Static build of PhysX has no working linking order

[JoeRosselli]

Hi,

When building PhysX 5.4.0 on Linux/clang with the PX_GENERATE_STATIC_LIBRARIES cmake flag set to True, it correctly builds/installs all static libraries (except for Gpu and PVDRuntime outputs which it outputs as dynamic libraries).

However, when attempting to manually link against these libraries in a consumer project, there's no linker order which doesn't result in undefined definitions in one way or another.

In particular, at the moment I'm wrestling with a circular dependency where if I link against PhysX before PhysXPvdSDK, I get a handful of linker errors, one of which being the PvdSDK project having an unresolved definition from PhysX:

/usr/bin/ld: /.../PhysX-5.4.0/physx/install/linux/PhysX/bin/linux.clang/checked/libPhysXPvdSDK_static_64.a(PxPvdImpl.cpp.o): in function physx::pvdsdk::PvdImpl::~PvdImpl(): 
/.../PhysX-5.4.0/physx/source/pvd/src/PxPvdImpl.cpp:108:(.text._ZN5physx6pvdsdk7PvdImplD2Ev+0x38): undefined reference to PxSetPhysXGpuProfilerCallback

However, if I switch the linking order of those two dependencies, to resolve the PvdSDK dependency, I then get different linking errors where PhysX now has undefined dependencies on PvdSDK:

`/usr/bin/ld: /.../PhysX-5.4.0/physx/install/linux/PhysX/bin/linux.clang/checked/libPhysX_static_64.a(NpPvdSceneClient.cpp.o): in function physx::Vd::PvdSceneClient::onPvdConnected():
/.../PhysX-5.4.0/physx/source/physx/src/NpPvdSceneClient.cpp:325:
(.text._ZN5physx2Vd14PvdSceneClient14onPvdConnectedEv+0x28): undefined reference to physx::pvdsdk::PvdDataStream::create(physx::PxPvd*)

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The order in which I'm currently trying to link the libraries:

PhysXCharacterKinematic PhysXCooking PhysXExtensions PhysX PhysXPvdSDK PhysXCommon PhysXFoundation

I referenced this issue, https://github.com/NVIDIAGameWorks/PhysX/issues/53 , which states that the order should be:

PhysX PhysXExtensions PhysXCharacterKinematic PhysXCooking PhysXFoundation PhysXVehicle PhysXPvdSDK

That spawns a hundred times more linker errors about undefined definitions.

I referenced this issue: https://forums.developer.nvidia.com/t/linking-physx-in-cmake-project/78664 , which states that the order should be something like:

PhysXExtensions PhysX PhysXPvdSDK PhysXVehicle PhysXCharacterKinematic PhysXCooking PhysXCommon PhysXFoundation SnippetUtils

Again, that linking order spawns hundreds times more undefined definition linker errors.

No matter what order I put the various dependencies in it refuses to link. The only way I've gotten things to work in the past was with PX_GENERATE_STATIC_LIBRARIES set to false, which builds some of the libraries as dynamic, which seemed to somehow link properly, but the CMake code involved to manually import and link against that output, and install it all properly with my application was extremely ugly so I'm trying to get it working with a static build now.

I'd love to just include PhysX via CMake or via package management but both of those options are either not available or broken on Linux (https://github.com/NVIDIA-Omniverse/PhysX/issues/277 , https://github.com/NVIDIA-Omniverse/PhysX/discussions/278).

Any advice?