plugin.h

//===-------------------------------*- C++ -*--------------------------------===//
/*
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*/
#ifndef PLUGIN_H
#define PLUGIN_H

#include <vector>
#include <cstddef>
#include <string>
#include <map>
//#include <memory> // unique_ptr C++11 feature!!
#include <dlfcn.h> // dlopen()

class SgProject; 
namespace Rose {
  // internal storage to store plugin options from command line options
  extern std::vector<std::string> PluginLibs; // one or more plugin shared libraries  
  extern std::vector<std::string> PluginActions; // one or more actions defined in the shared libs
  extern std::map<std::string, std::vector <std::string> > PluginArgs; // map between plugin_name and their arguments

  // Hooked up with frontend(..) to process command line options related to plugins
  void processPluginCommandLine(std::vector<std::string>& input_argv); 
  // iterate through all registered plugins, executing specified ones. 
  int obtainAndExecuteActions(SgProject* n);
  //------------ plugin -------------------------
  class PluginAction {
    public:

      virtual void process(SgProject*) {}; 

      virtual bool ParseArgs(const std::vector<std::string> &arg) {return true; };
      virtual ~PluginAction(){} // must have virtual destructor
  };

  //------------------iterator range----------------
  template <typename IteratorT>
    class iterator_range {
      IteratorT begin_iterator, end_iterator;

      public:
      //TODO: Add SFINAE to test that the Container's iterators match the range's
      //      iterators.
      template <typename Container>
        iterator_range(Container &c)
        //TODO: Consider ADL/non-member begin/end calls.
        : begin_iterator(c.begin()), end_iterator(c.end()) {}
      iterator_range(IteratorT begin_iterator, IteratorT end_iterator)
        : begin_iterator(begin_iterator),
        end_iterator(end_iterator) {}

      IteratorT begin() const { return begin_iterator; }
      IteratorT end() const { return end_iterator; }
    };

  template <class T> iterator_range<T> make_range(T x, T y) {
    return iterator_range<T>(x, y);
  }

  template <typename T> iterator_range<T> make_range(std::pair<T, T> p) {
    return iterator_range<T>(p.first, p.second);
  }
#if 0 // not used
  template<typename T>
    iterator_range<decltype(begin(std::declval<T>()))> drop_begin(T &&t, int n) {
      return make_range(std::next(begin(t), n), end(t));
    }
#endif
  //------------------------------------- Registry --------------
  template <typename T>
    class SimpleRegistryEntry {
      const char *Name, *Desc;
      T* (*Ctor)();

      public:
      SimpleRegistryEntry(const char *N, const char *D, T* (*C)())
        : Name(N), Desc(D), Ctor(C)
      {}

      const char *getName() const { return Name; }
      const char *getDesc() const { return Desc; }
      T* instantiate() const { return Ctor(); }
      //T* instantiate() const { return Ctor(); }
    };

  template <typename T>
    class RegistryTraits {
      //RegistryTraits() = delete;
      RegistryTraits(){} ;

      public:
      typedef SimpleRegistryEntry<T> entry;

      //                  used to generate help for command-line options.
      static const char *nameof(const entry &Entry) { return Entry.getName(); }
      static const char *descof(const entry &Entry) { return Entry.getDesc(); }
    };

  template <typename T, typename U = RegistryTraits<T> >
    class Registry {
      public:
        typedef U traits;
        typedef typename U::entry entry;

        class node;
        class listener;
        class iterator;

      private:
        //Registry() = delete;
        Registry() {};

        static void Announce(const entry &E) {
          for (listener *Cur = ListenerHead; Cur; Cur = Cur->Next)
            Cur->registered(E);
        }

        friend class node;
        static node *Head, *Tail;

        friend class listener;
        static listener *ListenerHead, *ListenerTail;

      public:
        class node {
          friend class iterator;

          node *Next;
          const entry& Val;

          public:
          node(const entry& V) : Next(NULL), Val(V) {
            if (Tail)
              Tail->Next = this;
            else
              Head = this;
            Tail = this;

            Announce(V);
          }
        };

        class iterator {
          const node *Cur;

          public:
          explicit iterator(const node *N) : Cur(N) {}

          bool operator==(const iterator &That) const { return Cur == That.Cur; }
          bool operator!=(const iterator &That) const { return Cur != That.Cur; }
          iterator &operator++() { Cur = Cur->Next; return *this; }
          const entry &operator*() const { return Cur->Val; }
          const entry *operator->() const { return &Cur->Val; }
        };

        static iterator begin() { return iterator(Head); }
        static iterator end()   { return iterator(NULL); }

        static iterator_range<iterator> entries() {
          return make_range(begin(), end());
        }

        class listener {
          listener *Prev, *Next;

          friend void Registry::Announce(const entry &E);

          protected:
          virtual void registered(const entry &) = 0;

          void init() {
            for (iterator I = begin(), E = end(); I != E; ++I)
              registered(*I);
          }

          public:
          listener() : Prev(ListenerTail), Next(NULL) {
            if (Prev)
              Prev->Next = this;
            else
              ListenerHead = this;
            ListenerTail = this;
          }

          virtual ~listener() {
            if (Next)
              Next->Prev = Prev;
            else
              ListenerTail = Prev;
            if (Prev)
              Prev->Next = Next;
            else
              ListenerHead = Next;
          }
        };

        //   Registry<Collector>::Add<FancyGC>
        //
        template <typename V>
          class Add {
            entry Entry;
            node Node;

            static T* CtorFn() { return new V(); }

            public:
            Add(const char *Name, const char *Desc)
              : Entry(Name, Desc, CtorFn), Node(Entry) {}
          };

    };

  // Since these are defined in a header file, plugins must be sure to export
  // these symbols.

  template <typename T, typename U>
    typename Registry<T,U>::node *Registry<T,U>::Head;

  template <typename T, typename U>
    typename Registry<T,U>::node *Registry<T,U>::Tail;

  template <typename T, typename U>
    typename Registry<T,U>::listener *Registry<T,U>::ListenerHead;

  template <typename T, typename U>
    typename Registry<T,U>::listener *Registry<T,U>::ListenerTail;
  //---------------------------------------------------   

  extern template class Registry<PluginAction>; 

  typedef Registry<PluginAction> PluginRegistry;


} // end of namespace

#endif