Re: External C DLL crashes Octave

[Tatsuro MATSUOKA]

Hello

If you would like to link to your *.dll source code from octave on MinGW, it is 
required link with
().dll.a which is produced by MinGW , to my knowledge.

For examplle, in the libraries on the GnuWin32 project xxx.dll files.
For VC++, xxx.lib anf xxx.def are prepared and for MinGW compiler xxx.dll.a is 
prepared.

Perhaps there are methods build .dll files and linking files (.lib and .def or 
.dll.a )  for VC++ and
MinGW but I do not the way to do that.

I think it is easy to build all binaries by MinGW compiler that shipped with 
octave/mingw32 package.
In addition, it is better use to mkoctfile command to build oct files.

I have little knowledge of VC++ complier so that I cannot mention anything to 
use VC++ for
octave/mingw32.

Regards

Tatsuro   

--- mishrapiy   wrote:

> 
> Tatsuro,
> 
>   Thanks for replying to promptly.. I am using Octave 3.2.0, which is the
> latest Win binary. I believe it is the MinGW version. I am able to compile
> and call the sample application (d_gcc) but was having problem with my Cpp
> code.
> 
>    In the meantime, I have found the reason of crash - it was due to an
> error in my DEFUN_DLD function. Basically, I want to pass an array of
> Doubles to my C function, say, as follows:
> x = [10 100 1000 10000] %array of Doubles
> mycodewrapper(x) %containing func1
> 
> as stated earlier, func1 is defined as follows:
> extern "C" unsigned int func1(double *x);
> 
> I have tried:
> Matrix B = args(0).matrix_value();
> double* A = B.Rep->data;"
>   but rep is now protected and hence compilation fails.
> 
> Could you recommend a good way to convert args of DEFUN_DLD into a pointer
> of doubles. Is there a variation on "double* A = B.data()" which will allow
> me to cast const double* to double*?
> 
> Thanks again,
> Piyush
> 
> 
> Tatsuro MATSUOKA-2 wrote:
> > 
> > Hello
> > 
> > Please show the version of octave and whether it is MSVC version or MinGW
> > Version.
> > 
> > Regards
> > 
> > Tatsuro
> > --- mishrapiyush wrote:
> > 
> >> 
> >> Hi all,
> >> 
> >>   I followed the example on wiki
> >> (http://wiki.octave.org/wiki.pl?OctaveLinkToWindowsDLLs) to compile my
> >> c/c++
> >> code into an .oct file but when I try to call this function, octave
> >> crashes.
> >> A snippet of my codes is attached below for your reference.
> >> 
> >> I had compiled mycode.cpp as Win DLL using MS Visual Studio 2008 and
> >> tested
> >> it on Matlab. Next I had copied the mycode.dll and mycode.lib into my
> >> Octave
> >> project folder and compiled them with mycodewrapper.cc to generate
> >> func1.oct, which I call in a matlab function.
> >> 
> >> I have recetly started using Octave and have spent hours researching the
> >> process of integrating external function calls. In my opinion, the manual
> >> (Appendix A.1.9) does not do a good job of explaining C/C++ integration
> >> and
> >> should be supplemented with wiki entry mentioned above, which itself
> >> misses
> >> to mention that when linking the wrapper with external code, it should be
> >> done with .lib file and not the .dll file. I would very much appreciate
> >> any
> >> help in further resolving this problem. Thanks for your time.
> >> 
> >> ----------------------------dllmain.cpp------------------------------
> >> #include "stdafx.h"
> >> 
> >> BOOL APIENTRY DllMain( HMODULE hModule, DWORD  ul_reason_for_call, LPVOID
> >> lpReserved ) {
> >>    switch (ul_reason_for_call)
> >>    {
> >>    case DLL_PROCESS_ATTACH:
> >>    case DLL_THREAD_ATTACH:
> >>    case DLL_THREAD_DETACH:
> >>    case DLL_PROCESS_DETACH:
> >>            break;
> >>    }
> >>    return TRUE;
> >> }
> >> ----------------------------mycode.cpp------------------------------
> >> #include <stdio.h>
> >> #include <stdlib.h>
> >> 
> >> extern "C" unsigned int func1(double *x);
> >> 
> >> unsigned int func1(double *x)
> >> {
> >>     ...
> >> }
> >> ----------------------------mycodewrapper.cc------------------------------
> >>   #include <octave/oct.h>
> >>   
> >>   extern "C" {
> >>            unsigned int func1(double *x);
> >>   }
> >>   DEFUN_DLD (func1, args, , "usage func1('double')" ) {
> >>      octave_value_list retval;
> >>      Matrix B = args(0).matrix_value();
> >>      double* A;
> >>    *A = B.data(0);
> >>    retval(0) = (double) func1( A );
> >>    return retval;
> >>   }
> >> 
> >> -- 
> >> View this message in context:
> >> http://www.nabble.com/External-C-DLL-crashes-Octave-tp25189231p25189231.html
> >> Sent from the Octave - General mailing list archive at Nabble.com.
> >> 
> >> _______________________________________________
> >> Help-octave mailing list
> >> address@hidden
> >> https://www-old.cae.wisc.edu/mailman/listinfo/help-octave
> >> 
> > 
> > 
> > --------------------------------------
> > Thanks 10 years!  Yahoo! Shopping and Yahoo! Auctions
> > http://pr.mail.yahoo.co.jp/ec10years/
> > _______________________________________________
> > Help-octave mailing list
> > address@hidden
> > https://www-old.cae.wisc.edu/mailman/listinfo/help-octave
> > 
> > 
> 
> -- 
> View this message in context:
> http://www.nabble.com/External-C-DLL-crashes-Octave-tp25189231p25195846.html
> Sent from the Octave - General mailing list archive at Nabble.com.
> 
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://www-old.cae.wisc.edu/mailman/listinfo/help-octave
> 


--------------------------------------
Thanks 10 years!  Yahoo! Shopping and Yahoo! Auctions
http://pr.mail.yahoo.co.jp/ec10years/