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Reply-To: <kris DOT thielemans AT ic DOT ac DOT uk>
From: "Kris Thielemans" <kris DOT thielemans AT ic DOT ac DOT uk>
To: "Gnuwin" <cygwin AT sourceware DOT cygnus DOT com>
Subject: RE: problem with dynamic_cast
Date: Thu, 7 Sep 2000 16:50:18 +0100
Message-ID: <001301c018e3$52641f30$460a10ac@petnt1.rpms.ac.uk>
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Hi,

I have a tiny bit more information on this problem.

- I reproduced it on my own NT box, with cygwin 1.1.4 (it does NOT happen
with B20.1)

- I can reproduce it with a file (attached) that does not need linking with
any other file (except standard libs).
* If I do a normal "g++ dynamic_cast8.cxx", the program runs fine
* If I link it with another file I have "g++ dynamic_cast8.cxx bla.o" it
crashes.

The other file is also compiled with the same gcc (it's not specific to
which file exactly).


Weird.

Suggestions ?

Kris


> -----Original Message-----
> From: Kris Thielemans [mailto:kris DOT thielemans AT ic DOT ac DOT uk]
> Sent: 31 August 2000 15:58
> To: Gnuwin
> Subject: problem with dynamic_cast
>
>
> Hi,
>
> I have a problem with some of our own C++ software when compiled
> with gcc on cygwin cygwin v.1.1.4 on Windows NT4.00.1381 (Finnish
> language). Note that this program runs fine on my own NT 4.0 sp5
> or sp6 machines running cygwin B20.1 with gcc 2.95.2, and on
> Solaris with gcc 2.95.2, and on AIX with gcc 2.8.1).
>
> The problem occurs when executing a dynamic_cast on a pointer.
> Any suggestions ?
>
>
> details:
> ---------
> The program generates the following error:
>    0 [main] test_VoxelsOnCartesianGrid 1039 handle_exceptions: Exception:
> STATUS_ACCESS_VIOLATION
>    974 [main] test_VoxelsOnCartesianGrid 1039 stackdump: Dumping
> stack trace
> to test_VoxelsOnCartesianGrid.exe.stackdump
> make: *** [run_tests] Segmentation fault (core dumped)
>
> The file where it crashes is compiled as follows:
> g++  -g -D_DEBUG -g  -Wall  -I/home/PPhead/include  -o
> debug/VoxelsOnCartesianGrid.o -c VoxelsOnCartesianGrid.cxx
>
>
> When running the program in gdb, the stack trace after the crash is:
> Program received signal SIGSEGV, Segmentation fault.
> 0x611e4 in ?? ()
> (gdb) info stack
> #0  0x611e4 in ?? ()
> #1  0x41e484 in __si_type_info::dcast (this=0x460520, to=@0x4604c0,
>     require_public=1, addr=0xa057e90, sub=0x460280, subptr=0xa057e90)
>     at /cygnus/netrel/src/gcc-2.95.2-2/gcc/cp/tinfo.cc:76
> #2  0x41e6d3 in __dynamic_cast (
>     from=0x441658 <Tomo::ProjDataInfoCylindricalArcCorr type_info
> function>,
>     to=0x4415a4 <Tomo::ProjDataInfoCylindrical type_info function>,
>     require_public=1, address=0xa057e90,
>     sub=0x441544 <Tomo::ProjDataInfo type_info function>,
> subptr=0xa057e90)
>     at /cygnus/netrel/src/gcc-2.95.2-2/gcc/cp/tinfo2.cc:38
> #3  0x40ddda in Tomo::find_sampling_and_z_size (z_sampling=@0x266f898,
>     s_sampling=@0x266f894, z_size=@0x266f89c,
> proj_data_info_ptr=0xa057e90)
>     at VoxelsOnCartesianGrid.cxx:45
> #4  0x4325e8 in
> Tomo::VoxelsOnCartesianGrid<float>::VoxelsOnCartesianGrid (
>     this=0x266fc00, proj_data_info=@0xa057e90, zoom=2.29999995,
>     origin=@0x266fd10, make_xy_size_odd=false) at
> VoxelsOnCartesianGrid.cxx:138
> #5  0x4022a6 in Tomo::VoxelsOnCartesianGridTests::run_tests
> (this=0x266fd60)
>     at test_VoxelsOnCartesianGrid.cxx:103
> #6  0x403174 in main () at test_VoxelsOnCartesianGrid.cxx:180
> #7  0x61002272 in _size_of_stack_reserve__ ()
> #8  0x61002805 in _size_of_stack_reserve__ ()
> #9  0x61002843 in _size_of_stack_reserve__ ()
> #10 0x41cdd5 in cygwin_crt0 ()
>
>
> This seems to say there is something wrong in the dynamic_cast
> statement on that line, which looks as follows:
>   if (const ProjDataInfoCylindrical*
>         proj_data_info_cyl_ptr =
> 	dynamic_cast<const ProjDataInfoCylindrical*>(proj_data_info_ptr))
>   { ...}
>
> By the way, if you check the stack trace, you'll see that the
> dynamic cast is from a ProjDataInfoCylindricalArcCorr * to a
> ProjDataInfoCylindrical *, where ProjDataInfoCylindricalArcCorr
> is derived from ProjDataInfoCylindrical. (Not that it should
> crash in any case).
>
>
> Thanks !
>
>
>
> Kris Thielemans
> (kris DOT thielemans AT ic DOT ac DOT uk)
> MRC Cyclotron Unit,
> Hammersmith Hospital,
> DuCane Rd,London W12 0NN, United Kingdom
>
> Phone on :   +44 (020)8383 3731
> FAX on :     +44 (020)8383 2029
>
> NEW web site address:
> http://www.cu.mrc.ac.uk/~kris

