src/etc/natvis/libstd.natvis

   1 <?xml version="1.0" encoding="utf-8"?>
   2 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
   3   <!--
   4     std::collection::Hash* container visualizers
   5
   6     Current std impls:
   7       std::collections::hash::set::HashSet<K, S>      is implemented in terms of...
   8       std::collections::hash::map::HashMap<K, V, S>   is implemented in terms of...
   9       hashbrown::map::HashMap<K, V, S>                is implemented in terms of...
  10       hashbrown::raw::RawTable<(K, V)>
  11
  12     Ideally, we'd teach rustc to scan dependencies/crates for .natvis files so
  13     the bulk of this could live alongside the hashbrown crate implementation,
  14     and std would just forward using e.g. <ExpandedItem>base</ExpandedItem>.
  15
  16     However, Given that std...Hash*Set* is currently implemented in terms of
  17     hashbrown...Hash*Map*, which would visualize poorly, we want to customize the
  18     look/feel at the std type level *anyways*...
  19
  20     References:
  21       https://github.com/rust-lang/rust/blob/master/src/libstd/collections/hash/map.rs
  22       https://github.com/rust-lang/rust/blob/master/src/libstd/collections/hash/set.rs
  23       https://github.com/rust-lang/hashbrown/blob/master/src/map.rs
  24       https://github.com/rust-lang/hashbrown/blob/master/src/set.rs
  25       https://github.com/rust-lang/hashbrown/blob/master/src/raw/mod.rs
  26   -->
  27
  28   <Type Name="std::collections::hash::map::HashMap&lt;*,*,*&gt;">
  29     <DisplayString>{{ size={base.table.items} }}</DisplayString>
  30     <Expand>
  31       <Item Name="[size]">base.table.items</Item>
  32       <Item Name="[capacity]">base.table.items + base.table.growth_left</Item>
  33
  34       <CustomListItems>
  35         <Variable Name="i" InitialValue="0" />
  36         <Variable Name="n" InitialValue="base.table.items" />
  37         <Size>base.table.items</Size>
  38         <Loop>
  39           <Break Condition="n == 0" />
  40           <If Condition="(base.table.ctrl.pointer[i] &amp; 0x80) == 0">
  41             <!-- Bucket is populated -->
  42             <Exec>n--</Exec>
  43             <Item Name="{base.table.data.pointer[i].__0}">base.table.data.pointer[i].__1</Item>
  44           </If>
  45           <Exec>i++</Exec>
  46         </Loop>
  47       </CustomListItems>
  48     </Expand>
  49   </Type>
  50
  51   <Type Name="std::collections::hash::set::HashSet&lt;*,*&gt;">
  52     <DisplayString>{{ size={map.base.table.items} }}</DisplayString>
  53     <Expand>
  54       <Item Name="[size]">map.base.table.items</Item>
  55       <Item Name="[capacity]">map.base.table.items + map.base.table.growth_left</Item>
  56
  57       <CustomListItems>
  58         <Variable Name="i" InitialValue="0" />
  59         <Variable Name="n" InitialValue="map.base.table.items" />
  60         <Size>map.base.table.items</Size>
  61         <Loop>
  62           <Break Condition="n == 0" />
  63           <If Condition="(map.base.table.ctrl.pointer[i] &amp; 0x80) == 0">
  64             <!-- Bucket is populated -->
  65             <Exec>n--</Exec>
  66             <Item>map.base.table.data.pointer[i].__0</Item>
  67           </If>
  68           <Exec>i++</Exec>
  69         </Loop>
  70       </CustomListItems>
  71     </Expand>
  72   </Type>
  73
  74   <Type Name="hashbrown::raw::RawTable&lt;*&gt;">
  75     <!-- RawTable has a nice and simple layout.
  76       items                     Number of *populated* values in the RawTable (less than the size of ctrl.pointer / data.pointer)
  77       growth_left               Remaining capacity before growth
  78       ctrl.pointer[i] & 0x80    Indicates the bucket is empty / should be skipped / doesn't count towards items.
  79       data.pointer[i]           The (K,V) tuple, if not empty.
  80     -->
  81     <DisplayString>{{ size={items} }}</DisplayString>
  82     <Expand>
  83       <Item Name="[size]">items</Item>
  84       <Item Name="[capacity]">items + growth_left</Item>
  85
  86       <CustomListItems>
  87         <Variable Name="i" InitialValue="0" />
  88         <Variable Name="n" InitialValue="items" />
  89         <Size>items</Size>
  90         <Loop>
  91           <Break Condition="n == 0" />
  92           <If Condition="(ctrl.pointer[i] &amp; 0x80) == 0">
  93             <!-- Bucket is populated -->
  94             <Exec>n--</Exec>
  95             <Item>data.pointer[i]</Item>
  96           </If>
  97           <Exec>i++</Exec>
  98         </Loop>
  99       </CustomListItems>
 100     </Expand>
 101   </Type>
 102 </AutoVisualizer>