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//===- llvm/ADT/ValueMap.h - Safe map from Values to data -------*- C++ -*-===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file defines the ValueMap class. ValueMap maps Value* or any subclass
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// to an arbitrary other type. It provides the DenseMap interface but updates
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// itself to remain safe when keys are RAUWed or deleted. By default, when a
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// key is RAUWed from V1 to V2, the old mapping V1->target is removed, and a new
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// mapping V2->target is added. If V2 already existed, its old target is
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// overwritten. When a key is deleted, its mapping is removed.
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// You can override a ValueMap's Config parameter to control exactly what
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// happens on RAUW and destruction and to get called back on each event. It's
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// legal to call back into the ValueMap from a Config's callbacks. Config
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// parameters should inherit from ValueMapConfig<KeyT> to get default
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// implementations of all the methods ValueMap uses. See ValueMapConfig for
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// documentation of the functions you can override.
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ADT_VALUEMAP_H
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#define LLVM_ADT_VALUEMAP_H
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/Support/ValueHandle.h"
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#include "llvm/Support/type_traits.h"
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#include "llvm/System/Mutex.h"
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template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
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class ValueMapCallbackVH;
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template<typename DenseMapT, typename KeyT>
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class ValueMapIterator;
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template<typename DenseMapT, typename KeyT>
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class ValueMapConstIterator;
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/// This class defines the default behavior for configurable aspects of
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/// ValueMap<>. User Configs should inherit from this class to be as compatible
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/// as possible with future versions of ValueMap.
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template<typename KeyT>
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struct ValueMapConfig {
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/// If FollowRAUW is true, the ValueMap will update mappings on RAUW. If it's
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/// false, the ValueMap will leave the original mapping in place.
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enum { FollowRAUW = true };
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// All methods will be called with a first argument of type ExtraData. The
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// default implementations in this class take a templated first argument so
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// that users' subclasses can use any type they want without having to
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// override all the defaults.
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template<typename ExtraDataT>
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static void onRAUW(const ExtraDataT &Data, KeyT Old, KeyT New) {}
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template<typename ExtraDataT>
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static void onDelete(const ExtraDataT &Data, KeyT Old) {}
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/// Returns a mutex that should be acquired around any changes to the map.
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/// This is only acquired from the CallbackVH (and held around calls to onRAUW
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/// and onDelete) and not inside other ValueMap methods. NULL means that no
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/// mutex is necessary.
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template<typename ExtraDataT>
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static sys::Mutex *getMutex(const ExtraDataT &Data) { return NULL; }
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/// See the file comment.
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template<typename KeyT, typename ValueT, typename Config = ValueMapConfig<KeyT>,
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typename ValueInfoT = DenseMapInfo<ValueT> >
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friend class ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT>;
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typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> ValueMapCVH;
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typedef DenseMap<ValueMapCVH, ValueT, DenseMapInfo<ValueMapCVH>,
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typedef typename Config::ExtraData ExtraData;
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typedef KeyT key_type;
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typedef ValueT mapped_type;
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typedef std::pair<KeyT, ValueT> value_type;
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ValueMap(const ValueMap& Other) : Map(Other.Map), Data(Other.Data) {}
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explicit ValueMap(unsigned NumInitBuckets = 64)
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: Map(NumInitBuckets), Data() {}
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explicit ValueMap(const ExtraData &Data, unsigned NumInitBuckets = 64)
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: Map(NumInitBuckets), Data(Data) {}
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typedef ValueMapIterator<MapT, KeyT> iterator;
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typedef ValueMapConstIterator<MapT, KeyT> const_iterator;
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inline iterator begin() { return iterator(Map.begin()); }
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inline iterator end() { return iterator(Map.end()); }
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inline const_iterator begin() const { return const_iterator(Map.begin()); }
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inline const_iterator end() const { return const_iterator(Map.end()); }
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bool empty() const { return Map.empty(); }
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unsigned size() const { return Map.size(); }
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/// Grow the map so that it has at least Size buckets. Does not shrink
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void resize(size_t Size) { Map.resize(Size); }
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void clear() { Map.clear(); }
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/// count - Return true if the specified key is in the map.
