Move StringMap.h and StringExtras.h to public includes.

While these aren't required by the public interface, they are generally
useful classes for users of the library.

include/llvm/StringMap.h

@@ -0,0 +1,417 @@
+//===--- StringMap.h - String Hash table map interface ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the StringMap class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_STRINGMAP_H
+#define LLVM_ADT_STRINGMAP_H
+
+#include "llvm/StringRef.h"
+#include <cstdlib>
+#include <cstring>
+#include <utility>
+
+namespace llvm {
+  template<typename ValueT>
+  class StringMapConstIterator;
+  template<typename ValueT>
+  class StringMapIterator;
+  template<typename ValueTy>
+  class StringMapEntry;
+
+/// StringMapEntryBase - Shared base class of StringMapEntry instances.
+class StringMapEntryBase {
+  unsigned StrLen;
+public:
+  explicit StringMapEntryBase(unsigned Len) : StrLen(Len) {}
+
+  unsigned getKeyLength() const { return StrLen; }
+};
+
+/// StringMapImpl - This is the base class of StringMap that is shared among
+/// all of its instantiations.
+class StringMapImpl {
+protected:
+  // Array of NumBuckets pointers to entries, null pointers are holes.
+  // TheTable[NumBuckets] contains a sentinel value for easy iteration. Followed
+  // by an array of the actual hash values as unsigned integers.
+  StringMapEntryBase **TheTable;
+  unsigned NumBuckets;
+  unsigned NumItems;
+  unsigned NumTombstones;
+  unsigned ItemSize;
+protected:
+  explicit StringMapImpl(unsigned itemSize)
+      : TheTable(nullptr),
+        // Initialize the map with zero buckets to allocation.
+        NumBuckets(0), NumItems(0), NumTombstones(0), ItemSize(itemSize) {}
+  StringMapImpl(StringMapImpl &&RHS)
+      : TheTable(RHS.TheTable), NumBuckets(RHS.NumBuckets),
+        NumItems(RHS.NumItems), NumTombstones(RHS.NumTombstones),
+        ItemSize(RHS.ItemSize) {
+    RHS.TheTable = nullptr;
+    RHS.NumBuckets = 0;
+    RHS.NumItems = 0;
+    RHS.NumTombstones = 0;
+  }
+
+  StringMapImpl(unsigned InitSize, unsigned ItemSize);
+  unsigned RehashTable(unsigned BucketNo = 0);
+
+  /// LookupBucketFor - Look up the bucket that the specified string should end
+  /// up in.  If it already exists as a key in the map, the Item pointer for the
+  /// specified bucket will be non-null.  Otherwise, it will be null.  In either
+  /// case, the FullHashValue field of the bucket will be set to the hash value
+  /// of the string.
+  unsigned LookupBucketFor(StringRef Key);
+
+  /// FindKey - Look up the bucket that contains the specified key. If it exists
+  /// in the map, return the bucket number of the key.  Otherwise return -1.
+  /// This does not modify the map.
+  int FindKey(StringRef Key) const;
+
+  /// RemoveKey - Remove the specified StringMapEntry from the table, but do not
+  /// delete it.  This aborts if the value isn't in the table.
+  void RemoveKey(StringMapEntryBase *V);
+
+  /// RemoveKey - Remove the StringMapEntry for the specified key from the
+  /// table, returning it.  If the key is not in the table, this returns null.
+  StringMapEntryBase *RemoveKey(StringRef Key);
+private:
+  void init(unsigned Size);
+public:
+  static StringMapEntryBase *getTombstoneVal() {
+    return (StringMapEntryBase*)-1;
+  }
+
+  unsigned getNumBuckets() const { return NumBuckets; }
+  unsigned getNumItems() const { return NumItems; }
+
+  bool empty() const { return NumItems == 0; }
+  unsigned size() const { return NumItems; }
+
+  void swap(StringMapImpl &Other) {
+    std::swap(TheTable, Other.TheTable);
+    std::swap(NumBuckets, Other.NumBuckets);
+    std::swap(NumItems, Other.NumItems);
+    std::swap(NumTombstones, Other.NumTombstones);
+  }
+};
+
+/// StringMapEntry - This is used to represent one value that is inserted into
+/// a StringMap.  It contains the Value itself and the key: the string length
+/// and data.
