Need core.so/.lib when linking in 1.9?

C++ coding using Panda3D
1

With Panda 1.8.1, I was linking my C++ modules with these libraries:

-lpython2.7 -lpanda -lpandaexpress -lp3dtool -lp3dtoolconfig

When I try to build the same module with current master, I get linking errors of the type

/tmp/ccJAMaer.o: In function `Dtool_RandomBase_get_class_type_18(_object*)':
misc_c-igate.cpp:(.text+0x6f7): undefined reference to `Dtool_TypeHandle'
/tmp/ccJAMaer.o: In function `Dtool_PyModuleClassInit_NumRandom(_object*)':
misc_c-igate.cpp:(.text+0xb63): undefined reference to `Dtool_TypedObject'
...
misc_c-igate.cpp:(.text+0x23bd): undefined reference to `Dtool_LPoint3d'
misc_c-igate.cpp:(.text+0x241e): undefined reference to `Dtool_LVector3d'
misc_c-igate.cpp:(.text+0x2479): undefined reference to `Dtool_LVector3d'
misc_c-igate.cpp:(.text+0x24d5): undefined reference to `Dtool_LPoint3d'
...

I tried linking other Panda libraries, but that didn’t work. Eventually I could remove these errors by adding directly …/panda3d/core.so to compile line on Linux, and on Windows …panda3d/core.lib (which I had to copy over from Panda build directory to Panda installation directory, since only core.pyd is installed). What is the proper way to fix this?

2

We moved the Python bindings to core.so/core.pyd. If you don’t use the Python bindings, you shouldn’t need this for building C++ applications. But it is necessary when you have custom bindings of functions that depend on types part of the panda3d.core bindings.

We probably need to put core.lib in built/lib so that it is picked up and shipped as part of the installation for people who have custom bindings.

3

I expose my custom C++ functions/classes to Python (using interrogate), and these take some Panda3D types as arguments (like LVector3f). I guess this means what you said about custom bindings depending on panda3d.core bindings? If so, wouldn’t that be one rather usual use-case? Because the fact that bindings were moved to a somewhat-internal library (core.so/core.lib) implies it wasn’t…

4

I suppose it is a fairly normal use case. In this case, you do indeed need to link with core.lib to get the right bindings imported.

5

Some weeks ago, I checked in some changes to the master branch that remove the link-time dependency from Interrogate-generated stuff on core.lib. Instead, you need to add “-import panda3d.core” to have the dependencies loaded dynamically, when the module is loaded.

You do need to link to libp3interrogatedb.lib now, though, but that’s a normal library that’s in built/lib like all the others.