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/ValueHandle.h"
31 #include "llvm/Support/type_traits.h"
37 template<typename KeyT, typename ValueT, typename Config>
38 class ValueMapCallbackVH;
40 template<typename DenseMapT, typename KeyT>
41 class ValueMapIterator;
42 template<typename DenseMapT, typename KeyT>
43 class ValueMapConstIterator;
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 = std::recursive_mutex>
49 struct ValueMapConfig {
50 typedef MutexT mutex_type;
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 };
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.
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*/) {}
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; }
75 /// See the file comment.
76 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> >
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;
84 ValueMap(const ValueMap&) LLVM_DELETED_FUNCTION;
85 ValueMap& operator=(const ValueMap&) LLVM_DELETED_FUNCTION;
87 typedef KeyT key_type;
88 typedef ValueT mapped_type;
89 typedef std::pair<KeyT, ValueT> value_type;
91 explicit ValueMap(unsigned NumInitBuckets = 64)
92 : Map(NumInitBuckets), Data() {}
93 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64)
94 : Map(NumInitBuckets), Data(Data) {}
98 typedef ValueMapIterator<MapT, KeyT> iterator;
99 typedef ValueMapConstIterator<MapT, KeyT> const_iterator;
100 inline iterator begin() { return iterator(Map.begin()); }
101 inline iterator end() { return iterator(Map.end()); }
102 inline const_iterator begin() const { return const_iterator(Map.begin()); }
103 inline const_iterator end() const { return const_iterator(Map.end()); }
105 bool empty() const { return Map.empty(); }
106 unsigned size() const { return Map.size(); }
108 /// Grow the map so that it has at least Size buckets. Does not shrink
109 void resize(size_t Size) { Map.resize(Size); }
111 void clear() { Map.clear(); }
113 /// count - Return true if the specified key is in the map.
114 bool count(const KeyT &Val) const {
115 return Map.find_as(Val) != Map.end();
118 iterator find(const KeyT &Val) {
119 return iterator(Map.find_as(Val));
121 const_iterator find(const KeyT &Val) const {
122 return const_iterator(Map.find_as(Val));
125 /// lookup - Return the entry for the specified key, or a default
126 /// constructed value if no such entry exists.
127 ValueT lookup(const KeyT &Val) const {
128 typename MapT::const_iterator I = Map.find_as(Val);
129 return I != Map.end() ? I->second : ValueT();
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
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);
141 /// insert - Range insertion of pairs.
142 template<typename InputIt>
143 void insert(InputIt I, InputIt E) {
149 bool erase(const KeyT &Val) {
150 typename MapT::iterator I = Map.find_as(Val);
157 void erase(iterator I) {
158 return Map.erase(I.base());
161 value_type& FindAndConstruct(const KeyT &Key) {
162 return Map.FindAndConstruct(Wrap(Key));
165 ValueT &operator[](const KeyT &Key) {
166 return Map[Wrap(Key)];
169 /// isPointerIntoBucketsArray - Return true if the specified pointer points
170 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or
171 /// value in the ValueMap).
172 bool isPointerIntoBucketsArray(const void *Ptr) const {
173 return Map.isPointerIntoBucketsArray(Ptr);
176 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
177 /// array. In conjunction with the previous method, this can be used to
178 /// determine whether an insertion caused the ValueMap to reallocate.
179 const void *getPointerIntoBucketsArray() const {
180 return Map.getPointerIntoBucketsArray();
184 // Takes a key being looked up in the map and wraps it into a
185 // ValueMapCallbackVH, the actual key type of the map. We use a helper
186 // function because ValueMapCVH is constructed with a second parameter.
187 ValueMapCVH Wrap(KeyT key) const {
188 // The only way the resulting CallbackVH could try to modify *this (making
189 // the const_cast incorrect) is if it gets inserted into the map. But then
190 // this function must have been called from a non-const method, making the
192 return ValueMapCVH(key, const_cast<ValueMap*>(this));
196 // This CallbackVH updates its ValueMap when the contained Value changes,
197 // according to the user's preferences expressed through the Config object.
198 template<typename KeyT, typename ValueT, typename Config>
199 class ValueMapCallbackVH : public CallbackVH {
200 friend class ValueMap<KeyT, ValueT, Config>;
201 friend struct DenseMapInfo<ValueMapCallbackVH>;
202 typedef ValueMap<KeyT, ValueT, Config> ValueMapT;
203 typedef typename std::remove_pointer<KeyT>::type KeySansPointerT;
207 ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
208 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
212 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
214 void deleted() override {
215 // Make a copy that won't get changed even when *this is destroyed.
