| //===- Support/DepthFirstIterator.h - Depth First iterator ------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file builds on the Support/GraphTraits.h file to build generic depth |
| // first graph iterator. This file exposes the following functions/types: |
| // |
| // df_begin/df_end/df_iterator |
| // * Normal depth-first iteration - visit a node and then all of its children. |
| // |
| // idf_begin/idf_end/idf_iterator |
| // * Depth-first iteration on the 'inverse' graph. |
| // |
| // df_ext_begin/df_ext_end/df_ext_iterator |
| // * Normal depth-first iteration - visit a node and then all of its children. |
| // This iterator stores the 'visited' set in an external set, which allows |
| // it to be more efficient, and allows external clients to use the set for |
| // other purposes. |
| // |
| // idf_ext_begin/idf_ext_end/idf_ext_iterator |
| // * Depth-first iteration on the 'inverse' graph. |
| // This iterator stores the 'visited' set in an external set, which allows |
| // it to be more efficient, and allows external clients to use the set for |
| // other purposes. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SUPPORT_DEPTHFIRSTITERATOR_H |
| #define SUPPORT_DEPTHFIRSTITERATOR_H |
| |
| #include "Support/GraphTraits.h" |
| #include "Support/iterator" |
| #include <vector> |
| #include <set> |
| |
| namespace llvm { |
| |
| // df_iterator_storage - A private class which is used to figure out where to |
| // store the visited set. |
| template<class SetType, bool External> // Non-external set |
| class df_iterator_storage { |
| public: |
| SetType Visited; |
| }; |
| |
| template<class SetType> |
| class df_iterator_storage<SetType, true> { |
| public: |
| df_iterator_storage(SetType &VSet) : Visited(VSet) {} |
| df_iterator_storage(const df_iterator_storage &S) : Visited(S.Visited) {} |
| SetType &Visited; |
| }; |
| |
| |
| // Generic Depth First Iterator |
| template<class GraphT, class SetType = |
| std::set<typename GraphTraits<GraphT>::NodeType*>, |
| bool ExtStorage = false, class GT = GraphTraits<GraphT> > |
| class df_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t>, |
| public df_iterator_storage<SetType, ExtStorage> { |
| typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super; |
| |
| typedef typename GT::NodeType NodeType; |
| typedef typename GT::ChildIteratorType ChildItTy; |
| |
| // VisitStack - Used to maintain the ordering. Top = current block |
| // First element is node pointer, second is the 'next child' to visit |
| std::vector<std::pair<NodeType *, ChildItTy> > VisitStack; |
| private: |
| inline df_iterator(NodeType *Node) { |
| this->Visited.insert(Node); |
| VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node))); |
| } |
| inline df_iterator() { /* End is when stack is empty */ } |
| |
| inline df_iterator(NodeType *Node, SetType &S) |
| : df_iterator_storage<SetType, ExtStorage>(S) { |
| if (!S.count(Node)) { |
| this->Visited.insert(Node); |
| VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node))); |
| } |
| } |
| inline df_iterator(SetType &S) |
| : df_iterator_storage<SetType, ExtStorage>(S) { |
| // End is when stack is empty |
| } |
| |
| public: |
| typedef typename super::pointer pointer; |
| typedef df_iterator<GraphT, SetType, ExtStorage, GT> _Self; |
| |
| // Provide static begin and end methods as our public "constructors" |
| static inline _Self begin(GraphT G) { |
| return _Self(GT::getEntryNode(G)); |
| } |
| static inline _Self end(GraphT G) { return _Self(); } |
| |
| // Static begin and end methods as our public ctors for external iterators |
| static inline _Self begin(GraphT G, SetType &S) { |
| return _Self(GT::getEntryNode(G), S); |
| } |
| static inline _Self end(GraphT G, SetType &S) { return _Self(S); } |
| |
| inline bool operator==(const _Self& x) const { |
| return VisitStack.size() == x.VisitStack.size() && |
| VisitStack == x.VisitStack; |
