A CMake based C++ project with various libraries.
The top CMakeLists.txt presents two stages: "thirdparty" and "main".
When -DTHIRDPARTY=TRUE is passed to cmake configure command, the thirdparty stage is configured,
the "binary directory" is thirdparty/build. This build employs
ExternalProject feature of CMake
to download and build libraries.
This should be done before the "main" stage and rarely needs to repeat.
Without the "THIRDPARTY" variable set, the main stage is configured, the "binary directory" is "./build". This is the major playground for user. User's CMake targets can just link to those thirdparty libraries as CMake packages.
A "run-cmake" helper script (run-cmake.sh is for Unix, and run-cmake.bat is for Windows) runs
the "configure" and "build" for "thirdparty" stage directly, but for "main" stage, it only runs
"configure".
Note that for "thirdparty" stage, generator is set to platform specific (with preference to IDE favors if available), rather than Ninja, since "compile_commands.json" is not necessary for this stage. Using platform specific generator may ease the toolchain configuration.
CMake 3.15 or later versions should be OK, though more recent versions like 3.20+ are not tested.
In order to enable CMake to export "compile_commands.json" file, the "Ninja" generator is used for the user project.
You need to install the ninja build tool, I recommend going to
official release page to download the binary and
just put the binary at your PATH.
The following example applies on Linux. You should use run-cmake.bat for Windows.
# To configure and build the "thirdparty" stage
./run-cmake thirdparty
# To configure the "main" stage (must be done AFTER "thirdparty")
./run-cmakeIf you prefer to use Visual Studio (on Windows) or Xcode (on macOS), you should change the generator at "main" stage to the corresponding IDE's flavors, e.g. "Visual Studio 14 2015 Win64" for Windows, or "Xcode" for macOS).
(TODO)