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/Support/Mutex.h" 33 34#include <iterator> 35 36namespace llvm { 37 38template<typename KeyT, typename ValueT, typename Config> 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> > 76class ValueMap { 77 friend class ValueMapCallbackVH<KeyT, ValueT, Config>; 78 typedef ValueMapCallbackVH<KeyT, ValueT, Config> ValueMapCVH; 79 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH> > MapT; 80 typedef typename Config::ExtraData ExtraData; 81 MapT Map; 82 ExtraData Data; 83 ValueMap(const ValueMap&) LLVM_DELETED_FUNCTION; 84 ValueMap& operator=(const ValueMap&) LLVM_DELETED_FUNCTION; 85public: 86 typedef KeyT key_type; 87 typedef ValueT mapped_type; 88 typedef std::pair<KeyT, ValueT> value_type; 89 90 explicit ValueMap(unsigned NumInitBuckets = 64) 91 : Map(NumInitBuckets), Data() {} 92 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64) 93 : Map(NumInitBuckets), Data(Data) {} 94 95 ~ValueMap() {} 96 97 typedef ValueMapIterator<MapT, KeyT> iterator; 98 typedef ValueMapConstIterator<MapT, KeyT> const_iterator; 99 inline iterator begin() { return iterator(Map.begin()); } 100 inline iterator end() { return iterator(Map.end()); } 101 inline const_iterator begin() const { return const_iterator(Map.begin()); } 102 inline const_iterator end() const { return const_iterator(Map.end()); } 103 104 bool empty() const { return Map.empty(); } 105 unsigned size() const { return Map.size(); } 106 107 /// Grow the map so that it has at least Size buckets. Does not shrink 108 void resize(size_t Size) { Map.resize(Size); } 109 110 void clear() { Map.clear(); } 111 112 /// count - Return true if the specified key is in the map. 113 bool count(const KeyT &Val) const { 114 return Map.find_as(Val) != Map.end(); 115 } 116 117 iterator find(const KeyT &Val) { 118 return iterator(Map.find_as(Val)); 119 } 120 const_iterator find(const KeyT &Val) const { 121 return const_iterator(Map.find_as(Val)); 122 } 123 124 /// lookup - Return the entry for the specified key, or a default 125 /// constructed value if no such entry exists. 126 ValueT lookup(const KeyT &Val) const { 127 typename MapT::const_iterator I = Map.find_as(Val); 128 return I != Map.end() ? I->second : ValueT(); 129 } 130 131 // Inserts key,value pair into the map if the key isn't already in the map. 132 // If the key is already in the map, it returns false and doesn't update the 133 // value. 134 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { 135 std::pair<typename MapT::iterator, bool> map_result= 136 Map.insert(std::make_pair(Wrap(KV.first), KV.second)); 137 return std::make_pair(iterator(map_result.first), map_result.second); 138 } 139 140 /// insert - Range insertion of pairs. 141 template<typename InputIt> 142 void insert(InputIt I, InputIt E) { 143 for (; I != E; ++I) 144 insert(*I); 145 } 146 147 148 bool erase(const KeyT &Val) { 149 typename MapT::iterator I = Map.find_as(Val); 150 if (I == Map.end()) 151 return false; 152 153 Map.erase(I); 154 return true; 155 } 156 void erase(iterator I) { 157 return Map.erase(I.base()); 158 } 159 160 value_type& FindAndConstruct(const KeyT &Key) { 161 return Map.FindAndConstruct(Wrap(Key)); 162 } 163 164 ValueT &operator[](const KeyT &Key) { 165 return Map[Wrap(Key)]; 166 } 167 168 /// isPointerIntoBucketsArray - Return true if the specified pointer points 169 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or 170 /// value in the ValueMap). 171 bool isPointerIntoBucketsArray(const void *Ptr) const { 172 return Map.isPointerIntoBucketsArray(Ptr); 173 } 174 175 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets 176 /// array. In conjunction with the previous method, this can be used to 177 /// determine whether an insertion caused the ValueMap to reallocate. 178 const void *getPointerIntoBucketsArray() const { 179 return Map.getPointerIntoBucketsArray(); 180 } 181 182private: 183 // Takes a key being looked up in the map and wraps it into a 184 // ValueMapCallbackVH, the actual key type of the map. We use a helper 185 // function because ValueMapCVH is constructed with a second parameter. 186 ValueMapCVH Wrap(KeyT key) const { 187 // The only way the resulting CallbackVH could try to modify *this (making 188 // the const_cast incorrect) is if it gets inserted into the map. But then 189 // this function must have been called from a non-const method, making the 190 // const_cast ok. 191 return ValueMapCVH(key, const_cast<ValueMap*>(this)); 192 } 193}; 194 195// This CallbackVH updates its ValueMap when the contained Value changes, 196// according to the user's preferences expressed through the Config object. 197template<typename KeyT, typename ValueT, typename Config> 198class ValueMapCallbackVH : public CallbackVH { 199 friend class ValueMap<KeyT, ValueT, Config>; 200 friend struct DenseMapInfo<ValueMapCallbackVH>; 201 typedef ValueMap<KeyT, ValueT, Config> ValueMapT; 202 typedef typename llvm::remove_pointer<KeyT>::type KeySansPointerT; 203 204 ValueMapT *Map; 205 206 ValueMapCallbackVH(KeyT Key, ValueMapT *Map) 207 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))), 208 Map(Map) {} 209 210public: 211 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); } 212 213 virtual void deleted() { 214 // Make a copy that won't get changed even when *this is destroyed. 