text: //===-- DOTGraphTraitsPass.h - Print/View dotty graphs-----------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // Templates to create dotty viewer and printer passes for GraphTraits graphs.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_ANALYSIS_DOTGRAPHTRAITSPASS_H
  #define LLVM_ANALYSIS_DOTGRAPHTRAITSPASS_H
  
  #include "llvm/Analysis/CFGPrinter.h"
  #include "llvm/Pass.h"
  #include "llvm/Support/FileSystem.h"
  
  namespace llvm {
  
  /// Default traits class for extracting a graph from an analysis pass.
  ///
  /// This assumes that 'GraphT' is 'AnalysisT *' and so just passes it through.
  template <typename AnalysisT, typename GraphT = AnalysisT *>
  struct DefaultAnalysisGraphTraits {
    static GraphT getGraph(AnalysisT *A) { return A; }
  };
  
  template <
      typename AnalysisT, bool IsSimple, typename GraphT = AnalysisT *,
      typename AnalysisGraphTraitsT = DefaultAnalysisGraphTraits<AnalysisT, GraphT> >
  class DOTGraphTraitsViewer : public FunctionPass {
  public:
    DOTGraphTraitsViewer(StringRef GraphName, char &ID)
        : FunctionPass(ID), Name(GraphName) {}
  
    /// Return true if this function should be processed.
    ///
    /// An implementation of this class my override this function to indicate that
    /// only certain functions should be viewed.
    ///
    /// @param Analysis The current analysis result for this function.
    virtual bool processFunction(Function &F, AnalysisT &Analysis) {
      return true;
    }
  
    bool runOnFunction(Function &F) override {
      auto &Analysis = getAnalysis<AnalysisT>();
  
      if (!processFunction(F, Analysis))
        return false;
  
      GraphT Graph = AnalysisGraphTraitsT::getGraph(&Analysis);
      std::string GraphName = DOTGraphTraits<GraphT>::getGraphName(Graph);
      std::string Title = GraphName + " for '" + F.getName().str() + "' function";
  
      ViewGraph(Graph, Name, IsSimple, Title);
  
      return false;
    }
  
    void getAnalysisUsage(AnalysisUsage &AU) const override {
      AU.setPreservesAll();
      AU.addRequired<AnalysisT>();
    }
  
  private:
    std::string Name;
  };
  
  template <
      typename AnalysisT, bool IsSimple, typename GraphT = AnalysisT *,
      typename AnalysisGraphTraitsT = DefaultAnalysisGraphTraits<AnalysisT, GraphT> >
  class DOTGraphTraitsPrinter : public FunctionPass {
  public:
    DOTGraphTraitsPrinter(StringRef GraphName, char &ID)
        : FunctionPass(ID), Name(GraphName) {}
  
    /// Return true if this function should be processed.
    ///
    /// An implementation of this class my override this function to indicate that
    /// only certain functions should be printed.
    ///
    /// @param Analysis The current analysis result for this function.
    virtual bool processFunction(Function &F, AnalysisT &Analysis) {
      return true;
    }
  
    bool runOnFunction(Function &F) override {
      auto &Analysis = getAnalysis<AnalysisT>();
  
      if (!processFunction(F, Analysis))
        return false;
  
      GraphT Graph = AnalysisGraphTraitsT::getGraph(&Analysis);
      std::string Filename = Name + "." + F.getName().str() + ".dot";
      std::error_code EC;
  
      errs() << "Writing '" << Filename << "'...";
  
      raw_fd_ostream File(Filename, EC, sys::fs::F_Text);
      std::string GraphName = DOTGraphTraits<GraphT>::getGraphName(Graph);
      std::string Title = GraphName + " for '" + F.getName().str() + "' function";
  
      if (!EC)
        WriteGraph(File, Graph, IsSimple, Title);
      else
        errs() << "  error opening file for writing!";
      errs() << "\n";
  
      return false;
    }
  
    void getAnalysisUsage(AnalysisUsage &AU) const override {
      AU.setPreservesAll();
      AU.addRequired<AnalysisT>();
    }
  
  private:
    std::string Name;
  };
  
  template <
      typename AnalysisT, bool IsSimple, typename GraphT = AnalysisT *,
      typename AnalysisGraphTraitsT = DefaultAnalysisGraphTraits<AnalysisT, GraphT> >
  class DOTGraphTraitsModuleViewer : public ModulePass {
  public:
    DOTGraphTraitsModuleViewer(StringRef GraphName, char &ID)
        : ModulePass(ID), Name(GraphName) {}
  
    bool runOnModule(Module &M) override {
      GraphT Graph = AnalysisGraphTraitsT::getGraph(&getAnalysis<AnalysisT>());
      std::string Title = DOTGraphTraits<GraphT>::getGraphName(Graph);
  
      ViewGraph(Graph, Name, IsSimple, Title);
  
      return false;
    }
  
    void getAnalysisUsage(AnalysisUsage &AU) const override {
      AU.setPreservesAll();
      AU.addRequired<AnalysisT>();
    }
  
  private:
    std::string Name;
  };
  
  template <
      typename AnalysisT, bool IsSimple, typename GraphT = AnalysisT *,
      typename AnalysisGraphTraitsT = DefaultAnalysisGraphTraits<AnalysisT, GraphT> >
  class DOTGraphTraitsModulePrinter : public ModulePass {
  public:
    DOTGraphTraitsModulePrinter(StringRef GraphName, char &ID)
        : ModulePass(ID), Name(GraphName) {}
  
    bool runOnModule(Module &M) override {
      GraphT Graph = AnalysisGraphTraitsT::getGraph(&getAnalysis<AnalysisT>());
      std::string Filename = Name + ".dot";
      std::error_code EC;
  
      errs() << "Writing '" << Filename << "'...";
  
      raw_fd_ostream File(Filename, EC, sys::fs::F_Text);
      std::string Title = DOTGraphTraits<GraphT>::getGraphName(Graph);
  
      if (!EC)
        WriteGraph(File, Graph, IsSimple, Title);
      else
        errs() << "  error opening file for writing!";
      errs() << "\n";
  
      return false;
    }
  
    void getAnalysisUsage(AnalysisUsage &AU) const override {
      AU.setPreservesAll();
      AU.addRequired<AnalysisT>();
    }
  
  private:
    std::string Name;
  };
  
  } // end namespace llvm
  
  #endif
  