BUILD: Further restrict which backend source files are compiled

backends/module.mk

@@ -4,43 +4,23 @@ MODULE_OBJS := \
 	base-backend.o \
 	modular-backend.o \
 	audiocd/default/default-audiocd.o \
-	audiocd/sdl/sdl-audiocd.o \
 	events/default/default-events.o \
-	events/gp2xsdl/gp2xsdl-events.o \
-	events/gph/gph-events.o \
-	events/sdl/sdl-events.o \
 	fs/abstract-fs.o \
 	fs/stdiostream.o \
-	fs/amigaos4/amigaos4-fs.o \
-	fs/amigaos4/amigaos4-fs-factory.o \
-	fs/posix/posix-fs.o \
-	fs/posix/posix-fs-factory.o \
-	fs/windows/windows-fs.o \
-	fs/windows/windows-fs-factory.o \
-	graphics/gp2xsdl/gp2xsdl-graphics.o \
-	graphics/gph/gph-graphics.o \
 	graphics/opengl/glerrorcheck.o \
 	graphics/opengl/gltexture.o \
 	graphics/opengl/opengl-graphics.o \
 	graphics/openglsdl/openglsdl-graphics.o \
-	graphics/sdl/sdl-graphics.o \
 	keymapper/action.o \
 	keymapper/keymap.o \
 	keymapper/keymapper.o \
 	keymapper/remap-dialog.o \
 	log/log.o \
 	midi/alsa.o \
-	midi/camd.o \
-	midi/coreaudio.o \
-	midi/coremidi.o \
 	midi/dmedia.o \
 	midi/seq.o \
 	midi/stmidi.o \
 	midi/timidity.o \
-	midi/windows.o \
-	mixer/doublebuffersdl/doublebuffersdl-mixer.o \
-	mixer/sdl/sdl-mixer.o \
-	mutex/sdl/sdl-mutex.o \
 	plugins/elf/arm-loader.o \
 	plugins/elf/elf-loader.o \
 	plugins/elf/elf-provider.o \
@@ -49,20 +29,61 @@ MODULE_OBJS := \
 	plugins/elf/ppc-loader.o \
 	plugins/elf/shorts-segment-manager.o \
 	plugins/elf/version.o \
-	plugins/posix/posix-provider.o \
-	plugins/sdl/sdl-provider.o \
-	plugins/win32/win32-provider.o \
 	saves/savefile.o \
 	saves/default/default-saves.o \
-	saves/posix/posix-saves.o \
 	timer/default/default-timer.o \
-	timer/sdl/sdl-timer.o \
 	vkeybd/image-map.o \
 	vkeybd/polygon.o \
 	vkeybd/virtual-keyboard.o \
 	vkeybd/virtual-keyboard-gui.o \
 	vkeybd/virtual-keyboard-parser.o
 
+# SDL specific source files.
+# We cannot just check $BACKEND = sdl, as various other backends
+# derive from the SDL backend, and they all need the following files.
+# TODO: Add SDL_BACKEND to config.mk; this would match the fact that
+# we also add -DSDL_BACKEND to the DEFINES.
+# However, the latter is only done for *most* SDL based stuff, not always
+# so we really should unify the relevant code in configure.
+MODULE_OBJS += \
+	audiocd/sdl/sdl-audiocd.o \
+	events/sdl/sdl-events.o \
+	graphics/sdl/sdl-graphics.o \
+	mixer/doublebuffersdl/doublebuffersdl-mixer.o \
+	mixer/sdl/sdl-mixer.o \
+	mutex/sdl/sdl-mutex.o \
+	plugins/sdl/sdl-provider.o \
+	timer/sdl/sdl-timer.o
+
+ifdef UNIX
+MODULE_OBJS += \
+	fs/posix/posix-fs.o \
+	fs/posix/posix-fs-factory.o \
+	plugins/posix/posix-provider.o \
+	saves/posix/posix-saves.o
+endif
+
+ifdef MACOSX
+MODULE_OBJS += \
+	midi/coreaudio.o \
+	midi/coremidi.o
+endif
+
+ifdef WIN32
+MODULE_OBJS += \
+	fs/windows/windows-fs.o \
+	fs/windows/windows-fs-factory.o \
+	midi/windows.o \
+	plugins/win32/win32-provider.o
+endif
+
+ifdef AMIGAOS
+MODULE_OBJS += \
+	fs/amigaos4/amigaos4-fs.o \
+	fs/amigaos4/amigaos4-fs-factory.o \
+	midi/camd.o
+endif
+
 ifeq ($(BACKEND),ds)
 MODULE_OBJS += \
 	fs/ds/ds-fs.o \
@@ -76,6 +97,20 @@ MODULE_OBJS += \
 	graphics/dinguxsdl/dinguxsdl-graphics.o
 endif
 
+ifeq ($(BACKEND),gph)
+MODULE_OBJS += \
+	events/gph/gph-events.o \
+	graphics/gph/gph-graphics.o
+endif
+
+# TODO/FIXME: The gp2xsdl files are only compiled if GP2X_OLD is defined,
+# which currently is never the case (unless the user manually requests it).
+# ifeq ($(BACKEND),gp2x)
+# MODULE_OBJS += \
+# 	events/gp2xsdl/gp2xsdl-events.o \
+# 	graphics/gp2xsdl/gp2xsdl-graphics.o
+# endif
+
 ifeq ($(BACKEND),linuxmoto)
 MODULE_OBJS += \
 	events/linuxmotosdl/linuxmotosdl-events.o \