1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 04:02:41 +01:00
llvm-mirror/include/llvm/ADT/GraphTraits.h
Tim Shen 33e4d80307 [GraphTraits] Replace all NodeType usage with NodeRef
This should finish the GraphTraits migration.

Differential Revision: http://reviews.llvm.org/D23730

llvm-svn: 279475
2016-08-22 21:09:30 +00:00

92 lines
3.3 KiB
C++

//===-- llvm/ADT/GraphTraits.h - Graph traits template ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the little GraphTraits<X> template class that should be
// specialized by classes that want to be iteratable by generic graph iterators.
//
// This file also defines the marker class Inverse that is used to iterate over
// graphs in a graph defined, inverse ordering...
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_GRAPHTRAITS_H
#define LLVM_ADT_GRAPHTRAITS_H
namespace llvm {
// GraphTraits - This class should be specialized by different graph types...
// which is why the default version is empty.
//
template<class GraphType>
struct GraphTraits {
// Elements to provide:
// typedef NodeRef - Type of Node token in the graph, which should
// be cheap to copy.
// typedef ChildIteratorType - Type used to iterate over children in graph,
// dereference to a NodeRef.
// static NodeRef getEntryNode(const GraphType &)
// Return the entry node of the graph
// static ChildIteratorType child_begin(NodeRef)
// static ChildIteratorType child_end (NodeRef)
// Return iterators that point to the beginning and ending of the child
// node list for the specified node.
//
// typedef ...iterator nodes_iterator; - dereference to a NodeRef
// static nodes_iterator nodes_begin(GraphType *G)
// static nodes_iterator nodes_end (GraphType *G)
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
// static unsigned size (GraphType *G)
// Return total number of nodes in the graph
//
// If anyone tries to use this class without having an appropriate
// specialization, make an error. If you get this error, it's because you
// need to include the appropriate specialization of GraphTraits<> for your
// graph, or you need to define it for a new graph type. Either that or
// your argument to XXX_begin(...) is unknown or needs to have the proper .h
// file #include'd.
//
typedef typename GraphType::UnknownGraphTypeError NodeRef;
};
// Inverse - This class is used as a little marker class to tell the graph
// iterator to iterate over the graph in a graph defined "Inverse" ordering.
// Not all graphs define an inverse ordering, and if they do, it depends on
// the graph exactly what that is. Here's an example of usage with the
// df_iterator:
//
// idf_iterator<Method*> I = idf_begin(M), E = idf_end(M);
// for (; I != E; ++I) { ... }
//
// Which is equivalent to:
// df_iterator<Inverse<Method*> > I = idf_begin(M), E = idf_end(M);
// for (; I != E; ++I) { ... }
//
template <class GraphType>
struct Inverse {
const GraphType &Graph;
inline Inverse(const GraphType &G) : Graph(G) {}
};
// Provide a partial specialization of GraphTraits so that the inverse of an
// inverse falls back to the original graph.
template <class T> struct GraphTraits<Inverse<Inverse<T>>> : GraphTraits<T> {};
} // End llvm namespace
#endif