Godot Version
4.2 (on Manjaro Linux)
Question
Hello ! First post here 
So I’m trying to build multiple gdextensions lib, the goal is to have a “common” lib I reuse in all my game projects and another specific for each project.
I’ve made for this post a generic version of the architecture looking like that:
├── SConstruct
├── a
│ ├── a_test.h
│ ├── a_test.cpp
│ ├── register_types.h
│ ├── register_types.cpp
│ └── SConscript
──b
│ ├── b_test.h
│ ├── b_test.cpp
│ ├── register_types.h
│ ├── register_types.cpp
│ └── SConscript
With a being the “common” lib and b being the specific lib.
In a_test.h I’m defining a class inheriting from a Godot Node:
class aTest : public Node {
GDCLASS(aTest, Node)
protected:
static void _bind_methods();
};
And in b_test.h a class inheriting aTest:
class bTest : public aTest {
GDCLASS(bTest, aTest)
protected:
static void _bind_methods();
};
Here are the scons files:
scons
SConstruct
#!/usr/bin/env python
import os
import sys
env = SConscript("godot-cpp/SConstruct")
# env['CCCOMSTR'] = "Compiling $TARGET"
# env['LINKCOMSTR'] = "Linking $TARGET"
# env.Append(LINKFLAGS=['-Wl,-z,defs'])
# env.Append(LINKFLAGS=['-Wl,--start-group'])
subdirs = [
'a',
'b'
]
# The exports attribute allows you to pass variables to the subdir SConscripts
for dir in subdirs:
SConscript( os.path.join(dir, 'SConscript'), exports = ['env'])
a/SConscript
#!/usr/bin/env python
import os
import sys
Import('env')
# For reference:
# - CCFLAGS are compilation flags shared between C and C++
# - CFLAGS are for C-specific compilation flags
# - CXXFLAGS are for C++-specific compilation flags
# - CPPFLAGS are for pre-processor flags
# - CPPDEFINES are for pre-processor defines
# - LINKFLAGS are for linking flags
# tweak this if you want to use different folders, or more folders, to store your source code in.
sources = [
Glob("*.cpp"),]
env.Append(CPPPATH=Glob('.'))
nenv = env.Clone()
lib_folder = "../project/bin/"
if nenv["platform"] == "macos":
lib_name = "a.{}.{}.framework/liboldworld.{}.{}".format(
nenv["platform"], nenv["target"], nenv["platform"], nenv["target"]
)
else:
lib_name = "a{}{}".format(nenv["suffix"], nenv["SHLIBSUFFIX"])
library = nenv.SharedLibrary(
lib_folder+"lib"+lib_name,
source=sources,
)
Default(library)
b/SConscript
#!/usr/bin/env python
import os
import sys
Import('env')
# For reference:
# - CCFLAGS are compilation flags shared between C and C++
# - CFLAGS are for C-specific compilation flags
# - CXXFLAGS are for C++-specific compilation flags
# - CPPFLAGS are for pre-processor flags
# - CPPDEFINES are for pre-processor defines
# - LINKFLAGS are for linking flags
env.Append(CPPPATH=[".."])
owenv = env.Clone()
owenv.Append(LIBS=["a.linux.editor.dev.x86_64"], LIBPATH=["../project/bin/"])
# tweak this if you want to use different folders, or more folders, to store your source code in.
sources = [
Glob("*.cpp")]
if owenv["platform"] == "macos":
library = owenv.SharedLibrary(
"../project/bin/b.{}.{}.framework/b.{}.{}".format(
owenv["platform"], owenv["target"], owenv["platform"], owenv["target"]
),
source=sources,
)
else:
library = owenv.SharedLibrary(
"../project/bin/b{}{}".format(owenv["suffix"], owenv["SHLIBSUFFIX"]),
source=sources,
)
Default(library)
So the compilation works fine with no error, but when I launch Godot I get:
Can’t open dynamic library: /[mypath]/gdextensionmultiplelibs/project/bin/libb.linux.editor.dev.x86_64.so. Error: /[mypath]/gdextensionmultiplelibs/project/bin/libb.linux.editor.dev.x86_64.so: undefined symbol: _ZN5godot5aTest13_bind_methodsEv.
core/extension/gdextension.cpp:719 - GDExtension dynamic library not found: /run/media/paul/Developpement/gdextensionmultiplelibs/project/bin/libb.linux.editor.dev.x86_64.so
Failed loading resource: res://bin/b.gdextension. Make sure resources have been imported by opening the project in the editor at least once.
And I don’t understand what is missing for Godot to see _ZN5godot5aTest13_bind_methodsEv, I’ve check with nm and readelf and the a lib does contain it.
I’ve also made a repo with all the code of this example if you want to test building yourself: Pikario / GDExtensionMultipleLibs · GitLab
Thank you for your answers!
