googletest submodule

[phlptp]

@henryiii is there any desire to shift googletest from being a submodule to a separately download. I know on most of our other projects we have moved away from having googletest as a submodule since it wasn't required for all or even most builds and that made it an extra download that was unnecessary.

Instead it uses fetch_content or a GitUtils include on older cmake to do the same thing.

If this was of interest I could make a PR for this in the next couple weeks.

[sergeyklay]

How about conanfile.txt inside tests directory?

CMakeLists.txt

if(CLI11_TESTING_INTERNAL)
    enable_testing()
    add_subdirectory(tests)
endif()

tests/CMakeLists.txt

# Conan bootstrap
if(NOT EXISTS "${CMAKE_BINARY_DIR}/conan.cmake")
  message(
    STATUS
      "Downloading conan.cmake from https://github.com/conan-io/cmake-conan")
  file(DOWNLOAD "https://github.com/conan-io/cmake-conan/raw/v0.13/conan.cmake"
       "${CMAKE_BINARY_DIR}/conan.cmake")
endif()

include(${CMAKE_BINARY_DIR}/conan.cmake)
conan_check(REQUIRED)

conan_cmake_run(
  CONANFILE conanfile.txt
  BASIC_SETUP CMAKE_TARGETS
  BUILD missing)

include(GoogleTest) # Bundled

tests/conanfile.txt

[requires]
gtest/1.10.0

[generators]
cmake

[options]
# Possible gtest options are:
#   - shared
#   - build_gmock
#   - fPIC
#   - no_main
#   - debug_postfix
#   - hide_symbols
gtest:shared=False
gtest:no_main=True

---

Then you'll able to use something like this:

target_link_libraries(
  myTestExecutable
  PRIVATE CONAN_PKG::GTest)

Using this approach you don't need git submodule as well as calling fetch_content.

[henryiii]

I'm a fan of git submodules because a) dependencies are not duplicated for each build directory (I usually have several, up to a dozen or so), and b) you can get everything before building, so it's easy to continue to work even on a plane.

However, if there's enough of a reason to avoid submodules, I would consider alternatives, since we really only use it to get gtest. I wish it was easier to be selectively recursive.

[henryiii]

(And I haven't really played with Conan other than to support it, looks rather slick in that example...)

[phlptp]

I suppose that is a distinction that might be different for libraries are built and header only. In the case of CLI11 it might make more sense to have as a submodule. Some of our other libraries get built a lot but the testing is more rare and off by default so making everyone download Google test if they weren't testing it was overkill.

[henryiii]

I've shifted the other submodules away (just needed for one example or special procedures), just GTest is left. That will save lots of time/space (Json was huge if recursive checkouts were on)

[phlptp]

I think the calculus for GTEST is different for CLI11 than the other libraries I work with. In several of the others they are used as submodules themselves so having google test as a submodule often results in a bunch of copies of google test being downloaded with no purpose. But CLI11 is probably still used most commonly as a header only library so having an extra gtest as a submodule is not that big of deal.

That may change is CL11 shifts towards a compiled library option, where having subsubmodules becomes a somewhat bigger issue. But for now I think the changes are good, and we can reevaluate later as the library evolves.