| //===- llvm/ADT/ilist_node.h - Intrusive Linked List Helper -----*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the ilist_node class template, which is a convenient |
| // base class for creating classes that can be used with ilists. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ADT_ILIST_NODE_H |
| #define LLVM_ADT_ILIST_NODE_H |
| |
| #include "llvm/ADT/ilist_node_base.h" |
| #include "llvm/ADT/ilist_node_options.h" |
| |
| namespace llvm { |
| |
| namespace ilist_detail { |
| |
| struct NodeAccess; |
| |
| } // end namespace ilist_detail |
| |
| template <class OptionsT, bool IsReverse, bool IsConst> class ilist_iterator; |
| template <class OptionsT> class ilist_sentinel; |
| |
| /// Implementation for an ilist node. |
| /// |
| /// Templated on an appropriate \a ilist_detail::node_options, usually computed |
| /// by \a ilist_detail::compute_node_options. |
| /// |
| /// This is a wrapper around \a ilist_node_base whose main purpose is to |
| /// provide type safety: you can't insert nodes of \a ilist_node_impl into the |
| /// wrong \a simple_ilist or \a iplist. |
| template <class OptionsT> class ilist_node_impl : OptionsT::node_base_type { |
| using value_type = typename OptionsT::value_type; |
| using node_base_type = typename OptionsT::node_base_type; |
| using list_base_type = typename OptionsT::list_base_type; |
| |
| friend typename OptionsT::list_base_type; |
| friend struct ilist_detail::NodeAccess; |
| friend class ilist_sentinel<OptionsT>; |
| friend class ilist_iterator<OptionsT, false, false>; |
| friend class ilist_iterator<OptionsT, false, true>; |
| friend class ilist_iterator<OptionsT, true, false>; |
| friend class ilist_iterator<OptionsT, true, true>; |
| |
| protected: |
| using self_iterator = ilist_iterator<OptionsT, false, false>; |
| using const_self_iterator = ilist_iterator<OptionsT, false, true>; |
| using reverse_self_iterator = ilist_iterator<OptionsT, true, false>; |
| using const_reverse_self_iterator = ilist_iterator<OptionsT, true, true>; |
| |
| ilist_node_impl() = default; |
| |
| private: |
| ilist_node_impl *getPrev() { |
| return static_cast<ilist_node_impl *>(node_base_type::getPrev()); |
| } |
| |
| ilist_node_impl *getNext() { |
| return static_cast<ilist_node_impl *>(node_base_type::getNext()); |
| } |
| |
| const ilist_node_impl *getPrev() const { |
| return static_cast<ilist_node_impl *>(node_base_type::getPrev()); |
| } |
| |
| const ilist_node_impl *getNext() const { |
| return static_cast<ilist_node_impl *>(node_base_type::getNext()); |
| } |
| |
| void setPrev(ilist_node_impl *N) { node_base_type::setPrev(N); } |
| void setNext(ilist_node_impl *N) { node_base_type::setNext(N); } |
| |
| public: |
| self_iterator getIterator() { return self_iterator(*this); } |
| const_self_iterator getIterator() const { return const_self_iterator(*this); } |
| |
| reverse_self_iterator getReverseIterator() { |
| return reverse_self_iterator(*this); |
| } |
| |
| const_reverse_self_iterator getReverseIterator() const { |
| return const_reverse_self_iterator(*this); |
| } |
| |
| // Under-approximation, but always available for assertions. |
| using node_base_type::isKnownSentinel; |
| |
| /// Check whether this is the sentinel node. |
| /// |
| /// This requires sentinel tracking to be explicitly enabled. Use the |
| /// ilist_sentinel_tracking<true> option to get this API. |
| bool isSentinel() const { |
| static_assert(OptionsT::is_sentinel_tracking_explicit, |
| "Use ilist_sentinel_tracking<true> to enable isSentinel()"); |
| return node_base_type::isSentinel(); |
| } |
| }; |
| |
| /// An intrusive list node. |
| /// |
| /// A base class to enable membership in intrusive lists, including \a |
| /// simple_ilist, \a iplist, and \a ilist. The first template parameter is the |
| /// \a value_type for the list. |
| /// |
| /// An ilist node can be configured with compile-time options to change |
| /// behaviour and/or add API. |
| /// |
| /// By default, an \a ilist_node knows whether it is the list sentinel (an |
| /// instance of \a ilist_sentinel) if and only if |
| /// LLVM_ENABLE_ABI_BREAKING_CHECKS. The function \a isKnownSentinel() always |
| /// returns \c false tracking is off. Sentinel tracking steals a bit from the |
| /// "prev" link, which adds a mask operation when decrementing an iterator, but |
| /// enables bug-finding assertions in \a ilist_iterator. |
| /// |
| /// To turn sentinel tracking on all the time, pass in the |
| /// ilist_sentinel_tracking<true> template parameter. This also enables the \a |
| /// isSentinel() function. The same option must be passed to the intrusive |
| /// list. (ilist_sentinel_tracking<false> turns sentinel tracking off all the |
| /// time.) |
| /// |
| /// A type can inherit from ilist_node multiple times by passing in different |
| /// \a ilist_tag options. This allows a single instance to be inserted into |
| /// multiple lists simultaneously, where each list is given the same tag. |
| /// |
| /// \example |
| /// struct A {}; |
| /// struct B {}; |
| /// struct N : ilist_node<N, ilist_tag<A>>, ilist_node<N, ilist_tag<B>> {}; |
| /// |
| /// void foo() { |
| /// simple_ilist<N, ilist_tag<A>> ListA; |
