Auto merge of #70052 - Amanieu:hashbrown7, r=Mark-Simulacrum

Update hashbrown to 0.8.1 This update includes: - rust-lang/hashbrown#146, which improves the performance of `Clone` and implements `clone_from`. - rust-lang/hashbrown#159, which reduces the size of `HashMap` by 8 bytes. - rust-lang/hashbrown#162, which avoids creating small 1-element tables. Fixes #28481
rust-lang · Aug 7, 2020 · 8b26609 · 8b26609
2 parents d4c940f + e46bb17
commit 8b26609
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Showing 7 changed files with 47 additions and 66 deletions.
diff --git a/Cargo.lock b/Cargo.lock
@@ -137,12 +137,6 @@ dependencies = [
  "winapi 0.3.8",
 ]
 
-[[package]]
-name = "autocfg"
-version = "0.1.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
-
 [[package]]
 name = "autocfg"
 version = "1.0.0"
@@ -766,7 +760,7 @@ version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
 dependencies = [
- "autocfg 1.0.0",
+ "autocfg",
  "cfg-if",
  "lazy_static",
 ]
@@ -1245,11 +1239,11 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.6.2"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3cd9867f119b19fecb08cd5c326ad4488d7a1da4bf75b4d95d71db742525aaab"
+checksum = "34f595585f103464d8d2f6e9864682d74c1601fed5e07d62b1c9058dba8246fb"
 dependencies = [
- "autocfg 0.1.7",
+ "autocfg",
  "compiler_builtins",
  "rustc-std-workspace-alloc",
  "rustc-std-workspace-core",
@@ -2079,7 +2073,7 @@ version = "0.9.54"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1024c0a59774200a555087a6da3f253a9095a5f344e353b212ac4c8b8e450986"
 dependencies = [
- "autocfg 1.0.0",
+ "autocfg",
  "cc",
  "libc",
  "openssl-src",

diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml
@@ -20,7 +20,7 @@ libc = { version = "0.2.51", default-features = false, features = ['rustc-dep-of
 compiler_builtins = { version = "0.1.32" }
 profiler_builtins = { path = "../profiler_builtins", optional = true }
 unwind = { path = "../unwind" }
-hashbrown = { version = "0.6.2", default-features = false, features = ['rustc-dep-of-std'] }
+hashbrown = { version = "0.8.1", default-features = false, features = ['rustc-dep-of-std'] }
 
 # Dependencies of the `backtrace` crate
 addr2line = { version = "0.13.0", optional = true, default-features = false }

diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
@@ -580,7 +580,7 @@ where
     #[inline]
     #[unstable(feature = "try_reserve", reason = "new API", issue = "48043")]
     pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
-        self.base.try_reserve(additional).map_err(map_collection_alloc_err)
+        self.base.try_reserve(additional).map_err(map_try_reserve_error)
     }
 
     /// Shrinks the capacity of the map as much as possible. It will drop
@@ -2569,10 +2569,10 @@ fn map_entry<'a, K: 'a, V: 'a>(raw: base::RustcEntry<'a, K, V>) -> Entry<'a, K,
 }
 
 #[inline]
-fn map_collection_alloc_err(err: hashbrown::CollectionAllocErr) -> TryReserveError {
+fn map_try_reserve_error(err: hashbrown::TryReserveError) -> TryReserveError {
     match err {
-        hashbrown::CollectionAllocErr::CapacityOverflow => TryReserveError::CapacityOverflow,
-        hashbrown::CollectionAllocErr::AllocErr { layout } => {
+        hashbrown::TryReserveError::CapacityOverflow => TryReserveError::CapacityOverflow,
+        hashbrown::TryReserveError::AllocError { layout } => {
             TryReserveError::AllocError { layout, non_exhaustive: () }
         }
     }

diff --git a/src/etc/gdb_providers.py b/src/etc/gdb_providers.py
@@ -352,8 +352,13 @@ def __init__(self, valobj, show_values=True):
         ctrl = table["ctrl"]["pointer"]
 
         self.size = int(table["items"])
-        self.data_ptr = table["data"]["pointer"]
-        self.pair_type = self.data_ptr.dereference().type
+        self.pair_type = table.type.template_argument(0)
+
+        self.new_layout = not table.type.has_key("data")
+        if self.new_layout:
+            self.data_ptr = ctrl.cast(self.pair_type.pointer())
+        else:
+            self.data_ptr = table["data"]["pointer"]
 
         self.valid_indices = []
         for idx in range(capacity):
@@ -374,6 +379,8 @@ def children(self):
 
         for index in range(self.size):
             idx = self.valid_indices[index]
+            if self.new_layout:
+                idx = -(idx + 1)
             element = (pairs_start + idx).dereference()
             if self.show_values:
                 yield "key{}".format(index), element[ZERO_FIELD]

diff --git a/src/etc/lldb_providers.py b/src/etc/lldb_providers.py
@@ -514,6 +514,8 @@ def get_child_at_index(self, index):
         # type: (int) -> SBValue
         pairs_start = self.data_ptr.GetValueAsUnsigned()
         idx = self.valid_indices[index]
+        if self.new_layout:
+            idx = -(idx + 1)
         address = pairs_start + idx * self.pair_type_size
         element = self.data_ptr.CreateValueFromAddress("[%s]" % index, address, self.pair_type)
         if self.show_values:
@@ -529,10 +531,15 @@ def update(self):
         ctrl = table.GetChildMemberWithName("ctrl").GetChildAtIndex(0)
 
         self.size = table.GetChildMemberWithName("items").GetValueAsUnsigned()
-        self.data_ptr = table.GetChildMemberWithName("data").GetChildAtIndex(0)
-        self.pair_type = self.data_ptr.Dereference().GetType()
+        self.pair_type = table.type.template_args[0]
         self.pair_type_size = self.pair_type.GetByteSize()
 
