Prevent reading non-whitelisted properties of interface targets.

[de-vri-es]

Currently, catkin_replace_imported_library_targets(...) can attempt to read non-whitelisted properties of imported interface libraries. After a recent update on Arch Linux this caused atleast pcl-ros to fail at the cmake step with the below error.

My guess is that this is new behaviour introduced in cmake 3.10.2 for which I couldn't find release notes yet, or otherwise caused by an interface library now showing up in PCL_LIBRARIES.

This PR fixes the issue by detecting interface libraries and replacing them with their INTERFACE_LINK_LIBRARIES property instead of IMPORTED_LOCATION.

On an unrelated note, imported library targets may also have IMPORTED_LINK_INTERFACE_LIBRARIES(_$CONFIG) which don't seem to be handled. If that is desired I'd prefer to keep it out of this PR though.

Error message without this PR running cmake on pcl-ros:

CMake Error at /opt/ros/lunar/share/catkin/cmake/catkin_libraries.cmake:137 (get_target_property):
  INTERFACE_LIBRARY targets may only have whitelisted properties.  The
  property "IMPORTED_LOCATION" is not allowed.
Call Stack (most recent call first):
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:258 (catkin_replace_imported_library_targets)
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:102 (_catkin_package)
  CMakeLists.txt:63 (catkin_package)


CMake Error at /opt/ros/lunar/share/catkin/cmake/catkin_libraries.cmake:143 (get_target_property):
  INTERFACE_LIBRARY targets may only have whitelisted properties.  The
  property "IMPORTED_LOCATION_vtkm_imported_configurations-NOTFOUND" is not
  allowed.
Call Stack (most recent call first):
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:258 (catkin_replace_imported_library_targets)
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:102 (_catkin_package)
  CMakeLists.txt:63 (catkin_package)


CMake Error at /opt/ros/lunar/share/catkin/cmake/catkin_libraries.cmake:137 (get_target_property):
  INTERFACE_LIBRARY targets may only have whitelisted properties.  The
  property "IMPORTED_LOCATION" is not allowed.
Call Stack (most recent call first):
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:258 (catkin_replace_imported_library_targets)
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:102 (_catkin_package)
  CMakeLists.txt:63 (catkin_package)


CMake Error at /opt/ros/lunar/share/catkin/cmake/catkin_libraries.cmake:143 (get_target_property):
  INTERFACE_LIBRARY targets may only have whitelisted properties.  The
  property "IMPORTED_LOCATION_vtkm_imported_configurations-NOTFOUND" is not
  allowed.
Call Stack (most recent call first):
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:258 (catkin_replace_imported_library_targets)
  /opt/ros/lunar/share/catkin/cmake/catkin_package.cmake:102 (_catkin_package)
  CMakeLists.txt:63 (catkin_package)


-- Configuring incomplete, errors occurred!
See also "/tmp/makepkg/ros-lunar-pcl-ros/src/build/CMakeFiles/CMakeOutput.log".
See also "/tmp/makepkg/ros-lunar-pcl-ros/src/build/CMakeFiles/CMakeError.log".

[de-vri-es]

The issue was most likely triggered by an update to VTK 8.1, and not by a cmake update. VTK 8.1 now exports an interface target called vtkm that PCL re-exports.

[de-vri-es]

Fixed property name: INTERFACE_LINK_LIBRARIES instead of INTERFACE_LIBRARIES.

[de-vri-es]

I also had to recursively resolve any imported/interface targets in INTERFACE_LINK_LIBRARIES. Otherwise dependent packages will fail on the cmake step, since some exported libraries might still be imported targets.

That does mean that cycles could cause infinite recursion. If that happens, it would appear that cmake segfaults rather than hitting some recursion limit.

[dirk-thomas]

I couldn't find any documentation about the "string" INTERFACE_LIBRARY.

Maybe get_property(... SET/DEFINED) could be used instead if this can't be relied on?

[de-vri-es]

Documentation is here: https://cmake.org/cmake/help/v3.1/prop_tgt/TYPE.html

It first appeared in cmake 3.1, but since older cmakes will never report "INTERFACE_LIBRARY", it is automatically backwards compatible.

[dirk-thomas]

Ok, thanks for the reference. I was indeed looking at the 3.0 docs.

[dirk-thomas]

Thanks for the patch.