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/TrackingMDRef.h" 31 #include "llvm/IR/ValueHandle.h" 32 #include "llvm/Support/Mutex.h" 33 #include "llvm/Support/UniqueLock.h" 34 #include "llvm/Support/type_traits.h" 35 #include <iterator> 36 #include <memory> 37 38 namespace llvm { 39 40 template<typename KeyT, typename ValueT, typename Config> 41 class ValueMapCallbackVH; 42 43 template<typename DenseMapT, typename KeyT> 44 class ValueMapIterator; 45 template<typename DenseMapT, typename KeyT> 46 class ValueMapConstIterator; 47 48 /// This class defines the default behavior for configurable aspects of 49 /// ValueMap<>. User Configs should inherit from this class to be as compatible 50 /// as possible with future versions of ValueMap. 51 template<typename KeyT, typename MutexT = sys::Mutex> 52 struct ValueMapConfig { 53 typedef MutexT mutex_type; 54 55 /// If FollowRAUW is true, the ValueMap will update mappings on RAUW. If it's 56 /// false, the ValueMap will leave the original mapping in place. 57 enum { FollowRAUW = true }; 58 59 // All methods will be called with a first argument of type ExtraData. The 60 // default implementations in this class take a templated first argument so 61 // that users' subclasses can use any type they want without having to 62 // override all the defaults. 63 struct ExtraData {}; 64 65 template<typename ExtraDataT> 66 static void onRAUW(const ExtraDataT & /*Data*/, KeyT /*Old*/, KeyT /*New*/) {} 67 template<typename ExtraDataT> 68 static void onDelete(const ExtraDataT &/*Data*/, KeyT /*Old*/) {} 69 70 /// Returns a mutex that should be acquired around any changes to the map. 71 /// This is only acquired from the CallbackVH (and held around calls to onRAUW 72 /// and onDelete) and not inside other ValueMap methods. NULL means that no 73 /// mutex is necessary. 74 template<typename ExtraDataT> 75 static mutex_type *getMutex(const ExtraDataT &/*Data*/) { return nullptr; } 76 }; 77 78 /// See the file comment. 79 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> > 80 class ValueMap { 81 friend class ValueMapCallbackVH<KeyT, ValueT, Config>; 82 typedef ValueMapCallbackVH<KeyT, ValueT, Config> ValueMapCVH; 83 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH> > MapT; 84 typedef DenseMap<const Metadata *, TrackingMDRef> MDMapT; 85 typedef typename Config::ExtraData ExtraData; 86 MapT Map; 87 std::unique_ptr<MDMapT> MDMap; 88 ExtraData Data; 89 ValueMap(const ValueMap&) = delete; 90 ValueMap& operator=(const ValueMap&) = delete; 91 public: 92 typedef KeyT key_type; 93 typedef ValueT mapped_type; 94 typedef std::pair<KeyT, ValueT> value_type; 95 typedef unsigned size_type; 96 97 explicit ValueMap(unsigned NumInitBuckets = 64) 98 : Map(NumInitBuckets), Data() {} 99 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64) 100 : Map(NumInitBuckets), Data(Data) {} 101 102 bool hasMD() const { return MDMap; } 103 MDMapT &MD() { 104 if (!MDMap) 105 MDMap.reset(new MDMapT); 106 return *MDMap; 107 } 108 109 typedef ValueMapIterator<MapT, KeyT> iterator; 110 typedef ValueMapConstIterator<MapT, KeyT> const_iterator; 111 inline iterator begin() { return iterator(Map.begin()); } 112 inline iterator end() { return iterator(Map.end()); } 113 inline const_iterator begin() const { return const_iterator(Map.begin()); } 114 inline const_iterator end() const { return const_iterator(Map.end()); } 115 116 bool empty() const { return Map.empty(); } 117 size_type size() const { return Map.size(); } 118 119 /// Grow the map so that it has at least Size buckets. Does not shrink 120 void resize(size_t Size) { Map.resize(Size); } 121 122 void clear() { 123 Map.clear(); 124 MDMap.reset(); 125 } 126 127 /// Return 1 if the specified key is in the map, 0 otherwise. 128 size_type count(const KeyT &Val) const { 129 return Map.find_as(Val) == Map.end() ? 0 : 1; 130 } 131 132 iterator find(const KeyT &Val) { 133 return iterator(Map.find_as(Val)); 134 } 135 const_iterator find(const KeyT &Val) const { 136 return const_iterator(Map.find_as(Val)); 137 } 138 139 /// lookup - Return the entry for the specified key, or a default 140 /// constructed value if no such entry exists. 