Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

57 files changed, 1428 insertions, 0 deletions

diff --git a/src/test/ui/for-loop-while/auto-loop.rs b/src/test/ui/for-loop-while/auto-loop.rs
new file mode 100644
index 000000000..f02ac43c7
--- /dev/null
+++ b/src/test/ui/for-loop-while/auto-loop.rs
@@ -0,0 +1,10 @@
+// run-pass
+
+pub fn main() {
+    let mut sum = 0;
+    let xs = vec![1, 2, 3, 4, 5];
+    for x in &xs {
+        sum += *x;
+    }
+    assert_eq!(sum, 15);
+}
diff --git a/src/test/ui/for-loop-while/break-outside-loop.rs b/src/test/ui/for-loop-while/break-outside-loop.rs
new file mode 100644
index 000000000..26769b30d
--- /dev/null
+++ b/src/test/ui/for-loop-while/break-outside-loop.rs
@@ -0,0 +1,35 @@
+struct Foo {
+    t: String
+}
+
+fn cond() -> bool { true }
+
+fn foo<F>(_: F) where F: FnOnce() {}
+
+fn main() {
+    let pth = break; //~ ERROR: `break` outside of a loop
+    if cond() { continue } //~ ERROR: `continue` outside of a loop
+
+    while cond() {
+        if cond() { break }
+        if cond() { continue }
+        foo(|| {
+            if cond() { break } //~ ERROR: `break` inside of a closure
+            if cond() { continue } //~ ERROR: `continue` inside of a closure
+        })
+    }
+
+    let rs: Foo = Foo{t: pth};
+
+    let unconstrained = break; //~ ERROR: `break` outside of a loop
+
+    // This used to ICE because `target_id` passed to `check_expr_break` would be the closure and
+    // not the `loop`, which failed in the call to `find_breakable`. (#65383)
+    'lab: loop {
+        || {
+            break 'lab;
+            //~^ ERROR use of unreachable label `'lab`
+            //~| ERROR `break` inside of a closure
+        };
+    }
+}
diff --git a/src/test/ui/for-loop-while/break-outside-loop.stderr b/src/test/ui/for-loop-while/break-outside-loop.stderr
new file mode 100644
index 000000000..287bf9af6
--- /dev/null
+++ b/src/test/ui/for-loop-while/break-outside-loop.stderr
@@ -0,0 +1,58 @@
+error[E0767]: use of unreachable label `'lab`
+  --> $DIR/break-outside-loop.rs:30:19
+   |
+LL |     'lab: loop {
+   |     ---- unreachable label defined here
+LL |         || {
+LL |             break 'lab;
+   |                   ^^^^ unreachable label `'lab`
+   |
+   = note: labels are unreachable through functions, closures, async blocks and modules
+
+error[E0268]: `break` outside of a loop
+  --> $DIR/break-outside-loop.rs:10:15
+   |
+LL |     let pth = break;
+   |               ^^^^^ cannot `break` outside of a loop
+
+error[E0268]: `continue` outside of a loop
+  --> $DIR/break-outside-loop.rs:11:17
+   |
+LL |     if cond() { continue }
+   |                 ^^^^^^^^ cannot `continue` outside of a loop
+
+error[E0267]: `break` inside of a closure
+  --> $DIR/break-outside-loop.rs:17:25
+   |
+LL |         foo(|| {
+   |             -- enclosing closure
+LL |             if cond() { break }
+   |                         ^^^^^ cannot `break` inside of a closure
+
+error[E0267]: `continue` inside of a closure
+  --> $DIR/break-outside-loop.rs:18:25
+   |
+LL |         foo(|| {
+   |             -- enclosing closure
+LL |             if cond() { break }
+LL |             if cond() { continue }
+   |                         ^^^^^^^^ cannot `continue` inside of a closure
+
+error[E0268]: `break` outside of a loop
+  --> $DIR/break-outside-loop.rs:24:25
+   |
+LL |     let unconstrained = break;
+   |                         ^^^^^ cannot `break` outside of a loop
+
+error[E0267]: `break` inside of a closure
+  --> $DIR/break-outside-loop.rs:30:13
+   |
+LL |         || {
+   |         -- enclosing closure
+LL |             break 'lab;
+   |             ^^^^^^^^^^ cannot `break` inside of a closure
+
+error: aborting due to 7 previous errors
+
+Some errors have detailed explanations: E0267, E0268, E0767.
+For more information about an error, try `rustc --explain E0267`.
diff --git a/src/test/ui/for-loop-while/break-value.rs b/src/test/ui/for-loop-while/break-value.rs
new file mode 100644
index 000000000..9fc49fa81
--- /dev/null
+++ b/src/test/ui/for-loop-while/break-value.rs
@@ -0,0 +1,7 @@
+// run-pass
+#![allow(unreachable_code)]
+// pretty-expanded FIXME #23616
+
+fn int_id(x: isize) -> isize { return x; }
+
+pub fn main() { loop { int_id(break); } }
diff --git a/src/test/ui/for-loop-while/break-while-condition.rs b/src/test/ui/for-loop-while/break-while-condition.rs
new file mode 100644
index 000000000..6064e6ab0
--- /dev/null
+++ b/src/test/ui/for-loop-while/break-while-condition.rs
@@ -0,0 +1,29 @@
+#![feature(never_type)]
+
+fn main() {
+    // The `if false` expressions are simply to
+    // make sure we don't avoid checking everything
+    // simply because a few expressions are unreachable.
