Undefined reference to Urho3D::PASS_BASE (SOLVED)


I’m not super familiar with linking C++, but I’ve stumbled on a problem. When I try link the shared object (NOTE: using static build works fine!) using this:

g++ -I/usr/local/include/Urho3D -I/usr/local/include/Urho3D/ThirdParty -L/usr/local/lib64/Urho3D -lUrho3D -o urho3d_geometry_and_shader.bin urho3d_geometry_and_shader.cpp -lUrho3D -ldl -lpthread -lGL
/tmp/ccbaNWfo.o: In function MyApp::CreateMaterial(Urho3D::Color const&)': urho3d_geometry_and_shader.cpp:(.text._ZN5MyApp14CreateMaterialERKN6Urho3D5ColorE[_ZN5MyApp14CreateMaterialERKN6Urho3D5ColorE]+0x5a): undefined reference toUrho3D::PASS_BASE’
collect2: error: ld returned 1 exit status

The offending line does this:

if I change it to

it will build just fine. When ever I use the PASS_* symbols it will fail to link due to undefined reference.

Looking at the shared object I can see the following BSS symbols:
0000000001339100 b Urho3D::PASS_ALPHA
00000000013390fc b Urho3D::PASS_LIGHT
0000000001339108 b Urho3D::PASS_SHADOW
00000000013390f8 b Urho3D::PASS_LITBASE
0000000001339110 b Urho3D::PASS_PREPASS
000000000133911c b Urho3D::PASS_REFRACT
000000000133910c b Urho3D::PASS_DEFERRED
0000000001339104 b Urho3D::PASS_LITALPHA
0000000001339114 b Urho3D::PASS_MATERIAL
0000000001339120 b Urho3D::PASS_POSTALPHA
0000000001339118 b Urho3D::PASS_POSTOPAQUE
00000000013390f4 b Urho3D::PASS_BASE

In GraphicsDefs.h we can see

and in GraphicsDefs.cpp

Looks good to me if extern does roughly the same thing in C++ as it does for C.

I checked the build logs, including library link, it includes GraphicsDefs.cpp.o so it should be good, it’s there.

What am I messing up?

Turns out this has been added (or was it always there?) in the build " -fvisibility=hidden -fvisibility-inlines-hidden" and the extern symbol declarations now require the URHO3D_API.