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/System/Mutex.h"
38 template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
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>,
76 typename ValueInfoT = DenseMapInfo<ValueT> >
78 friend class ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT>;
79 typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> ValueMapCVH;
80 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH>,
82 typedef typename Config::ExtraData ExtraData;
86 typedef KeyT key_type;
87 typedef ValueT mapped_type;
88 typedef std::pair<KeyT, ValueT> value_type;
90 ValueMap(const ValueMap& Other) : Map(Other.Map), Data(Other.Data) {
91 // Each ValueMapCVH key contains a pointer to the containing ValueMap.
92 // The keys in the new map need to point to the new map, not Other.
93 for (typename MapT::iterator I = Map.begin(), E = Map.end(); I != E; ++I)
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 typedef ValueMapIterator<MapT, KeyT> iterator;
105 typedef ValueMapConstIterator<MapT, KeyT> const_iterator;
106 inline iterator begin() { return iterator(Map.begin()); }
107 inline iterator end() { return iterator(Map.end()); }
108 inline const_iterator begin() const { return const_iterator(Map.begin()); }
109 inline const_iterator end() const { return const_iterator(Map.end()); }
111 bool empty() const { return Map.empty(); }
112 unsigned size() const { return Map.size(); }
114 /// Grow the map so that it has at least Size buckets. Does not shrink
115 void resize(size_t Size) { Map.resize(Size); }
117 void clear() { Map.clear(); }
119 /// count - Return true if the specified key is in the map.
120 bool count(const KeyT &Val) const {
121 return Map.count(Wrap(Val));
124 iterator find(const KeyT &Val) {
125 return iterator(Map.find(Wrap(Val)));
127 const_iterator find(const KeyT &Val) const {
128 return const_iterator(Map.find(Wrap(Val)));
131 /// lookup - Return the entry for the specified key, or a default
132 /// constructed value if no such entry exists.
133 ValueT lookup(const KeyT &Val) const {
134 return Map.lookup(Wrap(Val));
137 // Inserts key,value pair into the map if the key isn't already in the map.
138 // If the key is already in the map, it returns false and doesn't update the
140 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
141 std::pair<typename MapT::iterator, bool> map_result=
142 Map.insert(std::make_pair(Wrap(KV.first), KV.second));
143 return std::make_pair(iterator(map_result.first), map_result.second);
146 /// insert - Range insertion of pairs.
147 template<typename InputIt>
148 void insert(InputIt I, InputIt E) {
154 bool erase(const KeyT &Val) {
155 return Map.erase(Wrap(Val));
157 bool 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 ValueMap& operator=(const ValueMap& Other) {
175 /// isPointerIntoBucketsArray - Return true if the specified pointer points
176 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or
177 /// value in the ValueMap).
178 bool isPointerIntoBucketsArray(const void *Ptr) const {
179 return Map.isPointerIntoBucketsArray(Ptr);
182 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
183 /// array. In conjunction with the previous method, this can be used to
184 /// determine whether an insertion caused the ValueMap to reallocate.
185 const void *getPointerIntoBucketsArray() const {
186 return Map.getPointerIntoBucketsArray();
190 // Takes a key being looked up in the map and wraps it into a
191 // ValueMapCallbackVH, the actual key type of the map. We use a helper
192 // function because ValueMapCVH is constructed with a second parameter.
193 ValueMapCVH Wrap(KeyT key) const {
194 // The only way the resulting CallbackVH could try to modify *this (making
195 // the const_cast incorrect) is if it gets inserted into the map. But then
196 // this function must have been called from a non-const method, making the
198 return ValueMapCVH(key, const_cast<ValueMap*>(this));
202 // This CallbackVH updates its ValueMap when the contained Value changes,
203 // according to the user's preferences expressed through the Config object.
204 template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
205 class ValueMapCallbackVH : public CallbackVH {
206 friend class ValueMap<KeyT, ValueT, Config, ValueInfoT>;
207 friend struct DenseMapInfo<ValueMapCallbackVH>;
208 typedef ValueMap<KeyT, ValueT, Config, ValueInfoT> ValueMapT;
209 typedef typename llvm::remove_pointer<KeyT>::type KeySansPointerT;
213 ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
214 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
218 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
220 virtual void deleted() {
221 // Make a copy that won't get changed even when *this is destroyed.
222 ValueMapCallbackVH Copy(*this);
223 sys::Mutex *M = Config::getMutex(Copy.Map->Data);
226 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
227 Copy.Map->Map.erase(Copy); // Definitely destroys *this.
231 virtual void allUsesReplacedWith(Value *new_key) {
232 assert(isa<KeySansPointerT>(new_key) &&
233 "Invalid RAUW on key of ValueMap<>");
234 // Make a copy that won't get changed even when *this is destroyed.
235 ValueMapCallbackVH Copy(*this);
236 sys::Mutex *M = Config::getMutex(Copy.Map->Data);
240 KeyT typed_new_key = cast<KeySansPointerT>(new_key);
241 // Can destroy *this:
242 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key);
243 if (Config::FollowRAUW) {
244 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy);
245 // I could == Copy.Map->Map.end() if the onRAUW callback already
246 // removed the old mapping.
247 if (I != Copy.Map->Map.end()) {
248 ValueT Target(I->second);
249 Copy.Map->Map.erase(I); // Definitely destroys *this.
250 Copy.Map->insert(std::make_pair(typed_new_key, Target));
258 template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
259 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > {
260 typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> VH;
261 typedef DenseMapInfo<KeyT> PointerInfo;
263 static inline VH getEmptyKey() {
264 return VH(PointerInfo::getEmptyKey(), NULL);
266 static inline VH getTombstoneKey() {
267 return VH(PointerInfo::getTombstoneKey(), NULL);
269 static unsigned getHashValue(const VH &Val) {
270 return PointerInfo::getHashValue(Val.Unwrap());
272 static bool isEqual(const VH &LHS, const VH &RHS) {
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