141 ValueT lookup(const KeyT &Val) const { 142 typename MapT::const_iterator I = Map.find_as(Val); 143 return I != Map.end() ? I->second : ValueT(); 144 } 145 146 // Inserts key,value pair into the map if the key isn't already in the map. 147 // If the key is already in the map, it returns false and doesn't update the 148 // value. 149 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { 150 auto MapResult = Map.insert(std::make_pair(Wrap(KV.first), KV.second)); 151 return std::make_pair(iterator(MapResult.first), MapResult.second); 152 } 153 154 std::pair<iterator, bool> insert(std::pair<KeyT, ValueT> &&KV) { 155 auto MapResult = 156 Map.insert(std::make_pair(Wrap(KV.first), std::move(KV.second))); 157 return std::make_pair(iterator(MapResult.first), MapResult.second); 158 } 159 160 /// insert - Range insertion of pairs. 161 template<typename InputIt> 162 void insert(InputIt I, InputIt E) { 163 for (; I != E; ++I) 164 insert(*I); 165 } 166 167 168 bool erase(const KeyT &Val) { 169 typename MapT::iterator I = Map.find_as(Val); 170 if (I == Map.end()) 171 return false; 172 173 Map.erase(I); 174 return true; 175 } 176 void erase(iterator I) { 177 return Map.erase(I.base()); 178 } 179 180 value_type& FindAndConstruct(const KeyT &Key) { 181 return Map.FindAndConstruct(Wrap(Key)); 182 } 183 184 ValueT &operator[](const KeyT &Key) { 185 return Map[Wrap(Key)]; 186 } 187 188 /// isPointerIntoBucketsArray - Return true if the specified pointer points 189 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or 190 /// value in the ValueMap). 191 bool isPointerIntoBucketsArray(const void *Ptr) const { 192 return Map.isPointerIntoBucketsArray(Ptr); 193 } 194 195 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets 196 /// array. In conjunction with the previous method, this can be used to 197 /// determine whether an insertion caused the ValueMap to reallocate. 198 const void *getPointerIntoBucketsArray() const { 199 return Map.getPointerIntoBucketsArray(); 200 } 201 202 private: 203 // Takes a key being looked up in the map and wraps it into a 204 // ValueMapCallbackVH, the actual key type of the map. We use a helper 205 // function because ValueMapCVH is constructed with a second parameter. 206 ValueMapCVH Wrap(KeyT key) const { 207 // The only way the resulting CallbackVH could try to modify *this (making 208 // the const_cast incorrect) is if it gets inserted into the map. But then 209 // this function must have been called from a non-const method, making the 210 // const_cast ok. 211 return ValueMapCVH(key, const_cast<ValueMap*>(this)); 212 } 213 }; 214 215 // This CallbackVH updates its ValueMap when the contained Value changes, 216 // according to the user's preferences expressed through the Config object. 217 template <typename KeyT, typename ValueT, typename Config> 218 class ValueMapCallbackVH final : public CallbackVH { 219 friend class ValueMap<KeyT, ValueT, Config>; 220 friend struct DenseMapInfo<ValueMapCallbackVH>; 221 typedef ValueMap<KeyT, ValueT, Config> ValueMapT; 222 typedef typename std::remove_pointer<KeyT>::type KeySansPointerT; 223 224 ValueMapT *Map; 225 226 ValueMapCallbackVH(KeyT Key, ValueMapT *Map) 227 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))), 228 Map(Map) {} 229 230 // Private constructor used to create empty/tombstone DenseMap keys. 231 ValueMapCallbackVH(Value *V) : CallbackVH(V), Map(nullptr) {} 232 233 public: 234 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); } 235 236 void deleted() override { 237 // Make a copy that won't get changed even when *this is destroyed. 238 ValueMapCallbackVH Copy(*this); 239 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data); 240 unique_lock<typename Config::mutex_type> Guard; 241 if (M) 242 Guard = unique_lock<typename Config::mutex_type>(*M); 243 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this. 244 Copy.Map->Map.erase(Copy); // Definitely destroys *this. 245 } 246 void allUsesReplacedWith(Value *new_key) override { 247 assert(isa<KeySansPointerT>(new_key) && 248 "Invalid RAUW on key of ValueMap<>"); 249 // Make a copy that won't get changed even when *this is destroyed. 