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/****************************************************************************
* *
* GNAT COMPILER 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 Ada Core Technologies, 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 2, 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. See the GNU General Public License *
* for more details. You should have received a copy of the GNU General *
* Public License distributed with GNAT; see file COPYING. If not, write *
* to the Free Software Foundation, 51 Franklin Street, Fifth Floor, *
* Boston, MA 02110-1301, USA. *
* *
* As a special exception, if you link this file with other files to *
* produce an executable, this file does not by itself cause the resulting *
* executable to be covered by the GNU General Public License. This except- *
* ion does not however invalidate any other reasons why the executable *
* file might be covered by the GNU Public License. *
* *
* 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 datastructure to keep track of the
input parameters we got as well as of the basic processing state. */
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;
/******************
* trace_callback *
******************/
static _Unwind_Reason_Code
trace_callback (struct _Unwind_Context * uw_context, uw_data_t * uw_data)
{
void * pc = (void *) _Unwind_GetIP (uw_context);
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 < uw_data->exclude_min || pc > uw_data->exclude_max)
uw_data->traceback [uw_data->n_entries_filled ++] = pc + PC_ADJUST;
return _URC_NO_REASON;
}
/********************
* __gnat_backtrace *
********************/
int
__gnat_backtrace (void ** traceback, int max_len,
void * exclude_min, void * exclude_max,
int skip_frames)
{
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;
}
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