PDB HashTable: Move TraitsT from class parameter to the methods that need it

The traits object is only used by a few methods. Deserializing a hash
table and walking it is possible without the traits object, so it
shouldn't be required to build a dummy object for that use case.

The TraitsT object used to be a function template parameter before
r327647, this restores it to that state.

This makes it clear that the traits object isn't needed at all in 1 of
the current 3 uses of HashTable (and I am going to add another use that
doesn't need it), and that the default PdbHashTraits isn't used outside
of tests.

While here, also re-enable 3 checks in the test that were commented out
(which requires making HashTableInternals templated and giving FooBar
an operator==).

No intended behavior change.

Differential Revision: https://reviews.llvm.org/D64640

llvm-svn: 365974

6 files changed, 102 insertions, 96 deletions

diff --git a/llvm/include/llvm/DebugInfo/PDB/Native/HashTable.h b/llvm/include/llvm/DebugInfo/PDB/Native/HashTable.h
index 86c43a482b8..b00873b575b 100644
--- a/llvm/include/llvm/DebugInfo/PDB/Native/HashTable.h
+++ b/llvm/include/llvm/DebugInfo/PDB/Native/HashTable.h
@@ -31,21 +31,21 @@ namespace pdb {
 Error readSparseBitVector(BinaryStreamReader &Stream, SparseBitVector<> &V);
 Error writeSparseBitVector(BinaryStreamWriter &Writer, SparseBitVector<> &Vec);
 
-template <typename ValueT, typename TraitsT> class HashTable;
+template <typename ValueT> class HashTable;
 
-template <typename ValueT, typename TraitsT>
+template <typename ValueT>
 class HashTableIterator
-    : public iterator_facade_base<HashTableIterator<ValueT, TraitsT>,
+    : public iterator_facade_base<HashTableIterator<ValueT>,
                                   std::forward_iterator_tag,
                                   std::pair<uint32_t, ValueT>> {
-  friend HashTable<ValueT, TraitsT>;
+  friend HashTable<ValueT>;
 
-  HashTableIterator(const HashTable<ValueT, TraitsT> &Map, uint32_t Index,
+  HashTableIterator(const HashTable<ValueT> &Map, uint32_t Index,
                     bool IsEnd)
       : Map(&Map), Index(Index), IsEnd(IsEnd) {}
 
 public:
-  HashTableIterator(const HashTable<ValueT, TraitsT> &Map) : Map(&Map) {
+  HashTableIterator(const HashTable<ValueT> &Map) : Map(&Map) {
     int I = Map.Present.find_first();
     if (I == -1) {
       Index = 0;
@@ -87,22 +87,14 @@ private:
   bool isEnd() const { return IsEnd; }
   uint32_t index() const { return Index; }
 
-  const HashTable<ValueT, TraitsT> *Map;
+  const HashTable<ValueT> *Map;
   uint32_t Index;
   bool IsEnd;
 };
 
-template <typename T> struct PdbHashTraits {};
-
-template <> struct PdbHashTraits<uint32_t> {
-  uint32_t hashLookupKey(uint32_t N) const { return N; }
-  uint32_t storageKeyToLookupKey(uint32_t N) const { return N; }
-  uint32_t lookupKeyToStorageKey(uint32_t N) { return N; }
-};
-
-template <typename ValueT, typename TraitsT = PdbHashTraits<ValueT>>
+template <typename ValueT>
 class HashTable {
-  using iterator = HashTableIterator<ValueT, TraitsT>;
+  using iterator = HashTableIterator<ValueT>;
   friend iterator;
 
   struct Header {
@@ -114,9 +106,7 @@ class HashTable {
 
 public:
   HashTable() { Buckets.resize(8); }
-
-  explicit HashTable(TraitsT Traits) : HashTable(8, std::move(Traits)) {}
-  HashTable(uint32_t Capacity, TraitsT Traits) : Traits(Traits) {
+  explicit HashTable(uint32_t Capacity) {
     Buckets.resize(Capacity);
   }
 
@@ -221,7 +211,8 @@ public:
 
   /// Find the entry whose key has the specified hash value, using the specified
   /// traits defining hash function and equality.
-  template <typename Key> iterator find_as(const Key &K) const {
+  template <typename Key, typename TraitsT>
+  iterator find_as(const Key &K, TraitsT &Traits) const {
     uint32_t H = Traits.hashLookupKey(K) % capacity();
     uint32_t I = H;
     Optional<uint32_t> FirstUnused;
@@ -252,12 +243,14 @@ public:
 
