Add cmake option NO_GPL3 to simplify building of GPL2 binaries

CMakeLists.txt

@@ -165,8 +165,8 @@ option(SC_MEMORY_DEBUGGING "Build sclang&scsynth for memory debugging (disable m
 option(GC_SANITYCHECK "Enable sanity checks in the sclang garbage collector.")
 
 option(NO_LIBSNDFILE "Disable soundfile functionality. (Not recommended.)" OFF)
-
 option(NO_AVAHI "Disable Avahi support. (Not recommended.)" OFF)
+option(NO_GPL3 "Disable GPL3 code, for pure-GPL2 situations. (Not recommended.)" OFF)
 
 option(SCLANG_SERVER "Build with internal server." ON)
 
@@ -287,6 +287,10 @@ if(MINGW)
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mstackrealign")
 endif()
 
+if (NO_GPL3)
+	add_definitions(-DNO_GPL3)
+endif()
+
 #############################################
 # subdirectories
 add_subdirectory(external_libraries)

editors/CMakeLists.txt

@@ -19,10 +19,18 @@ if(SC_EL)
 endif()
 
 if(SC_ED)
-	add_subdirectory(sced)
+	if(NO_GPL3)
+		message(WARNING "SC_ED requested, but NO_GPL3 flag is on, so not activated.")
+	else()
+		add_subdirectory(sced)
+	endif()
 endif()
 
 if(SC_VIM)
-	add_subdirectory(scvim)
+	if(NO_GPL3)
+		message(WARNING "SC_VIM requested, but NO_GPL3 flag is on, so not activated.")
+	else()
+		add_subdirectory(scvim)
+	endif()
 endif()