make: show diffence in buildsizes for two folders

Makefile.include

@@ -31,7 +31,8 @@ CFLAGS += -DBOARD_$(BB) -DCPU_$(CPUDEF)
 
 export CFLAGS
 
-export BINDIR =$(CURDIR)/bin/$(BOARD)/
+export BINDIRBASE ?= $(CURDIR)/bin
+export BINDIR ?= $(abspath $(BINDIRBASE)/$(BOARD))/
 
 ifeq ($(QUIET),1)
 	AD=@
@@ -82,7 +83,7 @@ BASELIBS += $(BINDIR)$(BOARD)_base.a
 BASELIBS += $(BINDIR)${PROJECT}.a
 BASELIBS += $(USEPKG:%=${BINDIR}%.a)
 
-.PHONY: all clean flash doc term objsize buildsize buildsizes
+.PHONY: all clean flash doc term objsize buildsize buildsizes buildsizes-diff
 
 ## make script for your application. Build RIOT-base here!
 all: $(BINDIR)$(PROJECT).a
@@ -187,6 +188,7 @@ buildtest:
 			RIOTBASE=$${RIOTBASE} \
 			RIOTBOARD=$${RIOTBOARD} \
 			RIOTCPU=$${RIOTCPU} \
+			BINDIRBASE=$${BINDIRBASE} \
 			$(MAKE) -B clean all 2>&1 >/dev/null) ; \
 		if [ "$${?}" = "0" ]; then \
 			$${ECHO} "$${GREEN}success$${RESET}"; \
@@ -238,5 +240,49 @@ buildsizes:
 			RIOTBASE=$${RIOTBASE} \
 			RIOTBOARD=$${RIOTBOARD} \
 			RIOTCPU=$${RIOTCPU} \
+			BINDIRBASE=$${BINDIRBASE} \
 			$(MAKE) buildsize 2>/dev/null | tail -n-1 | cut -f-4)" "$${BOARD}"; \
 	done;
+
+buildsizes-diff: SHELL=bash
+buildsizes-diff:
+	@if [[ -z "$(BOARD_WHITELIST)" ]]; then \
+		BOARDS=$$(find $(RIOTBOARD) -mindepth 1 -maxdepth 1 -type d \! -name \*-common -printf '%f\n' ); \
+	else \
+		BOARDS="$(BOARD_WHITELIST)"; \
+	fi; \
+	for BOARD in $(BOARD_BLACKLIST); do \
+		BOARDS=$$(sed -e "s/ $${BOARD} / /" <<< " $${BOARDS} "); \
+	done; \
+	\
+	GREEN='\033[1;32m'; RED='\033[1;31m'; RESET='\033[0m'; \
+	\
+	echo -e "text\tdata\tbss\tdec\tBOARD/BINDIRBASE\n"; \
+	for BOARD in $$(tr ' ' '\n' <<< $${BOARDS} | sort); do \
+		for BINDIRBASE in $${OLDBIN} $${NEWBIN}; do \
+			env -i \
+				HOME=$${HOME} \
+				PATH=$${PATH} \
+				BOARD=$${BOARD} \
+				RIOTBASE=$${RIOTBASE} \
+				RIOTBOARD=$${RIOTBOARD} \
+				RIOTCPU=$${RIOTCPU} \
+				BINDIRBASE=$${BINDIRBASE} \
+				$(MAKE) buildsize 2>/dev/null | tail -n-1 | cut -f-4; \
+		done | \
+		while read -a OLD && read -a NEW; do \
+			for I in 0 1 2 3; do \
+				if [[ -n "$${NEW[I]}" && -n "$${OLD[I]}" ]]; then \
+					DIFF=$$(($${NEW[I]} - $${OLD[I]})); \
+					if [[ "$${DIFF}" -gt 0 ]]; then echo -ne "$${RED}"; fi; \
+					if [[ "$${DIFF}" -lt 0 ]]; then echo -ne "$${GREEN}"; fi; \
+				else \
+					DIFF="$${RED}ERR"; \
+				fi; \
+				echo -ne "$${DIFF}\t$${RESET}"; \
+			done; \
+			echo "$${BOARD}"; \
+			for I in 0 1 2 3; do echo -ne "$${OLD[I]-$${RED}ERR$${RESET}}\t"; done; echo -e "$${OLDBIN}"; \
+			for I in 0 1 2 3; do echo -ne "$${NEW[I]-$${RED}ERR$${RESET}}\t"; done; echo -e "$${NEWBIN}\n"; \
+		done; \
+	done;