   /// Set the entry using a key type that the specified Traits can convert
   /// from a real key to an internal key.
-  template <typename Key> bool set_as(const Key &K, ValueT V) {
-    return set_as_internal(K, std::move(V), None);
+  template <typename Key, typename TraitsT>
+  bool set_as(const Key &K, ValueT V, TraitsT &Traits) {
+    return set_as_internal(K, std::move(V), Traits, None);
   }
 
-  template <typename Key> ValueT get(const Key &K) const {
-    auto Iter = find_as(K);
+  template <typename Key, typename TraitsT>
+  ValueT get(const Key &K, TraitsT &Traits) const {
+    auto Iter = find_as(K, Traits);
     assert(Iter != end());
     return (*Iter).second;
   }
@@ -266,7 +259,6 @@ protected:
   bool isPresent(uint32_t K) const { return Present.test(K); }
   bool isDeleted(uint32_t K) const { return Deleted.test(K); }
 
-  TraitsT Traits;
   BucketList Buckets;
   mutable SparseBitVector<> Present;
   mutable SparseBitVector<> Deleted;
@@ -274,9 +266,10 @@ protected:
 private:
   /// Set the entry using a key type that the specified Traits can convert
   /// from a real key to an internal key.
-  template <typename Key>
-  bool set_as_internal(const Key &K, ValueT V, Optional<uint32_t> InternalKey) {
-    auto Entry = find_as(K);
+  template <typename Key, typename TraitsT>
+  bool set_as_internal(const Key &K, ValueT V, TraitsT &Traits,
+                       Optional<uint32_t> InternalKey) {
+    auto Entry = find_as(K, Traits);
     if (Entry != end()) {
       assert(isPresent(Entry.index()));
       assert(Traits.storageKeyToLookupKey(Buckets[Entry.index()].first) == K);
@@ -293,15 +286,16 @@ private:
     Present.set(Entry.index());
     Deleted.reset(Entry.index());
 
-    grow();
+    grow(Traits);
 
-    assert((find_as(K)) != end());
+    assert((find_as(K, Traits)) != end());
     return true;
   }
 
   static uint32_t maxLoad(uint32_t capacity) { return capacity * 2 / 3 + 1; }
 
-  void grow() {
+  template <typename TraitsT>
+  void grow(TraitsT &Traits) {
     uint32_t S = size();
     uint32_t MaxLoad = maxLoad(capacity());
     if (S < maxLoad(capacity()))
@@ -313,10 +307,11 @@ private:
     // Growing requires rebuilding the table and re-hashing every item.  Make a
     // copy with a larger capacity, insert everything into the copy, then swap
     // it in.
-    HashTable NewMap(NewCapacity, Traits);
+    HashTable NewMap(NewCapacity);
     for (auto I : Present) {
       auto LookupKey = Traits.storageKeyToLookupKey(Buckets[I].first);
-      NewMap.set_as_internal(LookupKey, Buckets[I].second, Buckets[I].first);
+      NewMap.set_as_internal(LookupKey, Buckets[I].second, Traits,
+                             Buckets[I].first);
     }
 
     Buckets.swap(NewMap.Buckets);
diff --git a/llvm/include/llvm/DebugInfo/PDB/Native/NamedStreamMap.h b/llvm/include/llvm/DebugInfo/PDB/Native/NamedStreamMap.h
index c49d796356c..1df059ffa9f 100644
--- a/llvm/include/llvm/DebugInfo/PDB/Native/NamedStreamMap.h
+++ b/llvm/include/llvm/DebugInfo/PDB/Native/NamedStreamMap.h
@@ -59,7 +59,7 @@ private:
   NamedStreamMapTraits HashTraits;
   /// Closed hash table from Offset -> StreamNumber, where Offset is the offset
   /// of the stream name in NamesBuffer.
-  HashTable<support::ulittle32_t, NamedStreamMapTraits> OffsetIndexMap;
+  HashTable<support::ulittle32_t> OffsetIndexMap;
 
   /// Buffer of string data.
   std::vector<char> NamesBuffer;
diff --git a/llvm/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h b/llvm/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h
index 72000bdc011..2abaa5f4cdc 100644
--- a/llvm/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h
+++ b/llvm/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h
@@ -97,7 +97,7 @@ private:
 
   PDBStringTableBuilder Strings;
   StringTableHashTraits InjectedSourceHashTraits;
-  HashTable<SrcHeaderBlockEntry, StringTableHashTraits> InjectedSourceTable;
+  HashTable<SrcHeaderBlockEntry> InjectedSourceTable;
 
