Tests/RunCMake/InitialFlags/RunCMakeTest.cmake - third_party/github.com/Kitware/CMake - Git at Google

 include(RunCMake)

 set(ENV{CFLAGS} "$ENV{CFLAGS} -Denv=\"a\\b\"")
 run_cmake(C)

 set(ENV{CXXFLAGS} "$ENV{CXXFLAGS} -Denv=\"a\\b\"")
 run_cmake(CXX)
	include(RunCMake)

	set(ENV{CFLAGS} "$ENV{CFLAGS} -Denv=\"a\\b\"")
	run_cmake(C)

	set(ENV{CXXFLAGS} "$ENV{CXXFLAGS} -Denv=\"a\\b\"")
	run_cmake(CXX)