| /// simple_ilist<N, ilist_tag<B>> ListB; |
| /// N N1; |
| /// ListA.push_back(N1); |
| /// ListB.push_back(N1); |
| /// } |
| /// \endexample |
| /// |
| /// See \a is_valid_option for steps on adding a new option. |
| template <class T, class... Options> |
| class ilist_node |
| : public ilist_node_impl< |
| typename ilist_detail::compute_node_options<T, Options...>::type> { |
| static_assert(ilist_detail::check_options<Options...>::value, |
| "Unrecognized node option!"); |
| }; |
| |
| namespace ilist_detail { |
| |
| /// An access class for ilist_node private API. |
| /// |
| /// This gives access to the private parts of ilist nodes. Nodes for an ilist |
| /// should friend this class if they inherit privately from ilist_node. |
| /// |
| /// Using this class outside of the ilist implementation is unsupported. |
| struct NodeAccess { |
| protected: |
| template <class OptionsT> |
| static ilist_node_impl<OptionsT> *getNodePtr(typename OptionsT::pointer N) { |
| return N; |
| } |
| |
| template <class OptionsT> |
| static const ilist_node_impl<OptionsT> * |
| getNodePtr(typename OptionsT::const_pointer N) { |
| return N; |
| } |
| |
| template <class OptionsT> |
| static typename OptionsT::pointer getValuePtr(ilist_node_impl<OptionsT> *N) { |
| return static_cast<typename OptionsT::pointer>(N); |
| } |
| |
| template <class OptionsT> |
| static typename OptionsT::const_pointer |
| getValuePtr(const ilist_node_impl<OptionsT> *N) { |
| return static_cast<typename OptionsT::const_pointer>(N); |
| } |
| |
| template <class OptionsT> |
| static ilist_node_impl<OptionsT> *getPrev(ilist_node_impl<OptionsT> &N) { |
| return N.getPrev(); |
| } |
| |
| template <class OptionsT> |
| static ilist_node_impl<OptionsT> *getNext(ilist_node_impl<OptionsT> &N) { |
| return N.getNext(); |
| } |
| |
| template <class OptionsT> |
| static const ilist_node_impl<OptionsT> * |
| getPrev(const ilist_node_impl<OptionsT> &N) { |
| return N.getPrev(); |
| } |
| |
| template <class OptionsT> |
| static const ilist_node_impl<OptionsT> * |
| getNext(const ilist_node_impl<OptionsT> &N) { |
| return N.getNext(); |
| } |
| }; |
| |
| template <class OptionsT> struct SpecificNodeAccess : NodeAccess { |
| protected: |
| using pointer = typename OptionsT::pointer; |
| using const_pointer = typename OptionsT::const_pointer; |
| using node_type = ilist_node_impl<OptionsT>; |
| |
| static node_type *getNodePtr(pointer N) { |
| return NodeAccess::getNodePtr<OptionsT>(N); |
| } |
| |
| static const node_type *getNodePtr(const_pointer N) { |
| return NodeAccess::getNodePtr<OptionsT>(N); |
| } |
| |
| static pointer getValuePtr(node_type *N) { |
| return NodeAccess::getValuePtr<OptionsT>(N); |
| } |
| |
| static const_pointer getValuePtr(const node_type *N) { |
| return NodeAccess::getValuePtr<OptionsT>(N); |
| } |
| }; |
| |
| } // end namespace ilist_detail |
| |
| template <class OptionsT> |
| class ilist_sentinel : public ilist_node_impl<OptionsT> { |
| public: |
| ilist_sentinel() { |
| this->initializeSentinel(); |
| reset(); |
| } |
| |
| void reset() { |
| this->setPrev(this); |
| this->setNext(this); |
| } |
| |
| bool empty() const { return this == this->getPrev(); } |
| }; |
| |
| /// An ilist node that can access its parent list. |
| /// |
| /// Requires \c NodeTy to have \a getParent() to find the parent node, and the |
| /// \c ParentTy to have \a getSublistAccess() to get a reference to the list. |
| template <typename NodeTy, typename ParentTy, class... Options> |
| class ilist_node_with_parent : public ilist_node<NodeTy, Options...> { |
| protected: |
| ilist_node_with_parent() = default; |
| |
| private: |
| /// Forward to NodeTy::getParent(). |
| /// |
| /// Note: do not use the name "getParent()". We want a compile error |
| /// (instead of recursion) when the subclass fails to implement \a |
| /// getParent(). |
| const ParentTy *getNodeParent() const { |
| return static_cast<const NodeTy *>(this)->getParent(); |
| } |
| |
| public: |
| /// @name Adjacent Node Accessors |
| /// @{ |
| /// Get the previous node, or \c nullptr for the list head. |
| NodeTy *getPrevNode() { |
| // Should be separated to a reused function, but then we couldn't use auto |
| // (and would need the type of the list). |
| const auto &List = |
| getNodeParent()->*(ParentTy::getSublistAccess((NodeTy *)nullptr)); |
| return List.getPrevNode(*static_cast<NodeTy *>(this)); |
| } |
| |
| /// Get the previous node, or \c nullptr for the list head. |
| const NodeTy *getPrevNode() const { |
| return const_cast<ilist_node_with_parent *>(this)->getPrevNode(); |
| } |
| |
| /// Get the next node, or \c nullptr for the list tail. |
| NodeTy *getNextNode() { |
| // Should be separated to a reused function, but then we couldn't use auto |
| // (and would need the type of the list). |
| const auto &List = |
| getNodeParent()->*(ParentTy::getSublistAccess((NodeTy *)nullptr)); |
| return List.getNextNode(*static_cast<NodeTy *>(this)); |
| } |
| |
| /// Get the next node, or \c nullptr for the list tail. |
| const NodeTy *getNextNode() const { |
| return const_cast<ilist_node_with_parent *>(this)->getNextNode(); |
| } |
| /// @} |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_ADT_ILIST_NODE_H |