From 934c395e8d079c5e3b4c80b6ed535fa708088779 Mon Sep 17 00:00:00 2001
From: xezon <4720891+xezon@users.noreply.github.com>
Date: Sun, 13 Sep 2026 07:41:24 +0200
Subject: [PATCH 1/2] chore(natvis): Add Visual Studio debugger visualizers for
 the WWLib containers (#3283)

The WWLib containers showed up in the Visual Studio debugger as raw structs, so
reading their elements meant expanding pointers and slicing arrays by hand. Each
WWLib header that declares a container used by the game now has a matching natvis
file in resources/visualstudio/wwlib, registered alongside the existing natvis
files under MSVC_IDE, so the containers expand directly to their elements.

Covered are VectorClass, DynamicVectorClass, BooleanVectorClass, SimpleVecClass,
SimpleDynVecClass, ShareBufferClass, UniqueArrayClass, GenericList, List, Node,
DataNode, SList, the MultiList classes and their iterators, HashTableClass,
HashTemplateClass, StringClass, WideStringClass and MPSCIntrusiveQueue. Types with
no users outside WWLib are left out: IndexClass, NTreeClass, BinaryHeapClass,
HashListClass, DoubleNode and Buffer.

DynamicVectorClass, SimpleDynVecClass and the typed MultiList classes have rules of
their own because natvis rules are inherited, and the base class rule would list
the allocated slots instead of the live elements. BooleanVectorClass reports Copy
for LastIndex, because that bit is only written back into the packed array once a
different index is fetched. StringClass and WideStringClass count the characters
when the stored length is 0, as Get_Length does, since a write through Get_Buffer
leaves the stored length at 0.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
---
 resources/CMakeLists.txt                      |  12 ++
 resources/visualstudio/wwlib/hash.natvis      |  36 ++++++
 .../visualstudio/wwlib/hashtemplate.natvis    |  36 ++++++
 resources/visualstudio/wwlib/listnode.natvis  |  64 +++++++++++
 .../wwlib/mpsc_intrusive_queue.natvis         |  19 ++++
 resources/visualstudio/wwlib/multilist.natvis | 103 ++++++++++++++++++
 resources/visualstudio/wwlib/sharebuf.natvis  |  16 +++
 resources/visualstudio/wwlib/simplevec.natvis |  27 +++++
 resources/visualstudio/wwlib/slist.natvis     |  27 +++++
 resources/visualstudio/wwlib/uarray.natvis    |  17 +++
 resources/visualstudio/wwlib/vector.natvis    |  44 ++++++++
 .../visualstudio/wwlib/widestring.natvis      |  18 +++
 resources/visualstudio/wwlib/wwstring.natvis  |  18 +++
 13 files changed, 437 insertions(+)
 create mode 100644 resources/visualstudio/wwlib/hash.natvis
 create mode 100644 resources/visualstudio/wwlib/hashtemplate.natvis
 create mode 100644 resources/visualstudio/wwlib/listnode.natvis
 create mode 100644 resources/visualstudio/wwlib/mpsc_intrusive_queue.natvis
 create mode 100644 resources/visualstudio/wwlib/multilist.natvis
 create mode 100644 resources/visualstudio/wwlib/sharebuf.natvis
 create mode 100644 resources/visualstudio/wwlib/simplevec.natvis
 create mode 100644 resources/visualstudio/wwlib/slist.natvis
 create mode 100644 resources/visualstudio/wwlib/uarray.natvis
 create mode 100644 resources/visualstudio/wwlib/vector.natvis
 create mode 100644 resources/visualstudio/wwlib/widestring.natvis
 create mode 100644 resources/visualstudio/wwlib/wwstring.natvis

diff --git a/resources/CMakeLists.txt b/resources/CMakeLists.txt
index d8d613ca9b2..3dee5754d4b 100644
--- a/resources/CMakeLists.txt
+++ b/resources/CMakeLists.txt
@@ -23,5 +23,17 @@ if (MSVC_IDE)
         visualstudio/stllist.natvis
         visualstudio/stlvector.natvis
         visualstudio/unicodestring.natvis
+        visualstudio/wwlib/hash.natvis
+        visualstudio/wwlib/hashtemplate.natvis
+        visualstudio/wwlib/listnode.natvis
+        visualstudio/wwlib/mpsc_intrusive_queue.natvis
+        visualstudio/wwlib/multilist.natvis
+        visualstudio/wwlib/sharebuf.natvis
+        visualstudio/wwlib/simplevec.natvis
+        visualstudio/wwlib/slist.natvis
+        visualstudio/wwlib/uarray.natvis
+        visualstudio/wwlib/vector.natvis
+        visualstudio/wwlib/widestring.natvis
+        visualstudio/wwlib/wwstring.natvis
     )
 endif()
diff --git a/resources/visualstudio/wwlib/hash.natvis b/resources/visualstudio/wwlib/hash.natvis
new file mode 100644
index 00000000000..d31c64f960a
--- /dev/null
+++ b/resources/visualstudio/wwlib/hash.natvis
@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- Buckets hold the head of a chain that is threaded through HashableClass::NextHash,