+
+    if false {
+        let _: ! = { //~ ERROR mismatched types
+            'a: while break 'a {};
+        };
+    }
+
+    if false {
+        let _: ! = {
+            while false { //~ ERROR mismatched types
+                break
+            }
+        };
+    }
+
+    if false {
+        let _: ! = {
+            while false { //~ ERROR mismatched types
+                return
+            }
+        };
+    }
+}
diff --git a/src/test/ui/for-loop-while/break-while-condition.stderr b/src/test/ui/for-loop-while/break-while-condition.stderr
new file mode 100644
index 000000000..6960c4fd8
--- /dev/null
+++ b/src/test/ui/for-loop-while/break-while-condition.stderr
@@ -0,0 +1,37 @@
+error[E0308]: mismatched types
+  --> $DIR/break-while-condition.rs:9:20
+   |
+LL |           let _: ! = {
+   |  ____________________^
+LL | |             'a: while break 'a {};
+LL | |         };
+   | |_________^ expected `!`, found `()`
+   |
+   = note:   expected type `!`
+           found unit type `()`
+
+error[E0308]: mismatched types
+  --> $DIR/break-while-condition.rs:16:13
+   |
+LL | /             while false {
+LL | |                 break
+LL | |             }
+   | |_____________^ expected `!`, found `()`
+   |
+   = note:   expected type `!`
+           found unit type `()`
+
+error[E0308]: mismatched types
+  --> $DIR/break-while-condition.rs:24:13
+   |
+LL | /             while false {
+LL | |                 return
+LL | |             }
+   | |_____________^ expected `!`, found `()`
+   |
+   = note:   expected type `!`
+           found unit type `()`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/for-loop-while/break.rs b/src/test/ui/for-loop-while/break.rs
new file mode 100644
index 000000000..427b1b7a0
--- /dev/null
+++ b/src/test/ui/for-loop-while/break.rs
@@ -0,0 +1,25 @@
+// run-pass
+
+pub fn main() {
+    let mut i = 0;
+    while i < 20 { i += 1; if i == 10 { break; } }
+    assert_eq!(i, 10);
+    loop { i += 1; if i == 20 { break; } }
+    assert_eq!(i, 20);
+    let xs = [1, 2, 3, 4, 5, 6];
+    for x in &xs {
+        if *x == 3 { break; } assert!((*x <= 3));
+    }
+    i = 0;
+    while i < 10 { i += 1; if i % 2 == 0 { continue; } assert!((i % 2 != 0)); }
+    i = 0;
+    loop {
+        i += 1; if i % 2 == 0 { continue; } assert!((i % 2 != 0));
+        if i >= 10 { break; }
+    }
+    let ys = vec![1, 2, 3, 4, 5, 6];
+    for x in &ys {
+        if *x % 2 == 0 { continue; }
+        assert!((*x % 2 != 0));
+    }
+}
diff --git a/src/test/ui/for-loop-while/cleanup-rvalue-during-if-and-while.rs b/src/test/ui/for-loop-while/cleanup-rvalue-during-if-and-while.rs
new file mode 100644
index 000000000..afc77355a
--- /dev/null
+++ b/src/test/ui/for-loop-while/cleanup-rvalue-during-if-and-while.rs
@@ -0,0 +1,41 @@
+// run-pass
+// This test verifies that temporaries created for `while`'s and `if`
+// conditions are dropped after the condition is evaluated.
+
+struct Temporary;
+
+static mut DROPPED: isize = 0;
+
+impl Drop for Temporary {
+    fn drop(&mut self) {
+        unsafe { DROPPED += 1; }
+    }
+}
+
+impl Temporary {
+    fn do_stuff(&self) -> bool {true}
+}
+
+fn borrow() -> Box<Temporary> { Box::new(Temporary) }
+
+
+pub fn main() {
+    let mut i = 0;
+
+    // This loop's condition
+    // should call `Temporary`'s
+    // `drop` 6 times.
+    while borrow().do_stuff() {
+        i += 1;
+        unsafe { assert_eq!(DROPPED, i) }
+        if i > 5 {
+            break;
+        }
+    }
+
+    // This if condition should
+    // call it 1 time
+    if borrow().do_stuff() {
+        unsafe { assert_eq!(DROPPED, i + 1) }
+    }
+}
diff --git a/src/test/ui/for-loop-while/for-destruct.rs b/src/test/ui/for-loop-while/for-destruct.rs
new file mode 100644
index 000000000..7ca8d4ded
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-destruct.rs
@@ -0,0 +1,9 @@
+// run-pass
+
+struct Pair { x: isize, y: isize }
+
+pub fn main() {
+    for elt in &(vec![Pair {x: 10, y: 20}, Pair {x: 30, y: 0}]) {
+        assert_eq!(elt.x + elt.y, 30);
+    }
+}
diff --git a/src/test/ui/for-loop-while/for-loop-goofiness.rs b/src/test/ui/for-loop-while/for-loop-goofiness.rs
new file mode 100644
index 000000000..872ab168b
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-goofiness.rs
@@ -0,0 +1,16 @@
+// run-pass
+#![allow(dead_code)]
+
+enum BogusOption<T> {
+    None,
+    Some(T),
+}
+
+type Iterator = isize;
+
+pub fn main() {
+    let x = [ 3, 3, 3 ];
+    for i in &x {
+        assert_eq!(*i, 3);
+    }
+}
diff --git a/src/test/ui/for-loop-while/for-loop-has-unit-body.rs b/src/test/ui/for-loop-while/for-loop-has-unit-body.rs
new file mode 100644
index 000000000..eba385461
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-has-unit-body.rs
@@ -0,0 +1,13 @@
+// run-pass
+fn main() {
+    // Check that the tail statement in the body unifies with something
+    for _ in 0..3 {
+        // `()` is fine to zero-initialize as it is zero sized and inhabited.
+        unsafe { std::mem::zeroed() }
+    }
+
+    // Check that the tail statement in the body can be unit
+    for _ in 0..3 {
+        ()
+    }
+}
diff --git a/src/test/ui/for-loop-while/for-loop-into-iterator.rs b/src/test/ui/for-loop-while/for-loop-into-iterator.rs
new file mode 100644
index 000000000..199d4ddb2
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-into-iterator.rs
@@ -0,0 +1,19 @@
+// run-pass
+// Test that for loops can do what RFC #235 claims
+
+
+fn main() {
+    let mut v = vec![1];
+
+    for x in &v {
+        assert_eq!(x, &1);
+    }
+
+    for x in &mut v {
+        assert_eq!(x, &mut 1);
+    }
+
+    for x in v {
+        assert_eq!(x, 1);
+    }
+}
diff --git a/src/test/ui/for-loop-while/for-loop-lifetime-of-unbound-values.rs b/src/test/ui/for-loop-while/for-loop-lifetime-of-unbound-values.rs
new file mode 100644
index 000000000..6a38764a1
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-lifetime-of-unbound-values.rs
@@ -0,0 +1,34 @@
+// run-pass
+// Test when destructors run in a for loop. The intention is
+// that the value for each iteration is dropped *after* the loop
+// body has executed. This is true even when the value is assigned
+// to a `_` pattern (and hence ignored).
