/*!
 * \file symbolFinder.hpp
 * \brief This file is used by search symbol in library.
 * Copyright (C) 2011-2013 Nippon Telegraph and Telephone Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 */

#ifndef _SYMBOL_FINDER_HPP
#define _SYMBOL_FINDER_HPP

#include <stddef.h>
#include <bfd.h>

#ifndef DEBUGINFO_DIR
  
  /*!
   * \brief Debuginfo parent directory.
   */
  #define DEBUGINFO_DIR    "/usr/lib/debug"
#endif

#ifndef DEBUGINFO_SUFFIX
  
  /*!
   * \brief Debuginfo binary name suffix.
   */
  #define DEBUGINFO_SUFFIX ".debug"
#endif

/*!
 * \brief Data container of shared library name and loaded virtual address.
 */
typedef struct{
  char *libname;      /*!< Name of target library.          */
  size_t libname_len; /*!< Length of library name.          */
  ptrdiff_t baseaddr; /*!< Pointer of library base address. */
} TLibraryInfo;

/*!
 * \brief BFD symbol information structure.
 */
typedef struct{
  bfd *bfdInfo;               /*!< BFD descriptor.                     */
  char *staticSyms;           /*!< List stored static symbol.          */
  int staticSymCnt;           /*!< Count of static symbols.            */
  unsigned int staticSymSize; /*!< Size of single static symbols.      */
  char *dynSyms;              /*!< List stored dynamic symbol.         */
  int dynSymCnt;              /*!< Count of dynamic symbols.           */
  unsigned int dynSymSize;    /*!< Size of single dynamic symbols.     */
  bool hasSymtab;             /*!< Flag of BFD has .symtab section.    */
  asymbol *workSym;           /*!< Empty symbol for working temporary. */
} TLibBFDInfo;

/*!
 * \brief .note.gnu.build-id information structure.
 */
typedef struct{
  unsigned int name_size;  /*!< size of the name.              */
  unsigned int hash_size;  /*!< size of the hash.              */
  unsigned int identifier; /*!< NT_GNU_BUILD_ID == 0x3         */
  char contents;           /*!< name ("GNU") & hash (build id) */
} TBuildIdInfo;

/*!
 * \brief C++ class for symbol search.
 */
class TSymbolFinder{
  public:
    /*!
     * \brief TSymbolFinder constructor.
     */
    TSymbolFinder(void);
    
    /*!
     * \brief TSymbolFinder destructor.
     */
    virtual ~TSymbolFinder();
    
    /*!
     * \brief Load target libaray.
     * \param pathPattern [in] Pattern of target library path.
     * \return Is success load library.<br>
     */
    virtual bool loadLibrary(const char *pathPattern);
    
    /*!
     * \brief Find symbol in target library.
     * \param symbol [in] Symbol string.
     * \return Address of designated symbol.<br>
     *         value is null if process is failure.
     */
    virtual void *findSymbol(char const* symbol);
    
    /*!
     * \brief Get target library name.
     * \return String of library name.
     */
    const inline char *getLibraryName(void){
      return this->targetLibInfo.libname;
    };
    
    /*!
     * \brief Get target library base address.
     * \return Pointer of library base address.
     */
    const inline void *getLibraryAddress(void){
      return (void *)this->targetLibInfo.baseaddr;
    };
    
    /*!
     * \brief Get absolute address.
     * \param addr [in] Address of library symbol.
     * \return Absolute symbol address in library.
     */
    inline void *getAbsoluteAddress(void *addr){
      return (void *)((ptrdiff_t)this->targetLibInfo.baseaddr + (ptrdiff_t)addr);
    };
    
  protected:
    /*!
     * \brief Load target libaray information.
     * \param path  [in]  Target library path.
     * \param libInfo [out] BFD information record.<br>
     *        Value is null if process is failure.
     */
    virtual void loadLibraryInfo(char const* path, TLibBFDInfo *libInfo);
    
    /*!
     * \brief Find symbol in target library to use BFD.
     * \param libInfo  [in] BFD information record.
     * \param symbol   [in] Symbol string.
     * \param isDynSym [in] Symbol is dynamic symbol.
     * \return Address of designated symbol.<br>
     *         value is null if process is failure.
     */
    virtual void *doFindSymbol(TLibBFDInfo *libInfo,
                                       char const* symbol, bool isDynSym);
    
  private:
    /*!
     * \brief Flag of BFD libarary is already initialized.
     */
    static bool initFlag;
    
    /*!
     * \brief Record of target library information.
     */
    TLibraryInfo targetLibInfo;
    /*!
     * \brief BFD record of target library information.
     */
    TLibBFDInfo libBfdInfo;
    /*!
     * \brief BFD record of target library's debug information.
     */
    TLibBFDInfo debugBfdInfo;
};

#endif // _SYMBOL_FINDER_HPP