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//===- llvm/ADT/ilist_iterator.h - Intrusive List Iterator -------*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_ILIST_ITERATOR_H
#define LLVM_ADT_ILIST_ITERATOR_H
#include "llvm/ADT/ilist_node.h"
#include <cassert>
#include <cstddef>
#include <iterator>
#include <type_traits>
namespace llvm {
namespace ilist_detail {
/// Find const-correct node types.
template <class OptionsT, bool IsConst> struct IteratorTraits;
template <class OptionsT> struct IteratorTraits<OptionsT, false> {
typedef typename OptionsT::value_type value_type;
typedef typename OptionsT::pointer pointer;
typedef typename OptionsT::reference reference;
typedef ilist_node_impl<OptionsT> *node_pointer;
typedef ilist_node_impl<OptionsT> &node_reference;
};
template <class OptionsT> struct IteratorTraits<OptionsT, true> {
typedef const typename OptionsT::value_type value_type;
typedef typename OptionsT::const_pointer pointer;
typedef typename OptionsT::const_reference reference;
typedef const ilist_node_impl<OptionsT> *node_pointer;
typedef const ilist_node_impl<OptionsT> &node_reference;
};
template <bool IsReverse> struct IteratorHelper;
template <> struct IteratorHelper<false> : ilist_detail::NodeAccess {
typedef ilist_detail::NodeAccess Access;
template <class T> static void increment(T *&I) { I = Access::getNext(*I); }
template <class T> static void decrement(T *&I) { I = Access::getPrev(*I); }
};
template <> struct IteratorHelper<true> : ilist_detail::NodeAccess {
typedef ilist_detail::NodeAccess Access;
template <class T> static void increment(T *&I) { I = Access::getPrev(*I); }
template <class T> static void decrement(T *&I) { I = Access::getNext(*I); }
};
} // end namespace ilist_detail
/// Iterator for intrusive lists based on ilist_node.
template <class OptionsT, bool IsReverse, bool IsConst>
class ilist_iterator : ilist_detail::SpecificNodeAccess<OptionsT> {
friend ilist_iterator<OptionsT, IsReverse, !IsConst>;
friend ilist_iterator<OptionsT, !IsReverse, IsConst>;
friend ilist_iterator<OptionsT, !IsReverse, !IsConst>;
typedef ilist_detail::IteratorTraits<OptionsT, IsConst> Traits;
typedef ilist_detail::SpecificNodeAccess<OptionsT> Access;
public:
typedef typename Traits::value_type value_type;
typedef typename Traits::pointer pointer;
typedef typename Traits::reference reference;
typedef ptrdiff_t difference_type;
typedef std::bidirectional_iterator_tag iterator_category;
typedef typename OptionsT::const_pointer const_pointer;
typedef typename OptionsT::const_reference const_reference;
private:
typedef typename Traits::node_pointer node_pointer;
typedef typename Traits::node_reference node_reference;
node_pointer NodePtr;
public:
/// Create from an ilist_node.
explicit ilist_iterator(node_reference N) : NodePtr(&N) {}
explicit ilist_iterator(pointer NP) : NodePtr(Access::getNodePtr(NP)) {}
explicit ilist_iterator(reference NR) : NodePtr(Access::getNodePtr(&NR)) {}
ilist_iterator() : NodePtr(nullptr) {}
// This is templated so that we can allow constructing a const iterator from
// a nonconst iterator...
template <bool RHSIsConst>
ilist_iterator(
const ilist_iterator<OptionsT, IsReverse, RHSIsConst> &RHS,
typename std::enable_if<IsConst || !RHSIsConst, void *>::type = nullptr)
: NodePtr(RHS.NodePtr) {}
// This is templated so that we can allow assigning to a const iterator from
// a nonconst iterator...
template <bool RHSIsConst>
typename std::enable_if<IsConst || !RHSIsConst, ilist_iterator &>::type
operator=(const ilist_iterator<OptionsT, IsReverse, RHSIsConst> &RHS) {
NodePtr = RHS.NodePtr;
return *this;
}
/// Convert from an iterator to its reverse.
///
/// TODO: Roll this into the implicit constructor once we're sure that no one
/// is relying on the std::reverse_iterator off-by-one semantics.
ilist_iterator<OptionsT, !IsReverse, IsConst> getReverse() const {
if (NodePtr)
return ilist_iterator<OptionsT, !IsReverse, IsConst>(*NodePtr);
return ilist_iterator<OptionsT, !IsReverse, IsConst>();
}
/// Const-cast.
ilist_iterator<OptionsT, IsReverse, false> getNonConst() const {
if (NodePtr)
return ilist_iterator<OptionsT, IsReverse, false>(
const_cast<typename ilist_iterator<OptionsT, IsReverse,
false>::node_reference>(*NodePtr));
return ilist_iterator<OptionsT, IsReverse, false>();
}
// Accessors...
reference operator*() const {
assert(!NodePtr->isKnownSentinel());
return *Access::getValuePtr(NodePtr);
}
pointer operator->() const { return &operator*(); }
// Comparison operators
friend bool operator==(const ilist_iterator &LHS, const ilist_iterator &RHS) {
return LHS.NodePtr == RHS.NodePtr;
}
friend bool operator!=(const ilist_iterator &LHS, const ilist_iterator &RHS) {
return LHS.NodePtr != RHS.NodePtr;
}
// Increment and decrement operators...
ilist_iterator &operator--() {
NodePtr = IsReverse ? NodePtr->getNext() : NodePtr->getPrev();
return *this;
}
ilist_iterator &operator++() {
NodePtr = IsReverse ? NodePtr->getPrev() : NodePtr->getNext();
return *this;
}
ilist_iterator operator--(int) {
ilist_iterator tmp = *this;
--*this;
return tmp;
}
ilist_iterator operator++(int) {
ilist_iterator tmp = *this;
++*this;
return tmp;
}
/// Get the underlying ilist_node.
node_pointer getNodePtr() const { return static_cast<node_pointer>(NodePtr); }
/// Check for end. Only valid if ilist_sentinel_tracking<true>.
bool isEnd() const { return NodePtr ? NodePtr->isSentinel() : false; }
};
template <typename From> struct simplify_type;
/// Allow ilist_iterators to convert into pointers to a node automatically when
/// used by the dyn_cast, cast, isa mechanisms...
///
/// FIXME: remove this, since there is no implicit conversion to NodeTy.
template <class OptionsT, bool IsConst>
struct simplify_type<ilist_iterator<OptionsT, false, IsConst>> {
typedef ilist_iterator<OptionsT, false, IsConst> iterator;
typedef typename iterator::pointer SimpleType;
static SimpleType getSimplifiedValue(const iterator &Node) { return &*Node; }
};
template <class OptionsT, bool IsConst>
struct simplify_type<const ilist_iterator<OptionsT, false, IsConst>>
: simplify_type<ilist_iterator<OptionsT, false, IsConst>> {};
} // end namespace llvm
#endif // LLVM_ADT_ILIST_ITERATOR_H