1 //===- 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_IR_VALUEMAP_H 27 #define LLVM_IR_VALUEMAP_H 28 29 #include "llvm/ADT/DenseMap.h" 30 #include "llvm/IR/ValueHandle.h" 31 #include "llvm/Support/Mutex.h" 32 #include "llvm/Support/type_traits.h" 33 #include <iterator> 34 35 namespace llvm { 36 37 template<typename KeyT, typename ValueT, typename Config> 38 class ValueMapCallbackVH; 39 40 template<typename DenseMapT, typename KeyT> 41 class ValueMapIterator; 42 template<typename DenseMapT, typename KeyT> 43 class ValueMapConstIterator; 44 45 /// This class defines the default behavior for configurable aspects of 46 /// ValueMap<>. User Configs should inherit from this class to be as compatible 47 /// as possible with future versions of ValueMap. 48 template<typename KeyT, typename MutexT = sys::Mutex> 49 struct ValueMapConfig { 50 typedef MutexT mutex_type; 51 52 /// If FollowRAUW is true, the ValueMap will update mappings on RAUW. If it's 53 /// false, the ValueMap will leave the original mapping in place. 54 enum { FollowRAUW = true }; 55 56 // All methods will be called with a first argument of type ExtraData. The 57 // default implementations in this class take a templated first argument so 58 // that users' subclasses can use any type they want without having to 59 // override all the defaults. 60 struct ExtraData {}; 61 62 template<typename ExtraDataT> 63 static void onRAUW(const ExtraDataT & /*Data*/, KeyT /*Old*/, KeyT /*New*/) {} 64 template<typename ExtraDataT> 65 static void onDelete(const ExtraDataT &/*Data*/, KeyT /*Old*/) {} 66 67 /// Returns a mutex that should be acquired around any changes to the map. 68 /// This is only acquired from the CallbackVH (and held around calls to onRAUW 69 /// and onDelete) and not inside other ValueMap methods. NULL means that no 70 /// mutex is necessary. 71 template<typename ExtraDataT> 72 static mutex_type *getMutex(const ExtraDataT &/*Data*/) { return nullptr; } 73 }; 74 75 /// See the file comment. 76 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> > 77 class ValueMap { 78 friend class ValueMapCallbackVH<KeyT, ValueT, Config>; 79 typedef ValueMapCallbackVH<KeyT, ValueT, Config> ValueMapCVH; 80 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH> > MapT; 81 typedef typename Config::ExtraData ExtraData; 82 MapT Map; 83 ExtraData Data; 84 ValueMap(const ValueMap&) LLVM_DELETED_FUNCTION; 85 ValueMap& operator=(const ValueMap&) LLVM_DELETED_FUNCTION; 86 public: 87 typedef KeyT key_type; 88 typedef ValueT mapped_type; 89 typedef std::pair<KeyT, ValueT> value_type; 90 typedef unsigned size_type; 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 size_type 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 /// Return 1 if the specified key is in the map, 0 otherwise. 115 size_type count(const KeyT &Val) const { 116 return Map.find_as(Val) == Map.end() ? 0 : 1; 117 } 118 119 iterator find(const KeyT &Val) { 120 return iterator(Map.find_as(Val)); 121 } 122 const_iterator find(const KeyT &Val) const { 123 return const_iterator(Map.find_as(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 typename MapT::const_iterator I = Map.find_as(Val); 130 return I != Map.end() ? I->second : ValueT(); 131 } 132 133 // Inserts key,value pair into the map if the key isn't already in the map. 134 // If the key is already in the map, it returns false and doesn't update the 135 // value. 136 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { 137 std::pair<typename MapT::iterator, bool> map_result= 138 Map.insert(std::make_pair(Wrap(KV.first), KV.second)); 139 return std::make_pair(iterator(map_result.first), map_result.second); 140 } 141 142 /// insert - Range insertion of pairs. 143 template<typename InputIt> 144 void insert(InputIt I, InputIt E) { 145 for (; I != E; ++I) 146 insert(*I); 147 } 148 149 150 bool erase(const KeyT &Val) { 151 typename MapT::iterator I = Map.find_as(Val); 152 if (I == Map.end()) 153 return false; 154 155 Map.erase(I); 156 return true; 157 } 158 void erase(iterator I) { 159 return Map.erase(I.base()); 160 } 161 162 value_type& FindAndConstruct(const KeyT &Key) { 163 return Map.FindAndConstruct(Wrap(Key)); 164 } 165 166 ValueT &operator[](const KeyT &Key) { 167 return Map[Wrap(Key)]; 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 } 183 184 private: 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. 