ValueMap.h revision fe134fe9e5673d63b4b80392adcc5a3df928475f
1//===- llvm/ADT/ValueMap.h - Safe map from Values to data -------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines the ValueMap class. ValueMap maps Value* or any subclass 11// to an arbitrary other type. It provides the DenseMap interface but updates 12// itself to remain safe when keys are RAUWed or deleted. By default, when a 13// key is RAUWed from V1 to V2, the old mapping V1->target is removed, and a new 14// mapping V2->target is added. If V2 already existed, its old target is 15// overwritten. When a key is deleted, its mapping is removed. 16// 17// You can override a ValueMap's Config parameter to control exactly what 18// happens on RAUW and destruction and to get called back on each event. It's 19// legal to call back into the ValueMap from a Config's callbacks. Config 20// parameters should inherit from ValueMapConfig<KeyT> to get default 21// implementations of all the methods ValueMap uses. See ValueMapConfig for 22// documentation of the functions you can override. 23// 24//===----------------------------------------------------------------------===// 25 26#ifndef LLVM_ADT_VALUEMAP_H 27#define LLVM_ADT_VALUEMAP_H 28 29#include "llvm/ADT/DenseMap.h" 30#include "llvm/Support/ValueHandle.h" 31#include "llvm/Support/type_traits.h" 32#include "llvm/System/Mutex.h" 33 34#include <iterator> 35 36namespace llvm { 37 38template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT> 39class ValueMapCallbackVH; 40 41template<typename DenseMapT, typename KeyT> 42class ValueMapIterator; 43template<typename DenseMapT, typename KeyT> 44class ValueMapConstIterator; 45 46/// This class defines the default behavior for configurable aspects of 47/// ValueMap<>. User Configs should inherit from this class to be as compatible 48/// as possible with future versions of ValueMap. 49template<typename KeyT> 50struct ValueMapConfig { 51 /// If FollowRAUW is true, the ValueMap will update mappings on RAUW. If it's 52 /// false, the ValueMap will leave the original mapping in place. 53 enum { FollowRAUW = true }; 54 55 // All methods will be called with a first argument of type ExtraData. The 56 // default implementations in this class take a templated first argument so 57 // that users' subclasses can use any type they want without having to 58 // override all the defaults. 59 struct ExtraData {}; 60 61 template<typename ExtraDataT> 62 static void onRAUW(const ExtraDataT &Data, KeyT Old, KeyT New) {} 63 template<typename ExtraDataT> 64 static void onDelete(const ExtraDataT &Data, KeyT Old) {} 65 66 /// Returns a mutex that should be acquired around any changes to the map. 67 /// This is only acquired from the CallbackVH (and held around calls to onRAUW 68 /// and onDelete) and not inside other ValueMap methods. NULL means that no 69 /// mutex is necessary. 70 template<typename ExtraDataT> 71 static sys::Mutex *getMutex(const ExtraDataT &Data) { return NULL; } 72}; 73 74/// See the file comment. 75template<typename KeyT, typename ValueT, typename Config = ValueMapConfig<KeyT>, 76 typename ValueInfoT = DenseMapInfo<ValueT> > 77class ValueMap { 78 friend class ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT>; 79 typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> ValueMapCVH; 80 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH>, 81 ValueInfoT> MapT; 82 typedef typename Config::ExtraData ExtraData; 83 MapT Map; 84 ExtraData Data; 85public: 86 typedef KeyT key_type; 87 typedef ValueT mapped_type; 88 typedef std::pair<KeyT, ValueT> value_type; 89 90 ValueMap(const ValueMap& Other) : Map(Other.Map), Data(Other.Data) {} 91 92 explicit ValueMap(unsigned NumInitBuckets = 64) 93 : Map(NumInitBuckets), Data() {} 94 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64) 95 : Map(NumInitBuckets), Data(Data) {} 96 97 ~ValueMap() {} 98 99 typedef ValueMapIterator<MapT, KeyT> iterator; 100 typedef ValueMapConstIterator<MapT, KeyT> const_iterator; 101 inline iterator begin() { return iterator(Map.begin()); } 102 inline iterator end() { return iterator(Map.end()); } 103 inline const_iterator begin() const { return const_iterator(Map.begin()); } 104 inline const_iterator end() const { return const_iterator(Map.end()); } 105 106 