   SmallVector<InjectedSourceDescriptor, 2> InjectedSources;
 
diff --git a/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp b/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp
index 1c044e0c265..4a88391494c 100644
--- a/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp
@@ -46,8 +46,7 @@ uint32_t NamedStreamMapTraits::lookupKeyToStorageKey(StringRef S) {
   return NS->appendStringData(S);
 }
 
-NamedStreamMap::NamedStreamMap()
-    : HashTraits(*this), OffsetIndexMap(1, HashTraits) {}
+NamedStreamMap::NamedStreamMap() : HashTraits(*this), OffsetIndexMap(1) {}
 
 Error NamedStreamMap::load(BinaryStreamReader &Stream) {
   uint32_t StringBufferSize;
@@ -99,7 +98,7 @@ uint32_t NamedStreamMap::hashString(uint32_t Offset) const {
 }
 
 bool NamedStreamMap::get(StringRef Stream, uint32_t &StreamNo) const {
-  auto Iter = OffsetIndexMap.find_as(Stream);
+  auto Iter = OffsetIndexMap.find_as(Stream, HashTraits);
   if (Iter == OffsetIndexMap.end())
     return false;
   StreamNo = (*Iter).second;
@@ -123,5 +122,5 @@ uint32_t NamedStreamMap::appendStringData(StringRef S) {
 }
 
 void NamedStreamMap::set(StringRef Stream, uint32_t StreamNo) {
-  OffsetIndexMap.set_as(Stream, support::ulittle32_t(StreamNo));
+  OffsetIndexMap.set_as(Stream, support::ulittle32_t(StreamNo), HashTraits);
 }
diff --git a/llvm/lib/DebugInfo/PDB/Native/PDBFileBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/PDBFileBuilder.cpp
index 84eb4fbbfa6..8f5a048ea4b 100644
--- a/llvm/lib/DebugInfo/PDB/Native/PDBFileBuilder.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/PDBFileBuilder.cpp
@@ -34,7 +34,7 @@ using namespace llvm::support;
 
 PDBFileBuilder::PDBFileBuilder(BumpPtrAllocator &Allocator)
     : Allocator(Allocator), InjectedSourceHashTraits(Strings),
-      InjectedSourceTable(2, InjectedSourceHashTraits) {}
+      InjectedSourceTable(2) {}
 
 PDBFileBuilder::~PDBFileBuilder() {}
 
@@ -189,7 +189,8 @@ Error PDBFileBuilder::finalizeMsfLayout() {
           static_cast<uint32_t>(PdbRaw_SrcHeaderBlockVer::SrcVerOne);
       Entry.CRC = CRC.getCRC();
       StringRef VName = getStringTableBuilder().getStringForId(IS.VNameIndex);
-      InjectedSourceTable.set_as(VName, std::move(Entry));
+      InjectedSourceTable.set_as(VName, std::move(Entry),
+                                 InjectedSourceHashTraits);
     }
 
     uint32_t SrcHeaderBlockSize =
diff --git a/llvm/unittests/DebugInfo/PDB/HashTableTest.cpp b/llvm/unittests/DebugInfo/PDB/HashTableTest.cpp
index 4ebde45ff9a..5f0695bc4cb 100644
--- a/llvm/unittests/DebugInfo/PDB/HashTableTest.cpp
+++ b/llvm/unittests/DebugInfo/PDB/HashTableTest.cpp
@@ -27,27 +27,35 @@ using namespace llvm::support;
 
 namespace {
 
-class HashTableInternals : public HashTable<uint32_t> {
+struct IdentityHashTraits {
+  uint32_t hashLookupKey(uint32_t N) const { return N; }
+  uint32_t storageKeyToLookupKey(uint32_t N) const { return N; }
+  uint32_t lookupKeyToStorageKey(uint32_t N) { return N; }
+};
+
+template <class T = uint32_t>
+class HashTableInternals : public HashTable<T> {
 public:
-  using HashTable::Buckets;
-  using HashTable::Present;
-  using HashTable::Deleted;
+  using HashTable<T>::Buckets;
+  using HashTable<T>::Present;
+  using HashTable<T>::Deleted;
 };
 }
 
 TEST(HashTableTest, TestSimple) {
-  HashTableInternals Table;
+  HashTableInternals<> Table;
   EXPECT_EQ(0u, Table.size());
   EXPECT_GT(Table.capacity(), 0u);
 
-  Table.set_as(3u, 7);
+  IdentityHashTraits Traits;
+  Table.set_as(3u, 7, Traits);
   EXPECT_EQ(1u, Table.size());
-  ASSERT_NE(Table.end(), Table.find_as(3u));
-  EXPECT_EQ(7u, Table.get(3u));
+  ASSERT_NE(Table.end(), Table.find_as(3u, Traits));
+  EXPECT_EQ(7u, Table.get(3u, Traits));
 }
 