+
+use std::cell::Cell;
+
+struct Flag<'a>(&'a Cell<bool>);
+
+impl<'a> Drop for Flag<'a> {
+    fn drop(&mut self) {
+        self.0.set(false)
+    }
+}
+
+fn main() {
+    let alive2 = Cell::new(true);
+    for _i in std::iter::once(Flag(&alive2)) {
+        // The Flag value should be alive in the for loop body
+        assert_eq!(alive2.get(), true);
+    }
+    // The Flag value should be dead outside of the loop
+    assert_eq!(alive2.get(), false);
+
+    let alive = Cell::new(true);
+    for _ in std::iter::once(Flag(&alive)) {
+        // The Flag value should be alive in the for loop body even if it wasn't
+        // bound by the for loop
+        assert_eq!(alive.get(), true);
+    }
+    // The Flag value should be dead outside of the loop
+    assert_eq!(alive.get(), false);
+}
diff --git a/src/test/ui/for-loop-while/for-loop-macro.rs b/src/test/ui/for-loop-while/for-loop-macro.rs
new file mode 100644
index 000000000..5abccd2a1
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-macro.rs
@@ -0,0 +1,11 @@
+// run-pass
+macro_rules! var {
+    ( $name:ident ) => ( $name );
+}
+
+pub fn main() {
+    let x = [ 3, 3, 3 ];
+    for var!(i) in &x {
+        assert_eq!(*i, 3);
+    }
+}
diff --git a/src/test/ui/for-loop-while/for-loop-mut-ref-element.rs b/src/test/ui/for-loop-while/for-loop-mut-ref-element.rs
new file mode 100644
index 000000000..a3d82ace9
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-mut-ref-element.rs
@@ -0,0 +1,6 @@
+// run-pass
+// Tests that for loops can bind elements as mutable references
+
+fn main() {
+    for ref mut _a in std::iter::once(true) {}
+}
diff --git a/src/test/ui/for-loop-while/for-loop-no-std.rs b/src/test/ui/for-loop-while/for-loop-no-std.rs
new file mode 100644
index 000000000..65a33c5f1
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-no-std.rs
@@ -0,0 +1,14 @@
+// run-pass
+#![allow(unused_imports)]
+#![feature(lang_items, start)]
+#![no_std]
+
+extern crate std as other;
+
+#[macro_use] extern crate alloc;
+
+#[start]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+    for _ in [1,2,3].iter() { }
+    0
+}
diff --git a/src/test/ui/for-loop-while/for-loop-panic.rs b/src/test/ui/for-loop-while/for-loop-panic.rs
new file mode 100644
index 000000000..ac607d6d7
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-panic.rs
@@ -0,0 +1,4 @@
+// run-pass
+
+
+pub fn main() { let x: Vec<isize> = Vec::new(); for _ in &x { panic!("moop"); } }
diff --git a/src/test/ui/for-loop-while/for-loop-unconstrained-element-type-i32-fallback.rs b/src/test/ui/for-loop-while/for-loop-unconstrained-element-type-i32-fallback.rs
new file mode 100644
index 000000000..a1e9b1ed8
--- /dev/null
+++ b/src/test/ui/for-loop-while/for-loop-unconstrained-element-type-i32-fallback.rs
@@ -0,0 +1,11 @@
+// run-pass
+// Test that the type of `sum` falls back to `i32` here,
+// and that the for loop desugaring doesn't interfere with
+// that.
+
+fn main() {
+    let mut sum = 0;
+    for i in Vec::new() {
+        sum += &i;
+    }
+}
diff --git a/src/test/ui/for-loop-while/foreach-external-iterators-break.rs b/src/test/ui/for-loop-while/foreach-external-iterators-break.rs
new file mode 100644
index 000000000..7de6a4f8a
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-external-iterators-break.rs
@@ -0,0 +1,13 @@
+// run-pass
+
+pub fn main() {
+    let x = [1; 100];
+    let mut y = 0;
+    for i in &x[..] {
+        if y > 10 {
+            break;
+        }
+        y += *i;
+    }
+    assert_eq!(y, 11);
+}
diff --git a/src/test/ui/for-loop-while/foreach-external-iterators-hashmap-break-restart.rs b/src/test/ui/for-loop-while/foreach-external-iterators-hashmap-break-restart.rs
new file mode 100644
index 000000000..5d690807e
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-external-iterators-hashmap-break-restart.rs
@@ -0,0 +1,33 @@
+// run-pass
+
+use std::collections::HashMap;
+
+// This is a fancy one: it uses an external iterator established
+// outside the loop, breaks, then _picks back up_ and continues
+// iterating with it.
+
+pub fn main() {
+    let mut h = HashMap::new();
+    let kvs = [(1, 10), (2, 20), (3, 30)];
+    for &(k,v) in &kvs {
+        h.insert(k,v);
+    }
+    let mut x = 0;
+    let mut y = 0;
+
+    let mut i = h.iter();
+
+    for (&k,&v) in i.by_ref() {
+        x += k;
+        y += v;
+        break;
+    }
+
+    for (&k,&v) in i {
+        x += k;
+        y += v;
+    }
+
+    assert_eq!(x, 6);
+    assert_eq!(y, 60);
+}
diff --git a/src/test/ui/for-loop-while/foreach-external-iterators-hashmap.rs b/src/test/ui/for-loop-while/foreach-external-iterators-hashmap.rs
new file mode 100644
index 000000000..9f2ca05cd
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-external-iterators-hashmap.rs
@@ -0,0 +1,19 @@
+// run-pass
+
+use std::collections::HashMap;
+
+pub fn main() {
+    let mut h = HashMap::new();
+    let kvs = [(1, 10), (2, 20), (3, 30)];
+    for &(k,v) in &kvs {
+        h.insert(k,v);
+    }
+    let mut x = 0;
+    let mut y = 0;
+    for (&k,&v) in &h {
+        x += k;
+        y += v;
+    }
+    assert_eq!(x, 6);
+    assert_eq!(y, 60);
+}
diff --git a/src/test/ui/for-loop-while/foreach-external-iterators-loop.rs b/src/test/ui/for-loop-while/foreach-external-iterators-loop.rs
new file mode 100644
index 000000000..78af195bc
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-external-iterators-loop.rs
@@ -0,0 +1,13 @@
+// run-pass
+
+pub fn main() {
+    let x = [1; 100];
+    let mut y = 0;
+    for (n,i) in x.iter().enumerate() {
+        if n < 10 {
+            continue;
+        }
+        y += *i;
+    }
+    assert_eq!(y, 90);
+}
diff --git a/src/test/ui/for-loop-while/foreach-external-iterators-nested.rs b/src/test/ui/for-loop-while/foreach-external-iterators-nested.rs
new file mode 100644
index 000000000..8a95f160a
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-external-iterators-nested.rs
@@ -0,0 +1,15 @@
+// run-pass
+
+pub fn main() {
+    let x = [1; 100];
+    let y = [2; 100];
+    let mut p = 0;
+    let mut q = 0;
+    for i in &x[..] {
+        for j in &y[..] {
+            p += *j;
+        }