215 ValueMapCallbackVH Copy(*this); 216 sys::Mutex *M = Config::getMutex(Copy.Map->Data); 217 if (M) 218 M->acquire(); 219 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this. 220 Copy.Map->Map.erase(Copy); // Definitely destroys *this. 221 if (M) 222 M->release(); 223 } 224 virtual void allUsesReplacedWith(Value *new_key) { 225 assert(isa<KeySansPointerT>(new_key) && 226 "Invalid RAUW on key of ValueMap<>"); 227 // Make a copy that won't get changed even when *this is destroyed. 228 ValueMapCallbackVH Copy(*this); 229 sys::Mutex *M = Config::getMutex(Copy.Map->Data); 230 if (M) 231 M->acquire(); 232 233 KeyT typed_new_key = cast<KeySansPointerT>(new_key); 234 // Can destroy *this: 235 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key); 236 if (Config::FollowRAUW) { 237 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy); 238 // I could == Copy.Map->Map.end() if the onRAUW callback already 239 // removed the old mapping. 240 if (I != Copy.Map->Map.end()) { 241 ValueT Target(I->second); 242 Copy.Map->Map.erase(I); // Definitely destroys *this. 243 Copy.Map->insert(std::make_pair(typed_new_key, Target)); 244 } 245 } 246 if (M) 247 M->release(); 248 } 249}; 250 251template<typename KeyT, typename ValueT, typename Config> 252struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > { 253 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH; 254 typedef DenseMapInfo<KeyT> PointerInfo; 255 256 static inline VH getEmptyKey() { 257 return VH(PointerInfo::getEmptyKey(), NULL); 258 } 259 static inline VH getTombstoneKey() { 260 return VH(PointerInfo::getTombstoneKey(), NULL); 261 } 262 static unsigned getHashValue(const VH &Val) { 263 return PointerInfo::getHashValue(Val.Unwrap()); 264 } 265 static unsigned getHashValue(const KeyT &Val) { 266 return PointerInfo::getHashValue(Val); 267 } 268 static bool isEqual(const VH &LHS, const VH &RHS) { 269 return LHS == RHS; 270 } 271 static bool isEqual(const KeyT &LHS, const VH &RHS) { 272 return LHS == RHS.getValPtr(); 273 } 274}; 275 276 277template<typename DenseMapT, typename KeyT> 278class ValueMapIterator : 279 public std::iterator<std::forward_iterator_tag, 280 std::pair<KeyT, typename DenseMapT::mapped_type>, 281 ptrdiff_t> { 282 typedef typename DenseMapT::iterator BaseT; 283 typedef typename DenseMapT::mapped_type ValueT; 284 BaseT I; 285public: 286 ValueMapIterator() : I() {} 287 288 ValueMapIterator(BaseT I) : I(I) {} 289 290 BaseT base() const { return I; } 291 292 struct ValueTypeProxy { 293 const KeyT first; 294 ValueT& second; 295 ValueTypeProxy *operator->() { return this; } 296 operator std::pair<KeyT, ValueT>() const { 297 return std::make_pair(first, second); 298 } 299 }; 300 301 ValueTypeProxy operator*() const { 302 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 303 return Result; 304 } 305 306 ValueTypeProxy operator->() const { 307 return operator*(); 308 } 309 310 bool operator==(const ValueMapIterator &RHS) const { 311 return I == RHS.I; 312 } 313 bool operator!=(const ValueMapIterator &RHS) const { 314 return I != RHS.I; 315 } 316 317 inline ValueMapIterator& operator++() { // Preincrement 318 ++I; 319 return *this; 320 } 321 ValueMapIterator operator++(int) { // Postincrement 322 ValueMapIterator tmp = *this; ++*this; return tmp; 323 } 324}; 325 326template<typename DenseMapT, typename KeyT> 327class ValueMapConstIterator : 328 public std::iterator<std::forward_iterator_tag, 329 std::pair<KeyT, typename DenseMapT::mapped_type>, 330 ptrdiff_t> { 331 typedef typename DenseMapT::const_iterator BaseT; 332 typedef typename DenseMapT::mapped_type ValueT; 333 BaseT I; 334public: 335 ValueMapConstIterator() : I() {} 336 ValueMapConstIterator(BaseT I) : I(I) {} 337 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other) 338 : I(Other.base()) {} 339 340 BaseT base() const { return I; } 341 342 struct ValueTypeProxy { 343 const KeyT first; 344 const ValueT& second; 345 ValueTypeProxy *operator->() { return this; } 346 operator std::pair<KeyT, ValueT>() const { 347 return std::make_pair(first, second); 348 } 349 }; 350 351 ValueTypeProxy operator*() const { 352 ValueTypeProxy Result = {I->first.Unwrap(), I->second}; 353 return Result; 354 } 355 356 ValueTypeProxy operator->() const { 357 return operator*(); 358 } 359 360 bool operator==(const ValueMapConstIterator &RHS) const { 361 return I == RHS.I; 362 } 363 bool operator!=(const ValueMapConstIterator &RHS) const { 364 return I != RHS.I; 365 } 366 367 inline ValueMapConstIterator& operator++() { // Preincrement 368 ++I; 369 return *this; 370 } 371 ValueMapConstIterator operator++(int) { // Postincrement 372 ValueMapConstIterator tmp = *this; ++*this; return tmp; 373 } 374}; 375 376} // end namespace llvm 377 378#endif 379