+         so the entries are gathered with a bucket loop wrapped around a chain loop. -->
+    <Type Name="HashTableClass">
+        <DisplayString>{{ buckets={HashTableSize} }}</DisplayString>
+        <Expand>
+            <Item Name="[buckets]" ExcludeView="simple">HashTableSize</Item>
+            <CustomListItems>
+                <Variable Name="bucket" InitialValue="0"/>
+                <Variable Name="entry" InitialValue="(HashableClass *)0"/>
+                <Loop>
+                    <Break Condition="bucket &gt;= HashTableSize"/>
+                    <Exec>entry = HashTable[bucket]</Exec>
+                    <Loop>
+                        <Break Condition="entry == 0"/>
+                        <Item>entry</Item>
+                        <Exec>entry = entry-&gt;NextHash</Exec>
+                    </Loop>
+                    <Exec>bucket = bucket + 1</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <Type Name="HashTableIteratorClass">
+        <DisplayString Condition="CurrentEntry == 0">{{ done }}</DisplayString>
+        <DisplayString>{*CurrentEntry}</DisplayString>
+        <Expand>
+            <Item Name="[current]">CurrentEntry</Item>
+            <Item Name="[next]" ExcludeView="simple">NextEntry</Item>
+            <Item Name="[bucket]" ExcludeView="simple">Index</Item>
+            <Item Name="[table]" ExcludeView="simple">Table</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/hashtemplate.natvis b/resources/visualstudio/wwlib/hashtemplate.natvis
new file mode 100644
index 00000000000..dbf81cc1d50
--- /dev/null
+++ b/resources/visualstudio/wwlib/hashtemplate.natvis
@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- Hash holds one handle per bucket into Table, and the chain is threaded through
+         Table[handle].Next. Both use the class's NIL sentinel, which is -1. -->
+    <Type Name="HashTemplateClass&lt;*,*&gt;">
+        <DisplayString>{{ buckets={(int)Size} }}</DisplayString>
+        <Expand>
+            <Item Name="[buckets]" ExcludeView="simple">(int)Size</Item>
+            <CustomListItems>
+                <Variable Name="bucket" InitialValue="0"/>
+                <Variable Name="handle" InitialValue="-1"/>
+                <Loop>
+                    <Break Condition="bucket &gt;= (int)Size"/>
+                    <Exec>handle = Hash[bucket]</Exec>
+                    <Loop>
+                        <Break Condition="handle == -1"/>
+                        <Item Name="{Table[handle].Key}">Table[handle].Value</Item>
+                        <Exec>handle = Table[handle].Next</Exec>
+                    </Loop>
+                    <Exec>bucket = bucket + 1</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <Type Name="HashTemplateIterator&lt;*,*&gt;">
+        <DisplayString Condition="Handle == -1">{{ done }}</DisplayString>
+        <DisplayString>{HashTable.Table[Handle].Value}</DisplayString>
+        <Expand>
+            <Item Name="[key]" Condition="Handle != -1">HashTable.Table[Handle].Key</Item>
+            <Item Name="[value]" Condition="Handle != -1">HashTable.Table[Handle].Value</Item>
+            <Item Name="[bucket]" ExcludeView="simple">HashIndex</Item>
+            <Item Name="[table]" ExcludeView="simple">HashTable</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/listnode.natvis b/resources/visualstudio/wwlib/listnode.natvis
new file mode 100644
index 00000000000..dc33d3d54e2
--- /dev/null
+++ b/resources/visualstudio/wwlib/listnode.natvis
@@ -0,0 +1,64 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- GenericList embeds two sentinel nodes by value. FirstNode.NextNode is the first
+         real entry, and LastNode is recognised by having no NextNode of its own. -->
+    <Type Name="GenericList">
+        <DisplayString Condition="FirstNode.NextNode-&gt;NextNode == 0">{{ size=0 }}</DisplayString>
+        <DisplayString>{{ GenericList }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="FirstNode.NextNode"/>
+                <Loop>
+                    <Break Condition="node == 0 || node-&gt;NextNode == 0"/>
+                    <Item>node</Item>
+                    <Exec>node = node-&gt;NextNode</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <!-- List's template argument is already a pointer type, so the item cast is ($T1)
+         rather than ($T1 *). This only works because GenericNode must be the first base
+         of the linked object, which is what the class comment in LISTNODE.h requires. -->
