DOTGraphTraits.h

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//===-- llvm/Support/DOTGraphTraits.h - Customize .dot output ---*- 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 a template class that can be used to customize dot output
// graphs generated by the GraphWriter.h file.  The default implementation of
// this file will produce a simple, but not very polished graph.  By
// specializing this template, lots of customization opportunities are possible.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_SUPPORT_DOTGRAPHTRAITS_H
#define LLVM_SUPPORT_DOTGRAPHTRAITS_H
 
#include <string>
 
namespace llvm {
 
/// DefaultDOTGraphTraits - This class provides the default implementations of
/// all of the DOTGraphTraits methods.  If a specialization does not need to
/// override all methods here it should inherit so that it can get the default
/// implementations.
///
struct DefaultDOTGraphTraits {
private:
  bool IsSimple;
 
protected:
  bool isSimple() {
    return IsSimple;
  }
 
public:
  explicit DefaultDOTGraphTraits(bool simple=false) : IsSimple (simple) {}
 
  /// getGraphName - Return the label for the graph as a whole.  Printed at the
  /// top of the graph.
  ///
  template<typename GraphType>
  static std::string getGraphName(const GraphType &) { return ""; }
 
  /// getGraphProperties - Return any custom properties that should be included
  /// in the top level graph structure for dot.
  ///
  template<typename GraphType>
  static std::string getGraphProperties(const GraphType &) {
    return "";
  }
 
  /// renderGraphFromBottomUp - If this function returns true, the graph is
  /// emitted bottom-up instead of top-down.  This requires graphviz 2.0 to work
  /// though.
  static bool renderGraphFromBottomUp() {
    return false;
  }
 
  /// isNodeHidden - If the function returns true, the given node is not
  /// displayed in the graph.
  template <typename GraphType>
  static bool isNodeHidden(const void *, const GraphType &) {
    return false;
  }
 
  // renderNodesUsingHTML - If the function returns true, nodes will be
  // rendered using HTML-like labels which allows colors, etc in the nodes
  // and the edge source labels.
  static bool renderNodesUsingHTML() { return false; }
 
  /// getNodeLabel - Given a node and a pointer to the top level graph, return
  /// the label to print in the node.
  template<typename GraphType>
  std::string getNodeLabel(const void *, const GraphType &) {
    return "";
  }
 
  // getNodeIdentifierLabel - Returns a string representing the
  // address or other unique identifier of the node. (Only used if
  // non-empty.)
  template <typename GraphType>
  static std::string getNodeIdentifierLabel(const void *, const GraphType &) {
    return "";
  }
 
  template<typename GraphType>
  static std::string getNodeDescription(const void *, const GraphType &) {
    return "";
  }
 
  /// If you want to specify custom node attributes, this is the place to do so
  ///
  template<typename GraphType>
  static std::string getNodeAttributes(const void *,
                                       const GraphType &) {
    return "";
  }
 
  /// If you want to override the dot attributes printed for a particular edge,
  /// override this method.
  template<typename EdgeIter, typename GraphType>
  static std::string getEdgeAttributes(const void *, EdgeIter,
                                       const GraphType &) {
    return "";
  }
 
  /// getEdgeSourceLabel - If you want to label the edge source itself,
  /// implement this method.
  template<typename EdgeIter>
  static std::string getEdgeSourceLabel(const void *, EdgeIter) {
    return "";
  }
 
  /// edgeTargetsEdgeSource - This method returns true if this outgoing edge
  /// should actually target another edge source, not a node.  If this method is
  /// implemented, getEdgeTarget should be implemented.
  template<typename EdgeIter>
  static bool edgeTargetsEdgeSource(const void *, EdgeIter) {
    return false;
  }
 
  /// getEdgeTarget - If edgeTargetsEdgeSource returns true, this method is
  /// called to determine which outgoing edge of Node is the target of this
  /// edge.
  template<typename EdgeIter>
  static EdgeIter getEdgeTarget(const void *, EdgeIter I) {
    return I;
  }
 
  /// hasEdgeDestLabels - If this function returns true, the graph is able
  /// to provide labels for edge destinations.
  static bool hasEdgeDestLabels() {
    return false;
  }
 
  /// numEdgeDestLabels - If hasEdgeDestLabels, this function returns the
  /// number of incoming edge labels the given node has.
  static unsigned numEdgeDestLabels(const void *) {
    return 0;
  }
 
  /// getEdgeDestLabel - If hasEdgeDestLabels, this function returns the
  /// incoming edge label with the given index in the given node.
  static std::string getEdgeDestLabel(const void *, unsigned) {
    return "";
  }
 
  /// addCustomGraphFeatures - If a graph is made up of more than just
  /// straight-forward nodes and edges, this is the place to put all of the
  /// custom stuff necessary.  The GraphWriter object, instantiated with your
  /// GraphType is passed in as an argument.  You may call arbitrary methods on
  /// it to add things to the output graph.
  ///
  template<typename GraphType, typename GraphWriter>
  static void addCustomGraphFeatures(const GraphType &, GraphWriter &) {}
};
 
 
/// DOTGraphTraits - Template class that can be specialized to customize how
/// graphs are converted to 'dot' graphs.  When specializing, you may inherit
/// from DefaultDOTGraphTraits if you don't need to override everything.
///
template <typename Ty>
struct DOTGraphTraits : public DefaultDOTGraphTraits {
  DOTGraphTraits (bool simple=false) : DefaultDOTGraphTraits (simple) {}
};
 
} // End llvm namespace
 
#endif