+template<typename ValueTy>
+class StringMapEntry : public StringMapEntryBase {
+  StringMapEntry(StringMapEntry &E) = delete;
+public:
+  ValueTy second;
+
+  explicit StringMapEntry(unsigned strLen)
+    : StringMapEntryBase(strLen), second() {}
+  template <class InitTy>
+  StringMapEntry(unsigned strLen, InitTy &&V)
+      : StringMapEntryBase(strLen), second(std::forward<InitTy>(V)) {}
+
+  StringRef getKey() const {
+    return StringRef(getKeyData(), getKeyLength());
+  }
+
+  const ValueTy &getValue() const { return second; }
+  ValueTy &getValue() { return second; }
+
+  void setValue(const ValueTy &V) { second = V; }
+
+  /// getKeyData - Return the start of the string data that is the key for this
+  /// value.  The string data is always stored immediately after the
+  /// StringMapEntry object.
+  const char *getKeyData() const {return reinterpret_cast<const char*>(this+1);}
+
+  StringRef first() const { return StringRef(getKeyData(), getKeyLength()); }
+
+  /// Create - Create a StringMapEntry for the specified key and default
+  /// construct the value.
+  template <typename InitType>
+  static StringMapEntry *Create(StringRef Key, InitType &&InitVal) {
+    unsigned KeyLength = Key.size();
+
+    // Allocate a new item with space for the string at the end and a null
+    // terminator.
+    unsigned AllocSize = static_cast<unsigned>(sizeof(StringMapEntry))+
+      KeyLength+1;
+
+    StringMapEntry *NewItem =
+      static_cast<StringMapEntry*>(std::malloc(AllocSize));
+
+    // Default construct the value.
+    new (NewItem) StringMapEntry(KeyLength, std::forward<InitType>(InitVal));
+
+    // Copy the string information.
+    char *StrBuffer = const_cast<char*>(NewItem->getKeyData());
+    memcpy(StrBuffer, Key.data(), KeyLength);
+    StrBuffer[KeyLength] = 0;  // Null terminate for convenience of clients.
+    return NewItem;
+  }
+
+  static StringMapEntry *Create(StringRef Key) {
+    return Create(Key, ValueTy());
+  }
+
+  /// GetStringMapEntryFromKeyData - Given key data that is known to be embedded
+  /// into a StringMapEntry, return the StringMapEntry itself.
+  static StringMapEntry &GetStringMapEntryFromKeyData(const char *KeyData) {
+    char *Ptr = const_cast<char*>(KeyData) - sizeof(StringMapEntry<ValueTy>);
+    return *reinterpret_cast<StringMapEntry*>(Ptr);
+  }
+
+  /// Destroy - Destroy this StringMapEntry, releasing memory back to the
+  /// specified allocator.
+  void Destroy() {
+    // Free memory referenced by the item.
+    this->~StringMapEntry();
+    std::free(static_cast<void *>(this));
+  }
+};
+
+
+/// StringMap - This is an unconventional map that is specialized for handling
+/// keys that are "strings", which are basically ranges of bytes. This does some
+/// funky memory allocation and hashing things to make it extremely efficient,
+/// storing the string data *after* the value in the map.
+template<typename ValueTy>
+class StringMap : public StringMapImpl {
+public:
+  typedef StringMapEntry<ValueTy> MapEntryTy;
+  
+  StringMap() : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))) {}
+  explicit StringMap(unsigned InitialSize)
+    : StringMapImpl(InitialSize, static_cast<unsigned>(sizeof(MapEntryTy))) {}
+
+  StringMap(StringMap &&RHS)
+      : StringMapImpl(std::move(RHS)) {}
+
+  StringMap &operator=(StringMap RHS) {
+    StringMapImpl::swap(RHS);
+    return *this;
+  }
+
+  // FIXME: Implement copy operations if/when they're needed.
