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"
39 template<typename KeyT, typename ValueT, typename Config>
40 class ValueMapCallbackVH;
42 template<typename DenseMapT, typename KeyT>
43 class ValueMapIterator;
44 template<typename DenseMapT, typename KeyT>
45 class ValueMapConstIterator;
47 /// This class defines the default behavior for configurable aspects of
48 /// ValueMap<>. User Configs should inherit from this class to be as compatible
49 /// as possible with future versions of ValueMap.
50 template<typename KeyT, typename MutexT = sys::Mutex>
51 struct ValueMapConfig {
52 typedef MutexT mutex_type;
54 /// If FollowRAUW is true, the ValueMap will update mappings on RAUW. If it's
55 /// false, the ValueMap will leave the original mapping in place.
56 enum { FollowRAUW = true };
58 // All methods will be called with a first argument of type ExtraData. The
59 // default implementations in this class take a templated first argument so
60 // that users' subclasses can use any type they want without having to
61 // override all the defaults.
64 template<typename ExtraDataT>
65 static void onRAUW(const ExtraDataT & /*Data*/, KeyT /*Old*/, KeyT /*New*/) {}
66 template<typename ExtraDataT>
67 static void onDelete(const ExtraDataT &/*Data*/, KeyT /*Old*/) {}
69 /// Returns a mutex that should be acquired around any changes to the map.
70 /// This is only acquired from the CallbackVH (and held around calls to onRAUW
71 /// and onDelete) and not inside other ValueMap methods. NULL means that no
72 /// mutex is necessary.
73 template<typename ExtraDataT>
74 static mutex_type *getMutex(const ExtraDataT &/*Data*/) { return nullptr; }
77 /// See the file comment.
78 template<typename KeyT, typename ValueT, typename Config =ValueMapConfig<KeyT> >
80 friend class ValueMapCallbackVH<KeyT, ValueT, Config>;
81 typedef ValueMapCallbackVH<KeyT, ValueT, Config> ValueMapCVH;
82 typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH> > MapT;
83 typedef DenseMap<const Metadata *, TrackingMDRef> MDMapT;
84 typedef typename Config::ExtraData ExtraData;
86 std::unique_ptr<MDMapT> MDMap;
88 ValueMap(const ValueMap&) LLVM_DELETED_FUNCTION;
89 ValueMap& operator=(const ValueMap&) LLVM_DELETED_FUNCTION;
91 typedef KeyT key_type;
92 typedef ValueT mapped_type;
93 typedef std::pair<KeyT, ValueT> value_type;
94 typedef unsigned size_type;
96 explicit ValueMap(unsigned NumInitBuckets = 64)
97 : Map(NumInitBuckets), Data() {}
98 explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64)
99 : Map(NumInitBuckets), Data(Data) {}
103 bool hasMD() const { return MDMap; }
106 MDMap.reset(new MDMapT);
110 typedef ValueMapIterator<MapT, KeyT> iterator;
111 typedef ValueMapConstIterator<MapT, KeyT> const_iterator;
112 inline iterator begin() { return iterator(Map.begin()); }
113 inline iterator end() { return iterator(Map.end()); }
114 inline const_iterator begin() const { return const_iterator(Map.begin()); }
115 inline const_iterator end() const { return const_iterator(Map.end()); }
117 bool empty() const { return Map.empty(); }
118 size_type size() const { return Map.size(); }
120 /// Grow the map so that it has at least Size buckets. Does not shrink
121 void resize(size_t Size) { Map.resize(Size); }
128 /// Return 1 if the specified key is in the map, 0 otherwise.
129 size_type count(const KeyT &Val) const {
130 return Map.find_as(Val) == Map.end() ? 0 : 1;
133 iterator find(const KeyT &Val) {
134 return iterator(Map.find_as(Val));
136 const_iterator find(const KeyT &Val) const {
137 return const_iterator(Map.find_as(Val));
140 /// lookup - Return the entry for the specified key, or a default
141 /// constructed value if no such entry exists.
142 ValueT lookup(const KeyT &Val) const {
143 typename MapT::const_iterator I = Map.find_as(Val);
144 return I != Map.end() ? I->second : ValueT();
147 // Inserts key,value pair into the map if the key isn't already in the map.
148 // If the key is already in the map, it returns false and doesn't update the
150 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
151 std::pair<typename MapT::iterator, bool> map_result=
152 Map.insert(std::make_pair(Wrap(KV.first), KV.second));
153 return std::make_pair(iterator(map_result.first), map_result.second);
156 /// insert - Range insertion of pairs.
157 template<typename InputIt>
158 void insert(InputIt I, InputIt E) {
164 bool erase(const KeyT &Val) {
165 typename MapT::iterator I = Map.find_as(Val);
172 void erase(iterator I) {
173 return Map.erase(I.base());
176 value_type& FindAndConstruct(const KeyT &Key) {
177 return Map.FindAndConstruct(Wrap(Key));
180 ValueT &operator[](const KeyT &Key) {
181 return Map[Wrap(Key)];
184 /// isPointerIntoBucketsArray - Return true if the specified pointer points
185 /// somewhere into the ValueMap's array of buckets (i.e. either to a key or
186 /// value in the ValueMap).
187 bool isPointerIntoBucketsArray(const void *Ptr) const {
188 return Map.isPointerIntoBucketsArray(Ptr);
191 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
192 /// array. In conjunction with the previous method, this can be used to
193 /// determine whether an insertion caused the ValueMap to reallocate.
194 const void *getPointerIntoBucketsArray() const {
195 return Map.getPointerIntoBucketsArray();
199 // Takes a key being looked up in the map and wraps it into a
200 // ValueMapCallbackVH, the actual key type of the map. We use a helper
201 // function because ValueMapCVH is constructed with a second parameter.