250 ValueMapCallbackVH Copy(*this); 251 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data); 252 unique_lock<typename Config::mutex_type> Guard; 253 if (M) 254 Guard = unique_lock<typename Config::mutex_type>(*M); 255 256 KeyT typed_new_key = cast<KeySansPointerT>(new_key); 257 // Can destroy *this: 258 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key); 259 if (Config::FollowRAUW) { 260 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy); 261 // I could == Copy.Map->Map.end() if the onRAUW callback already 262 // removed the old mapping. 263 if (I != Copy.Map->Map.end()) { 264 ValueT Target(std::move(I->second)); 265 Copy.Map->Map.erase(I); // Definitely destroys *this. 266 Copy.Map->insert(std::make_pair(typed_new_key, std::move(Target))); 267 } 268 } 269 } 270 }; 271 272 template<typename KeyT, typename ValueT, typename Config> 273 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > { 274 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH; 275 276 static inline VH getEmptyKey() { 277 return VH(DenseMapInfo<Value *>::getEmptyKey()); 278 } 279 static inline VH getTombstoneKey() { 280 return VH(DenseMapInfo<Value *>::getTombstoneKey()); 281 } 282 static unsigned getHashValue(const VH &Val) { 283 return DenseMapInfo<KeyT>::getHashValue(Val.Unwrap()); 284 } 285 static unsigned getHashValue(const KeyT &Val) { 286 return DenseMapInfo<KeyT>::getHashValue(Val); 287 } 288 static bool isEqual(const VH &LHS, const VH &RHS) { 289 return LHS == RHS; 290 } 291 static bool isEqual(const KeyT &LHS, const VH &RHS) { 292 return LHS == RHS.getValPtr(); 293 } 294 }; 295 296 297 template<typename DenseMapT, typename KeyT> 298 class ValueMapIterator : 299 public std::iterator<std::forward_iterator_tag, 300 std::pair<KeyT, typename DenseMapT::mapped_type>, 301 ptrdiff_t> { 302 typedef typename DenseMapT::iterator BaseT; 303 typedef typename DenseMapT::mapped_type ValueT; 304 BaseT I; 305 public: 306 ValueMapIterator() : I() {} 307 308 ValueMapIterator(BaseT I) : I(I) {} 309 310 BaseT base() const { return I; } 311 312 struct ValueTypeProxy { 313 const KeyT first; 314 ValueT& second; 315 ValueTypeProxy *operator->() { return this; } 316 operator std::pair<KeyT, ValueT>() const { 317 return std::make_pair(first, second); 318 } 319 }; 320 321 ValueTypeProxy operator*() const { 322 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 323 return Result; 324 } 325 326 ValueTypeProxy operator->() const { 327 return operator*(); 328 } 329 330 bool operator==(const ValueMapIterator &RHS) const { 331 return I == RHS.I; 332 } 333 bool operator!=(const ValueMapIterator &RHS) const { 334 return I != RHS.I; 335 } 336 337 inline ValueMapIterator& operator++() { // Preincrement 338 ++I; 339 return *this; 340 } 341 ValueMapIterator operator++(int) { // Postincrement 342 ValueMapIterator tmp = *this; ++*this; return tmp; 343 } 344 }; 345 346 template<typename DenseMapT, typename KeyT> 347 class ValueMapConstIterator : 348 public std::iterator<std::forward_iterator_tag, 349 std::pair<KeyT, typename DenseMapT::mapped_type>, 350 ptrdiff_t> { 351 typedef typename DenseMapT::const_iterator BaseT; 352 typedef typename DenseMapT::mapped_type ValueT; 353 BaseT I; 354 public: 355 ValueMapConstIterator() : I() {} 356 ValueMapConstIterator(BaseT I) : I(I) {} 357 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other) 358 : I(Other.base()) {} 359 360 BaseT base() const { return I; } 361 362 struct ValueTypeProxy { 363 const KeyT first; 364 const ValueT& second; 365 ValueTypeProxy *operator->() { return this; } 366 operator std::pair<KeyT, ValueT>() const { 367 return std::make_pair(first, second); 368 } 369 }; 370 371 ValueTypeProxy operator*() const { 372 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 373 return Result; 374 } 375 376 ValueTypeProxy operator->() const { 377 return operator*(); 378 } 379 380 bool operator==(const ValueMapConstIterator &RHS) const { 381 return I == RHS.I; 382 } 383 bool operator!=(const ValueMapConstIterator &RHS) const { 384 return I != RHS.I; 385 } 386 387 inline ValueMapConstIterator& operator++() { // Preincrement 388 ++I; 389 return *this; 390 } 391 ValueMapConstIterator operator++(int) { // Postincrement 392 ValueMapConstIterator tmp = *this; ++*this; return tmp; 393 } 394 }; 395 396 } // end namespace llvm 397 398 #endif 399
