diff --git a/src/etc/natvis/liballoc.natvis b/src/etc/natvis/liballoc.natvis
index 83ca8ed932e46..912418fa7d1eb 100644
--- a/src/etc/natvis/liballoc.natvis
+++ b/src/etc/natvis/liballoc.natvis
@@ -59,39 +59,133 @@
     </Expand>
   </Type>
 
+  <!--
+      The display string for Rc, Arc, etc is optional because the expression cannot be evaluated
+      if the pointee is unsized (i.e. if `ptr.pointer` is a fat pointer).
+
+      There are also two versions for the reference count fields, one for sized and one for
+      dyn pointees.
+
+      Rc<[T]> and Arc<[T]> are handled separately altogether so we can actually show
+      the slice values.
+  -->
+  <!-- alloc::rc::Rc<T> -->
   <Type Name="alloc::rc::Rc&lt;*&gt;">
-    <DisplayString>{ptr.pointer->value}</DisplayString>
+    <DisplayString Optional="true">{ptr.pointer->value}</DisplayString>
     <Expand>
-      <ExpandedItem>ptr.pointer->value</ExpandedItem>
-      <Item Name="[Reference count]">ptr.pointer->strong</Item>
-      <Item Name="[Weak reference count]">ptr.pointer->weak</Item>
+      <!-- thin -->
+      <ExpandedItem Optional="true">ptr.pointer->value</ExpandedItem>
+      <Item Name="[Reference count]" Optional="true">ptr.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer->weak</Item>
+
+      <!-- dyn -->
+      <Item Name="[Reference count]" Optional="true">ptr.pointer.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer.pointer->weak</Item>
+    </Expand>
+  </Type>
+
+  <!-- alloc::rc::Rc<[T]> -->
+  <Type Name="alloc::rc::Rc&lt;slice$&lt;*&gt; &gt;">
+    <DisplayString>{{ len={ptr.pointer.length} }}</DisplayString>
+    <Expand>
+      <Item Name="[Length]" ExcludeView="simple">ptr.pointer.length</Item>
+      <Item Name="[Reference count]">ptr.pointer.data_ptr->strong</Item>
+      <Item Name="[Weak reference count]">ptr.pointer.data_ptr->weak</Item>
+      <ArrayItems>
+        <Size>ptr.pointer.length</Size>
+        <!-- We add +2 to the data_ptr in order to skip the ref count fields in the RcBox -->
+        <ValuePointer>($T1*)(((size_t*)ptr.pointer.data_ptr) + 2)</ValuePointer>
+      </ArrayItems>
     </Expand>
   </Type>
+
+  <!-- alloc::rc::Weak<T> -->
   <Type Name="alloc::rc::Weak&lt;*&gt;">
-    <DisplayString>{ptr.pointer->value}</DisplayString>
+    <DisplayString Optional="true">{ptr.pointer->value}</DisplayString>
+    <Expand>
+      <!-- thin -->
+      <ExpandedItem Optional="true">ptr.pointer->value</ExpandedItem>
+      <Item Name="[Reference count]" Optional="true">ptr.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer->weak</Item>
+
+      <!-- dyn -->
+      <Item Name="[Reference count]" Optional="true">ptr.pointer.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer.pointer->weak</Item>
+    </Expand>
+  </Type>
+
+  <!-- alloc::rc::Weak<[T]> -->
+  <Type Name="alloc::rc::Weak&lt;slice$&lt;*&gt; &gt;">
+    <DisplayString>{{ len={ptr.pointer.length} }}</DisplayString>
     <Expand>
-      <ExpandedItem>ptr.pointer->value</ExpandedItem>
-      <Item Name="[Reference count]">ptr.pointer->strong</Item>
-      <Item Name="[Weak reference count]">ptr.pointer->weak</Item>
+      <Item Name="[Length]" ExcludeView="simple">ptr.pointer.length</Item>
+      <Item Name="[Reference count]">ptr.pointer.data_ptr->strong</Item>
+      <Item Name="[Weak reference count]">ptr.pointer.data_ptr->weak</Item>
+      <ArrayItems>
+        <Size>ptr.pointer.length</Size>
+        <ValuePointer>($T1*)(((size_t*)ptr.pointer.data_ptr) + 2)</ValuePointer>
+      </ArrayItems>
     </Expand>
   </Type>
 
