn main() {
+    let Some(x) = Some(1) else {
+        return;
+    };
+    assert_eq!(x, 1);
+}
-- 
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