202 ValueMapCVH Wrap(KeyT key) const {
203 // The only way the resulting CallbackVH could try to modify *this (making
204 // the const_cast incorrect) is if it gets inserted into the map. But then
205 // this function must have been called from a non-const method, making the
207 return ValueMapCVH(key, const_cast<ValueMap*>(this));
211 // This CallbackVH updates its ValueMap when the contained Value changes,
212 // according to the user's preferences expressed through the Config object.
213 template<typename KeyT, typename ValueT, typename Config>
214 class ValueMapCallbackVH : public CallbackVH {
215 friend class ValueMap<KeyT, ValueT, Config>;
216 friend struct DenseMapInfo<ValueMapCallbackVH>;
217 typedef ValueMap<KeyT, ValueT, Config> ValueMapT;
218 typedef typename std::remove_pointer<KeyT>::type KeySansPointerT;
222 ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
223 : CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
227 KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
229 void deleted() override {
230 // Make a copy that won't get changed even when *this is destroyed.
231 ValueMapCallbackVH Copy(*this);
232 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data);
233 unique_lock<typename Config::mutex_type> Guard;
235 Guard = unique_lock<typename Config::mutex_type>(*M);
236 Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
237 Copy.Map->Map.erase(Copy); // Definitely destroys *this.
239 void allUsesReplacedWith(Value *new_key) override {
240 assert(isa<KeySansPointerT>(new_key) &&
241 "Invalid RAUW on key of ValueMap<>");
242 // Make a copy that won't get changed even when *this is destroyed.
243 ValueMapCallbackVH Copy(*this);
244 typename Config::mutex_type *M = Config::getMutex(Copy.Map->Data);
245 unique_lock<typename Config::mutex_type> Guard;
247 Guard = unique_lock<typename Config::mutex_type>(*M);
249 KeyT typed_new_key = cast<KeySansPointerT>(new_key);
250 // Can destroy *this:
251 Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key);
252 if (Config::FollowRAUW) {
253 typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy);
254 // I could == Copy.Map->Map.end() if the onRAUW callback already
255 // removed the old mapping.
256 if (I != Copy.Map->Map.end()) {
257 ValueT Target(I->second);
258 Copy.Map->Map.erase(I); // Definitely destroys *this.
259 Copy.Map->insert(std::make_pair(typed_new_key, Target));
265 template<typename KeyT, typename ValueT, typename Config>
266 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config> > {
267 typedef ValueMapCallbackVH<KeyT, ValueT, Config> VH;
268 typedef DenseMapInfo<KeyT> PointerInfo;
270 static inline VH getEmptyKey() {
271 return VH(PointerInfo::getEmptyKey(), nullptr);
273 static inline VH getTombstoneKey() {
274 return VH(PointerInfo::getTombstoneKey(), nullptr);
276 static unsigned getHashValue(const VH &Val) {
277 return PointerInfo::getHashValue(Val.Unwrap());
279 static unsigned getHashValue(const KeyT &Val) {
280 return PointerInfo::getHashValue(Val);
282 static bool isEqual(const VH &LHS, const VH &RHS) {
285 static bool isEqual(const KeyT &LHS, const VH &RHS) {
286 return LHS == RHS.getValPtr();
291 template<typename DenseMapT, typename KeyT>
292 class ValueMapIterator :
293 public std::iterator<std::forward_iterator_tag,
294 std::pair<KeyT, typename DenseMapT::mapped_type>,
296 typedef typename DenseMapT::iterator BaseT;
297 typedef typename DenseMapT::mapped_type ValueT;
300 ValueMapIterator() : I() {}
302 ValueMapIterator(BaseT I) : I(I) {}
304 BaseT base() const { return I; }
306 struct ValueTypeProxy {
309 ValueTypeProxy *operator->() { return this; }
310 operator std::pair<KeyT, ValueT>() const {
311 return std::make_pair(first, second);
315 ValueTypeProxy operator*() const {
316 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
320 ValueTypeProxy operator->() const {
324 bool operator==(const ValueMapIterator &RHS) const {
327 bool operator!=(const ValueMapIterator &RHS) const {
331 inline ValueMapIterator& operator++() { // Preincrement
335 ValueMapIterator operator++(int) { // Postincrement
336 ValueMapIterator tmp = *this; ++*this; return tmp;
340 template<typename DenseMapT, typename KeyT>
341 class ValueMapConstIterator :
342 public std::iterator<std::forward_iterator_tag,
343 std::pair<KeyT, typename DenseMapT::mapped_type>,
345 typedef typename DenseMapT::const_iterator BaseT;
346 typedef typename DenseMapT::mapped_type ValueT;
349 ValueMapConstIterator() : I() {}
350 ValueMapConstIterator(BaseT I) : I(I) {}
351 ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other)
354 BaseT base() const { return I; }
356 struct ValueTypeProxy {
358 const ValueT& second;
359 ValueTypeProxy *operator->() { return this; }
360 operator std::pair<KeyT, ValueT>() const {
361 return std::make_pair(first, second);
365 ValueTypeProxy operator*() const {
366 ValueTypeProxy Result = {I->first.Unwrap(), I->second};
370 ValueTypeProxy operator->() const {
374 bool operator==(const ValueMapConstIterator &RHS) const {
377 bool operator!=(const ValueMapConstIterator &RHS) const {
381 inline ValueMapConstIterator& operator++() { // Preincrement
385 ValueMapConstIterator operator++(int) { // Postincrement
386 ValueMapConstIterator tmp = *this; ++*this; return tmp;
390 } // end namespace llvm