| } |
| inline bool operator!=(const _Self& x) const { return !operator==(x); } |
| |
| inline pointer operator*() const { |
| return VisitStack.back().first; |
| } |
| |
| // This is a nonstandard operator-> that dereferences the pointer an extra |
| // time... so that you can actually call methods ON the Node, because |
| // the contained type is a pointer. This allows BBIt->getTerminator() f.e. |
| // |
| inline NodeType *operator->() const { return operator*(); } |
| |
| inline _Self& operator++() { // Preincrement |
| do { |
| std::pair<NodeType *, ChildItTy> &Top = VisitStack.back(); |
| NodeType *Node = Top.first; |
| ChildItTy &It = Top.second; |
| |
| while (It != GT::child_end(Node)) { |
| NodeType *Next = *It++; |
| if (!this->Visited.count(Next)) { // Has our next sibling been visited? |
| // No, do it now. |
| this->Visited.insert(Next); |
| VisitStack.push_back(std::make_pair(Next, GT::child_begin(Next))); |
| return *this; |
| } |
| } |
| |
| // Oops, ran out of successors... go up a level on the stack. |
| VisitStack.pop_back(); |
| } while (!VisitStack.empty()); |
| return *this; |
| } |
| |
| inline _Self operator++(int) { // Postincrement |
| _Self tmp = *this; ++*this; return tmp; |
| } |
| |
| // nodeVisited - return true if this iterator has already visited the |
| // specified node. This is public, and will probably be used to iterate over |
| // nodes that a depth first iteration did not find: ie unreachable nodes. |
| // |
| inline bool nodeVisited(NodeType *Node) const { |
| return this->Visited.count(Node) != 0; |
| } |
| }; |
| |
| |
| // Provide global constructors that automatically figure out correct types... |
| // |
| template <class T> |
| df_iterator<T> df_begin(T G) { |
| return df_iterator<T>::begin(G); |
| } |
| |
| template <class T> |
| df_iterator<T> df_end(T G) { |
| return df_iterator<T>::end(G); |
| } |
| |
| // Provide global definitions of external depth first iterators... |
| template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> > |
| struct df_ext_iterator : public df_iterator<T, SetTy, true> { |
| df_ext_iterator(const df_iterator<T, SetTy, true> &V) |
| : df_iterator<T, SetTy, true>(V) {} |
| }; |
| |
| template <class T, class SetTy> |
| df_ext_iterator<T, SetTy> df_ext_begin(T G, SetTy &S) { |
| return df_ext_iterator<T, SetTy>::begin(G, S); |
| } |
| |
| template <class T, class SetTy> |
| df_ext_iterator<T, SetTy> df_ext_end(T G, SetTy &S) { |
| return df_ext_iterator<T, SetTy>::end(G, S); |
| } |
| |
| |
| // Provide global definitions of inverse depth first iterators... |
| template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*>, |
| bool External = false> |
| struct idf_iterator : public df_iterator<Inverse<T>, SetTy, External> { |
| idf_iterator(const df_iterator<Inverse<T>, SetTy, External> &V) |
| : df_iterator<Inverse<T>, SetTy, External>(V) {} |
| }; |
| |
| template <class T> |
| idf_iterator<T> idf_begin(T G) { |
| return idf_iterator<T>::begin(G); |
| } |
| |
| template <class T> |
| idf_iterator<T> idf_end(T G){ |
| return idf_iterator<T>::end(G); |
| } |
| |
| // Provide global definitions of external inverse depth first iterators... |
| template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> > |
| struct idf_ext_iterator : public idf_iterator<T, SetTy, true> { |
| idf_ext_iterator(const idf_iterator<T, SetTy, true> &V) |
| : idf_iterator<T, SetTy, true>(V) {} |
| idf_ext_iterator(const df_iterator<Inverse<T>, SetTy, true> &V) |
| : idf_iterator<T, SetTy, true>(V) {} |
| }; |
| |
| template <class T, class SetTy> |
| idf_ext_iterator<T, SetTy> idf_ext_begin(T G, SetTy &S) { |
| return idf_ext_iterator<T, SetTy>::begin(G, S); |
| } |
| |
| template <class T, class SetTy> |
| idf_ext_iterator<T, SetTy> idf_ext_end(T G, SetTy &S) { |
| return idf_ext_iterator<T, SetTy>::end(G, S); |
| } |
| |
| } // End llvm namespace |
| |
| #endif |