From c66d02e3ba0d5ace4e42bab88e4df246f03b91d5 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Fri, 1 May 2020 11:16:38 +0200
Subject: [PATCH 1/8] liballoc tests: Miri supports threads now

---
 src/liballoc/alloc/tests.rs                   | 2 +-
 src/liballoc/collections/linked_list/tests.rs | 1 -
 src/liballoc/collections/vec_deque/tests.rs   | 8 ++++----
 src/liballoc/sync/tests.rs                    | 2 --
 4 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/liballoc/alloc/tests.rs b/src/liballoc/alloc/tests.rs
index 1ad40eca93b69..1c003983df989 100644
--- a/src/liballoc/alloc/tests.rs
+++ b/src/liballoc/alloc/tests.rs
@@ -23,7 +23,7 @@ fn allocate_zeroed() {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn alloc_owned_small(b: &mut Bencher) {
     b.iter(|| {
         let _: Box<_> = box 10;
diff --git a/src/liballoc/collections/linked_list/tests.rs b/src/liballoc/collections/linked_list/tests.rs
index 085f734ed916a..b8c93a28bba81 100644
--- a/src/liballoc/collections/linked_list/tests.rs
+++ b/src/liballoc/collections/linked_list/tests.rs
@@ -182,7 +182,6 @@ fn test_insert_prev() {
 
 #[test]
 #[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg_attr(miri, ignore)] // Miri does not support threads
 fn test_send() {
     let n = list_from(&[1, 2, 3]);
     thread::spawn(move || {
diff --git a/src/liballoc/collections/vec_deque/tests.rs b/src/liballoc/collections/vec_deque/tests.rs
index 0a3f33003233f..fc2ec7908e823 100644
--- a/src/liballoc/collections/vec_deque/tests.rs
+++ b/src/liballoc/collections/vec_deque/tests.rs
@@ -3,7 +3,7 @@ use super::*;
 use test;
 
 #[bench]
-#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_push_back_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::with_capacity(101);
     b.iter(|| {
@@ -16,7 +16,7 @@ fn bench_push_back_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_push_front_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::with_capacity(101);
     b.iter(|| {
@@ -29,7 +29,7 @@ fn bench_push_front_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_pop_back_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::<i32>::with_capacity(101);
 
@@ -43,7 +43,7 @@ fn bench_pop_back_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // isolated Miri does not support benchmarks
 fn bench_pop_front_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::<i32>::with_capacity(101);
 
diff --git a/src/liballoc/sync/tests.rs b/src/liballoc/sync/tests.rs
index edc2820ee22f1..4a5cc9aa5910f 100644
--- a/src/liballoc/sync/tests.rs
+++ b/src/liballoc/sync/tests.rs
@@ -32,7 +32,6 @@ impl Drop for Canary {
 
 #[test]
 #[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg_attr(miri, ignore)] // Miri does not support threads
 fn manually_share_arc() {
     let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
     let arc_v = Arc::new(v);
@@ -337,7 +336,6 @@ fn test_ptr_eq() {
 
 #[test]
 #[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg_attr(miri, ignore)] // Miri does not support threads
 fn test_weak_count_locked() {
     let mut a = Arc::new(atomic::AtomicBool::new(false));
     let a2 = a.clone();

From 6b96fb74fb3a6ad8aaf9042f9a6b1b7d4fea94df Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Fri, 1 May 2020 12:10:06 +0200
Subject: [PATCH 2/8] Pointer printing: do not print 0 offset

---
 src/librustc_middle/mir/interpret/pointer.rs  | 31 +++++++++++++------
 ...main.SimplifyCfg-elaborate-drops.after.mir |  4 +--
 .../rustc.BAR-promoted[0].ConstProp.after.mir |  6 ++--
 .../rustc.BAR.PromoteTemps.diff               |  6 ++--
 .../rustc.FOO-promoted[0].ConstProp.after.mir |  6 ++--
 .../rustc.FOO.PromoteTemps.diff               |  6 ++--
 .../32bit/rustc.main.ConstProp.after.mir      | 20 ++++++------
 .../64bit/rustc.main.ConstProp.after.mir      | 24 +++++++-------
 .../32bit/rustc.main.ConstProp.after.mir      | 18 +++++------
 .../64bit/rustc.main.ConstProp.after.mir      | 18 +++++------
 .../32bit/rustc.main.ConstProp.after.mir      | 12 +++----
 .../64bit/rustc.main.ConstProp.after.mir      | 12 +++----
 .../rustc.main.ConstProp.diff                 | 12 +++----
 ...nst-pointer-values-in-various-types.stderr | 14 ++++-----
 .../consts/const-eval/ref_to_int_match.stderr |  2 +-
 src/test/ui/consts/const-eval/ub-enum.stderr  | 10 +++---
 src/test/ui/consts/const-eval/ub-ref.stderr   |  2 +-
 17 files changed, 107 insertions(+), 96 deletions(-)

diff --git a/src/librustc_middle/mir/interpret/pointer.rs b/src/librustc_middle/mir/interpret/pointer.rs
index 7119cc58087f8..85de026534784 100644
--- a/src/librustc_middle/mir/interpret/pointer.rs
+++ b/src/librustc_middle/mir/interpret/pointer.rs
@@ -119,27 +119,38 @@ pub struct Pointer<Tag = (), Id = AllocId> {
 
 static_assert_size!(Pointer, 16);
 
+/// Print the address of a pointer (without the tag)
+fn print_ptr_addr<Tag, Id: fmt::Debug>(
+    ptr: &Pointer<Tag, Id>,
+    f: &mut fmt::Formatter<'_>,
+) -> fmt::Result {
+    // Forward `alternate` flag to `alloc_id` printing.
+    if f.alternate() {
+        write!(f, "{:#?}", ptr.alloc_id)?;
+    } else {
+        write!(f, "{:?}", ptr.alloc_id)?;
+    }
+    // Print offset only if it is non-zero.
+    if ptr.offset.bytes() > 0 {
+        write!(f, "+0x{:x}", ptr.offset.bytes())?;
+    }
+    Ok(())
+}
+
 // We want the `Debug` output to be readable as it is used by `derive(Debug)` for
 // all the Miri types.
 // We have to use `Debug` output for the tag, because `()` does not implement
 // `Display` so we cannot specialize that.
 impl<Tag: fmt::Debug, Id: fmt::Debug> fmt::Debug for Pointer<Tag, Id> {
     default fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if f.alternate() {
-            write!(f, "{:#?}+0x{:x}[{:?}]", self.alloc_id, self.offset.bytes(), self.tag)
-        } else {
-            write!(f, "{:?}+0x{:x}[{:?}]", self.alloc_id, self.offset.bytes(), self.tag)
-        }
+        print_ptr_addr(self, f)?;
+        write!(f, "[{:?}]", self.tag)
     }
 }
 // Specialization for no tag
 impl<Id: fmt::Debug> fmt::Debug for Pointer<(), Id> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if f.alternate() {
-            write!(f, "{:#?}+0x{:x}", self.alloc_id, self.offset.bytes())
-        } else {
-            write!(f, "{:?}+0x{:x}", self.alloc_id, self.offset.bytes())
-        }
+        print_ptr_addr(self, f)
     }
 }
 
