1 //===- ValueMap.h - Safe map from Values to data ----------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
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.
24 //===----------------------------------------------------------------------===//
26 #ifndef LLVM_IR_VALUEMAP_H
27 #define LLVM_IR_VALUEMAP_H
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"
40 template<typename KeyT, typename ValueT, typename Config>
41 class ValueMapCallbackVH;
43 template<typename DenseMapT, typename KeyT>
44 class ValueMapIterator;
45 template<typename DenseMapT, typename KeyT>
46 class ValueMapConstIterator;
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;
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 };
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.
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*/) {}
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; }
78 /// See the file comment.
79 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> >
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;
87 std::unique_ptr<MDMapT> MDMap;
89 ValueMap(const ValueMap&) = delete;
90 ValueMap& operator=(const ValueMap&) = delete;
92 typedef KeyT key_type;
93 typedef ValueT mapped_type;
94 typedef std::pair<KeyT, ValueT> value_type;
95 typedef unsigned size_type;
97 explicit ValueMap(unsigned NumInitBuckets = 64)
98 : Map(NumInitBuckets), Data() {}
99 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64)
100 : Map(NumInitBuckets), Data(Data) {}
104 bool hasMD() const { return MDMap; }
107 MDMap.reset(new MDMapT);
111 typedef ValueMapIterator<MapT, KeyT> iterator;
112 typedef ValueMapConstIterator<MapT, KeyT> const_iterator;
113 inline iterator begin() { return iterator(Map.begin()); }
114 inline iterator end() { return iterator(Map.end()); }
115 inline const_iterator begin() const { return const_iterator(Map.begin()); }
116 inline const_iterator end() const { return const_iterator(Map.end()); }
118 bool empty() const { return Map.empty(); }
119 size_type size() const { return Map.size(); }
121 /// Grow the map so that it has at least Size buckets. Does not shrink
122 void resize(size_t Size) { Map.resize(Size); }
129 /// Return 1 if the specified key is in the map, 0 otherwise.
130 size_type count(const KeyT &Val) const {
131 return Map.find_as(Val) == Map.end() ? 0 : 1;
134 iterator find(const KeyT &Val) {
135 return iterator(Map.find_as(Val));
137 const_iterator find(const KeyT &Val) const {
138 return const_iterator(Map.find_as(Val));
141 /// lookup - Return the entry for the specified key, or a default
142 /// constructed value if no such entry exists.
143 ValueT lookup(const KeyT &Val) const {
144 typename MapT::const_iterator I = Map.find_as(Val);
145 return I != Map.end() ? I->second : ValueT();
148 // Inserts key,value pair into the map if the key isn't already in the map.
149 // If the key is already in the map, it returns false and doesn't update the
151 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
152 std::pair<typename MapT::iterator, bool> map_result=
153 Map.insert(std::make_pair(Wrap(KV.first), KV.second));
154 return std::make_pair(iterator(map_result.first), map_result.second);
157 /// insert - Range insertion of pairs.
158 template<typename InputIt>
159 void insert(InputIt I, InputIt E) {
165 bool erase(const KeyT &Val) {
166 typename MapT::iterator I = Map.find_as(Val);
173 void erase(iterator I) {
174 return Map.erase(I.base());
177 value_type& FindAndConstruct(const KeyT &Key) {
178 return Map.FindAndConstruct(Wrap(Key));
181 ValueT &operator[](const KeyT &Key) {
182 return Map[Wrap(Key)];
185 /// isPointerIntoBucketsArray - Return true if the specified pointer points
186 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or
187 /// value in the ValueMap).
188 bool isPointerIntoBucketsArray(const void *Ptr) const {
189 return Map.isPointerIntoBucketsArray(Ptr);
192 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
193 /// array. In conjunction with the previous method, this can be used to
194 /// determine whether an insertion caused the ValueMap to reallocate.
195 const void *getPointerIntoBucketsArray() const {
196 return Map.getPointerIntoBucketsArray();
200 // Takes a key being looked up in the map and wraps it into a
201 // ValueMapCallbackVH, the actual key type of the map. We use a helper
202 // function because ValueMapCVH is constructed with a second parameter.
203 ValueMapCVH Wrap(KeyT key) const {
204 // The only way the resulting CallbackVH could try to modify *this (making
205 // the const_cast incorrect) is if it gets inserted into the map. But then
206 // this function must have been called from a non-const method, making the
208 return ValueMapCVH(key, const_cast<ValueMap*>(this));
212 // This CallbackVH updates its ValueMap when the contained Value changes,
213 // according to the user's preferences expressed through the Config object.
