XLink not installed with cmake install (only static issue?)

[diablodale]

For a static build of depthai, using DEPTHAI_XLINK_LOCAL... a cmake install

• does not install the XLink cmake files 😕
• does not install the XLink static libraries 😕
• does install the xlink includes 🙂

Setup

• Microsoft Windows [Version 10.0.19044.1348]
• VS2019 Community v16.11.7
• cmake v3.19.1
• depthai-core v2.12.1 + my local fixes

Repro

1. set depthai for a static build, x64, and opencv support
2. set depthai to use a local xlink with DEPTHAI_XLINK_LOCAL. Use the same commit as hunter would.
3. set depthai to install to a known location e.g. CMAKE_INSTALL_PREFIX=c:/myinstalldir
4. cmake configure, build, and then install

Result

Either try to find_package() and then compile an app that would use this depthai install
-or-
search c:/myinstalldir for the xlink cmake file XLinkConfig.cmake and its static libraries XLink.lib/XLinkd.lib
You will find none of these files.

Expected

Your app finds depthai and all its dependencies (like XLink) and cleanly builds.
-or-
You find XLink's cmake files and static libraries in the given install location c:/myinstalldir

Notes

I see all the needed files in the depthai build directory ...\depthai-core\build\XLink. This suggests their might be only a small change needed for cmake install process to use those and then do the install.

[diablodale]

Hacking some on this in depthaiDependencies.cmake (probably wrong approach)...

# XLink
if(NOT CONFIG_MODE)
    if(DEPTHAI_XLINK_LOCAL)
        add_subdirectory("${DEPTHAI_XLINK_LOCAL}" ${CMAKE_CURRENT_BINARY_DIR}/XLink EXCLUDE_FROM_ALL)
    else()
        find_package(XLink ${_QUIET} CONFIG REQUIRED)
    endif()
    if(NOT BUILD_SHARED_LIBS)
        list(APPEND targets_to_export XLink)
    endif()
endif()

I've got a few steps further, but app compile fails with depthai because it can't find XLink/XLinkPublicDefines.h
That header was not cmake-installed by depthai yet both XLinkConnection.hpp and XLinkStream.hpp need that include themselves.

[diablodale]

I've got a local hack almost working. I think are three things in play...

• depthai-core/depthaiDependencies.cmake includes a DEPTHAI_XLINK_LOCAL xlink with the EXCLUDE_FROM_ALL flag. I think that flag excludes that added thing from the ALL built target. And likely from the ALL install target. Therefore xlink isn't installed.
• You might be able to get it to install with cmake --install . --component XLink but the cmake code in the XLink project skips all installation steps when a component is defined. It doesn't realize the distinction between a component of depthai -vs- a component of XLink.
• Finally, after hacking the above with workarounds, i have the includes and libraries installing. The entire XLink/include directory is installed...all 15 include files. Probably only one needs to be installed XLinkPublicDefines.h

[themarpe]

I think removing the EXCLUDE_FROM_ALL is the way to go - although there might be way to specify it explicitly in installation part of core instead