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