+    <Type Name="List&lt;*&gt;">
+        <DisplayString Condition="FirstNode.NextNode-&gt;NextNode == 0">{{ size=0 }}</DisplayString>
+        <DisplayString>{{ List }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="FirstNode.NextNode"/>
+                <Loop>
+                    <Break Condition="node == 0 || node-&gt;NextNode == 0"/>
+                    <Item>($T1)node</Item>
+                    <Exec>node = node-&gt;NextNode</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <Type Name="GenericNode">
+        <DisplayString Condition="NextNode == 0 || PrevNode == 0">{{ unlinked }}</DisplayString>
+        <DisplayString>{{ GenericNode }}</DisplayString>
+        <Expand>
+            <Item Name="[next]">NextNode</Item>
+            <Item Name="[prev]">PrevNode</Item>
+        </Expand>
+    </Type>
+
+    <Type Name="Node&lt;*&gt;">
+        <DisplayString Condition="NextNode == 0 || PrevNode == 0">{{ unlinked }}</DisplayString>
+        <DisplayString>{{ Node }}</DisplayString>
+        <Expand>
+            <Item Name="[next]">($T1)NextNode</Item>
+            <Item Name="[prev]">($T1)PrevNode</Item>
+        </Expand>
+    </Type>
+
+    <Type Name="DataNode&lt;*&gt;">
+        <DisplayString>{Value}</DisplayString>
+        <Expand>
+            <Item Name="[value]">Value</Item>
+            <Item Name="[next]" ExcludeView="simple">(DataNode&lt;$T1&gt; *)NextNode</Item>
+            <Item Name="[prev]" ExcludeView="simple">(DataNode&lt;$T1&gt; *)PrevNode</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/mpsc_intrusive_queue.natvis b/resources/visualstudio/wwlib/mpsc_intrusive_queue.natvis
new file mode 100644
index 00000000000..543f35d07ff
--- /dev/null
+++ b/resources/visualstudio/wwlib/mpsc_intrusive_queue.natvis
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- Push prepends, and the chain is only reversed inside Flush, so the entries below
+         are listed newest first, which is the reverse of the order a consumer will see. -->
+    <Type Name="MPSCIntrusiveQueue&lt;*&gt;">
+        <DisplayString Condition="m_head == 0">{{ empty }}</DisplayString>
+        <DisplayString>{{ MPSCIntrusiveQueue }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="m_head"/>
+                <Loop>
+                    <Break Condition="node == 0"/>
+                    <Item>node</Item>
+                    <Exec>node = node-&gt;next</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/multilist.natvis b/resources/visualstudio/wwlib/multilist.natvis
new file mode 100644
index 00000000000..22e9d604af9
--- /dev/null
+++ b/resources/visualstudio/wwlib/multilist.natvis
@@ -0,0 +1,103 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- Head is an embedded sentinel and the list is circular, so the walk ends when it
+         comes back round to &Head rather than on a null link. -->
+    <Type Name="GenericMultiListClass">
+        <DisplayString Condition="Head.Next == &amp;Head">{{ size=0 }}</DisplayString>
+        <DisplayString>{{ GenericMultiList }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="Head.Next"/>
+                <Loop>
+                    <Break Condition="node == &amp;Head"/>
+                    <Item>node-&gt;Object</Item>
+                    <Exec>node = node-&gt;Next</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <!-- Must be spelled out even though GenericMultiListClass already matches by
+         inheritance, so that the entries come out as the list's own object type. -->
+    <Type Name="MultiListClass&lt;*&gt;">
+        <DisplayString Condition="Head.Next == &amp;Head">{{ size=0 }}</DisplayString>
+        <DisplayString>{{ MultiList }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="Head.Next"/>
+                <Loop>
+                    <Break Condition="node == &amp;Head"/>
+                    <Item>($T1 *)node-&gt;Object</Item>
+                    <Exec>node = node-&gt;Next</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <Type Name="RefMultiListClass&lt;*&gt;">
+        <DisplayString Condition="Head.Next == &amp;Head">{{ size=0 }}</DisplayString>
+        <DisplayString>{{ RefMultiList }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="Head.Next"/>
+                <Loop>
+                    <Break Condition="node == &amp;Head"/>
+                    <Item>($T1 *)node-&gt;Object</Item>
+                    <Exec>node = node-&gt;Next</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <!-- ListNode chains across every list the object is in, via NextList. -->