+
+  typedef const char* key_type;
+  typedef ValueTy mapped_type;
+  typedef StringMapEntry<ValueTy> value_type;
+  typedef size_t size_type;
+
+  typedef StringMapConstIterator<ValueTy> const_iterator;
+  typedef StringMapIterator<ValueTy> iterator;
+
+  iterator begin() {
+    return iterator(TheTable, NumBuckets == 0);
+  }
+  iterator end() {
+    return iterator(TheTable+NumBuckets, true);
+  }
+  const_iterator begin() const {
+    return const_iterator(TheTable, NumBuckets == 0);
+  }
+  const_iterator end() const {
+    return const_iterator(TheTable+NumBuckets, true);
+  }
+
+  iterator find(StringRef Key) {
+    int Bucket = FindKey(Key);
+    if (Bucket == -1) return end();
+    return iterator(TheTable+Bucket, true);
+  }
+
+  const_iterator find(StringRef Key) const {
+    int Bucket = FindKey(Key);
+    if (Bucket == -1) return end();
+    return const_iterator(TheTable+Bucket, true);
+  }
+
+  /// lookup - Return the entry for the specified key, or a default
+  /// constructed value if no such entry exists.
+  ValueTy lookup(StringRef Key) const {
+    const_iterator it = find(Key);
+    if (it != end())
+      return it->second;
+    return ValueTy();
+  }
+
+  ValueTy &operator[](StringRef Key) {
+    return insert(std::make_pair(Key, ValueTy())).first->second;
+  }
+
+  /// count - Return 1 if the element is in the map, 0 otherwise.
+  size_type count(StringRef Key) const {
+    return find(Key) == end() ? 0 : 1;
+  }
+
+  /// insert - Insert the specified key/value pair into the map.  If the key
+  /// already exists in the map, return false and ignore the request, otherwise
+  /// insert it and return true.
+  bool insert(MapEntryTy *KeyValue) {
+    unsigned BucketNo = LookupBucketFor(KeyValue->getKey());
+    StringMapEntryBase *&Bucket = TheTable[BucketNo];
+    if (Bucket && Bucket != getTombstoneVal())
+      return false;  // Already exists in map.
+
+    if (Bucket == getTombstoneVal())
+      --NumTombstones;
+    Bucket = KeyValue;
+    ++NumItems;
+    assert(NumItems + NumTombstones <= NumBuckets);
+
+    RehashTable();
+    return true;
+  }
+
+  /// insert - Inserts the specified key/value pair into the map if the key
+  /// isn't already in the map. The bool component of the returned pair is true
+  /// if and only if the insertion takes place, and the iterator component of
+  /// the pair points to the element with key equivalent to the key of the pair.
+  std::pair<iterator, bool> insert(std::pair<StringRef, ValueTy> KV) {
+    unsigned BucketNo = LookupBucketFor(KV.first);
+    StringMapEntryBase *&Bucket = TheTable[BucketNo];
+    if (Bucket && Bucket != getTombstoneVal())
+      return std::make_pair(iterator(TheTable + BucketNo, false),
+                            false); // Already exists in map.
+
+    if (Bucket == getTombstoneVal())
+      --NumTombstones;
+    Bucket =
+        MapEntryTy::Create(KV.first, std::move(KV.second));
+    ++NumItems;
+    assert(NumItems + NumTombstones <= NumBuckets);
+
+    BucketNo = RehashTable(BucketNo);
+    return std::make_pair(iterator(TheTable + BucketNo, false), true);
+  }
+
+  // clear - Empties out the StringMap
+  void clear() {
+    if (empty()) return;
+
+    // Zap all values, resetting the keys back to non-present (not tombstone),
+    // which is safe because we're removing all elements.
