Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/Support/OnDiskHashTable.h b/linux-x64/clang/include/llvm/Support/OnDiskHashTable.h
new file mode 100644
index 0000000..3ef004b
--- /dev/null
+++ b/linux-x64/clang/include/llvm/Support/OnDiskHashTable.h
@@ -0,0 +1,616 @@
+//===--- OnDiskHashTable.h - On-Disk Hash Table Implementation --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Defines facilities for reading and writing on-disk hash tables.
+///
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_SUPPORT_ONDISKHASHTABLE_H
+#define LLVM_SUPPORT_ONDISKHASHTABLE_H
+
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/EndianStream.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cassert>
+#include <cstdlib>
+
+namespace llvm {
+
+/// \brief Generates an on disk hash table.
+///
+/// This needs an \c Info that handles storing values into the hash table's
+/// payload and computes the hash for a given key. This should provide the
+/// following interface:
+///
+/// \code
+/// class ExampleInfo {
+/// public:
+///   typedef ExampleKey key_type;   // Must be copy constructible
+///   typedef ExampleKey &key_type_ref;
+///   typedef ExampleData data_type; // Must be copy constructible
+///   typedef ExampleData &data_type_ref;
+///   typedef uint32_t hash_value_type; // The type the hash function returns.
+///   typedef uint32_t offset_type; // The type for offsets into the table.
+///
+///   /// Calculate the hash for Key
+///   static hash_value_type ComputeHash(key_type_ref Key);
+///   /// Return the lengths, in bytes, of the given Key/Data pair.
+///   static std::pair<offset_type, offset_type>
+///   EmitKeyDataLength(raw_ostream &Out, key_type_ref Key, data_type_ref Data);
+///   /// Write Key to Out.  KeyLen is the length from EmitKeyDataLength.
+///   static void EmitKey(raw_ostream &Out, key_type_ref Key,
+///                       offset_type KeyLen);
+///   /// Write Data to Out.  DataLen is the length from EmitKeyDataLength.
+///   static void EmitData(raw_ostream &Out, key_type_ref Key,
+///                        data_type_ref Data, offset_type DataLen);
+///   /// Determine if two keys are equal. Optional, only needed by contains.
+///   static bool EqualKey(key_type_ref Key1, key_type_ref Key2);
+/// };
+/// \endcode
+template <typename Info> class OnDiskChainedHashTableGenerator {
+  /// \brief A single item in the hash table.
+  class Item {
+  public:
+    typename Info::key_type Key;
+    typename Info::data_type Data;
+    Item *Next;
+    const typename Info::hash_value_type Hash;
+
+    Item(typename Info::key_type_ref Key, typename Info::data_type_ref Data,
+         Info &InfoObj)
+        : Key(Key), Data(Data), Next(nullptr), Hash(InfoObj.ComputeHash(Key)) {}
+  };
+
+  typedef typename Info::offset_type offset_type;
+  offset_type NumBuckets;
+  offset_type NumEntries;
+  llvm::SpecificBumpPtrAllocator<Item> BA;
+
+  /// \brief A linked list of values in a particular hash bucket.
+  struct Bucket {
+    offset_type Off;
+    unsigned Length;
+    Item *Head;
+  };
+
+  Bucket *Buckets;
+
+private:
+  /// \brief Insert an item into the appropriate hash bucket.
+  void insert(Bucket *Buckets, size_t Size, Item *E) {
+    Bucket &B = Buckets[E->Hash & (Size - 1)];
+    E->Next = B.Head;
+    ++B.Length;
+    B.Head = E;
+  }
+
+  /// \brief Resize the hash table, moving the old entries into the new buckets.
+  void resize(size_t NewSize) {
+    Bucket *NewBuckets = static_cast<Bucket *>(
+        safe_calloc(NewSize, sizeof(Bucket)));
+    // Populate NewBuckets with the old entries.
+    for (size_t I = 0; I < NumBuckets; ++I)
+      for (Item *E = Buckets[I].Head; E;) {
+        Item *N = E->Next;
+        E->Next = nullptr;
+        insert(NewBuckets, NewSize, E);
+        E = N;
+      }
+
+    free(Buckets);
+    NumBuckets = NewSize;
+    Buckets = NewBuckets;
+  }
+
+public:
+  /// \brief Insert an entry into the table.
