[CMake] How would I use parallel make on ExternalProjects?

[kent williams]

On Wed, Oct 6, 2010 at 5:01 PM, Clifford Yapp <cliffyapp at gmail.com> wrote:
> I use $(MAKE) in my BUILD_COMMAND and that seems to do OK, although I
> don't know if it works universally.
>

That's an environment variable, as near as I can tell and isn't
mentioned in the current CMake documentation. So it's probably not the
best thing to do.

upon reflection, this would be a little safer:

if("${CMAKE_GENERATOR}" STREQUAL "Unix Makefiles")
set(BUILD_COMMAND_STRING "${CMAKE_MAKE_PROGRAM} -j4")
else()
set(BUILD_COMMAND_STRING "$(CMAKE_MAKE_PROGRAM)")
endif()