diff --git a/src/test/mir-opt/byte_slice/rustc.main.SimplifyCfg-elaborate-drops.after.mir b/src/test/mir-opt/byte_slice/rustc.main.SimplifyCfg-elaborate-drops.after.mir
index b8ecaf787fe72..88cb09ac15a9c 100644
--- a/src/test/mir-opt/byte_slice/rustc.main.SimplifyCfg-elaborate-drops.after.mir
+++ b/src/test/mir-opt/byte_slice/rustc.main.SimplifyCfg-elaborate-drops.after.mir
@@ -16,10 +16,10 @@ fn main() -> () {
         _1 = const b"foo";               // scope 0 at $DIR/byte_slice.rs:5:13: 5:19
                                          // ty::Const
                                          // + ty: &[u8; 3]
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/byte_slice.rs:5:13: 5:19
-                                         // + literal: Const { ty: &[u8; 3], val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &[u8; 3], val: Value(Scalar(alloc0)) }
         StorageLive(_2);                 // scope 1 at $DIR/byte_slice.rs:6:9: 6:10
         _2 = [const 5u8, const 120u8];   // scope 1 at $DIR/byte_slice.rs:6:13: 6:24
                                          // ty::Const
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.BAR-promoted[0].ConstProp.after.mir b/src/test/mir-opt/const-promotion-extern-static/rustc.BAR-promoted[0].ConstProp.after.mir
index d202531c7ab63..509947071b0c1 100644
--- a/src/test/mir-opt/const-promotion-extern-static/rustc.BAR-promoted[0].ConstProp.after.mir
+++ b/src/test/mir-opt/const-promotion-extern-static/rustc.BAR-promoted[0].ConstProp.after.mir
@@ -7,13 +7,13 @@ promoted[0] in BAR: &[&i32; 1] = {
     let mut _3: &i32;                    // in scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
 
     bb0: {
-        _3 = const {alloc0+0x0: &i32};   // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
+        _3 = const {alloc0: &i32};       // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
                                          // ty::Const
                                          // + ty: &i32
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const-promotion-extern-static.rs:9:33: 9:34
-                                         // + literal: Const { ty: &i32, val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &i32, val: Value(Scalar(alloc0)) }
         _2 = _3;                         // scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
         _1 = [move _2];                  // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
         _0 = &_1;                        // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.BAR.PromoteTemps.diff b/src/test/mir-opt/const-promotion-extern-static/rustc.BAR.PromoteTemps.diff
index 5b98830c62903..5c192979a8696 100644
--- a/src/test/mir-opt/const-promotion-extern-static/rustc.BAR.PromoteTemps.diff
+++ b/src/test/mir-opt/const-promotion-extern-static/rustc.BAR.PromoteTemps.diff
@@ -16,16 +16,16 @@
 -         StorageLive(_3);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
 -         StorageLive(_4);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
 -         StorageLive(_5);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
--         _5 = const {alloc0+0x0: &i32};   // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
+-         _5 = const {alloc0: &i32};       // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
 +         _6 = const BAR::promoted[0];     // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
                                            // ty::Const
 -                                          // + ty: &i32
--                                          // + val: Value(Scalar(alloc0+0x0))
+-                                          // + val: Value(Scalar(alloc0))
 +                                          // + ty: &[&i32; 1]
 +                                          // + val: Unevaluated(DefId(0:6 ~ const_promotion_extern_static[317d]::BAR[0]), [], Some(promoted[0]))
                                            // mir::Constant
 -                                          // + span: $DIR/const-promotion-extern-static.rs:9:33: 9:34
--                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc0+0x0)) }
+-                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc0)) }
 -         _4 = &(*_5);                     // scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
 -         _3 = [move _4];                  // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
 -         _2 = &_3;                        // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.FOO-promoted[0].ConstProp.after.mir b/src/test/mir-opt/const-promotion-extern-static/rustc.FOO-promoted[0].ConstProp.after.mir
index b49c1aaa86669..d9c6b4f0029a3 100644
--- a/src/test/mir-opt/const-promotion-extern-static/rustc.FOO-promoted[0].ConstProp.after.mir
+++ b/src/test/mir-opt/const-promotion-extern-static/rustc.FOO-promoted[0].ConstProp.after.mir
@@ -9,13 +9,13 @@ promoted[0] in FOO: &[&i32; 1] = {
     }
 
