Re: Calling Octave from C++

[Tatsuro MATSUOKA]

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

>>  From: Mike Miller 
>>  To: help-octave
>>  Cc: 
>>  Date: 2018/3/27, Tue 13:51
>>  Subject: Re: Calling Octave from C++
>> 
>>  On Tue, Mar 27, 2018 at 13:39:26 +0900, Tatsuro MATSUOKA wrote:
>>>   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.
>> 
>>  As I tried to show in my last message, the example is different for
>>  Octave 4.2 vs 4.4.
>> 
>>  In Octave 4.2, you need to initialize the interpreter with
>> 
>>      string_vector argv (2);
>>      argv(0) = "embedded";
>>      argv(1) = "-q";
>>      octave_main (2, argv.c_str_vec (), 1);
>> 
>>  In Octave 4.4, you need to initialize the interpreter with
>> 
>>      octave::interpreter interpreter;
>>      int status = interpreter.execute ();
>> 
>>  -- 
>>  mike
> 
> Thanks Mike. That worked.
> 
> #include <iostream>
> #include <octave/oct.h>
> #include <octave/octave.h>
> #include <octave/parse.h>
> #include <octave/interpreter.h>
> 
> int
> main (void)
> {
>     string_vector argv (2);
>     argv(0) = "test_01_03";
>     argv(1) = "-q";
>     octave_main (2, argv.c_str_vec (), 1);
> 
>     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;
>   return 0;
> }
> 
> the above worked
> 
> #include <iostream>
> #include <octave/oct.h>
> #include <octave/octave.h>
> #include <octave/parse.h>
> #include <octave/interpreter.h>
> 
> int
> main (void)
> {
>     string_vector argv (2);
>     argv(0) = "test_02";
>     argv(1) = "-q";
>     octave_main (2, argv.c_str_vec (), 1);
> 
>     octave_value_list in;
> 
>     // THIS CODE IS NOT WORKING
>     int qq =10;
>     int rr =15;
>     in(0) = octave_value(qq);
>     in(1) = octave_value(rr);
>     octave_value_list out = feval ("pp", in, 1);
>     std::cout << out(0).int_value ()
>               << std::endl;
>   return 0;
> }
> 
> the above hanged as original author (Andrea) told,
> 
> $ LC_ALL=C gdb ./test_02
> 
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library 
> "/lib/x86_64-linux-gnu/libthread_db.so.1".
> [New Thread 0x7fffe3cae700 (LWP 4060)]
> [New Thread 0x7fffe14ad700 (LWP 4061)]
> [New Thread 0x7fffdecac700 (LWP 4062)]
> [New Thread 0x7fffdc4ab700 (LWP 4063)]
> [New Thread 0x7fffd9caa700 (LWP 4064)]
> [New Thread 0x7fffd94a9700 (LWP 4065)]
> [New Thread 0x7fffd4ca8700 (LWP 4066)]
> 
> Thread 1 "test_02" received signal SIGSEGV, Segmentation fault.
> tree_statement_list::accept (this=0xa4dc30, tw=...)
>     at ../libinterp/parse-tree/pt-stmt.cc:326
> 326      tw.visit_statement_list (*this);
> (gdb) bt
> #0  tree_statement_list::accept (this=0xa4dc30, tw=...)
>     at ../libinterp/parse-tree/pt-stmt.cc:326
> #1  0x00007ffff731e106 in octave_user_function::do_multi_index_op (
>     this=0x7c1d80, nargout=1, _args=..., lvalue_list=0x0)
>     at ../libinterp/octave-value/ov-usr-fcn.cc:610
> #2  0x00007ffff7317b84 in octave_user_function::do_multi_index_op (
>     this=<optimized out>, nargout=<optimized out>, args=...)
>     at ../libinterp/octave-value/ov-usr-fcn.cc:461
> #3  0x00007ffff73218e5 in octave_value::do_multi_index_op (
>     address@hidden, address@hidden, idx=...)
>     at ../libinterp/octave-value/ov.cc:1529
> #4  0x00007ffff73aa69b in feval (name="pp", args=..., 
> address@hidden)
>     at libinterp/parse-tree/oct-parse.yy:4807
> #5  0x0000000000401d72 in main () at test_02.cc:22
> (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 4066) exited]
> [Thread 0x7fffd94a9700 (LWP 4065) exited]
> [Thread 0x7fffd9caa700 (LWP 4064) exited]
> [Thread 0x7fffdc4ab700 (LWP 4063) exited]
> [Thread 0x7fffdecac700 (LWP 4062) exited]
> [Thread 0x7fffe14ad700 (LWP 4061) exited]
> [Thread 0x7fffe3cae700 (LWP 4060) exited]
> 
> Tatsuro
Andrea

With Mike's helps, I could reproduce what you met.

Perhaps 4.2.2 is the last release for octave 4.2.
Realistic solutions are: (just my idea)
 1. Wait until octave 4.4 will be released.
 2. Build current stable (now 4.3.0+).

 For 2., you need to install mercurial and (autotools (autoconf, automake)).
 $ hg clone https://www.octave.org/hg/octave  
 $ cd octave
 $ hg update stable
 (Once you clone, you need hg pull && hg update stable)
 $ ./bootstrap
 Then configure script is generated and you can build in the same way as 
release version.

HTH

Tatsuro