c++ - CMake: rewrite project, only if modified? -

i have cmake project generates several visual studio projects single solution. if make change cmake scripts, affects single project (for example, add_target_definitions) , call cmake regenerate projects, of project files (*.vcxproj) rewritten disk. triggers rebuild of targets, though perhaps 1 of project files different was. adds build time of different configurations have.

i rebuild few projects these different target defines (eg. supplied on command line), , not recompile unaffected libraries. require solution works when compiling all_build target, , not split project multiple projects (solutions).

is there cmake option, or other trick avoid behavior?

it turns out cmake script using add_target_definitions in included in cmakelists.txt @ top level, , thus, cmakelists.txt in directories below dependency of it. found inspecting generated.stamp.depend 1 of projects.

if split out separate script included project requires it, projects no longer rewritten.