+        q += *i + p;
+    }
+    assert_eq!(q, 1010100);
+}
diff --git a/src/test/ui/for-loop-while/foreach-external-iterators.rs b/src/test/ui/for-loop-while/foreach-external-iterators.rs
new file mode 100644
index 000000000..24ecfe9b6
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-external-iterators.rs
@@ -0,0 +1,10 @@
+// run-pass
+
+pub fn main() {
+    let x = [1; 100];
+    let mut y = 0;
+    for i in &x[..] {
+        y += *i
+    }
+    assert_eq!(y, 100);
+}
diff --git a/src/test/ui/for-loop-while/foreach-nested.rs b/src/test/ui/for-loop-while/foreach-nested.rs
new file mode 100644
index 000000000..bb6edbc07
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-nested.rs
@@ -0,0 +1,16 @@
+// run-pass
+
+
+fn two<F>(mut it: F) where F: FnMut(isize) { it(0); it(1); }
+
+pub fn main() {
+    let mut a: Vec<isize> = vec![-1, -1, -1, -1];
+    let mut p: isize = 0;
+    two(|i| {
+        two(|j| { a[p as usize] = 10 * i + j; p += 1; })
+    });
+    assert_eq!(a[0], 0);
+    assert_eq!(a[1], 1);
+    assert_eq!(a[2], 10);
+    assert_eq!(a[3], 11);
+}
diff --git a/src/test/ui/for-loop-while/foreach-put-structured.rs b/src/test/ui/for-loop-while/foreach-put-structured.rs
new file mode 100644
index 000000000..3a47fcf34
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-put-structured.rs
@@ -0,0 +1,22 @@
+// run-pass
+
+
+fn pairs<F>(mut it: F) where F: FnMut((isize, isize)) {
+    let mut i: isize = 0;
+    let mut j: isize = 0;
+    while i < 10 { it((i, j)); i += 1; j += i; }
+}
+
+pub fn main() {
+    let mut i: isize = 10;
+    let mut j: isize = 0;
+    pairs(|p| {
+        let (_0, _1) = p;
+        println!("{}", _0);
+        println!("{}", _1);
+        assert_eq!(_0 + 10, i);
+        i += 1;
+        j = _1;
+    });
+    assert_eq!(j, 45);
+}
diff --git a/src/test/ui/for-loop-while/foreach-simple-outer-slot.rs b/src/test/ui/for-loop-while/foreach-simple-outer-slot.rs
new file mode 100644
index 000000000..a8d42a789
--- /dev/null
+++ b/src/test/ui/for-loop-while/foreach-simple-outer-slot.rs
@@ -0,0 +1,16 @@
+// run-pass
+
+
+
+pub fn main() {
+    let mut sum: isize = 0;
+    first_ten(|i| { println!("main"); println!("{}", i); sum = sum + i; });
+    println!("sum");
+    println!("{}", sum);
+    assert_eq!(sum, 45);
+}
+
+fn first_ten<F>(mut it: F) where F: FnMut(isize) {
+    let mut i: isize = 0;
+    while i < 10 { println!("first_ten"); it(i); i = i + 1; }
+}
diff --git a/src/test/ui/for-loop-while/issue-2216.rs b/src/test/ui/for-loop-while/issue-2216.rs
new file mode 100644
index 000000000..ad5410742
--- /dev/null
+++ b/src/test/ui/for-loop-while/issue-2216.rs
@@ -0,0 +1,24 @@
+// run-pass
+#![allow(unreachable_code)]
+pub fn main() {
+    let mut x = 0;
+
+    'foo: loop {
+        'bar: loop {
+            loop {
+                if 1 == 2 {
+                    break 'foo;
+                }
+                else {
+                    break 'bar;
+                }
+            }
+            continue 'foo;
+        }
+        x = 42;
+        break;
+    }
+
+    println!("{}", x);
+    assert_eq!(x, 42);
+}
diff --git a/src/test/ui/for-loop-while/issue-51345.rs b/src/test/ui/for-loop-while/issue-51345.rs
new file mode 100644
index 000000000..15571e8bf
--- /dev/null
+++ b/src/test/ui/for-loop-while/issue-51345.rs
@@ -0,0 +1,8 @@
+// run-pass
+#![allow(unreachable_code)]
+
+fn main() {
+    let mut v = Vec::new();
+
+    loop { v.push(break) }
+}
diff --git a/src/test/ui/for-loop-while/issue-69841.rs b/src/test/ui/for-loop-while/issue-69841.rs
new file mode 100644
index 000000000..1aca16ca8
--- /dev/null
+++ b/src/test/ui/for-loop-while/issue-69841.rs
@@ -0,0 +1,31 @@
+// This is a regression test for issue rust-lang/rust#69841, which exposed an
+// LLVM bug which needed a fix to be backported.
+
+// run-pass
+// no-system-llvm
+
+fn main() {
+    let buffer = [49u8, 10];
+    let mut a : u64 = 0;
+    'read: loop {
+        for c in &buffer {
+            match c {
+                48..=57 => {
+                    a*= 10;
+                    a+= *c as u64 - 48;
+                }
+                10 => {
+                    break 'read;
+                }
+                _ => {
+                    unsafe { std::hint::unreachable_unchecked() };
+                }
+            }
+        }
+    }
+    if a == 1 {
+        println!("What did you expect?");
+    } else {
+        panic!("this should be unreachable.");
+    }
+}
diff --git a/src/test/ui/for-loop-while/label_break_value.rs b/src/test/ui/for-loop-while/label_break_value.rs
new file mode 100644
index 000000000..ca9d71a7a
--- /dev/null
+++ b/src/test/ui/for-loop-while/label_break_value.rs
@@ -0,0 +1,167 @@
+// run-pass
+#![allow(dead_code)]
+#![allow(unused_assignments)]
+#![feature(label_break_value)]
+
+// Test control flow to follow label_break_value semantics
+fn label_break(a: bool, b: bool) -> u32 {
+    let mut v = 0;
+    'b: {
+        v = 1;
+        if a {
+            break 'b;
+        }
+        v = 2;
+        if b {
+            break 'b;
+        }
+        v = 3;
+    }
+    return v;
+}
+
+// Test that values can be returned
+fn break_value(a: bool, b: bool) -> u32 {
+    let result = 'block: {
+        if a { break 'block 1; }
+        if b { break 'block 2; }
+        3
+    };
+    result
+}
+
+// Test nesting of labeled blocks
+// here we only check that it compiles
+fn label_break_nested() {
+    'b: {
+        println!("hi");
+        if false {
+            break 'b;
+        }
+        'c: {
+            if false {
+                break 'b;
+            }
+            break 'c;
+        }
+        println!("hello");
+        if true {
+            break 'b;
+        }
+    }
+}
+
+// Tests for mixing labeled blocks with loop constructs
+// This function should be the identity function
+fn label_break_mixed(v: u32) -> u32 {
+    let mut r = 0;
+    'b: {
+        // Unlabeled break still works
+        // (only crossing boundaries is an error)
+        loop {
+            break;
+        }
+        if v == 0 {
+            break 'b;
+        }
+        // Labeled breaking an inner loop still works