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bool count(const KeyT &Val) const {
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return Map.count(Wrap(Val));
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iterator find(const KeyT &Val) {
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return iterator(Map.find(Wrap(Val)));
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const_iterator find(const KeyT &Val) const {
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return const_iterator(Map.find(Wrap(Val)));
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/// lookup - Return the entry for the specified key, or a default
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/// constructed value if no such entry exists.
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ValueT lookup(const KeyT &Val) const {
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return Map.lookup(Wrap(Val));
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// Inserts key,value pair into the map if the key isn't already in the map.
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// If the key is already in the map, it returns false and doesn't update the
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std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
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std::pair<typename MapT::iterator, bool> map_result=
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Map.insert(std::make_pair(Wrap(KV.first), KV.second));
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return std::make_pair(iterator(map_result.first), map_result.second);
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/// insert - Range insertion of pairs.
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template<typename InputIt>
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void insert(InputIt I, InputIt E) {
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bool erase(const KeyT &Val) {
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return Map.erase(Wrap(Val));
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bool erase(iterator I) {
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return Map.erase(I.base());
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value_type& FindAndConstruct(const KeyT &Key) {
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return Map.FindAndConstruct(Wrap(Key));
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ValueT &operator[](const KeyT &Key) {
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return Map[Wrap(Key)];
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ValueMap& operator=(const ValueMap& Other) {
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/// isPointerIntoBucketsArray - Return true if the specified pointer points
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/// somewhere into the ValueMap's array of buckets (i.e. either to a key or
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/// value in the ValueMap).
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bool isPointerIntoBucketsArray(const void *Ptr) const {
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return Map.isPointerIntoBucketsArray(Ptr);
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/// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
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/// array. In conjunction with the previous method, this can be used to
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/// determine whether an insertion caused the ValueMap to reallocate.
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const void *getPointerIntoBucketsArray() const {
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return Map.getPointerIntoBucketsArray();
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// Takes a key being looked up in the map and wraps it into a
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// ValueMapCallbackVH, the actual key type of the map. We use a helper
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// function because ValueMapCVH is constructed with a second parameter.
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ValueMapCVH Wrap(KeyT key) const {
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// The only way the resulting CallbackVH could try to modify *this (making
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// the const_cast incorrect) is if it gets inserted into the map. But then
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// this function must have been called from a non-const method, making the
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return ValueMapCVH(key, const_cast<ValueMap*>(this));
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// This CallbackVH updates its ValueMap when the contained Value changes,
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// according to the user's preferences expressed through the Config object.
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template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
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class ValueMapCallbackVH : public CallbackVH {
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friend class ValueMap<KeyT, ValueT, Config, ValueInfoT>;
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friend struct DenseMapInfo<ValueMapCallbackVH>;
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typedef ValueMap<KeyT, ValueT, Config, ValueInfoT> ValueMapT;
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typedef typename llvm::remove_pointer<KeyT>::type KeySansPointerT;
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ValueMapCallbackVH(KeyT Key, ValueMapT *Map)
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: CallbackVH(const_cast<Value*>(static_cast<const Value*>(Key))),
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KeyT Unwrap() const { return cast_or_null<KeySansPointerT>(getValPtr()); }
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virtual void deleted() {
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// Make a copy that won't get changed even when *this is destroyed.
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ValueMapCallbackVH Copy(*this);
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sys::Mutex *M = Config::getMutex(Copy.Map->Data);
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Config::onDelete(Copy.Map->Data, Copy.Unwrap()); // May destroy *this.
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Copy.Map->Map.erase(Copy); // Definitely destroys *this.
