1 //===- llvm/ADT/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_ADT_VALUEMAP_H
27 #define LLVM_ADT_VALUEMAP_H
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"
38 template<typename KeyT, typename ValueT, typename Config>
39 class ValueMapCallbackVH;
41 template<typename DenseMapT, typename KeyT>
42 class ValueMapIterator;
43 template<typename DenseMapT, typename KeyT>
44 class ValueMapConstIterator;
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.
49 template<typename KeyT>
50 struct 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 };
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.
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*/) {}
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; }
74 /// See the file comment.
75 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> >
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;
83 ValueMap(const ValueMap&) LLVM_DELETED_FUNCTION;
84 ValueMap& operator=(const ValueMap&) LLVM_DELETED_FUNCTION;
86 typedef KeyT key_type;
87 typedef ValueT mapped_type;
88 typedef std::pair<KeyT, ValueT> value_type;
90 explicit ValueMap(unsigned NumInitBuckets = 64)
91 : Map(NumInitBuckets), Data() {}
92 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64)
93 : Map(NumInitBuckets), Data(Data) {}
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()); }
104 bool empty() const { return Map.empty(); }
105 unsigned size() const { return Map.size(); }
107 /// Grow the map so that it has at least Size buckets. Does not shrink
108 void resize(size_t Size) { Map.resize(Size); }
110 void clear() { Map.clear(); }
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();
117 iterator find(const KeyT &Val) {
118 return iterator(Map.find_as(Val));
120 const_iterator find(const KeyT &Val) const {
121 return const_iterator(Map.find_as(Val));
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();
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
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);
140 /// insert - Range insertion of pairs.
141 template<typename InputIt>
142 void insert(InputIt I, InputIt E) {
148 bool erase(const KeyT &Val) {
149 typename MapT::iterator I = Map.find_as(Val);
156 void erase(iterator I) {
157 return Map.erase(I.base());
160 value_type& FindAndConstruct(const KeyT &Key) {
161 return Map.FindAndConstruct(Wrap(Key));
164 ValueT &operator[](const KeyT &Key) {
165 return Map[Wrap(Key)];
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);
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();
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
191 return ValueMapCVH(key, const_cast<ValueMap*>(this));
195 // This CallbackVH updates its ValueMap when the contained Value changes,
196 // according to the user's preferences expressed through the Config object.
197 template<typename KeyT, typename ValueT, typename Config>
198 class 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;
206 ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
207 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
211 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
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);
219 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
220 Copy.Map->Map.erase(Copy); // Definitely destroys *this.
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);
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));
251 template<typename KeyT, typename ValueT, typename Config>
252 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > {
253 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH;
254 typedef DenseMapInfo<KeyT> PointerInfo;
256 static inline VH getEmptyKey() {
257 return VH(PointerInfo::getEmptyKey(), NULL);
259 static inline VH getTombstoneKey() {
260 return VH(PointerInfo::getTombstoneKey(), NULL);
262 static unsigned getHashValue(const VH &Val) {
263 return PointerInfo::getHashValue(Val.Unwrap());
265 static unsigned getHashValue(const KeyT &Val) {
266 return PointerInfo::getHashValue(Val);
268 static bool isEqual(const VH &LHS, const VH &RHS) {
271 static bool isEqual(const KeyT &LHS, const VH &RHS) {
272 return LHS == RHS.getValPtr();
277 template<typename DenseMapT, typename KeyT>
278 class ValueMapIterator :
279 public std::iterator<std::forward_iterator_tag,
280 std::pair<KeyT, typename DenseMapT::mapped_type>,
282 typedef typename DenseMapT::iterator BaseT;
283 typedef typename DenseMapT::mapped_type ValueT;
286 ValueMapIterator() : I() {}
288 ValueMapIterator(BaseT I) : I(I) {}
290 BaseT base() const { return I; }
292 struct ValueTypeProxy {
295 ValueTypeProxy *operator->() { return this; }
296 operator std::pair<KeyT, ValueT>() const {
297 return std::make_pair(first, second);
301 ValueTypeProxy operator*() const {
302 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
306 ValueTypeProxy operator->() const {
310 bool operator==(const ValueMapIterator &RHS) const {
313 bool operator!=(const ValueMapIterator &RHS) const {
317 inline ValueMapIterator& operator++() { // Preincrement
321 ValueMapIterator operator++(int) { // Postincrement
322 ValueMapIterator tmp = *this; ++*this; return tmp;
326 template<typename DenseMapT, typename KeyT>
327 class ValueMapConstIterator :
328 public std::iterator<std::forward_iterator_tag,
329 std::pair<KeyT, typename DenseMapT::mapped_type>,
331 typedef typename DenseMapT::const_iterator BaseT;
332 typedef typename DenseMapT::mapped_type ValueT;
335 ValueMapConstIterator() : I() {}
336 ValueMapConstIterator(BaseT I) : I(I) {}
337 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other)
340 BaseT base() const { return I; }
342 struct ValueTypeProxy {
344 const ValueT& second;
345 ValueTypeProxy *operator->() { return this; }
346 operator std::pair<KeyT, ValueT>() const {
347 return std::make_pair(first, second);
351 ValueTypeProxy operator*() const {
352 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
356 ValueTypeProxy operator->() const {
360 bool operator==(const ValueMapConstIterator &RHS) const {
363 bool operator!=(const ValueMapConstIterator &RHS) const {
367 inline ValueMapConstIterator& operator++() { // Preincrement
371 ValueMapConstIterator operator++(int) { // Postincrement
372 ValueMapConstIterator tmp = *this; ++*this; return tmp;
376 } // end namespace llvm