+        'c: loop {
+            if r == 1 {
+                break 'c;
+            }
+            r += 1;
+        }
+        assert_eq!(r, 1);
+        if v == 1 {
+            break 'b;
+        }
+        // Labeled breaking an outer loop still works
+        'd: loop {
+            {
+                if v == r {
+                    break 'b;
+                }
+                if r == 5 {
+                    break 'd;
+                }
+                r += 1;
+            }
+        }
+        assert_eq!(r, 5);
+        assert!(v > r);
+        // Here we test return from inside a labeled block
+        return v;
+    }
+    r
+}
+
+fn label_break_match(c: u8, xe: u8, ye: i8) {
+    let mut x = 0;
+    let y = 'a: {
+        match c {
+            0 => break 'a 0,
+            v if { if v % 2 == 0 { break 'a 1; }; v % 3 == 0 } => { x += 1; },
+            v if { 'b: { break 'b v == 5; } } => { x = 41; },
+            _ => 'b: {
+                break 'b ();
+            },
+        }
+        x += 1;
+        -1
+    };
+
+    assert_eq!(x, xe);
+    assert_eq!(y, ye);
+}
+
+#[allow(unused_labels)]
+fn label_break_macro() {
+    macro_rules! mac1 {
+        ($target:lifetime, $val:expr) => {
+            break $target $val;
+        };
+    }
+    let x: u8 = 'a: {
+        'b: {
+            mac1!('b, 1);
+        };
+        0
+    };
+    assert_eq!(x, 0);
+    let x: u8 = 'a: {
+        'b: {
+            if true {
+                mac1!('a, 1);
+            }
+        };
+        0
+    };
+    assert_eq!(x, 1);
+}
+
+pub fn main() {
+    assert_eq!(label_break(true, false), 1);
+    assert_eq!(label_break(false, true), 2);
+    assert_eq!(label_break(false, false), 3);
+
+    assert_eq!(break_value(true, false), 1);
+    assert_eq!(break_value(false, true), 2);
+    assert_eq!(break_value(false, false), 3);
+
+    assert_eq!(label_break_mixed(0), 0);
+    assert_eq!(label_break_mixed(1), 1);
+    assert_eq!(label_break_mixed(2), 2);
+    assert_eq!(label_break_mixed(3), 3);
+    assert_eq!(label_break_mixed(4), 4);
+    assert_eq!(label_break_mixed(5), 5);
+    assert_eq!(label_break_mixed(6), 6);
+
+    label_break_match(0, 0, 0);
+    label_break_match(1, 1, -1);
+    label_break_match(2, 0, 1);
+    label_break_match(3, 2, -1);
+    label_break_match(5, 42, -1);
+    label_break_match(7, 1, -1);
+
+    label_break_macro();
+}
diff --git a/src/test/ui/for-loop-while/label_break_value_invalid.rs b/src/test/ui/for-loop-while/label_break_value_invalid.rs
new file mode 100644
index 000000000..149bf17b8
--- /dev/null
+++ b/src/test/ui/for-loop-while/label_break_value_invalid.rs
@@ -0,0 +1,36 @@
+#![crate_type = "lib"]
+#![feature(label_break_value)]
+
+fn lbv_macro_test_hygiene_respected() {
+    macro_rules! mac2 {
+        ($val:expr) => {
+            break 'a $val; //~ ERROR undeclared label `'a` [E0426]
+        };
+    }
+    let x: u8 = 'a: {
+        'b: {
+            if true {
+                mac2!(2);
+            }
+        };
+        0
+    };
+    assert_eq!(x, 2);
+
+    macro_rules! mac3 {
+        ($val:expr) => {
+            'a: {
+                $val
+            }
+        };
+    }
+    let x: u8 = mac3!('b: {
+        if true {
+            break 'a 3; //~ ERROR undeclared label `'a` [E0426]
+        }
+        0
+    });
+    assert_eq!(x, 3);
+    let x: u8 = mac3!(break 'a 4); //~ ERROR undeclared label `'a` [E0426]
+    assert_eq!(x, 4);
+}
diff --git a/src/test/ui/for-loop-while/label_break_value_invalid.stderr b/src/test/ui/for-loop-while/label_break_value_invalid.stderr
new file mode 100644
index 000000000..7182b8f59
--- /dev/null
+++ b/src/test/ui/for-loop-while/label_break_value_invalid.stderr
@@ -0,0 +1,32 @@
+error[E0426]: use of undeclared label `'a`
+  --> $DIR/label_break_value_invalid.rs:7:19
+   |
+LL |             break 'a $val;
+   |                   ^^ undeclared label `'a`
+...
+LL |                 mac2!(2);
+   |                 -------- in this macro invocation
+   |
+   = note: this error originates in the macro `mac2` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0426]: use of undeclared label `'a`
+  --> $DIR/label_break_value_invalid.rs:29:19
+   |
+LL |     let x: u8 = mac3!('b: {
+   |                       -- a label with a similar name is reachable
+LL |         if true {
+LL |             break 'a 3;
+   |                   ^^
+   |                   |
+   |                   undeclared label `'a`
+   |                   help: try using similarly named label: `'b`
+
+error[E0426]: use of undeclared label `'a`
+  --> $DIR/label_break_value_invalid.rs:34:29
+   |
+LL |     let x: u8 = mac3!(break 'a 4);
+   |                             ^^ undeclared label `'a`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0426`.
diff --git a/src/test/ui/for-loop-while/labeled-break.rs b/src/test/ui/for-loop-while/labeled-break.rs
new file mode 100644
index 000000000..4dacc5757
--- /dev/null
+++ b/src/test/ui/for-loop-while/labeled-break.rs
@@ -0,0 +1,22 @@
+// run-pass
+// pretty-expanded FIXME #23616
+
+pub fn main() {
+    'foo: loop {
+        loop {
+            break 'foo;
+        }
+    }
+
+    'bar: for _ in 0..100 {
+        loop {
+            break 'bar;
+        }
+    }
+
+    'foobar: while 1 + 1 == 2 {
+        loop {
+            break 'foobar;
+        }
+    }
+}
diff --git a/src/test/ui/for-loop-while/linear-for-loop.rs b/src/test/ui/for-loop-while/linear-for-loop.rs
new file mode 100644
index 000000000..3c573db1d
--- /dev/null
+++ b/src/test/ui/for-loop-while/linear-for-loop.rs
@@ -0,0 +1,23 @@
+// run-pass
+pub fn main() {
+    let x = vec![1, 2, 3];
+    let mut y = 0;
+    for i in &x { println!("{}", *i); y += *i; }
+    println!("{}", y);
+    assert_eq!(y, 6);
+    let s = "hello there".to_string();
+    let mut i: isize = 0;
+    for c in s.bytes() {
+        if i == 0 { assert_eq!(c, 'h' as u8); }
+        if i == 1 { assert_eq!(c, 'e' as u8); }
+        if i == 2 { assert_eq!(c, 'l' as u8); }
+        if i == 3 { assert_eq!(c, 'l' as u8); }
+        if i == 4 { assert_eq!(c, 'o' as u8); }
+        // ...
