Re: Calling Octave from C++

[Tatsuro MATSUOKA]

----- Original Message -----

> From: Tatsuro MATSUOKA 
> To: tmacchan; Mike Miller  "help-octave andrea.delbravo 
> Cc: 
> Date: 2018/3/27, Tue 13:19
> Subject: Re: Calling Octave from C++

Try on octave 4.2.2
cd /home/mousei7/work/Octave/octave-ML/Calling_Octave_from_Cpp/octave-4.2.2

export LD_LIBRARY_PATH=/opt/octave-4.2.2/lib/octave/4.2.2:$LD_LIBRARY_PATH
export PATH=/opt/octave-4.2.2/bin:$PATH
echo $LD_LIBRARY_PATH
echo $PATH
octave --version

$ echo $LD_LIBRARY_PATH
/opt/octave-4.2.2/lib/octave/4.2.2:/usr/local/lib
$ echo $PATH
/opt/octave-4.2.2/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
$ octave --version
GNU Octave, version 4.2.2

$ LC_ALL=C ./test_01_02
Segmentation fault (core dump)

compiled with -g 

$ LC_ALL=C gdb ./test_01_02 

Thread 1 "test_01_02" received signal SIGSEGV, Segmentation fault.
octave::cmdline_options::cmdline_options (this=0x7fffffffdcb0, opts=...)
    at ../libinterp/octave.cc:249
249        : m_force_gui (opts.m_force_gui),
(gdb) bt
#0  octave::cmdline_options::cmdline_options (this=0x7fffffffdcb0, opts=...)
    at ../libinterp/octave.cc:249
#1  0x00007ffff770e2f4 in octave::application::options (this=<optimized out>)
    at ../libinterp/octave.h:197
#2  octave::interpreter::interpreter (this=0x7fffffffddf0, app_context=0x0, 
    embedded=<optimized out>) at ../libinterp/corefcn/interpreter.cc:533
#3  0x0000000000401c85 in main () at test_01_02.cc:12
(gdb) s
Couldn't get registers: No such process.
Couldn't get registers: No such process.
Couldn't get registers: No such process.
(gdb) [Thread 0x7fffd4ca8700 (LWP 3558) exited]
[Thread 0x7fffd74a9700 (LWP 3557) exited]
[Thread 0x7fffdbcaa700 (LWP 3556) exited]
[Thread 0x7fffe0cac700 (LWP 3554) exited]
[Thread 0x7fffe14ad700 (LWP 3553) exited]
[Thread 0x7fffe3cae700 (LWP 3552) exited]
[Thread 0x7ffff7fa77c0 (LWP 3548) exited]
Couldn't get registers: No such process.
(gdb) [Thread 0x7ffff7fa77c0 (LWP 3548) exited]
Couldn't get registers: No such process.
(gdb) [Thread 0x7fffde4ab700 (LWP 3555) exited]

Program terminated with signal SIGSEGV, Segmentation fault.
The program no longer exists.

For me something seems wrong with octave-4.2.2.
Upcoming 4.4 (now still 4.3.0+), code rewrite as indicated by Mike,
problem seems to be solved.

Tatsuro

// C++ code used
#include <iostream>
#include <octave/oct.h>
#include <octave/octave.h>
#include <octave/parse.h>
#include <octave/interpreter.h>

int
main (void)
{
  // Create interpreter.

  octave::interpreter interpreter;

  try
    {
      int status = interpreter.execute ();

      if (status != 0)
        {
          std::cerr << "creating embedded Octave interpreter failed!"
                    << std::endl;
          return status;
        }

        octave_value_list in;

        // THIS CODE IS WORKING
        int qq =10;
        int rr =15;
        in(0) = octave_value(qq);
        in(1) = octave_value(rr);
        octave_value_list out = feval ("gcd", in, 1);
        std::cout << out(0).int_value ()
                  << std::endl;
        //clean_up_and_exit(0);
      
    }
  catch (const octave::exit_exception& ex)
    {
      std::cerr << "Octave interpreter exited with status = "
                << ex.exit_status () << std::endl;
    }
  catch (const octave::execution_exception&)
    {
      std::cerr << "error encountered in Octave evaluator!" << std::endl;
    }

  return 0;
}
> 
> $ ./test_02
>  5
>  6
> error: octave_base_value::double_value (): wrong type argument '<unknown 
> type>'
> error: octave_base_value::int_value (): wrong type argument '<unknown 
> type>'
> error encountered in Octave evaluator!
> 
> Perhaps I have make mistakes but does not hang.
> 
> Tatsuro