/*
 * See the dyninst/COPYRIGHT file for copyright information.
 * 
 * We provide the Paradyn Tools (below described as "Paradyn")
 * on an AS IS basis, and do not warrant its validity or performance.
 * We reserve the right to update, modify, or discontinue this
 * software at any time.  We shall have no obligation to supply such
 * updates or modifications or any other form of support to you.
 * 
 * By your use of Paradyn, you understand and agree that we (or any
 * other person or entity with proprietary rights in Paradyn) are
 * under no obligation to provide either maintenance services,
 * update services, notices of latent defects, or correction of
 * defects for Paradyn.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#if !defined(INSTRUCTIONAST_H)
#define INSTRUCTIONAST_H


#include "util.h"
#include <string>
#include <vector>
#include <set>
#include <iostream>
#include "Result.h"
#include "ArchSpecificFormatters.h"
#include "dyncompat/enable_shared_from_this.hpp"

namespace Dyninst
{
  namespace InstructionAPI
  {
  
    class InstructionAST;
  
    using std::vector;
    using std::set;
    enum formatStyle
    {
        defaultStyle,
        memoryAccessStyle
    };
    /// The %InstructionAST class is the base class for all nodes in the ASTs used by the %Operand class.
    /// It defines the necessary interfaces for traversing and searching
    /// an abstract syntax tree representing an operand.
    /// For the purposes of searching an %InstructionAST, we provide two related interfaces.  The first,
    /// \c getUses, will return the registers that appear in a given tree.  The second, \c isUsed, will
    /// take as input another tree and return true if that tree is a (not necessarily proper) subtree of this one.
    /// \c isUsed requires us to define an equality relation on these abstract
    /// syntax trees, and the equality operator is provided by the %InstructionAST, with the details
    /// implemented by the classes derived from %InstructionAST.  Two AST nodes are equal if the following conditions hold:
    /// - They are of the same type
    /// - If leaf nodes, they represent the same immediate value or the same register
    /// - If non-leaf nodes, they represent the same operation and their corresponding children are equal
    class INSTRUCTION_EXPORT InstructionAST : public dyncompat::enable_shared_from_this<InstructionAST>
    {
    public:
      typedef dyncompat::shared_ptr<InstructionAST> Ptr;

      InstructionAST();
      InstructionAST(const InstructionAST&) = default;
      virtual ~InstructionAST();

      /// Compare two AST nodes for equality.  
      ///
      /// Non-leaf nodes are equal
      /// if they are of the same type and their children are equal.  %RegisterASTs
      /// are equal if they represent the same register.  %Immediates are equal if they
      /// represent the same value.
      bool operator==(const InstructionAST& rhs) const;

      /// Children of this node are appended to the vector \c children
      virtual void getChildren(vector<InstructionAST::Ptr>& children) const = 0;

      /// \param uses The use set of this node is appended to the vector \c uses
      ///
      /// The use set of an %InstructionAST is defined as follows:
      ///   - A %RegisterAST uses itself
      ///   - A %BinaryFunction uses the use sets of its children
      ///   - An %Immediate uses nothing
      ///   - A %Dereference uses the use set of its child
      virtual void getUses(set<InstructionAST::Ptr>& uses) = 0;

      /// \return True if \c findMe is used by this AST node.
      /// \param findMe AST node to find in the use set of this node
      ///
      /// Unlike \c getUses, \c isUsed looks for \c findMe as a subtree
      /// of the current tree.  \c getUses is designed to return a minimal
      /// set of registers used in this tree, whereas \c isUsed is designed
      /// to allow searches for arbitrary subexpressions
      virtual bool isUsed(InstructionAST::Ptr findMe) const = 0;

      /// The \c format interface returns the contents of an %InstructionAST
      /// object as a string.  By default, \c format() produces assembly language.
      virtual std::string format(Architecture arch, formatStyle how = defaultStyle) const = 0;

      /// The \c format interface returns the contents of an %InstructionAST
      /// object as a string.  By default, \c format() produces assembly language.
      virtual std::string format(formatStyle how = defaultStyle) const = 0;
  
    protected:
      friend class RegisterAST;
      friend class Immediate;
      virtual bool isStrictEqual(const InstructionAST& rhs) const= 0;
      virtual bool checkRegID(MachRegister, unsigned int = 0, unsigned int = 0) const;
      virtual const Result& eval() const = 0;
    };
  }
}


#endif //!defined(INSTRUCTIONAST_H)