+    <Type Name="MultiListObjectClass">
+        <DisplayString Condition="ListNode == 0">{{ not in any list }}</DisplayString>
+        <DisplayString>{{ in list(s) }}</DisplayString>
+        <Expand>
+            <Synthetic Name="[lists]">
+                <DisplayString>lists this object belongs to</DisplayString>
+                <Expand>
+                    <CustomListItems>
+                        <Variable Name="node" InitialValue="ListNode"/>
+                        <Loop>
+                            <Break Condition="node == 0"/>
+                            <Item>node-&gt;List</Item>
+                            <Exec>node = node-&gt;NextList</Exec>
+                        </Loop>
+                    </CustomListItems>
+                </Expand>
+            </Synthetic>
+        </Expand>
+    </Type>
+
+    <Type Name="MultiListNodeClass">
+        <DisplayString>{{ object={Object} }}</DisplayString>
+        <Expand>
+            <Item Name="[object]">Object</Item>
+            <Item Name="[list]">List</Item>
+            <Item Name="[next]" ExcludeView="simple">Next</Item>
+            <Item Name="[prev]" ExcludeView="simple">Prev</Item>
+            <Item Name="[next list]" ExcludeView="simple">NextList</Item>
+        </Expand>
+    </Type>
+
+    <Type Name="GenericMultiListIterator">
+        <DisplayString Condition="CurNode == &amp;List-&gt;Head">{{ done }}</DisplayString>
+        <DisplayString>{CurNode-&gt;Object}</DisplayString>
+        <Expand>
+            <Item Name="[current]" Condition="CurNode != &amp;List-&gt;Head">CurNode-&gt;Object</Item>
+            <Item Name="[list]">List</Item>
+        </Expand>
+    </Type>
+
+    <Type Name="MultiListIterator&lt;*&gt;">
+        <AlternativeType Name="RefMultiListIterator&lt;*&gt;"/>
+        <AlternativeType Name="PriorityMultiListIterator&lt;*&gt;"/>
+        <DisplayString Condition="CurNode == &amp;List-&gt;Head">{{ done }}</DisplayString>
+        <DisplayString>{*($T1 *)CurNode-&gt;Object}</DisplayString>
+        <Expand>
+            <Item Name="[current]" Condition="CurNode != &amp;List-&gt;Head">($T1 *)CurNode-&gt;Object</Item>
+            <Item Name="[list]">List</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/sharebuf.natvis b/resources/visualstudio/wwlib/sharebuf.natvis
new file mode 100644
index 00000000000..ed69a353423
--- /dev/null
+++ b/resources/visualstudio/wwlib/sharebuf.natvis
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <Type Name="ShareBufferClass&lt;*&gt;">
+        <DisplayString>{{ size={Count} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">Count</Item>
+            <Item Name="[refs]" ExcludeView="simple">NumRefs</Item>
+            <!-- Msg only exists in RTS_DEBUG builds. -->
+            <Item Name="[msg]" Optional="true" ExcludeView="simple">Msg,s</Item>
+            <ArrayItems>
+                <Size>Count</Size>
+                <ValuePointer>Array</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/simplevec.natvis b/resources/visualstudio/wwlib/simplevec.natvis
new file mode 100644
index 00000000000..8d46ec4fc69
--- /dev/null
+++ b/resources/visualstudio/wwlib/simplevec.natvis
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <Type Name="SimpleVecClass&lt;*&gt;">
+        <DisplayString>{{ size={VectorMax} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">VectorMax</Item>
+            <ArrayItems>
+                <Size>VectorMax</Size>
+                <ValuePointer>Vector</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+
+    <!-- Must be spelled out even though SimpleVecClass already matches by inheritance,
+         because the live element count here is ActiveCount and not VectorMax. -->
+    <Type Name="SimpleDynVecClass&lt;*&gt;">
+        <DisplayString>{{ size={ActiveCount} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">ActiveCount</Item>
+            <Item Name="[capacity]" ExcludeView="simple">VectorMax</Item>
+            <ArrayItems>
+                <Size>ActiveCount</Size>
+                <ValuePointer>Vector</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/slist.natvis b/resources/visualstudio/wwlib/slist.natvis
new file mode 100644
index 00000000000..f7f26038b3e
--- /dev/null
+++ b/resources/visualstudio/wwlib/slist.natvis
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- The links and the payload both live in the GenericSLNode base as void pointers,