 TEST(HashTableTest, TestCollision) {
-  HashTableInternals Table;
+  HashTableInternals<> Table;
   EXPECT_EQ(0u, Table.size());
   EXPECT_GT(Table.capacity(), 0u);
 
@@ -57,33 +65,35 @@ TEST(HashTableTest, TestCollision) {
   uint32_t N1 = Table.capacity() + 1;
   uint32_t N2 = 2 * N1;
 
-  Table.set_as(N1, 7);
-  Table.set_as(N2, 12);
+  IdentityHashTraits Traits;
+  Table.set_as(N1, 7, Traits);
+  Table.set_as(N2, 12, Traits);
   EXPECT_EQ(2u, Table.size());
-  ASSERT_NE(Table.end(), Table.find_as(N1));
-  ASSERT_NE(Table.end(), Table.find_as(N2));
+  ASSERT_NE(Table.end(), Table.find_as(N1, Traits));
+  ASSERT_NE(Table.end(), Table.find_as(N2, Traits));
 
-  EXPECT_EQ(7u, Table.get(N1));
-  EXPECT_EQ(12u, Table.get(N2));
+  EXPECT_EQ(7u, Table.get(N1, Traits));
+  EXPECT_EQ(12u, Table.get(N2, Traits));
 }
 
 TEST(HashTableTest, TestRemove) {
-  HashTableInternals Table;
+  HashTableInternals<> Table;
   EXPECT_EQ(0u, Table.size());
   EXPECT_GT(Table.capacity(), 0u);
 
-  Table.set_as(1u, 2);
-  Table.set_as(3u, 4);
+  IdentityHashTraits Traits;
+  Table.set_as(1u, 2, Traits);
+  Table.set_as(3u, 4, Traits);
   EXPECT_EQ(2u, Table.size());
-  ASSERT_NE(Table.end(), Table.find_as(1u));
-  ASSERT_NE(Table.end(), Table.find_as(3u));
+  ASSERT_NE(Table.end(), Table.find_as(1u, Traits));
+  ASSERT_NE(Table.end(), Table.find_as(3u, Traits));
 
-  EXPECT_EQ(2u, Table.get(1u));
-  EXPECT_EQ(4u, Table.get(3u));
+  EXPECT_EQ(2u, Table.get(1u, Traits));
+  EXPECT_EQ(4u, Table.get(3u, Traits));
 }
 
 TEST(HashTableTest, TestCollisionAfterMultipleProbes) {
-  HashTableInternals Table;
+  HashTableInternals<> Table;
   EXPECT_EQ(0u, Table.size());
   EXPECT_GT(Table.capacity(), 0u);
 
@@ -94,17 +104,18 @@ TEST(HashTableTest, TestCollisionAfterMultipleProbes) {
   uint32_t N2 = N1 + 1;
   uint32_t N3 = 2 * N1;
 
-  Table.set_as(N1, 7);
-  Table.set_as(N2, 11);
-  Table.set_as(N3, 13);
+  IdentityHashTraits Traits;
+  Table.set_as(N1, 7, Traits);
+  Table.set_as(N2, 11, Traits);
+  Table.set_as(N3, 13, Traits);
   EXPECT_EQ(3u, Table.size());
-  ASSERT_NE(Table.end(), Table.find_as(N1));
-  ASSERT_NE(Table.end(), Table.find_as(N2));
-  ASSERT_NE(Table.end(), Table.find_as(N3));
+  ASSERT_NE(Table.end(), Table.find_as(N1, Traits));
+  ASSERT_NE(Table.end(), Table.find_as(N2, Traits));
+  ASSERT_NE(Table.end(), Table.find_as(N3, Traits));
 
-  EXPECT_EQ(7u, Table.get(N1));
-  EXPECT_EQ(11u, Table.get(N2));
-  EXPECT_EQ(13u, Table.get(N3));
+  EXPECT_EQ(7u, Table.get(N1, Traits));
+  EXPECT_EQ(11u, Table.get(N2, Traits));
+  EXPECT_EQ(13u, Table.get(N3, Traits));
 }
 
 TEST(HashTableTest, Grow) {
@@ -112,24 +123,26 @@ TEST(HashTableTest, Grow) {
   // guaranteed to trigger a grow.  Then verify that the size is the same, the
   // capacity is larger, and all the original items are still in the table.
 