+  void insert(typename Info::key_type_ref Key,
+              typename Info::data_type_ref Data) {
+    Info InfoObj;
+    insert(Key, Data, InfoObj);
+  }
+
+  /// \brief Insert an entry into the table.
+  ///
+  /// Uses the provided Info instead of a stack allocated one.
+  void insert(typename Info::key_type_ref Key,
+              typename Info::data_type_ref Data, Info &InfoObj) {
+    ++NumEntries;
+    if (4 * NumEntries >= 3 * NumBuckets)
+      resize(NumBuckets * 2);
+    insert(Buckets, NumBuckets, new (BA.Allocate()) Item(Key, Data, InfoObj));
+  }
+
+  /// \brief Determine whether an entry has been inserted.
+  bool contains(typename Info::key_type_ref Key, Info &InfoObj) {
+    unsigned Hash = InfoObj.ComputeHash(Key);
+    for (Item *I = Buckets[Hash & (NumBuckets - 1)].Head; I; I = I->Next)
+      if (I->Hash == Hash && InfoObj.EqualKey(I->Key, Key))
+        return true;
+    return false;
+  }
+
+  /// \brief Emit the table to Out, which must not be at offset 0.
+  offset_type Emit(raw_ostream &Out) {
+    Info InfoObj;
+    return Emit(Out, InfoObj);
+  }
+
+  /// \brief Emit the table to Out, which must not be at offset 0.
+  ///
+  /// Uses the provided Info instead of a stack allocated one.
+  offset_type Emit(raw_ostream &Out, Info &InfoObj) {
+    using namespace llvm::support;
+    endian::Writer<little> LE(Out);
+
+    // Now we're done adding entries, resize the bucket list if it's
+    // significantly too large. (This only happens if the number of
+    // entries is small and we're within our initial allocation of
+    // 64 buckets.) We aim for an occupancy ratio in [3/8, 3/4).
+    //
+    // As a special case, if there are two or fewer entries, just
+    // form a single bucket. A linear scan is fine in that case, and
+    // this is very common in C++ class lookup tables. This also
+    // guarantees we produce at least one bucket for an empty table.
+    //
+    // FIXME: Try computing a perfect hash function at this point.
+    unsigned TargetNumBuckets =
+        NumEntries <= 2 ? 1 : NextPowerOf2(NumEntries * 4 / 3);
+    if (TargetNumBuckets != NumBuckets)
+      resize(TargetNumBuckets);
+
+    // Emit the payload of the table.
+    for (offset_type I = 0; I < NumBuckets; ++I) {
+      Bucket &B = Buckets[I];
+      if (!B.Head)
+        continue;
+
+      // Store the offset for the data of this bucket.
+      B.Off = Out.tell();
+      assert(B.Off && "Cannot write a bucket at offset 0. Please add padding.");
+
+      // Write out the number of items in the bucket.
+      LE.write<uint16_t>(B.Length);
+      assert(B.Length != 0 && "Bucket has a head but zero length?");
+
+      // Write out the entries in the bucket.
+      for (Item *I = B.Head; I; I = I->Next) {
+        LE.write<typename Info::hash_value_type>(I->Hash);
+        const std::pair<offset_type, offset_type> &Len =
+            InfoObj.EmitKeyDataLength(Out, I->Key, I->Data);
+#ifdef NDEBUG
+        InfoObj.EmitKey(Out, I->Key, Len.first);
+        InfoObj.EmitData(Out, I->Key, I->Data, Len.second);
+#else
+        // In asserts mode, check that the users length matches the data they
+        // wrote.
+        uint64_t KeyStart = Out.tell();
+        InfoObj.EmitKey(Out, I->Key, Len.first);
+        uint64_t DataStart = Out.tell();
+        InfoObj.EmitData(Out, I->Key, I->Data, Len.second);
+        uint64_t End = Out.tell();
+        assert(offset_type(DataStart - KeyStart) == Len.first &&
+               "key length does not match bytes written");
+        assert(offset_type(End - DataStart) == Len.second &&
+               "data length does not match bytes written");
+#endif
+      }
+    }
+
+    // Pad with zeros so that we can start the hashtable at an aligned address.