     bb0: {
-        _3 = const {alloc2+0x0: &i32};   // scope 0 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
+        _3 = const {alloc2: &i32};       // scope 0 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
                                          // ty::Const
                                          // + ty: &i32
-                                         // + val: Value(Scalar(alloc2+0x0))
+                                         // + val: Value(Scalar(alloc2))
                                          // mir::Constant
                                          // + span: $DIR/const-promotion-extern-static.rs:13:42: 13:43
-                                         // + literal: Const { ty: &i32, val: Value(Scalar(alloc2+0x0)) }
+                                         // + literal: Const { ty: &i32, val: Value(Scalar(alloc2)) }
         _2 = _3;                         // scope 0 at $DIR/const-promotion-extern-static.rs:13:41: 13:43
         _1 = [move _2];                  // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
         _0 = &_1;                        // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.FOO.PromoteTemps.diff b/src/test/mir-opt/const-promotion-extern-static/rustc.FOO.PromoteTemps.diff
index 0724575b9d23b..649cea6493e45 100644
--- a/src/test/mir-opt/const-promotion-extern-static/rustc.FOO.PromoteTemps.diff
+++ b/src/test/mir-opt/const-promotion-extern-static/rustc.FOO.PromoteTemps.diff
@@ -18,16 +18,16 @@
 -         StorageLive(_3);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
 -         StorageLive(_4);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:32: 13:45
 -         StorageLive(_5);                 // scope 1 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
--         _5 = const {alloc2+0x0: &i32};   // scope 1 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
+-         _5 = const {alloc2: &i32};       // scope 1 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
 +         _6 = const FOO::promoted[0];     // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
                                            // ty::Const
 -                                          // + ty: &i32
--                                          // + val: Value(Scalar(alloc2+0x0))
+-                                          // + val: Value(Scalar(alloc2))
 +                                          // + ty: &[&i32; 1]
 +                                          // + val: Unevaluated(DefId(0:7 ~ const_promotion_extern_static[317d]::FOO[0]), [], Some(promoted[0]))
                                            // mir::Constant
 -                                          // + span: $DIR/const-promotion-extern-static.rs:13:42: 13:43
--                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc2+0x0)) }
+-                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc2)) }
 -         _4 = &(*_5);                     // scope 1 at $DIR/const-promotion-extern-static.rs:13:41: 13:43
 -         _3 = [move _4];                  // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
 -         _2 = &_3;                        // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
diff --git a/src/test/mir-opt/const_allocation/32bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation/32bit/rustc.main.ConstProp.after.mir
index a20dd7bf0fc91..30a383fd162b2 100644
--- a/src/test/mir-opt/const_allocation/32bit/rustc.main.ConstProp.after.mir
+++ b/src/test/mir-opt/const_allocation/32bit/rustc.main.ConstProp.after.mir
@@ -8,13 +8,13 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
         StorageLive(_2);                 // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
-        _2 = const {alloc0+0x0: &&[(std::option::Option<i32>, &[&str])]}; // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
+        _2 = const {alloc0: &&[(std::option::Option<i32>, &[&str])]}; // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
                                          // ty::Const
                                          // + ty: &&[(std::option::Option<i32>, &[&str])]
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation.rs:8:5: 8:8
-                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&str])], val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&str])], val: Value(Scalar(alloc0)) }
         _1 = (*_2);                      // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
         StorageDead(_2);                 // scope 0 at $DIR/const_allocation.rs:8:8: 8:9
         StorageDead(_1);                 // scope 0 at $DIR/const_allocation.rs:8:8: 8:9
@@ -30,19 +30,19 @@ fn main() -> () {
 }
 
 alloc0 (static: FOO, size: 8, align: 4) {
-    ╾─a17+0x0─╼ 03 00 00 00                         │ ╾──╼....
+    ╾─alloc17─╼ 03 00 00 00                         │ ╾──╼....
 }
 
 alloc17 (size: 48, align: 4) {
-    0x00 │ 00 00 00 00 __ __ __ __ ╾─a4+0x0──╼ 00 00 00 00 │ ....░░░░╾──╼....
-    0x10 │ 00 00 00 00 __ __ __ __ ╾─a8+0x0──╼ 02 00 00 00 │ ....░░░░╾──╼....
-    0x20 │ 01 00 00 00 2a 00 00 00 ╾─a13+0x0─╼ 03 00 00 00 │ ....*...╾──╼....
+    0x00 │ 00 00 00 00 __ __ __ __ ╾─alloc4──╼ 00 00 00 00 │ ....░░░░╾──╼....
+    0x10 │ 00 00 00 00 __ __ __ __ ╾─alloc8──╼ 02 00 00 00 │ ....░░░░╾──╼....
+    0x20 │ 01 00 00 00 2a 00 00 00 ╾─alloc13─╼ 03 00 00 00 │ ....*...╾──╼....
 }
 
 alloc4 (size: 0, align: 4) {}
 
 alloc8 (size: 16, align: 4) {
-    ╾─a7+0x0──╼ 03 00 00 00 ╾─a9+0x0──╼ 03 00 00 00 │ ╾──╼....╾──╼....
+    ╾─alloc7──╼ 03 00 00 00 ╾─alloc9──╼ 03 00 00 00 │ ╾──╼....╾──╼....
 }
 
 alloc7 (size: 3, align: 1) {
@@ -54,8 +54,8 @@ alloc9 (size: 3, align: 1) {
 }
 
 alloc13 (size: 24, align: 4) {
-    0x00 │ ╾─a12+0x0─╼ 03 00 00 00 ╾─a14+0x0─╼ 03 00 00 00 │ ╾──╼....╾──╼....
-    0x10 │ ╾─a15+0x0─╼ 04 00 00 00                         │ ╾──╼....
+    0x00 │ ╾─alloc12─╼ 03 00 00 00 ╾─alloc14─╼ 03 00 00 00 │ ╾──╼....╾──╼....
+    0x10 │ ╾─alloc15─╼ 04 00 00 00                         │ ╾──╼....
 }
 
 alloc12 (size: 3, align: 1) {
diff --git a/src/test/mir-opt/const_allocation/64bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation/64bit/rustc.main.ConstProp.after.mir
index ff89ac9ad936c..5fa54ae5a58ec 100644
--- a/src/test/mir-opt/const_allocation/64bit/rustc.main.ConstProp.after.mir
+++ b/src/test/mir-opt/const_allocation/64bit/rustc.main.ConstProp.after.mir
@@ -8,13 +8,13 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
         StorageLive(_2);                 // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
-        _2 = const {alloc0+0x0: &&[(std::option::Option<i32>, &[&str])]}; // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
+        _2 = const {alloc0: &&[(std::option::Option<i32>, &[&str])]}; // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
                                          // ty::Const
                                          // + ty: &&[(std::option::Option<i32>, &[&str])]
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation.rs:8:5: 8:8
-                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&str])], val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&str])], val: Value(Scalar(alloc0)) }
         _1 = (*_2);                      // scope 0 at $DIR/const_allocation.rs:8:5: 8:8
         StorageDead(_2);                 // scope 0 at $DIR/const_allocation.rs:8:8: 8:9
         StorageDead(_1);                 // scope 0 at $DIR/const_allocation.rs:8:8: 8:9
@@ -30,22 +30,22 @@ fn main() -> () {
 }
 
 alloc0 (static: FOO, size: 16, align: 8) {
-    ╾─────alloc17+0x0─────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
+    ╾───────alloc17───────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
 }
 