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#define END_NAMESPACE_TOMO
#define START_NAMESPACE_TOMO
#define USING_NAMESPACE_TOMO

=20
template <class NUMBER>=20
inline NUMBER square(const NUMBER &x) { return x*x; }

#include <iostream>

#ifndef __ProjDataInfo_H__
#define __ProjDataInfo_H__



START_NAMESPACE_TOMO

template <typename elemT> class Sinogram;
template <typename elemT> class Viewgram;
template <typename elemT> class SegmentByView;
template <typename elemT> class SegmentBySinogram;
template <typename elemT> class RelatedViewgrams;
class DataSymmetriesForViewSegmentNumbers;
class ViewSegmentNumbers;
class PMessage;

class ProjDataInfo
{
 =20
public:

 =20
 =20
  /************ constructors ***********/
  // TODO should probably be protected

  //! Construct an empty object
  inline  ProjDataInfo();


  //! Standard trick for a 'virtual copy-constructor'=20
  virtual ProjDataInfo* clone() const =3D 0;

  //! Destructor
  virtual ~ProjDataInfo() {}

  /**************** member functions *********/

  // TODOdoc coordinate system
  //! Get tangent of the co-polar angle, tan(theta)
  virtual float get_tantheta(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const =3D0;
  //! Get azimuthal angle phi
  virtual float get_phi(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const =3D0;
 =20
  //! Get value of the (roughly) axial coordinate in the projection =
plane (in mm)
  virtual float get_t(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const =3D0;

  //! Get value of the tangential coordinate in the projection plane (in =
mm)
  virtual float get_s(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const =3D0;
 =20
 =20
private:

  int min_view_num;
  int max_view_num;
  int min_tangential_pos_num;
  int max_tangential_pos_num;
 =20
};

END_NAMESPACE_TOMO

//#include "ProjDataInfo.inl"
//
// @(#)ProjDataInfo.inl	1.1: 00/06/14
//

START_NAMESPACE_TOMO


ProjDataInfo::ProjDataInfo()
{}
 =20


END_NAMESPACE_TOMO


#endif //  __ProjDataInfo_H__

#ifndef __ProjDataInfoCylindrical_H__
#define __ProjDataInfoCylindrical_H__


//#include"ProjDataInfo.h"

START_NAMESPACE_TOMO
/*!
  \ingroup buildblock=20
  \brief projection data info for data corresponding to a=20
  'cylindrical' sampling.