+    offset_type TableOff = Out.tell();
+    uint64_t N = llvm::OffsetToAlignment(TableOff, alignof(offset_type));
+    TableOff += N;
+    while (N--)
+      LE.write<uint8_t>(0);
+
+    // Emit the hashtable itself.
+    LE.write<offset_type>(NumBuckets);
+    LE.write<offset_type>(NumEntries);
+    for (offset_type I = 0; I < NumBuckets; ++I)
+      LE.write<offset_type>(Buckets[I].Off);
+
+    return TableOff;
+  }
+
+  OnDiskChainedHashTableGenerator() {
+    NumEntries = 0;
+    NumBuckets = 64;
+    // Note that we do not need to run the constructors of the individual
+    // Bucket objects since 'calloc' returns bytes that are all 0.
+    Buckets = static_cast<Bucket *>(safe_calloc(NumBuckets, sizeof(Bucket)));
+  }
+
+  ~OnDiskChainedHashTableGenerator() { std::free(Buckets); }
+};
+
+/// \brief Provides lookup on an on disk hash table.
+///
+/// This needs an \c Info that handles reading values from the hash table's
+/// payload and computes the hash for a given key. This should provide the
+/// following interface:
+///
+/// \code
+/// class ExampleLookupInfo {
+/// public:
+///   typedef ExampleData data_type;
+///   typedef ExampleInternalKey internal_key_type; // The stored key type.
+///   typedef ExampleKey external_key_type; // The type to pass to find().
+///   typedef uint32_t hash_value_type; // The type the hash function returns.
+///   typedef uint32_t offset_type; // The type for offsets into the table.
+///
+///   /// Compare two keys for equality.
+///   static bool EqualKey(internal_key_type &Key1, internal_key_type &Key2);
+///   /// Calculate the hash for the given key.
+///   static hash_value_type ComputeHash(internal_key_type &IKey);
+///   /// Translate from the semantic type of a key in the hash table to the
+///   /// type that is actually stored and used for hashing and comparisons.
+///   /// The internal and external types are often the same, in which case this
+///   /// can simply return the passed in value.
+///   static const internal_key_type &GetInternalKey(external_key_type &EKey);
+///   /// Read the key and data length from Buffer, leaving it pointing at the
+///   /// following byte.
+///   static std::pair<offset_type, offset_type>
+///   ReadKeyDataLength(const unsigned char *&Buffer);
+///   /// Read the key from Buffer, given the KeyLen as reported from
+///   /// ReadKeyDataLength.
+///   const internal_key_type &ReadKey(const unsigned char *Buffer,
+///                                    offset_type KeyLen);
+///   /// Read the data for Key from Buffer, given the DataLen as reported from
+///   /// ReadKeyDataLength.
+///   data_type ReadData(StringRef Key, const unsigned char *Buffer,
+///                      offset_type DataLen);
+/// };
+/// \endcode
+template <typename Info> class OnDiskChainedHashTable {
+  const typename Info::offset_type NumBuckets;
+  const typename Info::offset_type NumEntries;
+  const unsigned char *const Buckets;
+  const unsigned char *const Base;
+  Info InfoObj;
+
+public:
+  typedef Info InfoType;
+  typedef typename Info::internal_key_type internal_key_type;
+  typedef typename Info::external_key_type external_key_type;
+  typedef typename Info::data_type data_type;
+  typedef typename Info::hash_value_type hash_value_type;
+  typedef typename Info::offset_type offset_type;
+
+  OnDiskChainedHashTable(offset_type NumBuckets, offset_type NumEntries,
+                         const unsigned char *Buckets,
+                         const unsigned char *Base,
+                         const Info &InfoObj = Info())
+      : NumBuckets(NumBuckets), NumEntries(NumEntries), Buckets(Buckets),
+        Base(Base), InfoObj(InfoObj) {
+    assert((reinterpret_cast<uintptr_t>(Buckets) & 0x3) == 0 &&
+           "'buckets' must have a 4-byte alignment");
+  }
+
+  /// Read the number of buckets and the number of entries from a hash table
+  /// produced by OnDiskHashTableGenerator::Emit, and advance the Buckets
+  /// pointer past them.
