FetchContent support about glog

[valaxkong]

I found the solutions.

FetchContent_Declare(
  glog
  GIT_REPOSITORY https://github.com/google/glog.git
  GIT_TAG        v0.6.0
)
FetchContent_GetProperties(glog)
if(NOT glog_POPULATED)
  FetchContent_Populate(glog)
  add_subdirectory(${glog_SOURCE_DIR} ${glog_BINARY_DIR})
endif()

And I will give a PR later.

[sergiud]

add_subdirectory mentioned in the docs does not use FetchContent. You need to specify the build directory only for the latter explicitly.

[sergiud]

The issue is not actionable. You can however extend the README with a link to CMake reference documentation that explains how to use FetchContent correctly if you want.

[valaxkong]

@sergiud I opened a PR which gives an example to show the usage of FetchContent and add_subdirectory. #1067