214 template<typename KeyT, typename ValueT, typename Config>
215 class ValueMapCallbackVH : public CallbackVH {
216 friend class ValueMap<KeyT, ValueT, Config>;
217 friend struct DenseMapInfo<ValueMapCallbackVH>;
218 typedef ValueMap<KeyT, ValueT, Config> ValueMapT;
219 typedef typename std::remove_pointer<KeyT>::type KeySansPointerT;
223 ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
224 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
227 // Private constructor used to create empty/tombstone DenseMap keys.
228 ValueMapCallbackVH(Value *V) : CallbackVH(V), Map(nullptr) {}
231 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
233 void deleted() override {
234 // Make a copy that won't get changed even when *this is destroyed.
235 ValueMapCallbackVH Copy(*this);
236 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data);
237 unique_lock<typename Config::mutex_type> Guard;
239 Guard = unique_lock<typename Config::mutex_type>(*M);
240 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
241 Copy.Map->Map.erase(Copy); // Definitely destroys *this.
243 void allUsesReplacedWith(Value *new_key) override {
244 assert(isa<KeySansPointerT>(new_key) &&
245 "Invalid RAUW on key of ValueMap<>");
246 // Make a copy that won't get changed even when *this is destroyed.
247 ValueMapCallbackVH Copy(*this);
248 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data);
249 unique_lock<typename Config::mutex_type> Guard;
251 Guard = unique_lock<typename Config::mutex_type>(*M);
253 KeyT typed_new_key = cast<KeySansPointerT>(new_key);
254 // Can destroy *this:
255 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key);
256 if (Config::FollowRAUW) {
257 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy);
258 // I could == Copy.Map->Map.end() if the onRAUW callback already
259 // removed the old mapping.
260 if (I != Copy.Map->Map.end()) {
261 ValueT Target(I->second);
262 Copy.Map->Map.erase(I); // Definitely destroys *this.
263 Copy.Map->insert(std::make_pair(typed_new_key, Target));
269 template<typename KeyT, typename ValueT, typename Config>
270 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > {
271 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH;
273 static inline VH getEmptyKey() {
274 return VH(DenseMapInfo<Value *>::getEmptyKey());
276 static inline VH getTombstoneKey() {
277 return VH(DenseMapInfo<Value *>::getTombstoneKey());
279 static unsigned getHashValue(const VH &Val) {
280 return DenseMapInfo<KeyT>::getHashValue(Val.Unwrap());
282 static unsigned getHashValue(const KeyT &Val) {
283 return DenseMapInfo<KeyT>::getHashValue(Val);
285 static bool isEqual(const VH &LHS, const VH &RHS) {
288 static bool isEqual(const KeyT &LHS, const VH &RHS) {
289 return LHS == RHS.getValPtr();
294 template<typename DenseMapT, typename KeyT>
295 class ValueMapIterator :
296 public std::iterator<std::forward_iterator_tag,
297 std::pair<KeyT, typename DenseMapT::mapped_type>,
299 typedef typename DenseMapT::iterator BaseT;
300 typedef typename DenseMapT::mapped_type ValueT;
303 ValueMapIterator() : I() {}
305 ValueMapIterator(BaseT I) : I(I) {}
307 BaseT base() const { return I; }
309 struct ValueTypeProxy {
312 ValueTypeProxy *operator->() { return this; }
313 operator std::pair<KeyT, ValueT>() const {
314 return std::make_pair(first, second);
318 ValueTypeProxy operator*() const {
319 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
323 ValueTypeProxy operator->() const {
327 bool operator==(const ValueMapIterator &RHS) const {
330 bool operator!=(const ValueMapIterator &RHS) const {
334 inline ValueMapIterator& operator++() { // Preincrement
338 ValueMapIterator operator++(int) { // Postincrement
339 ValueMapIterator tmp = *this; ++*this; return tmp;
343 template<typename DenseMapT, typename KeyT>
344 class ValueMapConstIterator :
345 public std::iterator<std::forward_iterator_tag,
346 std::pair<KeyT, typename DenseMapT::mapped_type>,
348 typedef typename DenseMapT::const_iterator BaseT;
349 typedef typename DenseMapT::mapped_type ValueT;
352 ValueMapConstIterator() : I() {}
353 ValueMapConstIterator(BaseT I) : I(I) {}
354 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other)
357 BaseT base() const { return I; }
359 struct ValueTypeProxy {
361 const ValueT& second;
362 ValueTypeProxy *operator->() { return this; }
363 operator std::pair<KeyT, ValueT>() const {
364 return std::make_pair(first, second);
368 ValueTypeProxy operator*() const {
369 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
373 ValueTypeProxy operator->() const {
377 bool operator==(const ValueMapConstIterator &RHS) const {
380 bool operator!=(const ValueMapConstIterator &RHS) const {
384 inline ValueMapConstIterator& operator++() { // Preincrement
388 ValueMapConstIterator operator++(int) { // Postincrement
389 ValueMapConstIterator tmp = *this; ++*this; return tmp;
393 } // end namespace llvm