+    for (unsigned I = 0, E = NumBuckets; I != E; ++I) {
+      StringMapEntryBase *&Bucket = TheTable[I];
+      if (Bucket && Bucket != getTombstoneVal()) {
+        static_cast<MapEntryTy*>(Bucket)->Destroy();
+      }
+      Bucket = nullptr;
+    }
+
+    NumItems = 0;
+    NumTombstones = 0;
+  }
+
+  /// remove - Remove the specified key/value pair from the map, but do not
+  /// erase it.  This aborts if the key is not in the map.
+  void remove(MapEntryTy *KeyValue) {
+    RemoveKey(KeyValue);
+  }
+
+  void erase(iterator I) {
+    MapEntryTy &V = *I;
+    remove(&V);
+    V.Destroy();
+  }
+
+  bool erase(StringRef Key) {
+    iterator I = find(Key);
+    if (I == end()) return false;
+    erase(I);
+    return true;
+  }
+
+  ~StringMap() {
+    // Delete all the elements in the map, but don't reset the elements
+    // to default values.  This is a copy of clear(), but avoids unnecessary
+    // work not required in the destructor.
+    if (!empty()) {
+      for (unsigned I = 0, E = NumBuckets; I != E; ++I) {
+        StringMapEntryBase *Bucket = TheTable[I];
+        if (Bucket && Bucket != getTombstoneVal()) {
+          static_cast<MapEntryTy*>(Bucket)->Destroy();
+        }
+      }
+    }
+    free(TheTable);
+  }
+};
+
+
+template<typename ValueTy>
+class StringMapConstIterator {
+protected:
+  StringMapEntryBase **Ptr;
+public:
+  typedef StringMapEntry<ValueTy> value_type;
+
+  StringMapConstIterator() : Ptr(nullptr) { }
+
+  explicit StringMapConstIterator(StringMapEntryBase **Bucket,
+                                  bool NoAdvance = false)
+  : Ptr(Bucket) {
+    if (!NoAdvance) AdvancePastEmptyBuckets();
+  }
+
+  const value_type &operator*() const {
+    return *static_cast<StringMapEntry<ValueTy>*>(*Ptr);
+  }
+  const value_type *operator->() const {
+    return static_cast<StringMapEntry<ValueTy>*>(*Ptr);
+  }
+
+  bool operator==(const StringMapConstIterator &RHS) const {
+    return Ptr == RHS.Ptr;
+  }
+  bool operator!=(const StringMapConstIterator &RHS) const {
+    return Ptr != RHS.Ptr;
+  }
+
+  inline StringMapConstIterator& operator++() {   // Preincrement
+    ++Ptr;
+    AdvancePastEmptyBuckets();
+    return *this;
+  }
+  StringMapConstIterator operator++(int) {        // Postincrement
+    StringMapConstIterator tmp = *this; ++*this; return tmp;
+  }
+
+private:
+  void AdvancePastEmptyBuckets() {
+    while (*Ptr == nullptr || *Ptr == StringMapImpl::getTombstoneVal())
+      ++Ptr;
+  }
+};
+
+template<typename ValueTy>
+class StringMapIterator : public StringMapConstIterator<ValueTy> {
+public:
+  StringMapIterator() {}
+  explicit StringMapIterator(StringMapEntryBase **Bucket,
+                             bool NoAdvance = false)
+    : StringMapConstIterator<ValueTy>(Bucket, NoAdvance) {
+  }
+  StringMapEntry<ValueTy> &operator*() const {
+    return *static_cast<StringMapEntry<ValueTy>*>(*this->Ptr);
+  }
+  StringMapEntry<ValueTy> *operator->() const {
+    return static_cast<StringMapEntry<ValueTy>*>(*this->Ptr);
+  }
+};
+
+} // namespace llvm
+
+#endif