#ifndef LLVM_ADT_DEPTHFIRSTITERATOR_H
#define LLVM_ADT_DEPTHFIRSTITERATOR_H
+#include "llvm/ADT/iterator_range.h"
#include "llvm/ADT/GraphTraits.h"
-#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/SmallPtrSet.h"
#include <set>
#include <vector>
template<class GraphT,
class SetType = llvm::SmallPtrSet<typename GraphTraits<GraphT>::NodeType*, 8>,
bool ExtStorage = false, class GT = GraphTraits<GraphT> >
-class df_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t>,
+class df_iterator : public std::iterator<std::forward_iterator_tag,
+ typename GT::NodeType, ptrdiff_t>,
public df_iterator_storage<SetType, ExtStorage> {
- typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super;
+ typedef std::iterator<std::forward_iterator_tag,
+ typename GT::NodeType, ptrdiff_t> super;
typedef typename GT::NodeType NodeType;
typedef typename GT::ChildIteratorType ChildItTy;
+ typedef PointerIntPair<NodeType*, 1> PointerIntTy;
// 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;
+ // if the int in PointerIntTy is 0, the 'next child' to visit is invalid
+ std::vector<std::pair<PointerIntTy, ChildItTy> > VisitStack;
private:
inline df_iterator(NodeType *Node) {
this->Visited.insert(Node);
- VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
+ VisitStack.push_back(std::make_pair(PointerIntTy(Node, 0),
+ GT::child_begin(Node)));
+ }
+ inline df_iterator() {
+ // End is when stack is empty
}
- 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)) {
+ VisitStack.push_back(std::make_pair(PointerIntTy(Node, 0),
+ GT::child_begin(Node)));
this->Visited.insert(Node);
- VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
}
}
inline df_iterator(SetType &S)
// End is when stack is empty
}
+ inline void toNext() {
+ do {
+ std::pair<PointerIntTy, ChildItTy> &Top = VisitStack.back();
+ NodeType *Node = Top.first.getPointer();
+ ChildItTy &It = Top.second;
+ if (!Top.first.getInt()) {
+ // now retrieve the real begin of the children before we dive in
+ It = GT::child_begin(Node);
+ Top.first.setInt(1);
+ }
+
+ while (It != GT::child_end(Node)) {
+ NodeType *Next = *It++;
+ // Has our next sibling been visited?
+ if (Next && !this->Visited.count(Next)) {
+ // No, do it now.
+ this->Visited.insert(Next);
+ VisitStack.push_back(std::make_pair(PointerIntTy(Next, 0),
+ GT::child_begin(Next)));
+ return;
+ }
+ }
+
+ // Oops, ran out of successors... go up a level on the stack.
+ VisitStack.pop_back();
+ } while (!VisitStack.empty());
+ }
+
public:
typedef typename super::pointer pointer;
typedef df_iterator<GraphT, SetType, ExtStorage, GT> _Self;
static inline _Self end(const GraphT& G, SetType &S) { return _Self(S); }
inline bool operator==(const _Self& x) const {
- return VisitStack.size() == x.VisitStack.size() &&
- VisitStack == x.VisitStack;
+ return VisitStack == x.VisitStack;
}
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const {
- return VisitStack.back().first;
+ return VisitStack.back().first.getPointer();
}
// This is a nonstandard operator-> that dereferences the pointer an extra
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;
- }
- }
+ toNext();
+ return *this;
+ }
- // Oops, ran out of successors... go up a level on the stack.
- VisitStack.pop_back();
- } while (!VisitStack.empty());
+ // skips all children of the current node and traverses to next node
+ //
+ inline _Self& skipChildren() {
+ VisitStack.pop_back();
+ if (!VisitStack.empty())
+ toNext();
return *this;
}
inline bool nodeVisited(NodeType *Node) const {
return this->Visited.count(Node) != 0;
}
+
+ /// getPathLength - Return the length of the path from the entry node to the
+ /// current node, counting both nodes.
+ unsigned getPathLength() const { return VisitStack.size(); }
+
+ /// getPath - Return the n'th node in the path from the entry node to the
+ /// current node.
+ NodeType *getPath(unsigned n) const {
+ return VisitStack[n].first.getPointer();
+ }
};
return df_iterator<T>::end(G);
}
+// Provide an accessor method to use them in range-based patterns.
+template <class T>
+iterator_range<df_iterator<T>> depth_first(const T& G) {
+ return iterator_range<df_iterator<T>>(df_begin(G), df_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> {
return df_ext_iterator<T, SetTy>::end(G, S);
}
+template <class T, class SetTy>
+iterator_range<df_ext_iterator<T, SetTy>> depth_first_ext(const T& G,
+ SetTy &S) {
+ return iterator_range<df_ext_iterator<T, SetTy>>(df_ext_begin(G, S),
+ df_ext_end(G, S));
+}
+
// Provide global definitions of inverse depth first iterators...
template <class T,
return idf_iterator<T>::end(Inverse<T>(G));
}
+// Provide an accessor method to use them in range-based patterns.
+template <class T>
+iterator_range<idf_iterator<T>> inverse_depth_first(const T& G) {
+ return iterator_range<idf_iterator<T>>(idf_begin(G), idf_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> {
return idf_ext_iterator<T, SetTy>::end(Inverse<T>(G), S);
}
+template <class T, class SetTy>
+iterator_range<idf_ext_iterator<T, SetTy>> inverse_depth_first_ext(const T& G,
+ SetTy &S) {
+ return iterator_range<idf_ext_iterator<T, SetTy>>(idf_ext_begin(G, S),
+ idf_ext_end(G, S));
+}
+
} // End llvm namespace
#endif
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