 alloc17 (size: 72, align: 8) {
-    0x00 │ 00 00 00 00 __ __ __ __ ╾─────alloc4+0x0──────╼ │ ....░░░░╾──────╼
+    0x00 │ 00 00 00 00 __ __ __ __ ╾───────alloc4────────╼ │ ....░░░░╾──────╼
     0x10 │ 00 00 00 00 00 00 00 00 00 00 00 00 __ __ __ __ │ ............░░░░
-    0x20 │ ╾─────alloc8+0x0──────╼ 02 00 00 00 00 00 00 00 │ ╾──────╼........
-    0x30 │ 01 00 00 00 2a 00 00 00 ╾─────alloc13+0x0─────╼ │ ....*...╾──────╼
+    0x20 │ ╾───────alloc8────────╼ 02 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x30 │ 01 00 00 00 2a 00 00 00 ╾───────alloc13───────╼ │ ....*...╾──────╼
     0x40 │ 03 00 00 00 00 00 00 00                         │ ........
 }
 
 alloc4 (size: 0, align: 8) {}
 
 alloc8 (size: 32, align: 8) {
-    0x00 │ ╾─────alloc7+0x0──────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
-    0x10 │ ╾─────alloc9+0x0──────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x00 │ ╾───────alloc7────────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x10 │ ╾───────alloc9────────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
 }
 
 alloc7 (size: 3, align: 1) {
@@ -57,9 +57,9 @@ alloc9 (size: 3, align: 1) {
 }
 
 alloc13 (size: 48, align: 8) {
-    0x00 │ ╾─────alloc12+0x0─────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
-    0x10 │ ╾─────alloc14+0x0─────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
-    0x20 │ ╾─────alloc15+0x0─────╼ 04 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x00 │ ╾───────alloc12───────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x10 │ ╾───────alloc14───────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x20 │ ╾───────alloc15───────╼ 04 00 00 00 00 00 00 00 │ ╾──────╼........
 }
 
 alloc12 (size: 3, align: 1) {
diff --git a/src/test/mir-opt/const_allocation2/32bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation2/32bit/rustc.main.ConstProp.after.mir
index e392eaa6aedab..d386d24782926 100644
--- a/src/test/mir-opt/const_allocation2/32bit/rustc.main.ConstProp.after.mir
+++ b/src/test/mir-opt/const_allocation2/32bit/rustc.main.ConstProp.after.mir
@@ -8,13 +8,13 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
         StorageLive(_2);                 // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
-        _2 = const {alloc0+0x0: &&[(std::option::Option<i32>, &[&u8])]}; // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
+        _2 = const {alloc0: &&[(std::option::Option<i32>, &[&u8])]}; // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
                                          // ty::Const
                                          // + ty: &&[(std::option::Option<i32>, &[&u8])]
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation2.rs:5:5: 5:8
-                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&u8])], val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&u8])], val: Value(Scalar(alloc0)) }
         _1 = (*_2);                      // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
         StorageDead(_2);                 // scope 0 at $DIR/const_allocation2.rs:5:8: 5:9
         StorageDead(_1);                 // scope 0 at $DIR/const_allocation2.rs:5:8: 5:9
@@ -30,19 +30,19 @@ fn main() -> () {
 }
 
 alloc0 (static: FOO, size: 8, align: 4) {
-    ╾─a21+0x0─╼ 03 00 00 00                         │ ╾──╼....
+    ╾─alloc21─╼ 03 00 00 00                         │ ╾──╼....
 }
 
 alloc21 (size: 48, align: 4) {
-    0x00 │ 00 00 00 00 __ __ __ __ ╾─a4+0x0──╼ 00 00 00 00 │ ....░░░░╾──╼....
-    0x10 │ 00 00 00 00 __ __ __ __ ╾─a9+0x0──╼ 02 00 00 00 │ ....░░░░╾──╼....
-    0x20 │ 01 00 00 00 2a 00 00 00 ╾─a19+0x0─╼ 03 00 00 00 │ ....*...╾──╼....
+    0x00 │ 00 00 00 00 __ __ __ __ ╾─alloc4──╼ 00 00 00 00 │ ....░░░░╾──╼....
+    0x10 │ 00 00 00 00 __ __ __ __ ╾─alloc9──╼ 02 00 00 00 │ ....░░░░╾──╼....
+    0x20 │ 01 00 00 00 2a 00 00 00 ╾─alloc19─╼ 03 00 00 00 │ ....*...╾──╼....
 }
 
 alloc4 (size: 0, align: 4) {}
 
 alloc9 (size: 8, align: 4) {
-    ╾─a7+0x0──╼ ╾─a8+0x0──╼                         │ ╾──╼╾──╼
+    ╾─alloc7──╼ ╾─alloc8──╼                         │ ╾──╼╾──╼
 }
 
 alloc7 (size: 1, align: 1) {
@@ -54,7 +54,7 @@ alloc8 (size: 1, align: 1) {
 }
 
 alloc19 (size: 12, align: 4) {
-    ╾─a15+0x3─╼ ╾─a16+0x0─╼ ╾─a18+0x2─╼             │ ╾──╼╾──╼╾──╼
+    ╾─a15+0x3─╼ ╾─alloc16─╼ ╾─a18+0x2─╼             │ ╾──╼╾──╼╾──╼
 }
 
 alloc15 (size: 4, align: 1) {
diff --git a/src/test/mir-opt/const_allocation2/64bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation2/64bit/rustc.main.ConstProp.after.mir
index 81dc0372b5d10..d7acd0f0f4335 100644
--- a/src/test/mir-opt/const_allocation2/64bit/rustc.main.ConstProp.after.mir
+++ b/src/test/mir-opt/const_allocation2/64bit/rustc.main.ConstProp.after.mir
@@ -8,13 +8,13 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
         StorageLive(_2);                 // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
-        _2 = const {alloc0+0x0: &&[(std::option::Option<i32>, &[&u8])]}; // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
+        _2 = const {alloc0: &&[(std::option::Option<i32>, &[&u8])]}; // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
                                          // ty::Const
                                          // + ty: &&[(std::option::Option<i32>, &[&u8])]
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation2.rs:5:5: 5:8
-                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&u8])], val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &&[(std::option::Option<i32>, &[&u8])], val: Value(Scalar(alloc0)) }
         _1 = (*_2);                      // scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
         StorageDead(_2);                 // scope 0 at $DIR/const_allocation2.rs:5:8: 5:9
         StorageDead(_1);                 // scope 0 at $DIR/const_allocation2.rs:5:8: 5:9
@@ -30,21 +30,21 @@ fn main() -> () {
 }
 
 alloc0 (static: FOO, size: 16, align: 8) {
-    ╾─────alloc21+0x0─────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
+    ╾───────alloc21───────╼ 03 00 00 00 00 00 00 00 │ ╾──────╼........
 }
 
