Set RULE_LAUNCH_COMPILE/LINK to ccache if CMAKE_VERSION < 3.4

[furushchev]

Since the use of RULE_LAUNCH_COMPILE / RULE_LAUNCH_LINK is not recommended at least from CMake version 3.4, I added a condition to use set_property only if the cmake version is more than or equal to 3.4, where the variable CXX_COMPILE_LAUNCHER is introduced.

ref:
https://cmake.org/cmake/help/latest/prop_gbl/RULE_LAUNCH_COMPILE.html
https://cmake.org/cmake/help/latest/prop_tgt/LANG_COMPILER_LAUNCHER.html#prop_tgt:%3CLANG%3E_COMPILER_LAUNCHER

[mqcmd196]

Thank you for your contribution. I think the approach like https://github.com/apache/tvm/pull/8373/files , adding CXX_COMPILER_LAUNCHER is better instead of removing ccache flag if CMake >= 3.4. What do you think?

[furushchev]

@mqcmd196 Thank you for the reply.

adding CXX_COMPILER_LAUNCHER is better instead of removing ccache flag

This is for sure another way for the update, however it overwrites the variable to ccache and affects all packages that depend on the packages in this repository.
As we can specify the default arguments on running cmake internally in catkin build command by setting, for instance, catkin config --cmake-args -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -DCMAKE_C_COMPILER_LAUNCHER=ccache, I think it's nice to leave the CXX_COMPILER_LAUNCHER undefined in CMakeLists.txt and configurable by developers.

[mqcmd196]

I see, so you mean that advanced users who want to use ccache can specify ccache on the command line themselves. And this PR only guarantees backward compatibility, right?

[furushchev]

I see, so you mean that advanced users who want to use ccache can specify ccache on the command line themselves. And this PR only guarantees backward compatibility, right?

Yes. If you think this change is inconvenient for the existing users, it's also a good idea to add a variable USE_CCACHE to switch the prefix as seen in the link you shared.

[mqcmd196]

lgtm