Re: [Discuss-gnuradio] Undefined reference to gr_fxpt

[Eric Blossom]

On Mon, Oct 03, 2005 at 04:24:13PM -0600, Robitaille, Michael wrote:
> Hello all,
> 
>  
> 
> I have been trying to get the Gnu Radio 2.5 core to compile under the Fedora
> 4 Core.   I have been following the instruction given at KD7lmo and with
> some work; I have gotten the baseline packages to work.  I am using the
> tarball files since our network will not allow me to download with CVS.  I
> am getting the following errors:
> 
> ../../src/lib/.libs/libgnuradio-core.so: undefined reference to
> `gr_fxpt::TWO_TO_THE_31'
> 
> ../../src/lib/.libs/libgnuradio-core.so: undefined reference to `gr_fxpt::PI
> 
> Checking the archive I found that Eric Blossom said "this is our
> problem...".  I am using gcc 4.0.0.  Is there a fix for this problem or do I
> need to use gcc 3.4.1?
>  
> 
> Michael A. Robitaille
> Senior Engineer

This is fixed in CVS.
Here's the current version of gr_fxpt.cc that I believe fixed the problem.

/* -*- c++ -*- */
/*
 * Copyright 2004 Free Software Foundation, Inc.
 * 
 * This file is part of GNU Radio
 * 
 * GNU Radio 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, or (at your option)
 * any later version.
 * 
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gr_fxpt.h>

const float gr_fxpt::s_sine_table[1 << NBITS][2] = {
#include "sine_table.h"
};

// gcc 4.x fix
const float gr_fxpt::TWO_TO_THE_31;
const float gr_fxpt::PI;

#if 0
/*
 * Compute sine using table lookup with linear interpolation.
 * Each table entry contains slope and intercept.
 */
float
gr_fxpt::sin (gr_int32 x)
{
  gr_uint32 ux = x;
  int index = ux >> (WORDBITS - NBITS);
  return s_sine_table[index][0] * (ux >> 1) + s_sine_table[index][1];
}

float
gr_fxpt::cos (gr_int32 x)
{
  gr_uint32 ux = x + 0x40000000;
  int index = ux >> (WORDBITS - NBITS);
  return s_sine_table[index][0] * (ux >> 1) + s_sine_table[index][1];
}
#endif