bool empty() const { return Map.empty(); } 107 unsigned size() const { return Map.size(); } 108 109 /// Grow the map so that it has at least Size buckets. Does not shrink 110 void resize(size_t Size) { Map.resize(Size); } 111 112 void clear() { Map.clear(); } 113 114 /// count - Return true if the specified key is in the map. 115 bool count(const KeyT &Val) const { 116 return Map.count(Wrap(Val)); 117 } 118 119 iterator find(const KeyT &Val) { 120 return iterator(Map.find(Wrap(Val))); 121 } 122 const_iterator find(const KeyT &Val) const { 123 return const_iterator(Map.find(Wrap(Val))); 124 } 125 126 /// lookup - Return the entry for the specified key, or a default 127 /// constructed value if no such entry exists. 128 ValueT lookup(const KeyT &Val) const { 129 return Map.lookup(Wrap(Val)); 130 } 131 132 // Inserts key,value pair into the map if the key isn't already in the map. 133 // If the key is already in the map, it returns false and doesn't update the 134 // value. 135 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { 136 std::pair<typename MapT::iterator, bool> map_result= 137 Map.insert(std::make_pair(Wrap(KV.first), KV.second)); 138 return std::make_pair(iterator(map_result.first), map_result.second); 139 } 140 141 /// insert - Range insertion of pairs. 142 template<typename InputIt> 143 void insert(InputIt I, InputIt E) { 144 for (; I != E; ++I) 145 insert(*I); 146 } 147 148 149 bool erase(const KeyT &Val) { 150 return Map.erase(Wrap(Val)); 151 } 152 bool erase(iterator I) { 153 return Map.erase(I.base()); 154 } 155 156 value_type& FindAndConstruct(const KeyT &Key) { 157 return Map.FindAndConstruct(Wrap(Key)); 158 } 159 160 ValueT &operator[](const KeyT &Key) { 161 return Map[Wrap(Key)]; 162 } 163 164 ValueMap& operator=(const ValueMap& Other) { 165 Map = Other.Map; 166 Data = Other.Data; 167 return *this; 168 } 169 170 /// isPointerIntoBucketsArray - Return true if the specified pointer points 171 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or 172 /// value in the ValueMap). 173 bool isPointerIntoBucketsArray(const void *Ptr) const { 174 return Map.isPointerIntoBucketsArray(Ptr); 175 } 176 177 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets 178 /// array. In conjunction with the previous method, this can be used to 179 /// determine whether an insertion caused the ValueMap to reallocate. 180 const void *getPointerIntoBucketsArray() const { 181 return Map.getPointerIntoBucketsArray(); 182 } 183 184private: 185 // Takes a key being looked up in the map and wraps it into a 186 // ValueMapCallbackVH, the actual key type of the map. We use a helper 187 // function because ValueMapCVH is constructed with a second parameter. 188 ValueMapCVH Wrap(KeyT key) const { 189 // The only way the resulting CallbackVH could try to modify *this (making 190 // the const_cast incorrect) is if it gets inserted into the map. But then 191 // this function must have been called from a non-const method, making the 192 // const_cast ok. 193 return ValueMapCVH(key, const_cast<ValueMap*>(this)); 194 } 195}; 196 197// This CallbackVH updates its ValueMap when the contained Value changes, 198// according to the user's preferences expressed through the Config object. 199template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT> 200class ValueMapCallbackVH : public CallbackVH { 201 friend class ValueMap<KeyT, ValueT, Config, ValueInfoT>; 202 friend struct DenseMapInfo<ValueMapCallbackVH>; 203 typedef ValueMap<KeyT, ValueT, Config, ValueInfoT> ValueMapT; 204 typedef typename llvm::remove_pointer<KeyT>::type KeySansPointerT; 205 206 ValueMapT *Map; 207 208 ValueMapCallbackVH(KeyT Key, ValueMapT *Map) 209 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))), 210 Map(Map) {} 211 212public: 213 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); } 214 215 virtual void deleted() { 216 // Make a copy that won't get changed even when *this is destroyed. 217 ValueMapCallbackVH Copy(*this); 218 sys::Mutex *M = Config::getMutex(Copy.Map->Data); 219 if (M) 220 M->acquire(); 221 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this. 222 Copy.Map->Map.erase(Copy); // Definitely destroys *this. 223 if (M) 224 M->release(); 225 } 226 virtual void allUsesReplacedWith(Value *new_key) { 227 assert(isa<KeySansPointerT>(new_key) && 228 "Invalid RAUW on key of ValueMap<>"); 229 // Make a copy that won't get changed even when *this is destroyed. 