  These data are organised by ring differences (allowing for
  merging of some ring differences into 1 segment). It is general
  enough to have both the CTI 'spanned' format, and the GE Advance
  format.
*/
// TODOdoc more
class ProjDataInfoCylindrical: public ProjDataInfo
{

public:
  //! Constructors
  inline ProjDataInfoCylindrical();
		      =20
  inline float get_phi(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const;=20
=20
  inline float get_t(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const;



protected:

  float azimuthal_angle_sampling;
  float ring_radius;

private:
  float ring_spacing;

};


END_NAMESPACE_TOMO

//#include "ProjDataInfoCylindrical.inl"

//
// @(#)ProjDataInfoCylindrical.inl	1.1: 00/06/14
//
START_NAMESPACE_TOMO

ProjDataInfoCylindrical::ProjDataInfoCylindrical()
{}


float
ProjDataInfoCylindrical::get_phi(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num)const
{ return view_num*azimuthal_angle_sampling;}

float
ProjDataInfoCylindrical::get_t(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const
{return axial_position_num;}





END_NAMESPACE_TOMO


 =20

#endif

#ifndef __ProjDataInfoCylindricalArcCorr_H__
#define __ProjDataInfoCylindricalArcCorr_H__


//#include "ProjDataInfoCylindrical.h"

START_NAMESPACE_TOMO

/*!
  \ingroup buildblock=20
  \brief projection data info for arc-corrected data
  */
class ProjDataInfoCylindricalArcCorr : public ProjDataInfoCylindrical
{

public:
  //! Constructors
  inline ProjDataInfoCylindricalArcCorr();

 =20
  inline virtual float get_tantheta(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const;=20
  inline virtual float get_s(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const;
  inline ProjDataInfo* clone() const;

private:
 =20
  float bin_size;
 =20

};

END_NAMESPACE_TOMO

//#include "ProjDataInfoCylindricalArcCorr.inl"

//
// @(#)ProjDataInfoCylindricalArcCorr.inl	1.1: 00/06/14
//

START_NAMESPACE_TOMO
ProjDataInfoCylindricalArcCorr:: ProjDataInfoCylindricalArcCorr()

{}

float
ProjDataInfoCylindricalArcCorr::get_s(int segment_num,int view_num,int =
axial_position_num, int transaxial_position_num) const
{return transaxial_position_num*bin_size;}


float
ProjDataInfoCylindricalArcCorr::get_tantheta(int segment_num,int =
view_num,int axial_position_num, int transaxial_position_num) const
{
  return
    =
(2*sqrt(square(ring_radius)-square(get_s(segment_num,view_num,axial_posit=
ion_num, transaxial_position_num))));
 =20
}





ProjDataInfo*
ProjDataInfoCylindricalArcCorr::clone() const
{
 return static_cast<ProjDataInfo*>(new =
ProjDataInfoCylindricalArcCorr(*this));

}


END_NAMESPACE_TOMO


#endif

//#include "ProjDataInfoCylindricalArcCorr.h"


USING_NAMESPACE_TOMO

// a local help function to find appropriate sizes etc.

static void find_sampling_and_z_size(
				 const ProjDataInfo* proj_data_info_ptr)
{

  // first z- things

  const ProjDataInfoCylindrical*
        proj_data_info_cyl_ptr =3D=20
    dynamic_cast<const ProjDataInfoCylindrical*>(proj_data_info_ptr);

  if (proj_data_info_cyl_ptr)
   {
     std::cerr << "OK !\n";
   }
  else
    {
      std::cerr << " Not OK!\n";
    }
}


int main()
{

  ProjDataInfo * proj_data_info_ptr =3D=20
    new ProjDataInfoCylindricalArcCorr;

  find_sampling_and_z_size(proj_data_info_ptr);
  return 0;

}




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