flang/test/Preprocessing/pp129.F90 - third_party/github.com/llvm/llvm-project - Git at Google

 ! #define KWM !, then KWM works as comment line initiator
 #define KWM !
 KWM   print *, 'pp129.F90 FAIL HARD!'; stop
       print *, 'pp129.F90 pass'
       end
	! #define KWM !, then KWM works as comment line initiator
	#define KWM !
	KWM print *, 'pp129.F90 FAIL HARD!'; stop
	print *, 'pp129.F90 pass'
	end