230 ValueMapCallbackVH Copy(*this); 231 sys::Mutex *M = Config::getMutex(Copy.Map->Data); 232 if (M) 233 M->acquire(); 234 235 KeyT typed_new_key = cast<KeySansPointerT>(new_key); 236 // Can destroy *this: 237 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key); 238 if (Config::FollowRAUW) { 239 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy); 240 // I could == Copy.Map->Map.end() if the onRAUW callback already 241 // removed the old mapping. 242 if (I != Copy.Map->Map.end()) { 243 ValueT Target(I->second); 244 Copy.Map->Map.erase(I); // Definitely destroys *this. 245 Copy.Map->insert(std::make_pair(typed_new_key, Target)); 246 } 247 } 248 if (M) 249 M->release(); 250 } 251}; 252 253template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT> 254struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > { 255 typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> VH; 256 typedef DenseMapInfo<KeyT> PointerInfo; 257 258 static inline VH getEmptyKey() { 259 return VH(PointerInfo::getEmptyKey(), NULL); 260 } 261 static inline VH getTombstoneKey() { 262 return VH(PointerInfo::getTombstoneKey(), NULL); 263 } 264 static unsigned getHashValue(const VH &Val) { 265 return PointerInfo::getHashValue(Val.Unwrap()); 266 } 267 static bool isEqual(const VH &LHS, const VH &RHS) { 268 return LHS == RHS; 269 } 270 static bool isPod() { return false; } 271}; 272 273 274template<typename DenseMapT, typename KeyT> 275class ValueMapIterator : 276 public std::iterator<std::forward_iterator_tag, 277 std::pair<KeyT, typename DenseMapT::mapped_type>, 278 ptrdiff_t> { 279 typedef typename DenseMapT::iterator BaseT; 280 typedef typename DenseMapT::mapped_type ValueT; 281 BaseT I; 282public: 283 ValueMapIterator() : I() {} 284 285 ValueMapIterator(BaseT I) : I(I) {} 286 287 BaseT base() const { return I; } 288 289 struct ValueTypeProxy { 290 const KeyT first; 291 ValueT& second; 292 ValueTypeProxy *operator->() { return this; } 293 operator std::pair<KeyT, ValueT>() const { 294 return std::make_pair(first, second); 295 } 296 }; 297 298 ValueTypeProxy operator*() const { 299 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 300 return Result; 301 } 302 303 ValueTypeProxy operator->() const { 304 return operator*(); 305 } 306 307 bool operator==(const ValueMapIterator &RHS) const { 308 return I == RHS.I; 309 } 310 bool operator!=(const ValueMapIterator &RHS) const { 311 return I != RHS.I; 312 } 313 314 inline ValueMapIterator& operator++() { // Preincrement 315 ++I; 316 return *this; 317 } 318 ValueMapIterator operator++(int) { // Postincrement 319 ValueMapIterator tmp = *this; ++*this; return tmp; 320 } 321}; 322 323template<typename DenseMapT, typename KeyT> 324class ValueMapConstIterator : 325 public std::iterator<std::forward_iterator_tag, 326 std::pair<KeyT, typename DenseMapT::mapped_type>, 327 ptrdiff_t> { 328 typedef typename DenseMapT::const_iterator BaseT; 329 typedef typename DenseMapT::mapped_type ValueT; 330 BaseT I; 331public: 332 ValueMapConstIterator() : I() {} 333 ValueMapConstIterator(BaseT I) : I(I) {} 334 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other) 335 : I(Other.base()) {} 336 337 BaseT base() const { return I; } 338 339 struct ValueTypeProxy { 340 const KeyT first; 341 const ValueT& second; 342 ValueTypeProxy *operator->() { return this; } 343 operator std::pair<KeyT, ValueT>() const { 344 return std::make_pair(first, second); 345 } 346 }; 347 348 ValueTypeProxy operator*() const { 349 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 350 return Result; 351 } 352 353 ValueTypeProxy operator->() const { 354 return operator*(); 355 } 356 357 bool operator==(const ValueMapConstIterator &RHS) const { 358 return I == RHS.I; 359 } 360 bool operator!=(const ValueMapConstIterator &RHS) const { 361 return I != RHS.I; 362 } 363 364 inline ValueMapConstIterator& operator++() { // Preincrement 365 ++I; 366 return *this; 367 } 368 ValueMapConstIterator operator++(int) { // Postincrement 369 ValueMapConstIterator tmp = *this; ++*this; return tmp; 370 } 371}; 372 373} // end namespace llvm 374 375#endif 376