+  <!-- alloc::sync::Arc<T> -->
   <Type Name="alloc::sync::Arc&lt;*&gt;">
-    <DisplayString>{ptr.pointer->data}</DisplayString>
+    <DisplayString Optional="true">{ptr.pointer->data}</DisplayString>
     <Expand>
-      <ExpandedItem>ptr.pointer->data</ExpandedItem>
-      <Item Name="[Reference count]">ptr.pointer->strong</Item>
-      <Item Name="[Weak reference count]">ptr.pointer->weak</Item>
+      <!-- thin -->
+      <ExpandedItem Optional="true">ptr.pointer->data</ExpandedItem>
+      <Item Name="[Reference count]" Optional="true">ptr.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer->weak</Item>
+
+      <!-- dyn -->
+      <Item Name="[Reference count]" Optional="true">ptr.pointer.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer.pointer->weak</Item>
+    </Expand>
+  </Type>
+
+  <!-- alloc::sync::Arc<[T]> -->
+  <Type Name="alloc::sync::Arc&lt;slice$&lt;*&gt; &gt;">
+    <DisplayString>{{ len={ptr.pointer.length} }}</DisplayString>
+    <Expand>
+      <Item Name="[Length]" ExcludeView="simple">ptr.pointer.length</Item>
+      <Item Name="[Reference count]">ptr.pointer.data_ptr->strong</Item>
+      <Item Name="[Weak reference count]">ptr.pointer.data_ptr->weak</Item>
+      <ArrayItems>
+        <Size>ptr.pointer.length</Size>
+        <ValuePointer>($T1*)(((size_t*)ptr.pointer.data_ptr) + 2)</ValuePointer>
+      </ArrayItems>
     </Expand>
   </Type>
+
+  <!-- alloc::sync::Weak<T> -->
   <Type Name="alloc::sync::Weak&lt;*&gt;">
-    <DisplayString>{ptr.pointer->data}</DisplayString>
+    <DisplayString Optional="true">{ptr.pointer->data}</DisplayString>
     <Expand>
-      <ExpandedItem>ptr.pointer->data</ExpandedItem>
-      <Item Name="[Reference count]">ptr.pointer->strong</Item>
-      <Item Name="[Weak reference count]">ptr.pointer->weak</Item>
+      <!-- thin -->
+      <ExpandedItem Optional="true">ptr.pointer->data</ExpandedItem>
+      <Item Name="[Reference count]" Optional="true">ptr.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer->weak</Item>
+
+      <!-- dyn -->
+      <Item Name="[Reference count]" Optional="true">ptr.pointer.pointer->strong</Item>
+      <Item Name="[Weak reference count]" Optional="true">ptr.pointer.pointer->weak</Item>
+    </Expand>
+  </Type>
+
+  <!-- alloc::sync::Weak<[T]> -->
+  <Type Name="alloc::sync::Weak&lt;slice$&lt;*&gt; &gt;">
+    <DisplayString>{{ len={ptr.pointer.length} }}</DisplayString>
+    <Expand>
+      <Item Name="[Length]" ExcludeView="simple">ptr.pointer.length</Item>
+      <Item Name="[Reference count]">ptr.pointer.data_ptr->strong</Item>
+      <Item Name="[Weak reference count]">ptr.pointer.data_ptr->weak</Item>
+      <ArrayItems>
+        <Size>ptr.pointer.length</Size>
+        <ValuePointer>($T1*)(((size_t*)ptr.pointer.data_ptr) + 2)</ValuePointer>
+      </ArrayItems>
     </Expand>
   </Type>
+
   <Type Name="alloc::borrow::Cow&lt;*&gt;">
     <DisplayString Condition="RUST$ENUM$DISR == 0x0">Borrowed({__0})</DisplayString>
     <DisplayString Condition="RUST$ENUM$DISR == 0x1">Owned({__0})</DisplayString>
diff --git a/src/test/debuginfo/rc_arc.rs b/src/test/debuginfo/rc_arc.rs
index 8470ace24b845..c05c565d95634 100644
--- a/src/test/debuginfo/rc_arc.rs
+++ b/src/test/debuginfo/rc_arc.rs
@@ -8,74 +8,138 @@
 
 // gdb-command:run
 
-// gdb-command:print r
-// gdb-check:[...]$1 = Rc(strong=2, weak=1) = {value = 42, strong = 2, weak = 1}
-// gdb-command:print a
-// gdb-check:[...]$2 = Arc(strong=2, weak=1) = {value = 42, strong = 2, weak = 1}
-
+// gdb-command:print rc
+// gdb-check:[...]$1 = Rc(strong=11, weak=1) = {value = 111, strong = 11, weak = 1}
+// gdb-command:print arc
+// gdb-check:[...]$2 = Arc(strong=21, weak=1) = {value = 222, strong = 21, weak = 1}
 