199 template<typename KeyT, typename ValueT, typename Config> 200 class ValueMapCallbackVH : public CallbackVH { 201 friend class ValueMap<KeyT, ValueT, Config>; 202 friend struct DenseMapInfo<ValueMapCallbackVH>; 203 typedef ValueMap<KeyT, ValueT, Config> ValueMapT; 204 typedef typename std::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) {} 211 212 public: 213 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); } 214 215 void deleted() override { 216 // Make a copy that won't get changed even when *this is destroyed. 217 ValueMapCallbackVH Copy(*this); 218 typename Config::mutex_type *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 void allUsesReplacedWith(Value *new_key) override { 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 typename Config::mutex_type *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 }; 252 253 template<typename KeyT, typename ValueT, typename Config> 254 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > { 255 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH; 256 typedef DenseMapInfo<KeyT> PointerInfo; 257 258 static inline VH getEmptyKey() { 259 return VH(PointerInfo::getEmptyKey(), nullptr); 260 } 261 static inline VH getTombstoneKey() { 262 return VH(PointerInfo::getTombstoneKey(), nullptr); 263 } 264 static unsigned getHashValue(const VH &Val) { 265 return PointerInfo::getHashValue(Val.Unwrap()); 266 } 267 static unsigned getHashValue(const KeyT &Val) { 268 return PointerInfo::getHashValue(Val); 269 } 270 static bool isEqual(const VH &LHS, const VH &RHS) { 271 return LHS == RHS; 272 } 273 static bool isEqual(const KeyT &LHS, const VH &RHS) { 274 return LHS == RHS.getValPtr(); 275 } 276 }; 277 278 279 template<typename DenseMapT, typename KeyT> 280 class ValueMapIterator : 281 public std::iterator<std::forward_iterator_tag, 282 std::pair<KeyT, typename DenseMapT::mapped_type>, 283 ptrdiff_t> { 284 typedef typename DenseMapT::iterator BaseT; 285 typedef typename DenseMapT::mapped_type ValueT; 286 BaseT I; 287 public: 288 ValueMapIterator() : I() {} 289 290 ValueMapIterator(BaseT I) : I(I) {} 291 292 BaseT base() const { return I; } 293 294 struct ValueTypeProxy { 295 const KeyT first; 296 ValueT& second; 297 ValueTypeProxy *operator->() { return this; } 298 operator std::pair<KeyT, ValueT>() const { 299 return std::make_pair(first, second); 300 } 301 }; 302 303 ValueTypeProxy operator*() const { 304 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 305 return Result; 306 } 307 308 ValueTypeProxy operator->() const { 309 return operator*(); 310 } 311 312 bool operator==(const ValueMapIterator &RHS) const { 313 return I == RHS.I; 314 } 315 bool operator!=(const ValueMapIterator &RHS) const { 316 return I != RHS.I; 317 } 318 319 inline ValueMapIterator& operator++() { // Preincrement 320 ++I; 321 return *this; 322 } 323 ValueMapIterator operator++(int) { // Postincrement 324 ValueMapIterator tmp = *this; ++*this; return tmp; 325 } 326 }; 327 328 template<typename DenseMapT, typename KeyT> 329 class ValueMapConstIterator : 330 public std::iterator<std::forward_iterator_tag, 331 std::pair<KeyT, typename DenseMapT::mapped_type>, 332 ptrdiff_t> { 333 typedef typename DenseMapT::const_iterator BaseT; 334 typedef typename DenseMapT::mapped_type ValueT; 335 BaseT I; 336 public: 337 ValueMapConstIterator() : I() {} 338 ValueMapConstIterator(BaseT I) : I(I) {} 339 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other) 340 : I(Other.base()) {} 341 342 BaseT base() const { return I; } 343 344 struct ValueTypeProxy { 345 const KeyT first; 346 const ValueT& second; 347 ValueTypeProxy *operator->() { return this; } 348 operator std::pair<KeyT, ValueT>() const { 349 return std::make_pair(first, second); 350 } 351 }; 352 353 ValueTypeProxy operator*() const { 354 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 355 return Result; 356 } 357 358 ValueTypeProxy operator->() const { 359 return operator*(); 360 } 361 362 bool operator==(const ValueMapConstIterator &RHS) const { 363 return I == RHS.I; 364 } 365 bool operator!=(const ValueMapConstIterator &RHS) const { 366 return I != RHS.I; 367 } 368 369 inline ValueMapConstIterator& operator++() { // Preincrement 370 ++I; 371 return *this; 372 } 373 ValueMapConstIterator operator++(int) { // Postincrement 374 ValueMapConstIterator tmp = *this; ++*this; return tmp; 375 } 376 }; 377 378 } // end namespace llvm 379 380 #endif 381