+         so each has to be cast back to the list's element type on the way out. -->
+    <Type Name="SList&lt;*&gt;">
+        <DisplayString Condition="HeadNode == 0">{{ size=0 }}</DisplayString>
+        <DisplayString>{{ SList }}</DisplayString>
+        <Expand>
+            <CustomListItems>
+                <Variable Name="node" InitialValue="HeadNode"/>
+                <Loop>
+                    <Break Condition="node == 0"/>
+                    <Item>($T1 *)node-&gt;NodeData</Item>
+                    <Exec>node = (SLNode&lt;$T1&gt; *)node-&gt;NodeNext</Exec>
+                </Loop>
+            </CustomListItems>
+        </Expand>
+    </Type>
+
+    <Type Name="SLNode&lt;*&gt;">
+        <DisplayString>{*($T1 *)NodeData}</DisplayString>
+        <Expand>
+            <Item Name="[data]">($T1 *)NodeData</Item>
+            <Item Name="[next]">(SLNode&lt;$T1&gt; *)NodeNext</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/uarray.natvis b/resources/visualstudio/wwlib/uarray.natvis
new file mode 100644
index 00000000000..93a7368af86
--- /dev/null
+++ b/resources/visualstudio/wwlib/uarray.natvis
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- The unique items live in a DynamicVectorClass of HashItem, so the element
+         value has to be reached through the Item member of each slot. -->
+    <Type Name="UniqueArrayClass&lt;*&gt;">
+        <DisplayString>{{ size={UniqueItems.ActiveCount} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">UniqueItems.ActiveCount</Item>
+            <Item Name="[capacity]" ExcludeView="simple">UniqueItems.VectorMax</Item>
+            <Item Name="[hash table size]" ExcludeView="simple">HashTableSize</Item>
+            <IndexListItems>
+                <Size>UniqueItems.ActiveCount</Size>
+                <ValueNode>UniqueItems.Vector[$i].Item</ValueNode>
+            </IndexListItems>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/vector.natvis b/resources/visualstudio/wwlib/vector.natvis
new file mode 100644
index 00000000000..af37c172136
--- /dev/null
+++ b/resources/visualstudio/wwlib/vector.natvis
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <Type Name="VectorClass&lt;*&gt;">
+        <DisplayString>{{ size={VectorMax} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">VectorMax</Item>
+            <Item Name="[allocated]" ExcludeView="simple">IsAllocated</Item>
+            <ArrayItems>
+                <Size>VectorMax</Size>
+                <ValuePointer>Vector</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+
+    <!-- Must be spelled out even though VectorClass already matches by inheritance,
+         because the live element count here is ActiveCount and not VectorMax. -->
+    <Type Name="DynamicVectorClass&lt;*&gt;">
+        <DisplayString>{{ size={ActiveCount} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">ActiveCount</Item>
+            <Item Name="[capacity]" ExcludeView="simple">VectorMax</Item>
+            <Item Name="[growth step]" ExcludeView="simple">GrowthStep</Item>
+            <ArrayItems>
+                <Size>ActiveCount</Size>
+                <ValuePointer>Vector</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+
+    <!-- Copy holds the value of element LastIndex and is only written back into BitArray
+         once a different index is fetched, so the packed bit for LastIndex is stale. -->
+    <Type Name="BooleanVectorClass">
+        <DisplayString>{{ size={BitCount} }}</DisplayString>
+        <Expand>
+            <Item Name="[size]" ExcludeView="simple">BitCount</Item>
+            <Item Name="[cached index]" ExcludeView="simple">LastIndex</Item>
+            <Item Name="[cached value]" ExcludeView="simple">Copy</Item>
+            <IndexListItems>
+                <Size>BitCount</Size>
+                <ValueNode>$i == LastIndex ? Copy : (bool)((BitArray.Vector[$i / 8] &gt;&gt; ($i % 8)) &amp; 1)</ValueNode>
+            </IndexListItems>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/widestring.natvis b/resources/visualstudio/wwlib/widestring.natvis
new file mode 100644
index 00000000000..815f6c61fab
--- /dev/null
+++ b/resources/visualstudio/wwlib/widestring.natvis
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- m_Buffer points just past a { int allocated_length; int length; } header, so the
+         two counters sit at [-2] and [-1]. An empty string instead points at the shared
+         static m_EmptyString, which has no header in front of it, hence the condition.