+  static std::pair<offset_type, offset_type>
+  readNumBucketsAndEntries(const unsigned char *&Buckets) {
+    assert((reinterpret_cast<uintptr_t>(Buckets) & 0x3) == 0 &&
+           "buckets should be 4-byte aligned.");
+    using namespace llvm::support;
+    offset_type NumBuckets =
+        endian::readNext<offset_type, little, aligned>(Buckets);
+    offset_type NumEntries =
+        endian::readNext<offset_type, little, aligned>(Buckets);
+    return std::make_pair(NumBuckets, NumEntries);
+  }
+
+  offset_type getNumBuckets() const { return NumBuckets; }
+  offset_type getNumEntries() const { return NumEntries; }
+  const unsigned char *getBase() const { return Base; }
+  const unsigned char *getBuckets() const { return Buckets; }
+
+  bool isEmpty() const { return NumEntries == 0; }
+
+  class iterator {
+    internal_key_type Key;
+    const unsigned char *const Data;
+    const offset_type Len;
+    Info *InfoObj;
+
+  public:
+    iterator() : Key(), Data(nullptr), Len(0), InfoObj(nullptr) {}
+    iterator(const internal_key_type K, const unsigned char *D, offset_type L,
+             Info *InfoObj)
+        : Key(K), Data(D), Len(L), InfoObj(InfoObj) {}
+
+    data_type operator*() const { return InfoObj->ReadData(Key, Data, Len); }
+
+    const unsigned char *getDataPtr() const { return Data; }
+    offset_type getDataLen() const { return Len; }
+
+    bool operator==(const iterator &X) const { return X.Data == Data; }
+    bool operator!=(const iterator &X) const { return X.Data != Data; }
+  };
+
+  /// \brief Look up the stored data for a particular key.
+  iterator find(const external_key_type &EKey, Info *InfoPtr = nullptr) {
+    const internal_key_type &IKey = InfoObj.GetInternalKey(EKey);
+    hash_value_type KeyHash = InfoObj.ComputeHash(IKey);
+    return find_hashed(IKey, KeyHash, InfoPtr);
+  }
+
+  /// \brief Look up the stored data for a particular key with a known hash.
+  iterator find_hashed(const internal_key_type &IKey, hash_value_type KeyHash,
+                       Info *InfoPtr = nullptr) {
+    using namespace llvm::support;
+
+    if (!InfoPtr)
+      InfoPtr = &InfoObj;
+
+    // Each bucket is just an offset into the hash table file.
+    offset_type Idx = KeyHash & (NumBuckets - 1);
+    const unsigned char *Bucket = Buckets + sizeof(offset_type) * Idx;
+
+    offset_type Offset = endian::readNext<offset_type, little, aligned>(Bucket);
+    if (Offset == 0)
+      return iterator(); // Empty bucket.
+    const unsigned char *Items = Base + Offset;
+
+    // 'Items' starts with a 16-bit unsigned integer representing the
+    // number of items in this bucket.
+    unsigned Len = endian::readNext<uint16_t, little, unaligned>(Items);
+
+    for (unsigned i = 0; i < Len; ++i) {
+      // Read the hash.
+      hash_value_type ItemHash =
+          endian::readNext<hash_value_type, little, unaligned>(Items);
+
+      // Determine the length of the key and the data.
+      const std::pair<offset_type, offset_type> &L =
+          Info::ReadKeyDataLength(Items);
+      offset_type ItemLen = L.first + L.second;
+
+      // Compare the hashes.  If they are not the same, skip the entry entirely.
+      if (ItemHash != KeyHash) {
+        Items += ItemLen;
+        continue;
+      }
+
+      // Read the key.
+      const internal_key_type &X =
+          InfoPtr->ReadKey((const unsigned char *const)Items, L.first);
+
+      // If the key doesn't match just skip reading the value.
+      if (!InfoPtr->EqualKey(X, IKey)) {
+        Items += ItemLen;
+        continue;
+      }
+
+      // The key matches!
