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/Mutex.h"
31 #include "llvm/Support/ValueHandle.h"
32 #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>
49 struct ValueMapConfig {
50 /// If FollowRAUW is true, the ValueMap will update mappings on RAUW. If it's
51 /// false, the ValueMap will leave the original mapping in place.
52 enum { FollowRAUW = true };
54 // All methods will be called with a first argument of type ExtraData. The
55 // default implementations in this class take a templated first argument so
56 // that users' subclasses can use any type they want without having to
57 // override all the defaults.
60 template<typename ExtraDataT>
61 static void onRAUW(const ExtraDataT & /*Data*/, KeyT /*Old*/, KeyT /*New*/) {}
62 template<typename ExtraDataT>
63 static void onDelete(const ExtraDataT &/*Data*/, KeyT /*Old*/) {}
65 /// Returns a mutex that should be acquired around any changes to the map.
66 /// This is only acquired from the CallbackVH (and held around calls to onRAUW
67 /// and onDelete) and not inside other ValueMap methods. NULL means that no
68 /// mutex is necessary.
69 template<typename ExtraDataT>
70 static sys::Mutex *getMutex(const ExtraDataT &/*Data*/) { return NULL; }
73 /// See the file comment.
74 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> >
76 friend class ValueMapCallbackVH<KeyT, ValueT, Config>;
77 typedef ValueMapCallbackVH<KeyT, ValueT, Config> ValueMapCVH;
78 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH> > MapT;
79 typedef typename Config::ExtraData ExtraData;
82 ValueMap(const ValueMap&) LLVM_DELETED_FUNCTION;
83 ValueMap& operator=(const ValueMap&) LLVM_DELETED_FUNCTION;
85 typedef KeyT key_type;
86 typedef ValueT mapped_type;
87 typedef std::pair<KeyT, ValueT> value_type;
89 explicit ValueMap(unsigned NumInitBuckets = 64)
90 : Map(NumInitBuckets), Data() {}
91 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64)
92 : Map(NumInitBuckets), Data(Data) {}
96 typedef ValueMapIterator<MapT, KeyT> iterator;
97 typedef ValueMapConstIterator<MapT, KeyT> const_iterator;
98 inline iterator begin() { return iterator(Map.begin()); }
99 inline iterator end() { return iterator(Map.end()); }
100 inline const_iterator begin() const { return const_iterator(Map.begin()); }
101 inline const_iterator end() const { return const_iterator(Map.end()); }
103 bool empty() const { return Map.empty(); }
104 unsigned size() const { return Map.size(); }
106 /// Grow the map so that it has at least Size buckets. Does not shrink
107 void resize(size_t Size) { Map.resize(Size); }
109 void clear() { Map.clear(); }
111 /// count - Return true if the specified key is in the map.
112 bool count(const KeyT &Val) const {
113 return Map.find_as(Val) != Map.end();
116 iterator find(const KeyT &Val) {
117 return iterator(Map.find_as(Val));
119 const_iterator find(const KeyT &Val) const {
120 return const_iterator(Map.find_as(Val));
123 /// lookup - Return the entry for the specified key, or a default
124 /// constructed value if no such entry exists.
125 ValueT lookup(const KeyT &Val) const {
126 typename MapT::const_iterator I = Map.find_as(Val);
127 return I != Map.end() ? I->second : ValueT();
130 // Inserts key,value pair into the map if the key isn't already in the map.
131 // If the key is already in the map, it returns false and doesn't update the
133 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
134 std::pair<typename MapT::iterator, bool> map_result=
135 Map.insert(std::make_pair(Wrap(KV.first), KV.second));
136 return std::make_pair(iterator(map_result.first), map_result.second);
139 /// insert - Range insertion of pairs.
140 template<typename InputIt>
141 void insert(InputIt I, InputIt E) {
147 bool erase(const KeyT &Val) {
148 typename MapT::iterator I = Map.find_as(Val);
155 void erase(iterator I) {
156 return Map.erase(I.base());
159 value_type& FindAndConstruct(const KeyT &Key) {
160 return Map.FindAndConstruct(Wrap(Key));
163 ValueT &operator[](const KeyT &Key) {
164 return Map[Wrap(Key)];
167 /// isPointerIntoBucketsArray - Return true if the specified pointer points
168 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or
169 /// value in the ValueMap).
170 bool isPointerIntoBucketsArray(const void *Ptr) const {
171 return Map.isPointerIntoBucketsArray(Ptr);
174 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
175 /// array. In conjunction with the previous method, this can be used to
176 /// determine whether an insertion caused the ValueMap to reallocate.
177 const void *getPointerIntoBucketsArray() const {
178 return Map.getPointerIntoBucketsArray();
182 // Takes a key being looked up in the map and wraps it into a
183 // ValueMapCallbackVH, the actual key type of the map. We use a helper
184 // function because ValueMapCVH is constructed with a second parameter.