-  HashTableInternals Table;
+  HashTableInternals<> Table;
+  IdentityHashTraits Traits;
   uint32_t OldCapacity = Table.capacity();
   for (uint32_t I = 0; I < OldCapacity; ++I) {
-    Table.set_as(OldCapacity + I * 2 + 1, I * 2 + 3);
+    Table.set_as(OldCapacity + I * 2 + 1, I * 2 + 3, Traits);
   }
   EXPECT_EQ(OldCapacity, Table.size());
   EXPECT_GT(Table.capacity(), OldCapacity);
   for (uint32_t I = 0; I < OldCapacity; ++I) {
-    ASSERT_NE(Table.end(), Table.find_as(OldCapacity + I * 2 + 1));
-    EXPECT_EQ(I * 2 + 3, Table.get(OldCapacity + I * 2 + 1));
+    ASSERT_NE(Table.end(), Table.find_as(OldCapacity + I * 2 + 1, Traits));
+    EXPECT_EQ(I * 2 + 3, Table.get(OldCapacity + I * 2 + 1, Traits));
   }
 }
 
 TEST(HashTableTest, Serialization) {
-  HashTableInternals Table;
+  HashTableInternals<> Table;
+  IdentityHashTraits Traits;
   uint32_t Cap = Table.capacity();
   for (uint32_t I = 0; I < Cap; ++I) {
-    Table.set_as(Cap + I * 2 + 1, I * 2 + 3);
+    Table.set_as(Cap + I * 2 + 1, I * 2 + 3, Traits);
   }
 
   std::vector<uint8_t> Buffer(Table.calculateSerializedLength());
@@ -139,7 +152,7 @@ TEST(HashTableTest, Serialization) {
   // We should have written precisely the number of bytes we calculated earlier.
   EXPECT_EQ(Buffer.size(), Writer.getOffset());
 
-  HashTableInternals Table2;
+  HashTableInternals<> Table2;
   BinaryStreamReader Reader(Stream);
   EXPECT_THAT_ERROR(Table2.load(Reader), Succeeded());
   // We should have read precisely the number of bytes we calculated earlier.
@@ -192,20 +205,19 @@ TEST(HashTableTest, NamedStreamMap) {
   } while (std::next_permutation(Streams.begin(), Streams.end()));
 }
 
-namespace {
 struct FooBar {
   uint32_t X;
   uint32_t Y;
-};
 
-} // namespace
+  bool operator==(const FooBar &RHS) const {
+    return X == RHS.X && Y == RHS.Y;
+  }
+};
 
-namespace llvm {
-namespace pdb {
-template <> struct PdbHashTraits<FooBar> {
+struct FooBarHashTraits {
   std::vector<char> Buffer;
 
-  PdbHashTraits() { Buffer.push_back(0); }
+  FooBarHashTraits() { Buffer.push_back(0); }
 
   uint32_t hashLookupKey(StringRef S) const {
     return llvm::pdb::hashStringV1(S);
@@ -225,17 +237,16 @@ template <> struct PdbHashTraits<FooBar> {
     return N;
   }
 };
-} // namespace pdb
-} // namespace llvm
 
 TEST(HashTableTest, NonTrivialValueType) {
-  HashTable<FooBar> Table;
+  HashTableInternals<FooBar> Table;
+  FooBarHashTraits Traits;
   uint32_t Cap = Table.capacity();
   for (uint32_t I = 0; I < Cap; ++I) {
     FooBar F;
     F.X = I;
     F.Y = I + 1;
-    Table.set_as(utostr(I), F);
+    Table.set_as(utostr(I), F, Traits);
   }
 
   std::vector<uint8_t> Buffer(Table.calculateSerializedLength());
@@ -245,7 +256,7 @@ TEST(HashTableTest, NonTrivialValueType) {
   // We should have written precisely the number of bytes we calculated earlier.
   EXPECT_EQ(Buffer.size(), Writer.getOffset());
 
-  HashTable<FooBar> Table2;
+  HashTableInternals<FooBar> Table2;
   BinaryStreamReader Reader(Stream);
   EXPECT_THAT_ERROR(Table2.load(Reader), Succeeded());
   // We should have read precisely the number of bytes we calculated earlier.
@@ -253,7 +264,7 @@ TEST(HashTableTest, NonTrivialValueType) {
 
   EXPECT_EQ(Table.size(), Table2.size());
   EXPECT_EQ(Table.capacity(), Table2.capacity());
-  // EXPECT_EQ(Table.Buckets, Table2.Buckets);
-  // EXPECT_EQ(Table.Present, Table2.Present);
-  // EXPECT_EQ(Table.Deleted, Table2.Deleted);
+  EXPECT_EQ(Table.Buckets, Table2.Buckets);
+  EXPECT_EQ(Table.Present, Table2.Present);
+  EXPECT_EQ(Table.Deleted, Table2.Deleted);
 }