216 ValueMapCallbackVH Copy(*this);
217 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data);
220 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
221 Copy.Map->Map.erase(Copy); // Definitely destroys *this.
225 void allUsesReplacedWith(Value *new_key) override {
226 assert(isa<KeySansPointerT>(new_key) &&
227 "Invalid RAUW on key of ValueMap<>");
228 // Make a copy that won't get changed even when *this is destroyed.
229 ValueMapCallbackVH Copy(*this);
230 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data);
234 KeyT typed_new_key = cast<KeySansPointerT>(new_key);
235 // Can destroy *this:
236 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key);
237 if (Config::FollowRAUW) {
238 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy);
239 // I could == Copy.Map->Map.end() if the onRAUW callback already
240 // removed the old mapping.
241 if (I != Copy.Map->Map.end()) {
242 ValueT Target(I->second);
243 Copy.Map->Map.erase(I); // Definitely destroys *this.
244 Copy.Map->insert(std::make_pair(typed_new_key, Target));
252 template<typename KeyT, typename ValueT, typename Config>
253 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > {
254 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH;
255 typedef DenseMapInfo<KeyT> PointerInfo;
257 static inline VH getEmptyKey() {
258 return VH(PointerInfo::getEmptyKey(), nullptr);
260 static inline VH getTombstoneKey() {
261 return VH(PointerInfo::getTombstoneKey(), nullptr);
263 static unsigned getHashValue(const VH &Val) {
264 return PointerInfo::getHashValue(Val.Unwrap());
266 static unsigned getHashValue(const KeyT &Val) {
267 return PointerInfo::getHashValue(Val);
269 static bool isEqual(const VH &LHS, const VH &RHS) {
272 static bool isEqual(const KeyT &LHS, const VH &RHS) {
273 return LHS == RHS.getValPtr();
278 template<typename DenseMapT, typename KeyT>
279 class ValueMapIterator :
280 public std::iterator<std::forward_iterator_tag,
281 std::pair<KeyT, typename DenseMapT::mapped_type>,
283 typedef typename DenseMapT::iterator BaseT;
284 typedef typename DenseMapT::mapped_type ValueT;
287 ValueMapIterator() : I() {}
289 ValueMapIterator(BaseT I) : I(I) {}
291 BaseT base() const { return I; }
293 struct ValueTypeProxy {
296 ValueTypeProxy *operator->() { return this; }
297 operator std::pair<KeyT, ValueT>() const {
298 return std::make_pair(first, second);
302 ValueTypeProxy operator*() const {
303 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
307 ValueTypeProxy operator->() const {
311 bool operator==(const ValueMapIterator &RHS) const {
314 bool operator!=(const ValueMapIterator &RHS) const {
318 inline ValueMapIterator& operator++() { // Preincrement
322 ValueMapIterator operator++(int) { // Postincrement
323 ValueMapIterator tmp = *this; ++*this; return tmp;
327 template<typename DenseMapT, typename KeyT>
328 class ValueMapConstIterator :
329 public std::iterator<std::forward_iterator_tag,
330 std::pair<KeyT, typename DenseMapT::mapped_type>,
332 typedef typename DenseMapT::const_iterator BaseT;
333 typedef typename DenseMapT::mapped_type ValueT;
336 ValueMapConstIterator() : I() {}
337 ValueMapConstIterator(BaseT I) : I(I) {}
338 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other)
341 BaseT base() const { return I; }
343 struct ValueTypeProxy {
345 const ValueT& second;
346 ValueTypeProxy *operator->() { return this; }
347 operator std::pair<KeyT, ValueT>() const {
348 return std::make_pair(first, second);
352 ValueTypeProxy operator*() const {
353 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
357 ValueTypeProxy operator->() const {
361 bool operator==(const ValueMapConstIterator &RHS) const {
364 bool operator!=(const ValueMapConstIterator &RHS) const {
368 inline ValueMapConstIterator& operator++() { // Preincrement
372 ValueMapConstIterator operator++(int) { // Postincrement
373 ValueMapConstIterator tmp = *this; ++*this; return tmp;
377 } // end namespace llvm