 alloc21 (size: 72, align: 8) {
-    0x00 │ 00 00 00 00 __ __ __ __ ╾─────alloc4+0x0──────╼ │ ....░░░░╾──────╼
+    0x00 │ 00 00 00 00 __ __ __ __ ╾───────alloc4────────╼ │ ....░░░░╾──────╼
     0x10 │ 00 00 00 00 00 00 00 00 00 00 00 00 __ __ __ __ │ ............░░░░
-    0x20 │ ╾─────alloc9+0x0──────╼ 02 00 00 00 00 00 00 00 │ ╾──────╼........
-    0x30 │ 01 00 00 00 2a 00 00 00 ╾─────alloc19+0x0─────╼ │ ....*...╾──────╼
+    0x20 │ ╾───────alloc9────────╼ 02 00 00 00 00 00 00 00 │ ╾──────╼........
+    0x30 │ 01 00 00 00 2a 00 00 00 ╾───────alloc19───────╼ │ ....*...╾──────╼
     0x40 │ 03 00 00 00 00 00 00 00                         │ ........
 }
 
 alloc4 (size: 0, align: 8) {}
 
 alloc9 (size: 16, align: 8) {
-    ╾─────alloc7+0x0──────╼ ╾─────alloc8+0x0──────╼ │ ╾──────╼╾──────╼
+    ╾───────alloc7────────╼ ╾───────alloc8────────╼ │ ╾──────╼╾──────╼
 }
 
 alloc7 (size: 1, align: 1) {
@@ -56,7 +56,7 @@ alloc8 (size: 1, align: 1) {
 }
 
 alloc19 (size: 24, align: 8) {
-    0x00 │ ╾─────alloc15+0x3─────╼ ╾─────alloc16+0x0─────╼ │ ╾──────╼╾──────╼
+    0x00 │ ╾─────alloc15+0x3─────╼ ╾───────alloc16───────╼ │ ╾──────╼╾──────╼
     0x10 │ ╾─────alloc18+0x2─────╼                         │ ╾──────╼
 }
 
diff --git a/src/test/mir-opt/const_allocation3/32bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation3/32bit/rustc.main.ConstProp.after.mir
index a29327eb9731a..39c60ad987a6f 100644
--- a/src/test/mir-opt/const_allocation3/32bit/rustc.main.ConstProp.after.mir
+++ b/src/test/mir-opt/const_allocation3/32bit/rustc.main.ConstProp.after.mir
@@ -8,13 +8,13 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
         StorageLive(_2);                 // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
-        _2 = const {alloc0+0x0: &&Packed}; // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
+        _2 = const {alloc0: &&Packed};   // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
                                          // ty::Const
                                          // + ty: &&Packed
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation3.rs:5:5: 5:8
-                                         // + literal: Const { ty: &&Packed, val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &&Packed, val: Value(Scalar(alloc0)) }
         _1 = (*_2);                      // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
         StorageDead(_2);                 // scope 0 at $DIR/const_allocation3.rs:5:8: 5:9
         StorageDead(_1);                 // scope 0 at $DIR/const_allocation3.rs:5:8: 5:9
@@ -30,19 +30,19 @@ fn main() -> () {
 }
 
 alloc0 (static: FOO, size: 4, align: 4) {
-    ╾─a9+0x0──╼                                     │ ╾──╼
+    ╾─alloc9──╼                                     │ ╾──╼
 }
 
 alloc9 (size: 168, align: 1) {
     0x00 │ ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab │ ................
-    0x10 │ ab ab ab ab ab ab ab ab ab ab ab ab ╾─a4+0x0──╼ │ ............╾──╼
+    0x10 │ ab ab ab ab ab ab ab ab ab ab ab ab ╾─alloc4──╼ │ ............╾──╼
     0x20 │ 01 ef cd ab 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x30 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x40 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x50 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x60 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x70 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
-    0x80 │ 00 00 00 00 00 00 00 00 00 00 ╾─a6+0x0──╼ 00 00 │ ..........╾──╼..
+    0x80 │ 00 00 00 00 00 00 00 00 00 00 ╾─alloc6──╼ 00 00 │ ..........╾──╼..
     0x90 │ ╾─a7+0x63─╼ 00 00 00 00 00 00 00 00 00 00 00 00 │ ╾──╼............
     0xa0 │ 00 00 00 00 00 00 00 00                         │ ........
 }
diff --git a/src/test/mir-opt/const_allocation3/64bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation3/64bit/rustc.main.ConstProp.after.mir
index 865c7c9343218..96024f1c82caa 100644
--- a/src/test/mir-opt/const_allocation3/64bit/rustc.main.ConstProp.after.mir
+++ b/src/test/mir-opt/const_allocation3/64bit/rustc.main.ConstProp.after.mir
@@ -8,13 +8,13 @@ fn main() -> () {
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
         StorageLive(_2);                 // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
-        _2 = const {alloc0+0x0: &&Packed}; // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
+        _2 = const {alloc0: &&Packed};   // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
                                          // ty::Const
                                          // + ty: &&Packed
-                                         // + val: Value(Scalar(alloc0+0x0))
+                                         // + val: Value(Scalar(alloc0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation3.rs:5:5: 5:8
-                                         // + literal: Const { ty: &&Packed, val: Value(Scalar(alloc0+0x0)) }
+                                         // + literal: Const { ty: &&Packed, val: Value(Scalar(alloc0)) }
         _1 = (*_2);                      // scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
         StorageDead(_2);                 // scope 0 at $DIR/const_allocation3.rs:5:8: 5:9
         StorageDead(_1);                 // scope 0 at $DIR/const_allocation3.rs:5:8: 5:9
@@ -30,12 +30,12 @@ fn main() -> () {
 }
 
 alloc0 (static: FOO, size: 8, align: 8) {
-    ╾─────alloc9+0x0──────╼                         │ ╾──────╼
+    ╾───────alloc9────────╼                         │ ╾──────╼
 }
 