+
+        i += 1;
+        println!("{}", i);
+        println!("{}", c);
+    }
+    assert_eq!(i, 11);
+}
diff --git a/src/test/ui/for-loop-while/liveness-assign-imm-local-after-loop.rs b/src/test/ui/for-loop-while/liveness-assign-imm-local-after-loop.rs
new file mode 100644
index 000000000..11b697165
--- /dev/null
+++ b/src/test/ui/for-loop-while/liveness-assign-imm-local-after-loop.rs
@@ -0,0 +1,18 @@
+// run-pass
+#![allow(dead_code)]
+#![allow(unused_assignments)]
+// pretty-expanded FIXME #23616
+
+#![allow(unreachable_code)]
+#![allow(unused_variables)]
+
+fn test(_cond: bool) {
+    let v: isize;
+    v = 1;
+    loop { } // loop never terminates, so no error is reported
+    v = 2;
+}
+
+pub fn main() {
+    // note: don't call test()... :)
+}
diff --git a/src/test/ui/for-loop-while/liveness-loop-break.rs b/src/test/ui/for-loop-while/liveness-loop-break.rs
new file mode 100644
index 000000000..60a63bccb
--- /dev/null
+++ b/src/test/ui/for-loop-while/liveness-loop-break.rs
@@ -0,0 +1,13 @@
+// run-pass
+fn test() {
+    let v;
+    loop {
+        v = 3;
+        break;
+    }
+    println!("{}", v);
+}
+
+pub fn main() {
+    test();
+}
diff --git a/src/test/ui/for-loop-while/liveness-move-in-loop.rs b/src/test/ui/for-loop-while/liveness-move-in-loop.rs
new file mode 100644
index 000000000..ce73d6335
--- /dev/null
+++ b/src/test/ui/for-loop-while/liveness-move-in-loop.rs
@@ -0,0 +1,20 @@
+// run-pass
+#![allow(dead_code)]
+
+// pretty-expanded FIXME #23616
+
+fn take(x: isize) -> isize {x}
+
+fn the_loop() {
+    let mut list = Vec::new();
+    loop {
+        let x = 5;
+        if x > 3 {
+            list.push(take(x));
+        } else {
+            break;
+        }
+    }
+}
+
+pub fn main() {}
diff --git a/src/test/ui/for-loop-while/long-while.rs b/src/test/ui/for-loop-while/long-while.rs
new file mode 100644
index 000000000..529cca7b7
--- /dev/null
+++ b/src/test/ui/for-loop-while/long-while.rs
@@ -0,0 +1,12 @@
+// run-pass
+// pretty-expanded FIXME #23616
+
+#![allow(unused_variables)]
+
+pub fn main() {
+    let mut i: isize = 0;
+    while i < 1000000 {
+        i += 1;
+        let x = 3;
+    }
+}
diff --git a/src/test/ui/for-loop-while/loop-break-cont-1.rs b/src/test/ui/for-loop-while/loop-break-cont-1.rs
new file mode 100644
index 000000000..f207746f0
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-break-cont-1.rs
@@ -0,0 +1,9 @@
+// run-pass
+
+pub fn main() {
+  let _i = 0_usize;
+  loop {
+    break;
+  }
+  assert!(true);
+}
diff --git a/src/test/ui/for-loop-while/loop-break-cont.rs b/src/test/ui/for-loop-while/loop-break-cont.rs
new file mode 100644
index 000000000..92d5a32c6
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-break-cont.rs
@@ -0,0 +1,39 @@
+// run-pass
+pub fn main() {
+  let mut i = 0_usize;
+  loop {
+    println!("a");
+    i += 1_usize;
+    if i == 10_usize {
+      break;
+    }
+  }
+  assert_eq!(i, 10_usize);
+  let mut is_even = false;
+  loop {
+    if i == 21_usize {
+        break;
+    }
+    println!("b");
+    is_even = false;
+    i += 1_usize;
+    if i % 2_usize != 0_usize {
+        continue;
+    }
+    is_even = true;
+  }
+  assert!(!is_even);
+  loop {
+    println!("c");
+    if i == 22_usize {
+        break;
+    }
+    is_even = false;
+    i += 1_usize;
+    if i % 2_usize != 0_usize {
+        continue;
+    }
+    is_even = true;
+  }
+  assert!(is_even);
+}
diff --git a/src/test/ui/for-loop-while/loop-break-value.rs b/src/test/ui/for-loop-while/loop-break-value.rs
new file mode 100644
index 000000000..d7209fc4d
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-break-value.rs
@@ -0,0 +1,139 @@
+// run-pass
+
+#![allow(unreachable_code)]
+#![feature(never_type)]
+
+#[allow(unused)]
+fn never_returns() {
+    loop {
+        break loop {};
+    }
+}
+
+pub fn main() {
+    let value = 'outer: loop {
+        if 1 == 1 {
+            break 13;
+        } else {
+            let _never: ! = loop {
+                break loop {
+                    break 'outer panic!();
+                }
+            };
+        }
+    };
+    assert_eq!(value, 13);
+
+    let x = [1, 3u32, 5];
+    let y = [17];
+    let z = [];
+    let coerced: &[_] = loop {
+        match 2 {
+            1 => break &x,
+            2 => break &y,
+            3 => break &z,
+            _ => (),
+        }
+    };
+    assert_eq!(coerced, &[17u32]);
+
+    let trait_unified = loop {
+        break if true {
+            break Default::default()
+        } else {
+            break [13, 14]
+        };
+    };
+    assert_eq!(trait_unified, [0, 0]);
+
+    let trait_unified_2 = loop {
+        if false {
+            break [String::from("Hello")]
+        } else {
+            break Default::default()
+        };
+    };
+    assert_eq!(trait_unified_2, [""]);
+
+    let trait_unified_3 = loop {
+        break if false {
+            break [String::from("Hello")]
+        } else {
+            ["Yes".into()]
+        };
+    };
+    assert_eq!(trait_unified_3, ["Yes"]);
+
+    let regular_break = loop {
+        if true {
+            break;
+        } else {
+            break break Default::default();
+        }
+    };
+    assert_eq!(regular_break, ());
+
+    let regular_break_2 = loop {
+        if true {
+            break Default::default();
+        } else {
+            break;
+        }
+    };
+    assert_eq!(regular_break_2, ());
+
+    let regular_break_3 = loop {
+        break if true {
+            Default::default()
+        } else {
+            break;
+        }
+    };
+    assert_eq!(regular_break_3, ());
+
+    let regular_break_4 = loop {
+        break ();
+        break;
+    };
+    assert_eq!(regular_break_4, ());
+
+    let regular_break_5 = loop {
+        break;
+        break ();
+    };
+    assert_eq!(regular_break_5, ());
+
+    let nested_break_value = 'outer2: loop {
+        let _a: u32 = 'inner: loop {
+            if true {
+                break 'outer2 "hello";
+            } else {
+                break 'inner 17;