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virtual void allUsesReplacedWith(Value *new_key) {
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assert(isa<KeySansPointerT>(new_key) &&
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"Invalid RAUW on key of ValueMap<>");
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// Make a copy that won't get changed even when *this is destroyed.
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ValueMapCallbackVH Copy(*this);
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sys::Mutex *M = Config::getMutex(Copy.Map->Data);
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KeyT typed_new_key = cast<KeySansPointerT>(new_key);
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// Can destroy *this:
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Config::onRAUW(Copy.Map->Data, Copy.Unwrap(), typed_new_key);
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if (Config::FollowRAUW) {
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typename ValueMapT::MapT::iterator I = Copy.Map->Map.find(Copy);
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// I could == Copy.Map->Map.end() if the onRAUW callback already
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// removed the old mapping.
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if (I != Copy.Map->Map.end()) {
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ValueT Target(I->second);
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Copy.Map->Map.erase(I); // Definitely destroys *this.
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Copy.Map->insert(std::make_pair(typed_new_key, Target));
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template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
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struct isPodLike<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > {
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static const bool value = true;
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template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
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struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > {
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typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> VH;
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typedef DenseMapInfo<KeyT> PointerInfo;
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static inline VH getEmptyKey() {
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return VH(PointerInfo::getEmptyKey(), NULL);
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static inline VH getTombstoneKey() {
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return VH(PointerInfo::getTombstoneKey(), NULL);
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static unsigned getHashValue(const VH &Val) {
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return PointerInfo::getHashValue(Val.Unwrap());
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static bool isEqual(const VH &LHS, const VH &RHS) {
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template<typename DenseMapT, typename KeyT>
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class ValueMapIterator :
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public std::iterator<std::forward_iterator_tag,
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std::pair<KeyT, typename DenseMapT::mapped_type>,
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typedef typename DenseMapT::iterator BaseT;
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typedef typename DenseMapT::mapped_type ValueT;
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ValueMapIterator() : I() {}
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ValueMapIterator(BaseT I) : I(I) {}
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BaseT base() const { return I; }
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struct ValueTypeProxy {
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ValueTypeProxy *operator->() { return this; }
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operator std::pair<KeyT, ValueT>() const {
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return std::make_pair(first, second);
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ValueTypeProxy operator*() const {
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ValueTypeProxy Result = {I->first.Unwrap(), I->second};
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ValueTypeProxy operator->() const {
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bool operator==(const ValueMapIterator &RHS) const {
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bool operator!=(const ValueMapIterator &RHS) const {
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inline ValueMapIterator& operator++() { // Preincrement
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ValueMapIterator operator++(int) { // Postincrement
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ValueMapIterator tmp = *this; ++*this; return tmp;
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template<typename DenseMapT, typename KeyT>
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class ValueMapConstIterator :
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public std::iterator<std::forward_iterator_tag,
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std::pair<KeyT, typename DenseMapT::mapped_type>,
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typedef typename DenseMapT::const_iterator BaseT;
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typedef typename DenseMapT::mapped_type ValueT;
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ValueMapConstIterator() : I() {}
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ValueMapConstIterator(BaseT I) : I(I) {}
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ValueMapConstIterator(ValueMapIterator<DenseMapT, KeyT> Other)
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BaseT base() const { return I; }
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struct ValueTypeProxy {
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const ValueT& second;
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ValueTypeProxy *operator->() { return this; }
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operator std::pair<KeyT, ValueT>() const {
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return std::make_pair(first, second);
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ValueTypeProxy operator*() const {
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ValueTypeProxy Result = {I->first.Unwrap(), I->second};
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ValueTypeProxy operator->() const {
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bool operator==(const ValueMapConstIterator &RHS) const {
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bool operator!=(const ValueMapConstIterator &RHS) const {
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inline ValueMapConstIterator& operator++() { // Preincrement
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ValueMapConstIterator operator++(int) { // Postincrement
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ValueMapConstIterator tmp = *this; ++*this; return tmp;
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} // end namespace llvm