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/****************************************************************************

 *                                                                          *

 *                         GNAT RUN-TIME COMPONENTS                         *

 *                                                                          *

 *                   T R A C E B A C K - G C C t a b l e s                  *

 *                                                                          *

 *                          C Implementation File                           *

 *                                                                          *

 *          Copyright (C) 2004-2011, Free Software Foundation, Inc.         *

 *                                                                          *

 * GNAT is free software;  you can  redistribute it  and/or modify it under *

 * terms of the  GNU General Public License as published  by the Free Soft- *

 * ware  Foundation;  either version 3,  or (at your option) any later ver- *

 * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *

 * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *

 * or FITNESS FOR A PARTICULAR PURPOSE.                                     *

 *                                                                          *

 * As a special exception under Section 7 of GPL version 3, you are granted *

 * additional permissions described in the GCC Runtime Library Exception,   *

 * version 3.1, as published by the Free Software Foundation.               *

 *                                                                          *

 * You should have received a copy of the GNU General Public License and    *

 * a copy of the GCC Runtime Library Exception along with this program;     *

 * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    *

 * <http://www.gnu.org/licenses/>.                                          *

 *                                                                          *

 * GNAT was originally developed  by the GNAT team at  New York University. *

 * Extensive contributions were provided by Ada Core Technologies Inc.      *

 *                                                                          *

 ****************************************************************************/

/* This is an implementation of the __gnat_backtrace routine using the

   underlying GCC unwinding support associated with the exception handling

   infrastructure.  This will only work for ZCX based applications.  */

#include <unwind.h>

/* The implementation boils down to a call to _Unwind_Backtrace with a

   tailored callback and carried-on data structure to keep track of the

   input parameters we got as well as of the basic processing state.  */

/******************

 * trace_callback *

 ******************/

#if !defined (__USING_SJLJ_EXCEPTIONS__)

typedef struct {

  void ** traceback;

  int max_len;

  void * exclude_min;

  void * exclude_max;

  int  n_frames_to_skip;

  int  n_frames_skipped;

  int  n_entries_filled;

} uw_data_t;

#if defined (__ia64__) && defined (__hpux__)

#include <uwx.h>

#endif

static _Unwind_Reason_Code

trace_callback (struct _Unwind_Context * uw_context, uw_data_t * uw_data)

{

  char * pc;

#if defined (__ia64__) && defined (__hpux__)

  /* Work around problem with _Unwind_GetIP on ia64 HP-UX. */

  uwx_get_reg ((struct uwx_env *) uw_context, UWX_REG_IP, (uint64_t *) &pc);

#else

  pc = (char *) _Unwind_GetIP (uw_context);

#endif

  if (uw_data->n_frames_skipped < uw_data->n_frames_to_skip)

    {

      uw_data->n_frames_skipped ++;

      return _URC_NO_REASON;

    }

  if (uw_data->n_entries_filled >= uw_data->max_len)

    return _URC_NORMAL_STOP;

  if (pc < (char *)uw_data->exclude_min || pc > (char *)uw_data->exclude_max)

    uw_data->traceback [uw_data->n_entries_filled ++] = pc + PC_ADJUST;

  return _URC_NO_REASON;

}

#endif

/********************

 * __gnat_backtrace *

 ********************/

int

__gnat_backtrace (void ** traceback __attribute__((unused)),

                  int max_len __attribute__((unused)),

                  void * exclude_min __attribute__((unused)),

                  void * exclude_max __attribute__((unused)),

                  int skip_frames __attribute__((unused)))

{

#if defined (__USING_SJLJ_EXCEPTIONS__)

  /* We have no unwind material (tables) at hand with sjlj eh, and no

     way to retrieve complete and accurate call chain information from

     the context stack we maintain.  */

  return 0;

#else

  uw_data_t uw_data;

  /* State carried over during the whole unwinding process.  */

  uw_data.traceback   = traceback;

  uw_data.max_len     = max_len;

  uw_data.exclude_min = exclude_min;

  uw_data.exclude_max = exclude_max;

  uw_data.n_frames_to_skip = skip_frames;

  uw_data.n_frames_skipped = 0;

  uw_data.n_entries_filled = 0;

  _Unwind_Backtrace ((_Unwind_Trace_Fn)trace_callback, &uw_data);

  return uw_data.n_entries_filled;

#endif

}