+      return iterator(X, Items + L.first, L.second, InfoPtr);
+    }
+
+    return iterator();
+  }
+
+  iterator end() const { return iterator(); }
+
+  Info &getInfoObj() { return InfoObj; }
+
+  /// \brief Create the hash table.
+  ///
+  /// \param Buckets is the beginning of the hash table itself, which follows
+  /// the payload of entire structure. This is the value returned by
+  /// OnDiskHashTableGenerator::Emit.
+  ///
+  /// \param Base is the point from which all offsets into the structure are
+  /// based. This is offset 0 in the stream that was used when Emitting the
+  /// table.
+  static OnDiskChainedHashTable *Create(const unsigned char *Buckets,
+                                        const unsigned char *const Base,
+                                        const Info &InfoObj = Info()) {
+    assert(Buckets > Base);
+    auto NumBucketsAndEntries = readNumBucketsAndEntries(Buckets);
+    return new OnDiskChainedHashTable<Info>(NumBucketsAndEntries.first,
+                                            NumBucketsAndEntries.second,
+                                            Buckets, Base, InfoObj);
+  }
+};
+
+/// \brief Provides lookup and iteration over an on disk hash table.
+///
+/// \copydetails llvm::OnDiskChainedHashTable
+template <typename Info>
+class OnDiskIterableChainedHashTable : public OnDiskChainedHashTable<Info> {
+  const unsigned char *Payload;
+
+public:
+  typedef OnDiskChainedHashTable<Info>          base_type;
+  typedef typename base_type::internal_key_type internal_key_type;
+  typedef typename base_type::external_key_type external_key_type;
+  typedef typename base_type::data_type         data_type;
+  typedef typename base_type::hash_value_type   hash_value_type;
+  typedef typename base_type::offset_type       offset_type;
+
+private:
+  /// \brief Iterates over all of the keys in the table.
+  class iterator_base {
+    const unsigned char *Ptr;
+    offset_type NumItemsInBucketLeft;
+    offset_type NumEntriesLeft;
+
+  public:
+    typedef external_key_type value_type;
+
+    iterator_base(const unsigned char *const Ptr, offset_type NumEntries)
+        : Ptr(Ptr), NumItemsInBucketLeft(0), NumEntriesLeft(NumEntries) {}
+    iterator_base()
+        : Ptr(nullptr), NumItemsInBucketLeft(0), NumEntriesLeft(0) {}
+
+    friend bool operator==(const iterator_base &X, const iterator_base &Y) {
+      return X.NumEntriesLeft == Y.NumEntriesLeft;
+    }
+    friend bool operator!=(const iterator_base &X, const iterator_base &Y) {
+      return X.NumEntriesLeft != Y.NumEntriesLeft;
+    }
+
+    /// Move to the next item.
+    void advance() {
+      using namespace llvm::support;
+      if (!NumItemsInBucketLeft) {
+        // 'Items' starts with a 16-bit unsigned integer representing the
+        // number of items in this bucket.
+        NumItemsInBucketLeft =
+            endian::readNext<uint16_t, little, unaligned>(Ptr);
+      }
+      Ptr += sizeof(hash_value_type); // Skip the hash.
+      // Determine the length of the key and the data.
+      const std::pair<offset_type, offset_type> &L =
+          Info::ReadKeyDataLength(Ptr);
+      Ptr += L.first + L.second;
+      assert(NumItemsInBucketLeft);
+      --NumItemsInBucketLeft;
+      assert(NumEntriesLeft);
+      --NumEntriesLeft;
+    }
+
+    /// Get the start of the item as written by the trait (after the hash and
+    /// immediately before the key and value length).
+    const unsigned char *getItem() const {
+      return Ptr + (NumItemsInBucketLeft ? 0 : 2) + sizeof(hash_value_type);
+    }
+  };
+
+public:
+  OnDiskIterableChainedHashTable(offset_type NumBuckets, offset_type NumEntries,
+                                 const unsigned char *Buckets,
+                                 const unsigned char *Payload,
+                                 const unsigned char *Base,
+                                 const Info &InfoObj = Info())
+      : base_type(NumBuckets, NumEntries, Buckets, Base, InfoObj),
+        Payload(Payload) {}
+
+  /// \brief Iterates over all of the keys in the table.
