Add CMake options for disabling ObjC++ entirely and for forcing the build of a separate libobjcxx.so.

CMakeLists.txt

@@ -174,34 +174,52 @@ set_source_files_properties(
 # C++ Runtime interaction
 #
 
-# Try to find libcxxrt.so.  We can link to this to provide the C++ ABI layer,
+set(ENABLE_OBJCXX true CACHE BOOL
-# if it exists.
+	"Enable support for Objective-C++")
-find_library(CXX_RUNTIME cxxrt)
+set(FORCE_LIBOBJCXX false CACHE BOOL
-# If it doesn't, then look for GNU libsupc++.so instead (either works, they're
+	"Force building a separate Objective-C++ runtime library")
-# ABI compatible).
+if (ENABLE_OBJCXX)
-if (NOT CXX_RUNTIME)
+	# Try to find libcxxrt.so.  We can link to this to provide the C++ ABI
-	find_library(CXX_RUNTIME supc++)
+	# layer, if it exists.
-endif (NOT CXX_RUNTIME)
+	find_library(CXX_RUNTIME cxxrt)
-
+	# If it doesn't, then look for GNU libsupc++.so instead (either works,
-# If we have a C++ ABI library, then we can produce a single libobjc that works
+	# they're ABI compatible).
-# for Objective-C and Objective-C++.  If not, then we need to provide a
+	if (NOT CXX_RUNTIME)
-# separate libobjcxx.
+		find_library(CXX_RUNTIME supc++)
-if (CXX_RUNTIME)
+	endif (NOT CXX_RUNTIME)
-	message(STATUS "Using ${CXX_RUNTIME} as the C++ runtime library")
+
-	set(libobjc_CXX_SRCS ${libobjcxx_CXX_SRCS})
+	# If we have a C++ ABI library, then we can produce a single libobjc that
-	# We don't want to link the STL implementation (e.g. libstdc++) if we have
+	# works for Objective-C and Objective-C++.  If not, then we need to provide
-	# a separate C++ runtime.
+	# a separate libobjcxx.
-	set(CMAKE_CXX_IMPLICIT_LINK_LIBRARIES "")
+	if (CXX_RUNTIME)
-else (CXX_RUNTIME)
+		message(STATUS "Using ${CXX_RUNTIME} as the C++ runtime library")
-	message(STATUS "No C++ runtime library found")
+		if (FORCE_LIBOBJCXX)
-	add_library(objcxx SHARED ${libobjcxx_CXX_SRCS})
+			message(STATUS "Forcing build of stand-alone libobjcxx")
-	set_target_properties(objcxx PROPERTIES
+			add_library(objcxx SHARED ${libobjcxx_CXX_SRCS})
-		LINKER_LANGUAGE C
+			set_target_properties(objcxx PROPERTIES
-		SOVERSION ${libobjc_VERSION}
+				LINKER_LANGUAGE C
-		)
+				SOVERSION ${libobjc_VERSION}
-	set(CXX_RUNTIME "")
+				)
-	list(APPEND INSTALL_TARGETS objcxx)
+			target_link_libraries(objcxx ${CXX_RUNTIME})
-endif (CXX_RUNTIME)
+			set(CXX_RUNTIME "")
+			list(APPEND INSTALL_TARGETS objcxx)
+		else ()
+			set(libobjc_CXX_SRCS ${libobjcxx_CXX_SRCS})
+			# We don't want to link the STL implementation (e.g. libstdc++) if
+			# we have a separate C++ runtime.
+			set(CMAKE_CXX_IMPLICIT_LINK_LIBRARIES "")
+		endif ()
+	else ()
+		message(STATUS "No C++ runtime library found")
+		add_library(objcxx SHARED ${libobjcxx_CXX_SRCS})
+		set_target_properties(objcxx PROPERTIES
+			LINKER_LANGUAGE C
+			SOVERSION ${libobjc_VERSION}
+			)
+		set(CXX_RUNTIME "")
+		list(APPEND INSTALL_TARGETS objcxx)
+	endif ()
+endif (ENABLE_OBJCXX)