+         A stored length of 0 means not yet computed, for example after a write through
+         Get_Buffer, so it falls back to counting like Get_Length does. -->
+    <Type Name="WideStringClass">
+        <DisplayString>{m_Buffer,su}</DisplayString>
+        <StringView>m_Buffer,su</StringView>
+        <Expand>
+            <Item Name="[length]" Optional="true" Condition="m_Buffer != m_EmptyString" ExcludeView="simple">((int *)m_Buffer)[-1] != 0 ? ((int *)m_Buffer)[-1] : (int)wcsnlen(m_Buffer, ((int *)m_Buffer)[-2])</Item>
+            <Item Name="[capacity]" Optional="true" Condition="m_Buffer != m_EmptyString" ExcludeView="simple">((int *)m_Buffer)[-2]</Item>
+            <Item Name="[str]">m_Buffer,su</Item>
+            <Item Name="[ptr]" ExcludeView="simple">m_Buffer</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>
diff --git a/resources/visualstudio/wwlib/wwstring.natvis b/resources/visualstudio/wwlib/wwstring.natvis
new file mode 100644
index 00000000000..9a4a1118879
--- /dev/null
+++ b/resources/visualstudio/wwlib/wwstring.natvis
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?> 
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- m_Buffer points just past a { int allocated_length; int length; } header, so the
+         two counters sit at [-2] and [-1]. An empty string instead points at the shared
+         static m_EmptyString, which has no header in front of it, hence the condition.
+         A stored length of 0 means not yet computed, for example after a write through
+         Get_Buffer, so it falls back to counting like Get_Length does. -->
+    <Type Name="StringClass">
+        <DisplayString>{m_Buffer,s}</DisplayString>
+        <StringView>m_Buffer,s</StringView>
+        <Expand>
+            <Item Name="[length]" Optional="true" Condition="m_Buffer != m_EmptyString" ExcludeView="simple">((int *)m_Buffer)[-1] != 0 ? ((int *)m_Buffer)[-1] : (int)strnlen(m_Buffer, ((int *)m_Buffer)[-2])</Item>
+            <Item Name="[capacity]" Optional="true" Condition="m_Buffer != m_EmptyString" ExcludeView="simple">((int *)m_Buffer)[-2]</Item>
+            <Item Name="[str]">m_Buffer,s</Item>
+            <Item Name="[ptr]" ExcludeView="simple">m_Buffer</Item>
+        </Expand>
+    </Type>
+</AutoVisualizer>

From bccf3f5959c3890cdb4c68c43b374016989a268e Mon Sep 17 00:00:00 2001
From: xezon <4720891+xezon@users.noreply.github.com>
Date: Mon, 14 Sep 2026 08:45:10 +0200
Subject: [PATCH 2/2] chore(natvis): Show length, capacity and reference count
 for AsciiString and UnicodeString (#3283)

The [data] item of both visualizers was bound to the ref counted header instead of
the text, so expanding it showed the reference count and the allocation size under
a misleading name, and the length was not shown at all.

