Fix compiler warnings related to gtest/gmock

[rhaschke]

With clang and rather strict settings for compiler warnings, downstream projects fail to build due to issues in gtest/gmock:
https://github.com/ubi-agni/moveit_task_constructor/actions/runs/3372692498/jobs/5596418220

This PR extends #94 introduced by @dirk-thomas by:

• adding -Wno-deprecated-copy to the _gmock_compile_flags
• declaring gtest/gmock include dirs as SYSTEM, such that compilers ignore issues in those headers

[clalancette]

Rather than disabling more warnings, I wonder if it would help to upgrade to gmock 1.11.0, which would match what is in Ubuntu 22.04 anyway. Can you give that a try and see if it resolves these warnings?

[rhaschke]

You are right, according to this, gtest/gmock 1.11 should resolve the clang compiler warnings.

However, `ament-cmake-gtest` / `ament-cmake-gmock` have issues building this version.

CMake Error at /usr/src/googletest/googletest/cmake/internal_utils.cmake:158 (add_library):
  add_library cannot create target "gtest" because another target with the
  same name already exists.  The existing target is a static library created
  in source directory "/opt/ros/rolling/src/gtest_vendor".  See documentation
  for policy CMP0002 for more details.
Call Stack (most recent call first):
  /usr/src/googletest/googletest/cmake/internal_utils.cmake:215 (cxx_library_with_type)
  /usr/src/googletest/googletest/CMakeLists.txt:133 (cxx_library)
CMake Error at /usr/src/googletest/googletest/cmake/internal_utils.cmake:158 (add_library):

add_library cannot create target "gtest_main" because another target with

the same name already exists.  The existing target is a static library

created in source directory "/opt/ros/rolling/src/gtest_vendor".  See

documentation for policy CMP0002 for more details.

Call Stack (most recent call first):

/usr/src/googletest/googletest/cmake/internal_utils.cmake:215 (cxx_library_with_type)

/usr/src/googletest/googletest/CMakeLists.txt:136 (cxx_library)
CMake Error at /usr/src/googletest/googletest/CMakeLists.txt:149 (target_link_libraries):

Attempt to add link library "gtest" to target "gtest_main" which is not

built in this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /usr/src/googletest/googletest/cmake/internal_utils.cmake:158 (add_library):

add_library cannot create target "gmock" because another target with the

same name already exists.  The existing target is a static library created

in source directory "/usr/src/googletest/googlemock".  See documentation

for policy CMP0002 for more details.

Call Stack (most recent call first):

/usr/src/googletest/googletest/cmake/internal_utils.cmake:215 (cxx_library_with_type)

/usr/src/gmock/CMakeLists.txt:103 (cxx_library)
CMake Error at /usr/src/gmock/CMakeLists.txt:104 (target_link_libraries):

Attempt to add link library "gtest" to target "gmock" which is not built in

this directory.
This is allowed only when policy CMP0079 is set to NEW.
CMake Error at /usr/src/googletest/googletest/cmake/internal_utils.cmake:158 (add_library):

add_library cannot create target "gmock_main" because another target with

the same name already exists.  The existing target is a static library

created in source directory "/usr/src/googletest/googlemock".  See

documentation for policy CMP0002 for more details.

Call Stack (most recent call first):

/usr/src/googletest/googletest/cmake/internal_utils.cmake:215 (cxx_library_with_type)

/usr/src/gmock/CMakeLists.txt:106 (cxx_library)
CMake Error at /usr/src/gmock/CMakeLists.txt:107 (target_link_libraries):

Attempt to add link library "gmock" to target "gmock_main" which is not

built in this directory.
This is allowed only when policy CMP0079 is set to NEW.

I just force-removed the vendor packages like so:

dpkg -r --force-depends ros-rolling-gmock-vendor
dpkg -r --force-depends ros-rolling-gtest-vendor

and then built from scratch.

I don't have enough insight into these ament packages to fix this issue.

[clalancette]

Can you try out ament/googletest#21 ?

[rhaschke]

Can you try out ament/googletest#21?

Yes, that works: https://github.com/ubi-agni/moveit_task_constructor/actions/runs/3413457294/jobs/5680185989. Thanks!

Maybe we can remove those warning relaxation completely. I added an appropriate commit and the test succeeded as well.
In any case, I think includes should be declared as SYSTEM. So this PR is still relevant 😉

[rhaschke]

@clalancette, any update on this? ament/googletest#21 fixes the warnings, but wasn't touched for 2 months.

[clalancette]

@clalancette, any update on this? ament/googletest#21 fixes the warnings, but wasn't touched for 2 months.

Unfortunately, it introduces new warnings, and I haven't had time to look into them.

[rhaschke]

What about merging this PR then? gtest and gmock should be handled as external sources, i.e. using SYSTEM includes as proposed in this PR.

[clalancette]

I do think we should upgrade gtest to version 1.11, but that doesn't block this PR. This looks OK, I'll run CI on it and see what comes back.

[clalancette]

Looks good with green CI.

[clalancette]

CI:

• Linux
• Linux-aarch64
• Windows