 // === LLDB TESTS ==================================================================================
 
 // lldb-command:run
 
-// lldb-command:print r
-// lldb-check:[...]$0 = strong=2, weak=1 { value = 42 }
-// lldb-command:print a
-// lldb-check:[...]$1 = strong=2, weak=1 { data = 42 }
+// lldb-command:print rc
+// lldb-check:[...]$0 = strong=11, weak=1 { value = 111 }
+// lldb-command:print arc
+// lldb-check:[...]$1 = strong=21, weak=1 { data = 222 }
 
 // === CDB TESTS ==================================================================================
 
 // cdb-command:g
 
-// cdb-command:dx r,d
-// cdb-check:r,d              : 42 [Type: alloc::rc::Rc<i32>]
-// cdb-check:    [<Raw View>]     [Type: alloc::rc::Rc<i32>]
-// cdb-check:    [Reference count] : 2 [Type: core::cell::Cell<usize>]
+// cdb-command:dx rc,d
+// cdb-check:rc,d             : 111 [Type: alloc::rc::Rc<i32>]
+// cdb-check:    [Reference count] : 11 [Type: core::cell::Cell<usize>]
+// cdb-check:    [Weak reference count] : 2 [Type: core::cell::Cell<usize>]
+
+// cdb-command:dx weak_rc,d
+// cdb-check:weak_rc,d        : 111 [Type: alloc::rc::Weak<i32>]
+// cdb-check:    [Reference count] : 11 [Type: core::cell::Cell<usize>]
+// cdb-check:    [Weak reference count] : 2 [Type: core::cell::Cell<usize>]
+
+// cdb-command:dx arc,d
+// cdb-check:arc,d            : 222 [Type: alloc::sync::Arc<i32>]
+// cdb-check:    [Reference count] : 21 [Type: core::sync::atomic::AtomicUsize]
+// cdb-check:    [Weak reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+
+// cdb-command:dx weak_arc,d
+// cdb-check:weak_arc,d       : 222 [Type: alloc::sync::Weak<i32>]
+// cdb-check:    [Reference count] : 21 [Type: core::sync::atomic::AtomicUsize]
+// cdb-check:    [Weak reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+
+// cdb-command:dx dyn_rc,d
+// cdb-check:dyn_rc,d         [Type: alloc::rc::Rc<dyn$<core::fmt::Debug> >]
+// cdb-check:    [Reference count] : 31 [Type: core::cell::Cell<usize>]
 // cdb-check:    [Weak reference count] : 2 [Type: core::cell::Cell<usize>]
 
-// cdb-command:dx r1,d
-// cdb-check:r1,d             : 42 [Type: alloc::rc::Rc<i32>]
-// cdb-check:    [<Raw View>]     [Type: alloc::rc::Rc<i32>]
-// cdb-check:    [Reference count] : 2 [Type: core::cell::Cell<usize>]
+// cdb-command:dx dyn_rc_weak,d
+// cdb-check:dyn_rc_weak,d    [Type: alloc::rc::Weak<dyn$<core::fmt::Debug> >]
+// cdb-check:    [Reference count] : 31 [Type: core::cell::Cell<usize>]
 // cdb-check:    [Weak reference count] : 2 [Type: core::cell::Cell<usize>]
 
-// cdb-command:dx w1,d
-// cdb-check:w1,d             : 42 [Type: alloc::rc::Weak<i32>]
-// cdb-check:    [<Raw View>]     [Type: alloc::rc::Weak<i32>]
-// cdb-check:    [Reference count] : 2 [Type: core::cell::Cell<usize>]
+// cdb-command:dx slice_rc,d
+// cdb-check:slice_rc,d       : { len=3 } [Type: alloc::rc::Rc<slice$<u32> >]
+// cdb-check:    [Length]         : 3 [Type: [...]]
+// cdb-check:    [Reference count] : 41 [Type: core::cell::Cell<usize>]
 // cdb-check:    [Weak reference count] : 2 [Type: core::cell::Cell<usize>]
+// cdb-check:    [0]              : 1 [Type: u32]
+// cdb-check:    [1]              : 2 [Type: u32]
+// cdb-check:    [2]              : 3 [Type: u32]
+
+// cdb-command:dx slice_rc_weak,d
+// cdb-check:slice_rc_weak,d  : { len=3 } [Type: alloc::rc::Weak<slice$<u32> >]
+// cdb-check:    [Length]         : 3 [Type: [...]]
+// cdb-check:    [Reference count] : 41 [Type: core::cell::Cell<usize>]
+// cdb-check:    [Weak reference count] : 2 [Type: core::cell::Cell<usize>]
+// cdb-check:    [0]              : 1 [Type: u32]
+// cdb-check:    [1]              : 2 [Type: u32]
+// cdb-check:    [2]              : 3 [Type: u32]
 