Both visualizers now list [length], [capacity] and [refs] as named items. No length
is stored, so [length] counts the characters like getLength does, capped at the
allocation so that a missing terminator cannot read past the buffer. [capacity]
includes the slot for the terminator, matching StringClass. A [refs] above 1 means
the buffer is shared and will be copied on the next write. A StringView adds the
text visualizer for long strings.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
---
 resources/visualstudio/asciistring.natvis   | 15 ++++++++++-----
 resources/visualstudio/unicodestring.natvis | 15 ++++++++++-----
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/resources/visualstudio/asciistring.natvis b/resources/visualstudio/asciistring.natvis
index 8f88151691e..4f9a8f1c48d 100644
--- a/resources/visualstudio/asciistring.natvis
+++ b/resources/visualstudio/asciistring.natvis
@@ -1,11 +1,16 @@
 <?xml version="1.0" encoding="utf-8"?> 
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- m_data points to a ref counted AsciiStringData header, and the characters follow
+         directly behind it. No length is stored, so it is counted like getLength does. -->
     <Type Name="AsciiString">
-        <DisplayString Condition="m_data != nullptr">{(const char *)(&amp; m_data[1]),s8}</DisplayString>
-        <DisplayString Condition="m_data == nullptr">""</DisplayString>
+        <DisplayString Condition="m_data == 0">""</DisplayString>
+        <DisplayString>{(const char *)(m_data + 1),s8}</DisplayString>
+        <StringView Condition="m_data != 0">(const char *)(m_data + 1),s8</StringView>
         <Expand>
-            <Item Name="[data]" Optional="true" Condition="m_data != nullptr">m_data</Item>
-            <Item Name="[str]" Optional="true" Condition="m_data != nullptr">(const char *)(&amp; m_data[1])</Item>
+            <Item Name="[length]" ExcludeView="simple">m_data == 0 ? 0 : (int)strnlen((const char *)(m_data + 1), m_data-&gt;m_numCharsAllocated)</Item>
+            <Item Name="[capacity]" Condition="m_data != 0" ExcludeView="simple">(int)m_data-&gt;m_numCharsAllocated</Item>
+            <Item Name="[refs]" Condition="m_data != 0" ExcludeView="simple">(int)m_data-&gt;m_refCount</Item>
+            <Item Name="[str]" Condition="m_data != 0">(const char *)(m_data + 1),s8</Item>
         </Expand>
     </Type>
-</AutoVisualizer>
\ No newline at end of file
+</AutoVisualizer>
diff --git a/resources/visualstudio/unicodestring.natvis b/resources/visualstudio/unicodestring.natvis
index 22aaf299cdc..a71be3c4ed9 100644
--- a/resources/visualstudio/unicodestring.natvis
+++ b/resources/visualstudio/unicodestring.natvis
@@ -1,11 +1,16 @@
 <?xml version="1.0" encoding="utf-8"?> 
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <!-- m_data points to a ref counted UnicodeStringData header, and the characters follow
+         directly behind it. No length is stored, so it is counted like getLength does. -->
     <Type Name="UnicodeString">
-        <DisplayString Condition="m_data != nullptr">{(const wchar_t *)(&amp; m_data[1]),su}</DisplayString>
-        <DisplayString Condition="m_data == nullptr">""</DisplayString>
+        <DisplayString Condition="m_data == 0">""</DisplayString>
+        <DisplayString>{(const wchar_t *)(m_data + 1),su}</DisplayString>
+        <StringView Condition="m_data != 0">(const wchar_t *)(m_data + 1),su</StringView>
         <Expand>
-            <Item Name="[data]" Optional="true" Condition="m_data != nullptr">m_data</Item>
-            <Item Name="[str]" Optional="true" Condition="m_data != nullptr">(const wchar_t *)(&amp; m_data[1])</Item>
+            <Item Name="[length]" ExcludeView="simple">m_data == 0 ? 0 : (int)wcsnlen((const wchar_t *)(m_data + 1), m_data-&gt;m_numCharsAllocated)</Item>
+            <Item Name="[capacity]" Condition="m_data != 0" ExcludeView="simple">(int)m_data-&gt;m_numCharsAllocated</Item>
+            <Item Name="[refs]" Condition="m_data != 0" ExcludeView="simple">(int)m_data-&gt;m_refCount</Item>
+            <Item Name="[str]" Condition="m_data != 0">(const wchar_t *)(m_data + 1),su</Item>
         </Expand>
     </Type>
-</AutoVisualizer>
\ No newline at end of file
+</AutoVisualizer>