 alloc9 (size: 180, align: 1) {
     0x00 │ ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab │ ................
-    0x10 │ ab ab ab ab ab ab ab ab ab ab ab ab ╾alloc4+0x0 │ ............╾───
+    0x10 │ ab ab ab ab ab ab ab ab ab ab ab ab ╾──alloc4── │ ............╾───
     0x20 │ ──────────╼ 01 ef cd ab 00 00 00 00 00 00 00 00 │ ───╼............
     0x30 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x40 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
@@ -43,7 +43,7 @@ alloc9 (size: 180, align: 1) {
     0x60 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x70 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0x80 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ╾──── │ ..............╾─
-    0x90 │ ───alloc6+0x0───╼ 00 00 ╾─────alloc7+0x63─────╼ │ ─────╼..╾──────╼
+    0x90 │ ─────alloc6─────╼ 00 00 ╾─────alloc7+0x63─────╼ │ ─────╼..╾──────╼
     0xa0 │ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
     0xb0 │ 00 00 00 00                                     │ ....
 }
diff --git a/src/test/mir-opt/const_prop/read_immutable_static/rustc.main.ConstProp.diff b/src/test/mir-opt/const_prop/read_immutable_static/rustc.main.ConstProp.diff
index bbe0d10601147..103444f796ec6 100644
--- a/src/test/mir-opt/const_prop/read_immutable_static/rustc.main.ConstProp.diff
+++ b/src/test/mir-opt/const_prop/read_immutable_static/rustc.main.ConstProp.diff
@@ -16,13 +16,13 @@
           StorageLive(_1);                 // scope 0 at $DIR/read_immutable_static.rs:7:9: 7:10
           StorageLive(_2);                 // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
           StorageLive(_3);                 // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
-          _3 = const {alloc0+0x0: &u8};    // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
+          _3 = const {alloc0: &u8};        // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
                                            // ty::Const
                                            // + ty: &u8
-                                           // + val: Value(Scalar(alloc0+0x0))
+                                           // + val: Value(Scalar(alloc0))
                                            // mir::Constant
                                            // + span: $DIR/read_immutable_static.rs:7:13: 7:16
-                                           // + literal: Const { ty: &u8, val: Value(Scalar(alloc0+0x0)) }
+                                           // + literal: Const { ty: &u8, val: Value(Scalar(alloc0)) }
 -         _2 = (*_3);                      // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
 +         _2 = const 2u8;                  // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
 +                                          // ty::Const
@@ -33,13 +33,13 @@
 +                                          // + literal: Const { ty: u8, val: Value(Scalar(0x02)) }
           StorageLive(_4);                 // scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
           StorageLive(_5);                 // scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
-          _5 = const {alloc0+0x0: &u8};    // scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
+          _5 = const {alloc0: &u8};        // scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
                                            // ty::Const
                                            // + ty: &u8
-                                           // + val: Value(Scalar(alloc0+0x0))
+                                           // + val: Value(Scalar(alloc0))
                                            // mir::Constant
                                            // + span: $DIR/read_immutable_static.rs:7:19: 7:22
-                                           // + literal: Const { ty: &u8, val: Value(Scalar(alloc0+0x0)) }
+                                           // + literal: Const { ty: &u8, val: Value(Scalar(alloc0)) }
 -         _4 = (*_5);                      // scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
 -         _1 = Add(move _2, move _4);      // scope 0 at $DIR/read_immutable_static.rs:7:13: 7:22
 +         _4 = const 2u8;                  // scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
diff --git a/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr b/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr
index 649105812b071..d24491e1bc5cb 100644
--- a/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr
+++ b/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr
@@ -2,7 +2,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:25:5
    |
 LL |     const I32_REF_USIZE_UNION: usize = unsafe { Nonsense { int_32_ref: &3 }.u };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc2+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc2, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -36,7 +36,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:37:5
    |
 LL |     const I32_REF_U64_UNION: u64 = unsafe { Nonsense { int_32_ref: &3 }.uint_64 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc22+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc22, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -76,7 +76,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:52:5
    |
 LL |     const I32_REF_I64_UNION: i64 = unsafe { Nonsense { int_32_ref: &3 }.int_64 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc47+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc47, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -100,7 +100,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:61:5
    |
 LL |     const I32_REF_F64_UNION: f64 = unsafe { Nonsense { int_32_ref: &3 }.float_64 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc62+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc62, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -148,7 +148,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:79:5
    |
 LL |     const STR_U64_UNION: u64 = unsafe { Nonsense { stringy: "3" }.uint_64 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc86+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc86, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -188,7 +188,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:94:5
    |
 LL |     const STR_I64_UNION: i64 = unsafe { Nonsense { stringy: "3" }.int_64 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc101+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc101, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -212,7 +212,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:103:5
    |
 LL |     const STR_F64_UNION: f64 = unsafe { Nonsense { stringy: "3" }.float_64 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc110+0x0, but expected initialized plain (non-pointer) bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc110, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
diff --git a/src/test/ui/consts/const-eval/ref_to_int_match.stderr b/src/test/ui/consts/const-eval/ref_to_int_match.stderr
index df6fc66620b3c..cb0ba5d9929b9 100644
--- a/src/test/ui/consts/const-eval/ref_to_int_match.stderr
+++ b/src/test/ui/consts/const-eval/ref_to_int_match.stderr
@@ -2,7 +2,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ref_to_int_match.rs:25:1
    |
 LL | const BAR: Int = unsafe { Foo { r: &42 }.f };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc2+0x0, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc2, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
diff --git a/src/test/ui/consts/const-eval/ub-enum.stderr b/src/test/ui/consts/const-eval/ub-enum.stderr
index 8f0ce58eaf5d0..d8dafac3e70a1 100644
--- a/src/test/ui/consts/const-eval/ub-enum.stderr
+++ b/src/test/ui/consts/const-eval/ub-enum.stderr
@@ -10,7 +10,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:27:1
    |
 LL | const BAD_ENUM_PTR: Enum = unsafe { mem::transmute(&1) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc8+0x0 at .<enum-tag>, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc8 at .<enum-tag>, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -18,7 +18,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:30:1
    |
 LL | const BAD_ENUM_WRAPPED: Wrap<Enum> = unsafe { mem::transmute(&1) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc13+0x0 at .0.<enum-tag>, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc13 at .0.<enum-tag>, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -34,7 +34,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:44:1
    |
 LL | const BAD_ENUM2_PTR: Enum2 = unsafe { mem::transmute(&0) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc20+0x0 at .<enum-tag>, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc20 at .<enum-tag>, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -42,7 +42,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:47:1
    |
 LL | const BAD_ENUM2_WRAPPED: Wrap<Enum2> = unsafe { mem::transmute(&0) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc25+0x0 at .0.<enum-tag>, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc25 at .0.<enum-tag>, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
@@ -58,7 +58,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:60:1
    |
 LL | const BAD_ENUM2_OPTION_PTR: Option<Enum2> = unsafe { mem::transmute(&0) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc32+0x0 at .<enum-tag>, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc32 at .<enum-tag>, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
diff --git a/src/test/ui/consts/const-eval/ub-ref.stderr b/src/test/ui/consts/const-eval/ub-ref.stderr
index 95a83d11acd07..a219679f18264 100644
--- a/src/test/ui/consts/const-eval/ub-ref.stderr
+++ b/src/test/ui/consts/const-eval/ub-ref.stderr
@@ -34,7 +34,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-ref.rs:24:1
    |
 LL | const REF_AS_USIZE: usize = unsafe { mem::transmute(&0) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc16+0x0, but expected initialized plain (non-pointer) bytes
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered pointer to alloc16, but expected initialized plain (non-pointer) bytes
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 