+            }
+        };
+        panic!();
+    };
+    assert_eq!(nested_break_value, "hello");
+
+    let break_from_while_cond = loop {
+        'inner_loop: while break 'inner_loop {
+            panic!();
+        }
+        break 123;
+    };
+    assert_eq!(break_from_while_cond, 123);
+
+    let break_from_while_to_outer = 'outer_loop: loop {
+        while break 'outer_loop 567 {
+            panic!("from_inner");
+        }
+        panic!("from outer");
+    };
+    assert_eq!(break_from_while_to_outer, 567);
+
+    let rust = true;
+    let value = loop {
+        break rust;
+    };
+    assert!(value);
+}
diff --git a/src/test/ui/for-loop-while/loop-diverges.rs b/src/test/ui/for-loop-while/loop-diverges.rs
new file mode 100644
index 000000000..f657bf9e0
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-diverges.rs
@@ -0,0 +1,14 @@
+// run-pass
+#![allow(unused_parens)]
+// pretty-expanded FIXME #23616
+
+/* Make sure a loop{} can be the tailexpr in the body
+of a diverging function */
+
+fn forever() -> ! {
+  loop{}
+}
+
+pub fn main() {
+  if (1 == 2) { forever(); }
+}
diff --git a/src/test/ui/for-loop-while/loop-label-shadowing.rs b/src/test/ui/for-loop-while/loop-label-shadowing.rs
new file mode 100644
index 000000000..9bedde67b
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-label-shadowing.rs
@@ -0,0 +1,12 @@
+// run-pass
+// Issue #12512.
+
+// pretty-expanded FIXME #23616
+
+fn main() {
+    let mut foo = Vec::new();
+    #[allow(unused_labels)]
+    'foo: for i in &[1, 2, 3] {
+        foo.push(*i);
+    }
+}
diff --git a/src/test/ui/for-loop-while/loop-labeled-break-value.rs b/src/test/ui/for-loop-while/loop-labeled-break-value.rs
new file mode 100644
index 000000000..cc8f82698
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-labeled-break-value.rs
@@ -0,0 +1,11 @@
+// run-pass
+// pretty-expanded FIXME #23616
+
+fn main() {
+    'outer: loop {
+        let _: i32 = loop { break 'outer };
+    }
+    'outer2: loop {
+        let _: i32 = loop { loop { break 'outer2 } };
+    }
+}
diff --git a/src/test/ui/for-loop-while/loop-no-reinit-needed-post-bot.rs b/src/test/ui/for-loop-while/loop-no-reinit-needed-post-bot.rs
new file mode 100644
index 000000000..1b5db2012
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-no-reinit-needed-post-bot.rs
@@ -0,0 +1,34 @@
+// run-pass
+// pretty-expanded FIXME #23616
+
+struct S;
+// Ensure S is moved, not copied, on assignment.
+impl Drop for S { fn drop(&mut self) { } }
+
+// user-defined function "returning" bottom (i.e., no return at all).
+fn my_panic() -> ! { loop {} }
+
+pub fn step(f: bool) {
+    let mut g = S;
+    let mut i = 0;
+    loop
+    {
+        if i > 10 { break; } else { i += 1; }
+
+        let _g = g;
+
+        if f {
+            // re-initialize g, but only before restarting loop.
+            g = S;
+            continue;
+        }
+
+        my_panic();
+
+        // we never get here, so we do not need to re-initialize g.
+    }
+}
+
+pub fn main() {
+    step(true);
+}
diff --git a/src/test/ui/for-loop-while/loop-scope.rs b/src/test/ui/for-loop-while/loop-scope.rs
new file mode 100644
index 000000000..73324a3e1
--- /dev/null
+++ b/src/test/ui/for-loop-while/loop-scope.rs
@@ -0,0 +1,8 @@
+// run-pass
+
+pub fn main() {
+    let x = vec![10, 20, 30];
+    let mut sum = 0;
+    for x in &x { sum += *x; }
+    assert_eq!(sum, 60);
+}
diff --git a/src/test/ui/for-loop-while/while-cont.rs b/src/test/ui/for-loop-while/while-cont.rs
new file mode 100644
index 000000000..a864e8ef7
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-cont.rs
@@ -0,0 +1,11 @@
+// run-pass
+// Issue #825: Should recheck the loop condition after continuing
+pub fn main() {
+    let mut i = 1;
+    while i > 0 {
+        assert!((i > 0));
+        println!("{}", i);
+        i -= 1;
+        continue;
+    }
+}
diff --git a/src/test/ui/for-loop-while/while-flow-graph.rs b/src/test/ui/for-loop-while/while-flow-graph.rs
new file mode 100644
index 000000000..1748964a7
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-flow-graph.rs
@@ -0,0 +1,6 @@
+// run-pass
+
+
+// pretty-expanded FIXME #23616
+
+pub fn main() { let x: isize = 10; while x == 10 && x == 11 { let _y = 0xf00_usize; } }
diff --git a/src/test/ui/for-loop-while/while-label.rs b/src/test/ui/for-loop-while/while-label.rs
new file mode 100644
index 000000000..5abc41daf
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-label.rs
@@ -0,0 +1,15 @@
+// run-pass
+#![allow(unreachable_code)]
+
+
+pub fn main() {
+    let mut i = 100;
+    'w: while 1 + 1 == 2 {
+        i -= 1;
+        if i == 95 {
+            break 'w;
+            panic!("Should have broken out of loop");
+        }
+    }
+    assert_eq!(i, 95);
+}
diff --git a/src/test/ui/for-loop-while/while-let-2.rs b/src/test/ui/for-loop-while/while-let-2.rs
new file mode 100644
index 000000000..b9a49b47c
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-let-2.rs
@@ -0,0 +1,31 @@
+// run-pass
+
+#[allow(dead_code)]
+fn macros() {
+    macro_rules! foo{
+        ($p:pat, $e:expr, $b:block) => {{
+            while let $p = $e $b
+            //~^ WARN irrefutable `while let`
+            //~| WARN irrefutable `while let`
+        }}
+    }
+    macro_rules! bar{
+        ($p:pat, $e:expr, $b:block) => {{
+            foo!($p, $e, $b)
+        }}
+    }
+
+    foo!(_a, 1, {
+        println!("irrefutable pattern");
+    });
+    bar!(_a, 1, {
+        println!("irrefutable pattern");
+    });
+}
+
+pub fn main() {
+    while let _a = 1 { //~ WARN irrefutable `while let`
+        println!("irrefutable pattern");
+        break;
+    }
+}
diff --git a/src/test/ui/for-loop-while/while-let-2.stderr b/src/test/ui/for-loop-while/while-let-2.stderr
new file mode 100644
index 000000000..2d23a6373
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-let-2.stderr
@@ -0,0 +1,42 @@
+warning: irrefutable `while let` pattern
+  --> $DIR/while-let-2.rs:7:19
+   |
+LL |               while let $p = $e $b
+   |                     ^^^
+...
