/*
 * File:	EvalContext.h
 *
 * Copyright (c) Freescale Semiconductor, Inc. All rights reserved.
 * See included license file for license details.
 */
#if !defined(_EvalContext_h_)
#define _EvalContext_h_

#include <map>
#include <string>
#include "Value.h"
#include "int_size.h"
#include "SourceFile.h"

namespace elftosb
{
/*!
 * \brief Context for evaluating AST tree and expressions.
 *
 * Keeps a map of variable names to integer values. Each integer value has a
 * size attribute in addition to the actual value. Variables can be locked, which
 * simply means that they cannot be assigned a new value.
 *
 * \todo Switch to using Value instances to keep track of variable values. This
 *		will enable variables to have string values, for one.
 */
class EvalContext
{
public:
    /*!
     * \brief Abstract interface for a manager of source files.
     */
    class SourceFileManager
    {
    public:
        //! \brief Returns true if a source file with the name \a name exists.
        virtual bool hasSourceFile(const std::string &name) = 0;

        //! \brief Gets the requested source file.
        virtual SourceFile *getSourceFile(const std::string &name) = 0;

        //! \brief Returns the default source file, or NULL if none is set.
        virtual SourceFile *getDefaultSourceFile() = 0;
    };

public:
    //! \brief Constructor.
    EvalContext();

    //! \brief Destructor.
    virtual ~EvalContext();

    //! \name Source file manager
    //@{
    //! \brief
    void setSourceFileManager(SourceFileManager *manager) { m_sourcesManager = manager; }
    //! \brief
    SourceFileManager *getSourceFileManager() { return m_sourcesManager; }
    //@}

    //! \name Variables
    //@{
    bool isVariableDefined(const std::string &name);
    uint32_t getVariableValue(const std::string &name);
    int_size_t getVariableSize(const std::string &name);
    void setVariable(const std::string &name, uint32_t value, int_size_t size = kWordSize);
    //@}

    //! \name Locks
    //@{
    bool isVariableLocked(const std::string &name);
    void lockVariable(const std::string &name);
    void unlockVariable(const std::string &name);
    //@}

    void dump();

protected:
    //! Information about a variable's value.
    struct variable_info_t
    {
        uint32_t m_value;  //!< Variable value.
        int_size_t m_size; //!< Number of bytes
        bool m_isLocked;   //!< Can this variable's value be changed?
    };

    //! Type to maps between the variable name and its info.
    typedef std::map<std::string, variable_info_t> variable_map_t;

    SourceFileManager *m_sourcesManager; //!< Interface to source file manager.
    variable_map_t m_variables;          //!< Map of variables to their final values.
};

}; // namespace elftosb

#endif // _EvalContext_h_