From 6f7e9a842debd31590d8f347bd4f7534159d6a91 Mon Sep 17 00:00:00 2001
From: mibac138 <5672750+mibac138@users.noreply.github.com>
Date: Tue, 5 May 2020 18:43:37 +0200
Subject: [PATCH 3/8] Add strikethrough support to rustdoc

---
 src/librustdoc/html/markdown.rs | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 4bb50f7579197..bdda45fdcd4d9 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -44,7 +44,7 @@ use pulldown_cmark::{html, CodeBlockKind, CowStr, Event, Options, Parser, Tag};
 mod tests;
 
 fn opts() -> Options {
-    Options::ENABLE_TABLES | Options::ENABLE_FOOTNOTES
+    Options::ENABLE_TABLES | Options::ENABLE_FOOTNOTES | Options::ENABLE_STRIKETHROUGH
 }
 
 /// When `to_string` is called, this struct will emit the HTML corresponding to
@@ -933,7 +933,11 @@ impl MarkdownSummaryLine<'_> {
             }
         };
 
-        let p = Parser::new_with_broken_link_callback(md, Options::empty(), Some(&replacer));
+        let p = Parser::new_with_broken_link_callback(
+            md,
+            Options::ENABLE_STRIKETHROUGH,
+            Some(&replacer),
+        );
 
         let mut s = String::new();
 
@@ -975,7 +979,11 @@ pub fn plain_summary_line(md: &str) -> String {
         }
     }
     let mut s = String::with_capacity(md.len() * 3 / 2);
-    let p = ParserWrapper { inner: Parser::new(md), is_in: 0, is_first: true };
+    let p = ParserWrapper {
+        inner: Parser::new_ext(md, Options::ENABLE_STRIKETHROUGH),
+        is_in: 0,
+        is_first: true,
+    };
     p.filter(|t| !t.is_empty()).for_each(|i| s.push_str(&i));
     s
 }

From bbda107436c01204614dce4cff70a0b475945a9d Mon Sep 17 00:00:00 2001
From: mibac138 <5672750+mibac138@users.noreply.github.com>
Date: Fri, 8 May 2020 18:14:57 +0200
Subject: [PATCH 4/8] Add test for strikethrough in rustdoc

---
 src/test/rustdoc/test-strikethrough.rs | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 src/test/rustdoc/test-strikethrough.rs

diff --git a/src/test/rustdoc/test-strikethrough.rs b/src/test/rustdoc/test-strikethrough.rs
new file mode 100644
index 0000000000000..c7855729a98ee
--- /dev/null
+++ b/src/test/rustdoc/test-strikethrough.rs
@@ -0,0 +1,6 @@
+#![crate_name = "foo"]
+
+// @has foo/fn.f.html
+// @has - //del "Y"
+/// ~~Y~~
+pub fn f() {}

From 23d880b127c346be631d2a9dbcef3bd5dff7d305 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 10 May 2020 23:36:41 +0200
Subject: [PATCH 5/8] rustc_driver: factor out computing the exit code

---
 src/librustc_driver/lib.rs     | 19 ++++++++++++-------
 src/tools/clippy/src/driver.rs |  4 +---
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index 913ccf8e68089..f8afaecf21858 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -1138,6 +1138,16 @@ pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorReported>
     })
 }
 
+/// Variant of `catch_fatal_errors` for the `interface::Result` return type
+/// that also computes the exit code.
+pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
+    let result = catch_fatal_errors(f).and_then(|result| result);
+    match result {
+        Ok(()) => EXIT_SUCCESS,
+        Err(_) => EXIT_FAILURE,
+    }
+}
+
 lazy_static! {
     static ref DEFAULT_HOOK: Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static> = {
         let hook = panic::take_hook();
@@ -1233,7 +1243,7 @@ pub fn main() {
     init_rustc_env_logger();
     let mut callbacks = TimePassesCallbacks::default();
     install_ice_hook();
-    let result = catch_fatal_errors(|| {
+    let exit_code = catch_with_exit_code(|| {
         let args = env::args_os()
             .enumerate()
             .map(|(i, arg)| {
@@ -1246,12 +1256,7 @@ pub fn main() {
             })
             .collect::<Vec<_>>();
         run_compiler(&args, &mut callbacks, None, None)
-    })
-    .and_then(|result| result);
-    let exit_code = match result {
-        Ok(_) => EXIT_SUCCESS,
-        Err(_) => EXIT_FAILURE,
-    };
+    });
     // The extra `\t` is necessary to align this label with the others.
     print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
     process::exit(exit_code);
diff --git a/src/tools/clippy/src/driver.rs b/src/tools/clippy/src/driver.rs
index 2c699998ea90e..1ce0300f23904 100644
--- a/src/tools/clippy/src/driver.rs
+++ b/src/tools/clippy/src/driver.rs
@@ -296,7 +296,7 @@ pub fn main() {
     rustc_driver::init_rustc_env_logger();
     lazy_static::initialize(&ICE_HOOK);
     exit(
-        rustc_driver::catch_fatal_errors(move || {
+        rustc_driver::catch_with_exit_code(move || {
             let mut orig_args: Vec<String> = env::args().collect();
 
             if orig_args.iter().any(|a| a == "--version" || a == "-V") {
@@ -411,7 +411,5 @@ pub fn main() {
                 if clippy_enabled { &mut clippy } else { &mut default };
             rustc_driver::run_compiler(&args, callbacks, None, None)
         })
-        .and_then(|result| result)
-        .is_err() as i32,
     )
 }

From 51e466de3cbfb94b7d0736066a765d8ea31394e4 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 11 May 2020 00:11:42 +0200
Subject: [PATCH 6/8] rustc_driver::main: more informative return type