+LL | /     foo!(_a, 1, {
+LL | |         println!("irrefutable pattern");
+LL | |     });
+   | |______- in this macro invocation
+   |
+   = note: `#[warn(irrefutable_let_patterns)]` on by default
+   = note: this pattern will always match, so the loop will never exit
+   = help: consider instead using a `loop { ... }` with a `let` inside it
+   = note: this warning originates in the macro `foo` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: irrefutable `while let` pattern
+  --> $DIR/while-let-2.rs:7:19
+   |
+LL |               while let $p = $e $b
+   |                     ^^^
+...
+LL | /     bar!(_a, 1, {
+LL | |         println!("irrefutable pattern");
+LL | |     });
+   | |______- in this macro invocation
+   |
+   = note: this pattern will always match, so the loop will never exit
+   = help: consider instead using a `loop { ... }` with a `let` inside it
+   = note: this warning originates in the macro `foo` which comes from the expansion of the macro `bar` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: irrefutable `while let` pattern
+  --> $DIR/while-let-2.rs:27:11
+   |
+LL |     while let _a = 1 {
+   |           ^^^^^^^^^^
+   |
+   = note: this pattern will always match, so the loop will never exit
+   = help: consider instead using a `loop { ... }` with a `let` inside it
+
+warning: 3 warnings emitted
+
diff --git a/src/test/ui/for-loop-while/while-let.rs b/src/test/ui/for-loop-while/while-let.rs
new file mode 100644
index 000000000..b9d70ff0b
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-let.rs
@@ -0,0 +1,46 @@
+// run-pass
+
+use std::collections::BinaryHeap;
+
+fn make_pq() -> BinaryHeap<isize> {
+    BinaryHeap::from(vec![1,2,3])
+}
+
+pub fn main() {
+    let mut pq = make_pq();
+    let mut sum = 0;
+    while let Some(x) = pq.pop() {
+        sum += x;
+    }
+    assert_eq!(sum, 6);
+
+    pq = make_pq();
+    sum = 0;
+    'a: while let Some(x) = pq.pop() {
+        sum += x;
+        if x == 2 {
+            break 'a;
+        }
+    }
+    assert_eq!(sum, 5);
+
+    pq = make_pq();
+    sum = 0;
+    'a2: while let Some(x) = pq.pop() {
+        if x == 3 {
+            continue 'a2;
+        }
+        sum += x;
+    }
+    assert_eq!(sum, 3);
+
+    let mut pq1 = make_pq();
+    sum = 0;
+    while let Some(x) = pq1.pop() {
+        let mut pq2 = make_pq();
+        while let Some(y) = pq2.pop() {
+            sum += x * y;
+        }
+    }
+    assert_eq!(sum, 6 + 12 + 18);
+}
diff --git a/src/test/ui/for-loop-while/while-loop-constraints-2.rs b/src/test/ui/for-loop-while/while-loop-constraints-2.rs
new file mode 100644
index 000000000..3c5cdf06c
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-loop-constraints-2.rs
@@ -0,0 +1,15 @@
+// run-pass
+#![allow(unused_assignments)]
+#![allow(unused_variables)]
+
+pub fn main() {
+    let mut y: isize = 42;
+    let mut z: isize = 42;
+    let mut x: isize;
+    while z < 50 {
+        z += 1;
+        while false { x = y; y = z; }
+        println!("{}", y);
+    }
+    assert!((y == 42 && z == 50));
+}
diff --git a/src/test/ui/for-loop-while/while-prelude-drop.rs b/src/test/ui/for-loop-while/while-prelude-drop.rs
new file mode 100644
index 000000000..196b9daf6
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-prelude-drop.rs
@@ -0,0 +1,24 @@
+// run-pass
+#![allow(non_camel_case_types)]
+
+use std::string::String;
+
+#[derive(PartialEq)]
+enum t { a, b(String), }
+
+fn make(i: isize) -> t {
+    if i > 10 { return t::a; }
+    let mut s = String::from("hello");
+    // Ensure s is non-const.
+
+    s.push_str("there");
+    return t::b(s);
+}
+
+pub fn main() {
+    let mut i = 0;
+
+
+    // The auto slot for the result of make(i) should not leak.
+    while make(i) != t::a { i += 1; }
+}
diff --git a/src/test/ui/for-loop-while/while-with-break.rs b/src/test/ui/for-loop-while/while-with-break.rs
new file mode 100644
index 000000000..a9d52dda5
--- /dev/null
+++ b/src/test/ui/for-loop-while/while-with-break.rs
@@ -0,0 +1,17 @@
+// run-pass
+
+pub fn main() {
+    let mut i: isize = 90;
+    while i < 100 {
+        println!("{}", i);
+        i = i + 1;
+        if i == 95 {
+            let _v: Vec<isize> =
+                vec![1, 2, 3, 4, 5]; // we check that it is freed by break
+
+            println!("breaking");
+            break;
+        }
+    }
+    assert_eq!(i, 95);
+}
diff --git a/src/test/ui/for-loop-while/while.rs b/src/test/ui/for-loop-while/while.rs
new file mode 100644
index 000000000..90f718a34
--- /dev/null
+++ b/src/test/ui/for-loop-while/while.rs
@@ -0,0 +1,13 @@
+// run-pass
+
+
+pub fn main() {
+    let mut x: isize = 10;
+    let mut y: isize = 0;
+    while y < x { println!("{}", y); println!("hello"); y = y + 1; }
+    while x > 0 {
+        println!("goodbye");
+        x = x - 1;
+        println!("{}", x);
+    }
+}