Problems linking against OSG on OS X Tiger (on a Power PC)

[Severin Kacianka]

Ryan Schmidt wrote:
> On Dec 7, 2008, at 15:39, Ryan Schmidt wrote:
> 
>> On Dec 7, 2008, at 09:57, Severin Kacianka wrote:
>>
>>> I hope I do not ask a too obvious question, but I am just trying to 
>>> get familiar with OSG and in the process want to be able to compile 
>>> it on Linux and OS X. On Linux I have no problems compiling a sample 
>>> program like this:
>>> g++ -I /usr/local/include/osg/ -losg -losgViewer -o foo test.cpp
>>>
>>> On OS X I installed OS X via macports. First I tried to compile it 
>>> directly form the sources, but ran into the bug described here:
>>> http://trac.macports.org/ticket/17294
>>>
>>> Compiling and installing via macports worked fine.
>>> However if I try to compile a sample program I get the following error:
>>>
>>> g++  -L/opt/local/lib/ -I/opt/local/include/  -losg -losgViewer -o 
>>> foo test.cpp
>>> /usr/bin/ld: warning can't open dynamic library: 
>>> libOpenThreads.11.dylib referenced from: /opt/local/lib//libosg.dylib 
>>> (checking for undefined symbols may be affected) (No such file or 
>>> directory, errno = 2)
>>> /usr/bin/ld: warning can't open dynamic library: libosgGA.48.dylib 
>>> referenced from: /opt/local/lib//libosgViewer.dylib (checking for 
>>> undefined symbols may be affected) (No such file or directory, errno 
>>> = 2)
>>> /usr/bin/ld: warning can't open dynamic library: libosgText.48.dylib 
>>> referenced from: /opt/local/lib//libosgViewer.dylib (checking for 
>>> undefined symbols may be affected) (No such file or directory, errno 
>>> = 2)
>>> /usr/bin/ld: warning can't open dynamic library: libosgDB.48.dylib 
>>> referenced from: /opt/local/lib//libosgViewer.dylib (checking for 
>>> undefined symbols may be affected) (No such file or directory, errno 
>>> = 2)
>>> /usr/bin/ld: warning can't open dynamic library: libosgUtil.48.dylib 
>>> referenced from: /opt/local/lib//libosgViewer.dylib (checking for 
>>> undefined symbols may be affected) (No such file or directory, errno 
>>> = 2)
>>> /usr/bin/ld: Undefined symbols:
>>> *snip long list of symbols*
>>> collect2: ld returned 1 exit status
>>>
>>> So for some reason ld cannot find the references from the libraries 
>>> among each other. The directory looks like this:
>>>
>>> libOpenThreads.11.dylib -> libOpenThreads.2.3.0.dylib
>>> libOpenThreads.2.3.0.dylib
>>> libOpenThreads.dylib -> libOpenThreads.11.dylib
>>>
>>>
>>> (other libs are linked in the same manner)
>>>
>>> So the libs are there, but somehow not referenced correctly. Does 
>>> anyone know what the problem may be, or any other way to use OSG on 
>>> OS X?
>>
>> I see that it's linked this way:
>>
>> $ otool -L /opt/local/lib/libosg.dylib
>> /opt/local/lib/libosg.dylib:
>>         libosg.48.dylib (compatibility version 48.0.0, current version 
>> 2.6.1)
>>         libOpenThreads.11.dylib (compatibility version 11.0.0, current 
>> version 2.3.0)
>>         /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, 
>> current version 88.3.10)
>>         /System/Library/Frameworks/AGL.framework/Versions/A/AGL 
>> (compatibility version 1.0.0, current version 1.0.0)
>>         /System/Library/Frameworks/OpenGL.framework/Versions/A/OpenGL 
>> (compatibility version 1.0.0, current version 1.0.0)
>>         /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, 
>> current version 7.4.0)
>>         /usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, 
>> current version 1.0.0)
>> $
>>
>> That looks wrong. It should look like this:
>>
>> $ otool -L /opt/local/lib/libosg.dylib
>> /opt/local/lib/libosg.dylib:
>>         /opt/local/lib/libosg.48.dylib (compatibility version 48.0.0, 
>> current version 2.6.1)
>>         /opt/local/lib/libOpenThreads.11.dylib (compatibility version 
>> 11.0.0, current version 2.3.0)
>>         /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, 
>> current version 88.3.10)
>>         /System/Library/Frameworks/AGL.framework/Versions/A/AGL 
>> (compatibility version 1.0.0, current version 1.0.0)
>>         /System/Library/Frameworks/OpenGL.framework/Versions/A/OpenGL 
>> (compatibility version 1.0.0, current version 1.0.0)
>>         /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, 
>> current version 7.4.0)
>>         /usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, 
>> current version 1.0.0)
>> $
>>
>> This probably means they're not using the -install_name parameter.
> 
> I filed a ticket:
> 
> http://trac.macports.org/ticket/17577
(uh - this time to the list and not only to you)

thank you very much for your help. With your pointers I managed to 
compile my sample program (although it takes a lot of hacking around):

It is possible to get around the linking errors by using ld's 
-dylib_file flag:
g++  -L/opt/local/lib/  -I/opt/local/include/  -losg -losgViewer -losgDB 
-losgGA -o foo test.cpp 
-Wl,-dylib_file,libOpenThreads.11.dylib:/opt/local/lib/libOpenThreads.2.3.0.dylib 
-Wl,-dylib_file,libosgGA.48.dylib:/opt/local/lib/libosgGA.2.6.1.dylib 
-Wl,-dylib_file,libosgText.48.dylib:/opt/local/lib/libosgText.2.6.1.dylib 
-Wl,-dylib_file,libosgDB.48.dylib:/opt/local/lib/libosgDB.2.6.1.dylib 
-Wl,-dylib_file,libosgUtil.48.dylib:/opt/local/lib/libosgUtil.2.6.1.dylib

(the -Wl,option,value just tells gcc to pass these arguments to the linker)

If you then try to execute the binary you will get the following error:
./foo
dyld: Library not loaded: libosg.48.dylib
   Referenced from: /Users/severin/Desktop/blabla/test/./foo
   Reason: image not found
Trace/BPT trap

to get around these errors, you have to symlink all the 'missing' 
libraries into the directory of foo:
ln -s /opt/local/lib/libosg.2.6.1.dylib libosg.48.dylib
(and repeat that for every library....)

then you will get the following error (if you load files):
./foo
Warning: Could not find plugin to read objects from file "dog_hut.3ds".
Warning: Could not find plugin to read objects from file "cube.3ds".
GraphicsWindowCarbon::grabFocusIfPointerInWindow

Now you have to symlink the osgPlugin directory into foo's directory:
ln -s /opt/local/lib/osgPlugins-2.6.1 .

Thank you again :)