+        self.new_layout = not table.GetChildMemberWithName("data").IsValid()
+        if self.new_layout:
+            self.data_ptr = ctrl.Cast(self.pair_type.GetPointerType())
+        else:
+            self.data_ptr = table.GetChildMemberWithName("data").GetChildAtIndex(0)
+
         u8_type = self.valobj.GetTarget().GetBasicType(eBasicTypeUnsignedChar)
         u8_type_size = self.valobj.GetTarget().GetBasicType(eBasicTypeUnsignedChar).GetByteSize()
 

diff --git a/src/etc/natvis/libstd.natvis b/src/etc/natvis/libstd.natvis
@@ -30,6 +30,7 @@
     <Expand>
       <Item Name="[size]">base.table.items</Item>
       <Item Name="[capacity]">base.table.items + base.table.growth_left</Item>
+      <Item Name="[state]">base.hash_builder</Item>
 
       <CustomListItems>
         <Variable Name="i" InitialValue="0" />
@@ -40,7 +41,7 @@
           <If Condition="(base.table.ctrl.pointer[i] &amp; 0x80) == 0">
             <!-- Bucket is populated -->
             <Exec>n--</Exec>
-            <Item Name="{base.table.data.pointer[i].__0}">base.table.data.pointer[i].__1</Item>
+            <Item Name="{static_cast&lt;tuple&lt;$T1, $T2&gt;*&gt;(base.table.ctrl.pointer)[-(i + 1)].__0}">static_cast&lt;tuple&lt;$T1, $T2&gt;*&gt;(base.table.ctrl.pointer)[-(i + 1)].__1</Item>
           </If>
           <Exec>i++</Exec>
         </Loop>
@@ -53,6 +54,7 @@
     <Expand>
       <Item Name="[size]">map.base.table.items</Item>
       <Item Name="[capacity]">map.base.table.items + map.base.table.growth_left</Item>
+      <Item Name="[state]">map.base.hash_builder</Item>
 
       <CustomListItems>
         <Variable Name="i" InitialValue="0" />
@@ -63,36 +65,7 @@
           <If Condition="(map.base.table.ctrl.pointer[i] &amp; 0x80) == 0">
             <!-- Bucket is populated -->
             <Exec>n--</Exec>
-            <Item>map.base.table.data.pointer[i].__0</Item>
-          </If>
-          <Exec>i++</Exec>
-        </Loop>
-      </CustomListItems>
-    </Expand>
-  </Type>
-
-  <Type Name="hashbrown::raw::RawTable&lt;*&gt;">
-    <!-- RawTable has a nice and simple layout.
-      items                     Number of *populated* values in the RawTable (less than the size of ctrl.pointer / data.pointer)
-      growth_left               Remaining capacity before growth
-      ctrl.pointer[i] & 0x80    Indicates the bucket is empty / should be skipped / doesn't count towards items.
-      data.pointer[i]           The (K,V) tuple, if not empty.
-    -->
-    <DisplayString>{{ size={items} }}</DisplayString>
-    <Expand>
-      <Item Name="[size]">items</Item>
-      <Item Name="[capacity]">items + growth_left</Item>
-
-      <CustomListItems>
-        <Variable Name="i" InitialValue="0" />
-        <Variable Name="n" InitialValue="items" />
-        <Size>items</Size>
-        <Loop>
-          <Break Condition="n == 0" />
-          <If Condition="(ctrl.pointer[i] &amp; 0x80) == 0">
-            <!-- Bucket is populated -->
-            <Exec>n--</Exec>
-            <Item>data.pointer[i]</Item>
+            <Item>static_cast&lt;$T1*&gt;(map.base.table.ctrl.pointer)[-(i + 1)]</Item>
           </If>
           <Exec>i++</Exec>
         </Loop>

diff --git a/src/test/debuginfo/pretty-std-collections-hash.rs b/src/test/debuginfo/pretty-std-collections-hash.rs
@@ -9,35 +9,35 @@
 // cdb-check:hash_set,d [...] : { size=15 } [Type: [...]::HashSet<u64, [...]>]
 // cdb-check:    [size]           : 15 [Type: [...]]
 // cdb-check:    [capacity]       : [...]
-// cdb-check:    [[...]] [...]    : 0 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 0 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 1 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 1 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 2 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 2 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 3 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 3 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 4 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 4 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 5 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 5 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 6 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 6 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 7 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 7 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 8 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 8 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 9 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 9 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 10 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 10 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 11 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 11 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 12 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 12 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 13 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 13 [Type: u64]
 // cdb-command: dx hash_set,d
-// cdb-check:    [[...]] [...]    : 14 [Type: unsigned __int64]
+// cdb-check:    [[...]] [...]    : 14 [Type: u64]
 
 // cdb-command: dx hash_map,d
 // cdb-check:hash_map,d [...] : { size=15 } [Type: [...]::HashMap<u64, u64, [...]>]