Allow adding extra common dependencies

HISTORY.md

@@ -5,6 +5,7 @@ The following is the rough list of changes that went into different versions. I
 
 ### 0.10.5 (in development)
 - Add USB_VID and USB_PID to CPPFLAGS only if the board is Leonardo.
+- Allow adding extra common dependencies (COMMON_DEPS) (https://github.com/gaftech)
 
 ### 0.10.4 (2013-05-31) @matthijskooijman
 - Improved BAUD_RATE detection logic

arduino-mk/Arduino.mk

@@ -689,8 +689,13 @@ $(OBJDIR)/libs/%.o: $(USER_LIB_PATH)/%.cpp | $(OBJDIR)
 $(OBJDIR)/libs/%.o: $(USER_LIB_PATH)/%.c | $(OBJDIR)
 	$(CC) -MMD -c $(CPPFLAGS) $(CFLAGS) $< -o $@
 
-# normal local sources
+ifdef COMMON_DEPS
+	COMMON_DEPS := $(COMMON_DEPS) Makefile
+else
 	COMMON_DEPS := Makefile
+endif
+
+# normal local sources
 $(OBJDIR)/%.o: %.c $(COMMON_DEPS) | $(OBJDIR)
 	$(CC) -MMD -c $(CPPFLAGS) $(CFLAGS) $< -o $@