30 Jun
2005
30 Jun
'05
2:58 p.m.
Hello all!
I have a question regarding linking multiple plugins into a single
library.
if I do:
$ ld -shared -o plugins.so plugins/*.o
- then ld complains that g_psStereoDescriptor and g_psMonoDescriptor
as well as _init and _fini functions are duplicate and does nothing.
If I try:
$ ld -shared -z muldefs -o plugins.so plugins/*.o
- this does some wizardry on changing the duplicate functions names
(_init and _fini) and in the host only the last plugin in the .o
files list is seen.
As I understand I cannot change the names of _init and _fini because
these are standard for libraries (or not?) and names of
g_psStereoDescriptor and g_psMonoDescriptor are standard for a LADSPA
plgin (or not?)... But what should I do? Or is is better to keep the
plugins in separate .so files?
Thanks very much!
Artemiy.
30 Jun
30 Jun
3:33 p.m.
On Thu, Jun 30, 2005 at 07:59:51PM +0300, Artemio wrote:
As I understand I cannot change the names of _init and
_fini because
these are standard for libraries (or not?) and names of
g_psStereoDescriptor and g_psMonoDescriptor are standard for a LADSPA
plgin (or not?)... But what should I do? Or is is better to keep the
plugins in separate .so files?
Just combine the two _init() functions into one, and the same
for _fini(). Or change their names and add _init() and _fini()
that call both. Or use static declarations of all the required
LADSPA structs and then you don't need _init() and _fini() at all.
--
FA
4:29 p.m.
Hello, Fons, and thank you for answering.
Just combine the two _init() functions into one, and
the same
for _fini(). Or change their names and add _init() and _fini()
that call both.
In both cases, you mean I need to create a separate .c file with
global _init() and _fini() functions that are for all plugins, and
then compile this file into .o and join with all plugins into .so? I
will try it now, thanks.
Regards,
Artemiy,
P.S. Fons, your Moog filters make me use them again and again, they
are like a bottle of fresh cool juice in a hot day. Thanks so
much! ;-)
9:27 p.m.
On Thu, Jun 30, 2005 at 09:31:08PM +0300, Artemio wrote:
Yes, that's correct. But I forgot one thing: you also need a global
LADSPA_Descriptor *ladspa_descriptor (unsigned long k)
{
switch (k)
{
case 0: return _the_ladspa_descriptor_for_the_first_plugin_;
case 1: return _the_ladspa_descriptor_for_the_second_plugin_;
default: return 0;
}
}
instead of the separate functions in each plugin.
Just combine
the two _init() functions into one, and the same
for _fini(). Or change their names and add _init() and _fini()
that call both.
In both cases, you mean I need to create a separate .c file with
global _init() and _fini() functions that are for all plugins, and
then compile this file into .o and join with all plugins into .so? I
will try it now, thanks. P.S. Fons, your Moog filters make me use them again
and again, they
are like a bottle of fresh cool juice in a hot day. Thanks so
much! ;-)
We had a *very hot* week over here, so I know what you mean :-)
Just write if you need more help.
--
FA
5 Jul
5 Jul
11:07 a.m.
New subject: [linux-audio-dev] linking multiple .o plugins into a single .so library
On Thu, 2005-06-30 at 19:32 +0200, fons adriaensen wrote:
On Thu, Jun 30, 2005 at 07:59:51PM +0300, Artemio
wrote:
and if you want to be really portable, don't use _init() or _fini(),
which are officially deprecated by gcc/glibc/ld.so, and use
void
myinitfunction() __attributes__((constructor))
{
}
void
myfinifunction() __attributes__((destructor))
{
}
i may have the syntax slightly wrong for that; the gcc info page will
reveal all. this will allow your plugins to be built on OS X, where they
have gone beyond deprecating support for _init()/_fini() and actually
removed it.
note that with this design, you can have multiple initialization and
finalization functions, which is why the _init()/fini() design was
deprecated in the first place.
--p
As I understand I cannot change the names of
_init and _fini because
these are standard for libraries (or not?) and names of
g_psStereoDescriptor and g_psMonoDescriptor are standard for a LADSPA
plgin (or not?)... But what should I do? Or is is better to keep the
plugins in separate .so files?
Just combine the two _init() functions into one, and the same
for _fini(). Or change their names and add _init() and _fini()
that call both. Or use static declarations of all the required
LADSPA structs and then you don't need _init() and _fini() at all. 
2:26 p.m.
New subject: [linux-audio-dev] linking multiple .o plugins into a single .so library
Paul Davis wrote on Thu, 30-Jun-2005:
and if you want to be really portable, don't use
_init() or _fini(),
which are officially deprecated by gcc/glibc/ld.so, and use
void
myinitfunction() __attributes__((constructor))
{
}
void
myfinifunction() __attributes__((destructor))
{
}
The proper syntax is:
void __attribute__((constructor)) myinitfunction() {}
void __attribute__((destructor)) myfinifunction() {}
jlc
6:22 p.m.
New subject: [linux-audio-dev] linking multiple .o plugins into a single .so library
On Thu, Jun 30, 2005 at 02:31:04PM -0400, Paul Davis wrote:
(this only dropped into my mailbox today, for some reason)
and if you want to be really portable, don't use
_init() or _fini(),
which are officially deprecated by gcc/glibc/ld.so, and use
void
myinitfunction() __attributes__((constructor))
{
}
void
myfinifunction() __attributes__((destructor))
{
}
Looks very C++ish. Upon load, call all constructors for static
objects. Before unload, all destructors for the same.
--
FA
7115
days inactive
7120
days old
linux-audio-dev@lists.linuxaudio.org
6 comments
4 participants
participants (4)
-
Artemio -
fons adriaensen -
Jesse Chappell -
Paul Davis