185 ValueMapCVH Wrap(KeyT key) const {
186 // The only way the resulting CallbackVH could try to modify *this (making
187 // the const_cast incorrect) is if it gets inserted into the map. But then
188 // this function must have been called from a non-const method, making the
190 return ValueMapCVH(key, const_cast<ValueMap*>(this));
194 // This CallbackVH updates its ValueMap when the contained Value changes,
195 // according to the user's preferences expressed through the Config object.
196 template<typename KeyT, typename ValueT, typename Config>
197 class ValueMapCallbackVH : public CallbackVH {
198 friend class ValueMap<KeyT, ValueT, Config>;
199 friend struct DenseMapInfo<ValueMapCallbackVH>;
200 typedef ValueMap<KeyT, ValueT, Config> ValueMapT;
201 typedef typename llvm::remove_pointer<KeyT>::type KeySansPointerT;
205 ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
206 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
210 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
212 virtual void deleted() {
213 // Make a copy that won't get changed even when *this is destroyed.
214 ValueMapCallbackVH Copy(*this);
215 sys::Mutex *M = Config::getMutex(Copy.Map->Data);
218 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
219 Copy.Map->Map.erase(Copy); // Definitely destroys *this.
223 virtual void allUsesReplacedWith(Value *new_key) {
224 assert(isa<KeySansPointerT>(new_key) &&
225 "Invalid RAUW on key of ValueMap<>");
226 // Make a copy that won't get changed even when *this is destroyed.
227 ValueMapCallbackVH Copy(*this);
228 sys::Mutex *M = Config::getMutex(Copy.Map->Data);
232 KeyT typed_new_key = cast<KeySansPointerT>(new_key);
233 // Can destroy *this:
234 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key);
235 if (Config::FollowRAUW) {
236 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy);
237 // I could == Copy.Map->Map.end() if the onRAUW callback already
238 // removed the old mapping.
239 if (I != Copy.Map->Map.end()) {
240 ValueT Target(I->second);
241 Copy.Map->Map.erase(I); // Definitely destroys *this.
242 Copy.Map->insert(std::make_pair(typed_new_key, Target));
250 template<typename KeyT, typename ValueT, typename Config>
251 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > {
252 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH;
253 typedef DenseMapInfo<KeyT> PointerInfo;
255 static inline VH getEmptyKey() {
256 return VH(PointerInfo::getEmptyKey(), NULL);
258 static inline VH getTombstoneKey() {
259 return VH(PointerInfo::getTombstoneKey(), NULL);
261 static unsigned getHashValue(const VH &Val) {
262 return PointerInfo::getHashValue(Val.Unwrap());
264 static unsigned getHashValue(const KeyT &Val) {
265 return PointerInfo::getHashValue(Val);
267 static bool isEqual(const VH &LHS, const VH &RHS) {
270 static bool isEqual(const KeyT &LHS, const VH &RHS) {
271 return LHS == RHS.getValPtr();
276 template<typename DenseMapT, typename KeyT>
277 class ValueMapIterator :
278 public std::iterator<std::forward_iterator_tag,
279 std::pair<KeyT, typename DenseMapT::mapped_type>,
281 typedef typename DenseMapT::iterator BaseT;
282 typedef typename DenseMapT::mapped_type ValueT;
285 ValueMapIterator() : I() {}
287 ValueMapIterator(BaseT I) : I(I) {}
289 BaseT base() const { return I; }
291 struct ValueTypeProxy {
294 ValueTypeProxy *operator->() { return this; }
295 operator std::pair<KeyT, ValueT>() const {
296 return std::make_pair(first, second);
300 ValueTypeProxy operator*() const {
301 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
305 ValueTypeProxy operator->() const {
309 bool operator==(const ValueMapIterator &RHS) const {
312 bool operator!=(const ValueMapIterator &RHS) const {
316 inline ValueMapIterator& operator++() { // Preincrement
320 ValueMapIterator operator++(int) { // Postincrement
321 ValueMapIterator tmp = *this; ++*this; return tmp;
325 template<typename DenseMapT, typename KeyT>
326 class ValueMapConstIterator :
327 public std::iterator<std::forward_iterator_tag,
328 std::pair<KeyT, typename DenseMapT::mapped_type>,
330 typedef typename DenseMapT::const_iterator BaseT;
331 typedef typename DenseMapT::mapped_type ValueT;
334 ValueMapConstIterator() : I() {}
335 ValueMapConstIterator(BaseT I) : I(I) {}
336 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other)
339 BaseT base() const { return I; }
341 struct ValueTypeProxy {
343 const ValueT& second;
344 ValueTypeProxy *operator->() { return this; }
345 operator std::pair<KeyT, ValueT>() const {
346 return std::make_pair(first, second);
350 ValueTypeProxy operator*() const {
351 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
355 ValueTypeProxy operator->() const {
359 bool operator==(const ValueMapConstIterator &RHS) const {
362 bool operator!=(const ValueMapConstIterator &RHS) const {
366 inline ValueMapConstIterator& operator++() { // Preincrement
370 ValueMapConstIterator operator++(int) { // Postincrement
371 ValueMapConstIterator tmp = *this; ++*this; return tmp;
375 } // end namespace llvm