RE: Dynamically Linked Functions, Cygwin and Octave

[Steve Goncalo]

I raised a similar question a few weeks ago. I got no response, but I did
find an oblique reference to DLLs not working on windows in the 2000
archives. I got things working on Linux, and pieced together a limited
understanding of what was going on by comparing the two builds.

Note that these are linker errors, not compile errors. When you build octave
on Linux, you get a main program, and a couple of shared libraries (what
windows calls DLLs). When you create an oct file on Linux, I believe the
linker sets up your code to access many functions in those shared libraries.
All the octave functions you can call are entry points to library functions,
not part of the octave main executable.

The executable built on windows appears to contain all the functions that
Linux puts in shared libraries. I'm not sure why that is, but I think it
means code in an oct file would be unable to access any of the octave
support routines. That is basically what the linker is trying to tell you.
If you add the code you would have put in a loadable oct file into the list
of files compiled and linked into octaveXXX.exe, you can build a custom
version of octave for windows with your command(s), but I think the ability
to load custom user code at run-time is broken on Cygwin's Octave.

[Note that there is a lot of guess-work in the explanation I just gave. If
someone can give a more authoritative answer, I would like to be
enlightened.]

-----Original Message-----
From: Craig Stoudt [mailto:address@hidden
Sent: Tuesday, October 09, 2001 9:42 AM
To: address@hidden
Subject: Dynamically Linked Functions, Cygwin and Octave


Has anyone had any success creating oct files with
cygwin running on windows?

I am currently running Cygwin version 2.78.2.9 on
Windows 2000.  I successfully compiled and installed
octave 2.1.31 on my system using cygwin.

When I try to compile a dynamically linked function as
described in the octave manual (octave_12.html) I get
numerous error messages of the following form:

/usr/local/include/octave-2.1.31/octave/str-vec.h:37:
undefined reference to `octave_value::list_value(void)
const'

There are lots of variations on the h-file, and the
undefined reference.

I have the same problem when I try to install the
matcompat package

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-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------