debugging dynamic functions

[John W. Eaton]

On  7-Feb-2001, Braddock Gaskill <address@hidden> wrote:

| Three questions:
| 
| 1) What is the proper way to debug dynamically loaded octave
|    functions using gdb?

I've had success starting gdb, running Octave, calling the function
once to load it, then simply setting a breakpoint in it.  The function
name is mangled by prepending an F to whatever you used in the
DEFUN_DLD macro.  So if you write

  DEFUN_DLD (my_fun, , , ...

the actual function name will be Fmy_fyn.

| 2) What is the 2.0.16 and 2.1.x behavior for loading and unloading
|    DL functions? 

I think they should behave similarly.  Do you have a more specific
question?

| 3) What is the proper way to have .oct files pull in an outside library
| they are dependant on?

Link only to shared libraries and add -lyour-library to the mkoctfile
command (or equivalent commands you run yourself or via make or
whatever).  How these are resolved and loaded may be system dependent
though.

| A few years ago, I seem to remember that once I called a DL function
| in octave, it stayed loaded, which actually caused symbol problems
| because I had multiple DL functions which were glue to a single static
| library of routines, so I statically linked one function which I ran
| first.  Since then, the behavior seems to have changed: I can now
| statically link the same library with a set of DL function .oct files
| and not have any symbol conflicts.  Will having the .oct files link to
| a shared library work?  I was assuming Octave now unloads the DLF
| right after the call is made now?  Is there a clean way to do this?

The .oct file is only unloaded after all the functions defined from it
are cleared.  If you have multiple routines that are supposed to share
a library of functions, you might want to define them all in one .oct
file.  A .oct file that contains multiple DLD functions should only be
loaded once now.

jwe



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