-// cdb-command:dx a,d
-// cdb-check:a,d              : 42 [Type: alloc::sync::Arc<i32>]
-// cdb-check:    [<Raw View>]     [Type: alloc::sync::Arc<i32>]
-// cdb-check:    [Reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+// cdb-command:dx dyn_arc,d
+// cdb-check:dyn_arc,d        [Type: alloc::sync::Arc<dyn$<core::fmt::Debug> >]
+// cdb-check:    [Reference count] : 51 [Type: core::sync::atomic::AtomicUsize]
 // cdb-check:    [Weak reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
 
-// cdb-command:dx a1,d
-// cdb-check:a1,d             : 42 [Type: alloc::sync::Arc<i32>]
-// cdb-check:    [<Raw View>]     [Type: alloc::sync::Arc<i32>]
-// cdb-check:    [Reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+// cdb-command:dx dyn_arc_weak,d
+// cdb-check:dyn_arc_weak,d   [Type: alloc::sync::Weak<dyn$<core::fmt::Debug> >]
+// cdb-check:    [Reference count] : 51 [Type: core::sync::atomic::AtomicUsize]
 // cdb-check:    [Weak reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
 
-// cdb-command:dx w2,d
-// cdb-check:w2,d             : 42 [Type: alloc::sync::Weak<i32>]
-// cdb-check:    [<Raw View>]     [Type: alloc::sync::Weak<i32>]
-// cdb-check:    [Reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+// cdb-command:dx slice_arc,d
+// cdb-check:slice_arc,d      : { len=3 } [Type: alloc::sync::Arc<slice$<u32> >]
+// cdb-check:    [Length]         : 3 [Type: [...]]
+// cdb-check:    [Reference count] : 61 [Type: core::sync::atomic::AtomicUsize]
+// cdb-check:    [Weak reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+// cdb-check:    [0]              : 4 [Type: u32]
+// cdb-check:    [1]              : 5 [Type: u32]
+// cdb-check:    [2]              : 6 [Type: u32]
+
+// cdb-command:dx slice_arc_weak,d
+// cdb-check:slice_arc_weak,d : { len=3 } [Type: alloc::sync::Weak<slice$<u32> >]
+// cdb-check:    [Length]         : 3 [Type: [...]]
+// cdb-check:    [Reference count] : 61 [Type: core::sync::atomic::AtomicUsize]
 // cdb-check:    [Weak reference count] : 2 [Type: core::sync::atomic::AtomicUsize]
+// cdb-check:    [0]              : 4 [Type: u32]
+// cdb-check:    [1]              : 5 [Type: u32]
+// cdb-check:    [2]              : 6 [Type: u32]
 
+use std::fmt::Debug;
 use std::rc::Rc;
 use std::sync::Arc;
 
 fn main() {
-    let r = Rc::new(42);
-    let r1 = Rc::clone(&r);
-    let w1 = Rc::downgrade(&r);
+    let rc = Rc::new(111);
+    inc_ref_count(&rc, 10);
+    let weak_rc = Rc::downgrade(&rc);
+
+    let arc = Arc::new(222);
+    inc_ref_count(&arc, 20);
+    let weak_arc = Arc::downgrade(&arc);
+
+    let dyn_rc: Rc<dyn Debug> = Rc::new(333);
+    inc_ref_count(&dyn_rc, 30);
+    let dyn_rc_weak = Rc::downgrade(&dyn_rc);
+
+    let slice_rc: Rc<[u32]> = Rc::from(vec![1, 2, 3]);
+    inc_ref_count(&slice_rc, 40);
+    let slice_rc_weak = Rc::downgrade(&slice_rc);
 
-    let a = Arc::new(42);
-    let a1 = Arc::clone(&a);
-    let w2 = Arc::downgrade(&a);
+    let dyn_arc: Arc<dyn Debug> = Arc::new(444);
+    inc_ref_count(&dyn_arc, 50);
+    let dyn_arc_weak = Arc::downgrade(&dyn_arc);
+
+    let slice_arc: Arc<[u32]> = Arc::from(vec![4, 5, 6]);
+    inc_ref_count(&slice_arc, 60);
+    let slice_arc_weak = Arc::downgrade(&slice_arc);
 
     zzz(); // #break
 }
 
-fn zzz() { () }
+fn inc_ref_count<T: Clone>(rc: &T, count: usize) {
+    for _ in 0..count {
+        std::mem::forget(rc.clone());
+    }
+}
+
+fn zzz() {
+    ()
+}