//===-- llvm/ValueHolder.h - Class to hold multiple values -------*- C++ -*--=//
//
// This defines a class that is used as a fancy Definition container.  It is
// special because it helps keep the symbol table of the container function up
// to date with the goings on inside of it.
//
// This is used to represent things like the instructions of a basic block and
// the arguments to a function.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_VALUEHOLDER_H
#define LLVM_VALUEHOLDER_H

#include <vector>

// ValueSubClass  - The type of objects that I hold
// ItemParentType - I call setParent() on all of my "ValueSubclass" items, and
//                  this is the value that I pass in.
// SymTabType     - This is the class type, whose symtab I insert my
//                  ValueSubClass items into.  Most of the time it is
//                  ItemParentType, but Instructions have item parents of BB's
//                  but symtabtype's of a Function
//
template<class ValueSubclass, class ItemParentType, class SymTabType> 
class ValueHolder {
  std::vector<ValueSubclass*> ValueList;

  ItemParentType *ItemParent;
  SymTabType *Parent;

  ValueHolder(const ValueHolder &V);   // DO NOT IMPLEMENT
public:
  inline ValueHolder(ItemParentType *IP, SymTabType *parent = 0) { 
    assert(IP && "Item parent may not be null!");
    ItemParent = IP;
    Parent = 0;
    setParent(parent); 
  }

  inline ~ValueHolder() {
    // The caller should have called delete_all first...
    assert(empty() && "ValueHolder contains definitions!");
    assert(Parent == 0 && "Should have been unlinked from function!");
  }

  inline const SymTabType *getParent() const { return Parent; }
  inline SymTabType *getParent() { return Parent; }
  void setParent(SymTabType *Parent);  // Defined in ValueHolderImpl.h

  inline             unsigned size()  const { return ValueList.size();  }
  inline                 bool empty() const { return ValueList.empty(); }
  inline const ValueSubclass *front() const { return ValueList.front(); }
  inline       ValueSubclass *front()       { return ValueList.front(); }
  inline const ValueSubclass *back()  const { return ValueList.back();  }
  inline       ValueSubclass *back()        { return ValueList.back();  }
  inline const ValueSubclass *operator[](unsigned i) const {
    return ValueList[i];
  }
  inline       ValueSubclass *operator[](unsigned i) {
    return ValueList[i];
  }

  //===--------------------------------------------------------------------===//
  // sub-Definition iterator code
  //===--------------------------------------------------------------------===//
  // 
  typedef std::vector<ValueSubclass*>::iterator               iterator;
  typedef std::vector<ValueSubclass*>::const_iterator   const_iterator;
  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
  typedef std::reverse_iterator<iterator>             reverse_iterator;

  inline iterator                begin()       { return ValueList.begin(); }
  inline const_iterator          begin() const { return ValueList.begin(); }
  inline iterator                end  ()       { return ValueList.end();   }
  inline const_iterator          end  () const { return ValueList.end();   }

  inline reverse_iterator       rbegin()       { return ValueList.rbegin(); }
  inline const_reverse_iterator rbegin() const { return ValueList.rbegin(); }
  inline reverse_iterator       rend  ()       { return ValueList.rend();   }
  inline const_reverse_iterator rend  () const { return ValueList.rend();   }
  
  // ValueHolder::remove(iterator &) this removes the element at the location 
  // specified by the iterator, and leaves the iterator pointing to the element 
  // that used to follow the element deleted.
  //
  ValueSubclass *remove(iterator &DI);         // Defined in ValueHolderImpl.h
  ValueSubclass *remove(const iterator &DI);   // Defined in ValueHolderImpl.h
  void           remove(ValueSubclass *D);     // Defined in ValueHolderImpl.h
  ValueSubclass *pop_back();                   // Defined in ValueHolderImpl.h

  // replaceWith - This removes the element pointed to by 'Where', and inserts
  // NewValue in it's place.  The old value is returned.  'Where' must be a
  // valid iterator!
  //
  ValueSubclass *replaceWith(iterator &Where, ValueSubclass *NewValue);

  // delete_span - Remove the elements from begin to end, deleting them as we
  // go.  This leaves the iterator pointing to the element that used to be end.
  //
  iterator delete_span(iterator begin, iterator end) {
    while (end != begin)
      delete remove(--end);
    return end;
  }

  void delete_all() {            // Delete all removes and deletes all elements
    delete_span(begin(), end());
  }

  void push_front(ValueSubclass *Inst);        // Defined in ValueHolderImpl.h
  void push_back(ValueSubclass *Inst);         // Defined in ValueHolderImpl.h

  // ValueHolder::insert - This method inserts the specified value *BEFORE* the 
  // indicated iterator position, and returns an interator to the newly inserted
  // value.
  //
  iterator insert(iterator Pos, ValueSubclass *Inst);

  // ValueHolder::insert - This method inserts the specified _range_ of values
  // before the 'Pos' iterator.  This currently only works for vector
  // iterators...
  //
  // FIXME: This is not generic so that the code does not have to be around
  // to be used... is this ok?
  //
  void insert(iterator Pos,                     // Where to insert
              iterator First, iterator Last);   // Vector to read insts from
};

#endif