---
 src/librustc_driver/lib.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index f8afaecf21858..6847b175e60eb 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -1238,7 +1238,7 @@ pub fn init_rustc_env_logger() {
     env_logger::init_from_env("RUSTC_LOG");
 }
 
-pub fn main() {
+pub fn main() -> ! {
     let start = Instant::now();
     init_rustc_env_logger();
     let mut callbacks = TimePassesCallbacks::default();
@@ -1259,5 +1259,5 @@ pub fn main() {
     });
     // The extra `\t` is necessary to align this label with the others.
     print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
-    process::exit(exit_code);
+    process::exit(exit_code)
 }

From 7bea58eeac3a5a5280810623f06eadb3a8b891a3 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 3 May 2020 12:34:53 +0200
Subject: [PATCH 7/8] fix test_weak_count_locked for Miri

---
 src/liballoc/sync/tests.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/liballoc/sync/tests.rs b/src/liballoc/sync/tests.rs
index 4a5cc9aa5910f..a2bb651e2b778 100644
--- a/src/liballoc/sync/tests.rs
+++ b/src/liballoc/sync/tests.rs
@@ -340,7 +340,9 @@ fn test_weak_count_locked() {
     let mut a = Arc::new(atomic::AtomicBool::new(false));
     let a2 = a.clone();
     let t = thread::spawn(move || {
-        for _i in 0..1000000 {
+        // Miri is too slow
+        let count = if cfg!(miri) { 1000 } else { 1000000 };
+        for _i in 0..count {
             Arc::get_mut(&mut a);
         }
         a.store(true, SeqCst);
@@ -349,6 +351,8 @@ fn test_weak_count_locked() {
     while !a2.load(SeqCst) {
         let n = Arc::weak_count(&a2);
         assert!(n < 2, "bad weak count: {}", n);
+        #[cfg(miri)] // Miri's scheduler does not guarantee liveness, and thus needs this hint.
+        atomic::spin_loop_hint();
     }
     t.join().unwrap();
 }

From 6f9810c981f43cab6f4598d2d3b3e6e9b82d56ee Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Tue, 12 May 2020 09:46:41 +0200
Subject: [PATCH 8/8] strings do not have to be valid UTF-8 any more

---
 src/librustc_mir/interpret/validity.rs           | 7 ++++---
 src/test/ui/consts/const-eval/ub-wide-ptr.rs     | 8 ++++----
 src/test/ui/consts/const-eval/ub-wide-ptr.stderr | 8 ++++----
 3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/librustc_mir/interpret/validity.rs b/src/librustc_mir/interpret/validity.rs
index 4f90f83b735d1..7eb05ba2d2c54 100644
--- a/src/librustc_mir/interpret/validity.rs
+++ b/src/librustc_mir/interpret/validity.rs
@@ -15,7 +15,7 @@ use rustc_middle::mir::interpret::{InterpError, InterpErrorInfo};
 use rustc_middle::ty;
 use rustc_middle::ty::layout::TyAndLayout;
 use rustc_span::symbol::{sym, Symbol};
-use rustc_target::abi::{Abi, LayoutOf, Scalar, VariantIdx, Variants};
+use rustc_target::abi::{Abi, LayoutOf, Scalar, Size, VariantIdx, Variants};
 
 use std::hash::Hash;
 
@@ -744,10 +744,11 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
         match op.layout.ty.kind {
             ty::Str => {
                 let mplace = op.assert_mem_place(self.ecx); // strings are never immediate
+                let len = mplace.len(self.ecx)?;
                 try_validation!(
-                    self.ecx.read_str(mplace),
+                    self.ecx.memory.read_bytes(mplace.ptr, Size::from_bytes(len)),
                     self.path,
-                    err_ub!(InvalidStr(..)) => { "uninitialized or non-UTF-8 data in str" },
+                    err_ub!(InvalidUninitBytes(..)) => { "uninitialized data in `str`" },
                 );
             }
             ty::Array(tys, ..) | ty::Slice(tys)
diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.rs b/src/test/ui/consts/const-eval/ub-wide-ptr.rs
index 29ac32fcf2204..f69f6a1109f76 100644
--- a/src/test/ui/consts/const-eval/ub-wide-ptr.rs
+++ b/src/test/ui/consts/const-eval/ub-wide-ptr.rs
@@ -42,11 +42,11 @@ const MY_STR_LENGTH_PTR: &MyStr = unsafe { mem::transmute((&42u8, &3)) };
 const MY_STR_MUCH_TOO_LONG: &MyStr = unsafe { mem::transmute((&42u8, usize::MAX)) };
 //~^ ERROR it is undefined behavior to use this value
 
-// invalid UTF-8
-const STR_NO_UTF8: &str = unsafe { mem::transmute::<&[u8], _>(&[0xFF]) };
+// uninitialized byte
+const STR_NO_INIT: &str = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
 //~^ ERROR it is undefined behavior to use this value
-// invalid UTF-8 in user-defined str-like
-const MYSTR_NO_UTF8: &MyStr = unsafe { mem::transmute::<&[u8], _>(&[0xFF]) };
+// uninitialized byte in user-defined str-like
+const MYSTR_NO_INIT: &MyStr = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
 //~^ ERROR it is undefined behavior to use this value
 
 // # slice
diff --git a/src/test/ui/consts/const-eval/ub-wide-ptr.stderr b/src/test/ui/consts/const-eval/ub-wide-ptr.stderr
index 063ea81036b69..47d29ffc9b3c1 100644
--- a/src/test/ui/consts/const-eval/ub-wide-ptr.stderr
+++ b/src/test/ui/consts/const-eval/ub-wide-ptr.stderr
@@ -41,16 +41,16 @@ LL | const MY_STR_MUCH_TOO_LONG: &MyStr = unsafe { mem::transmute((&42u8, usize:
 error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-wide-ptr.rs:46:1
    |
-LL | const STR_NO_UTF8: &str = unsafe { mem::transmute::<&[u8], _>(&[0xFF]) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or non-UTF-8 data in str at .<deref>
+LL | const STR_NO_INIT: &str = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized data in `str` at .<deref>
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
 error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-wide-ptr.rs:49:1
    |
-LL | const MYSTR_NO_UTF8: &MyStr = unsafe { mem::transmute::<&[u8], _>(&[0xFF]) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or non-UTF-8 data in str at .<deref>.0
+LL | const MYSTR_NO_INIT: &MyStr = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized data in `str` at .<deref>.0
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.