+  class key_iterator : public iterator_base {
+    Info *InfoObj;
+
+  public:
+    typedef external_key_type value_type;
+
+    key_iterator(const unsigned char *const Ptr, offset_type NumEntries,
+                 Info *InfoObj)
+        : iterator_base(Ptr, NumEntries), InfoObj(InfoObj) {}
+    key_iterator() : iterator_base(), InfoObj() {}
+
+    key_iterator &operator++() {
+      this->advance();
+      return *this;
+    }
+    key_iterator operator++(int) { // Postincrement
+      key_iterator tmp = *this;
+      ++*this;
+      return tmp;
+    }
+
+    internal_key_type getInternalKey() const {
+      auto *LocalPtr = this->getItem();
+
+      // Determine the length of the key and the data.
+      auto L = Info::ReadKeyDataLength(LocalPtr);
+
+      // Read the key.
+      return InfoObj->ReadKey(LocalPtr, L.first);
+    }
+
+    value_type operator*() const {
+      return InfoObj->GetExternalKey(getInternalKey());
+    }
+  };
+
+  key_iterator key_begin() {
+    return key_iterator(Payload, this->getNumEntries(), &this->getInfoObj());
+  }
+  key_iterator key_end() { return key_iterator(); }
+
+  iterator_range<key_iterator> keys() {
+    return make_range(key_begin(), key_end());
+  }
+
+  /// \brief Iterates over all the entries in the table, returning the data.
+  class data_iterator : public iterator_base {
+    Info *InfoObj;
+
+  public:
+    typedef data_type value_type;
+
+    data_iterator(const unsigned char *const Ptr, offset_type NumEntries,
+                  Info *InfoObj)
+        : iterator_base(Ptr, NumEntries), InfoObj(InfoObj) {}
+    data_iterator() : iterator_base(), InfoObj() {}
+
+    data_iterator &operator++() { // Preincrement
+      this->advance();
+      return *this;
+    }
+    data_iterator operator++(int) { // Postincrement
+      data_iterator tmp = *this;
+      ++*this;
+      return tmp;
+    }
+
+    value_type operator*() const {
+      auto *LocalPtr = this->getItem();
+
+      // Determine the length of the key and the data.
+      auto L = Info::ReadKeyDataLength(LocalPtr);
+
+      // Read the key.
+      const internal_key_type &Key = InfoObj->ReadKey(LocalPtr, L.first);
+      return InfoObj->ReadData(Key, LocalPtr + L.first, L.second);
+    }
+  };
+
+  data_iterator data_begin() {
+    return data_iterator(Payload, this->getNumEntries(), &this->getInfoObj());
+  }
+  data_iterator data_end() { return data_iterator(); }
+
+  iterator_range<data_iterator> data() {
+    return make_range(data_begin(), data_end());
+  }
+
+  /// \brief Create the hash table.
+  ///
+  /// \param Buckets is the beginning of the hash table itself, which follows
+  /// the payload of entire structure. This is the value returned by
+  /// OnDiskHashTableGenerator::Emit.
+  ///
+  /// \param Payload is the beginning of the data contained in the table.  This
+  /// is Base plus any padding or header data that was stored, ie, the offset
+  /// that the stream was at when calling Emit.
+  ///
+  /// \param Base is the point from which all offsets into the structure are
+  /// based. This is offset 0 in the stream that was used when Emitting the
+  /// table.
+  static OnDiskIterableChainedHashTable *
+  Create(const unsigned char *Buckets, const unsigned char *const Payload,
+         const unsigned char *const Base, const Info &InfoObj = Info()) {
+    assert(Buckets > Base);
+    auto NumBucketsAndEntries =
+        OnDiskIterableChainedHashTable<Info>::readNumBucketsAndEntries(Buckets);
+    return new OnDiskIterableChainedHashTable<Info>(
+        NumBucketsAndEntries.first, NumBucketsAndEntries.second,
+        Buckets, Payload, Base, InfoObj);
+  }
+};
+
+} // end namespace llvm
+
+#endif