1. Allow SCCIterator to work with GraphT types that are constant.

2.  Allow SCCIterator to work with inverse graphs.
3.  Fix an incorrect comment in GraphTraits.h (the type in the comment 
was given as GraphType* when it is actually const GraphType &).
Patch by Patrick Alexander Simmons.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89091 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 15 insertions, 5 deletions

diff --git a/include/llvm/ADT/GraphTraits.h b/include/llvm/ADT/GraphTraits.h
index 2d103cf..0fd1f50 100644
--- a/include/llvm/ADT/GraphTraits.h
+++ b/include/llvm/ADT/GraphTraits.h
@@ -30,7 +30,7 @@ struct GraphTraits {
   // typedef NodeType          - Type of Node in the graph
   // typedef ChildIteratorType - Type used to iterate over children in graph
 
-  // static NodeType *getEntryNode(GraphType *)
+  // static NodeType *getEntryNode(const GraphType &)
   //    Return the entry node of the graph
 
   // static ChildIteratorType child_begin(NodeType *)
diff --git a/include/llvm/ADT/SCCIterator.h b/include/llvm/ADT/SCCIterator.h
index db985b5..3afcabd 100644
--- a/include/llvm/ADT/SCCIterator.h
+++ b/include/llvm/ADT/SCCIterator.h
@@ -136,8 +136,8 @@ public:
   typedef scc_iterator<GraphT, GT> _Self;
 
   // Provide static "constructors"...
-  static inline _Self begin(GraphT& G) { return _Self(GT::getEntryNode(G)); }
-  static inline _Self end  (GraphT& G) { return _Self(); }
+  static inline _Self begin(const GraphT& G) { return _Self(GT::getEntryNode(G)); }
+  static inline _Self end  (const GraphT& G) { return _Self(); }
 
   // Direct loop termination test (I.fini() is more efficient than I == end())
   inline bool fini() const {
@@ -186,15 +186,25 @@ public:
 
 // Global constructor for the SCC iterator.
 template <class T>
-scc_iterator<T> scc_begin(T G) {
+scc_iterator<T> scc_begin(const T& G) {
   return scc_iterator<T>::begin(G);
 }
 
 template <class T>
-scc_iterator<T> scc_end(T G) {
+scc_iterator<T> scc_end(const T& G) {
   return scc_iterator<T>::end(G);
 }
 
+template <class T>
+scc_iterator<Inverse<T> > scc_begin(const Inverse<T>& G) {
+       return scc_iterator<Inverse<T> >::begin(G);
+}
+
+template <class T>
+scc_iterator<Inverse<T> > scc_end(const Inverse<T>& G) {
+       return scc_iterator<Inverse<T> >::end(G);
+}
+
 } // End llvm namespace
 
 #endif