Added a configurable linker flag to enable linker warnings as errors since OSX

requires a diffent linker flag.

Author: nfi

Makefile.include

@@ -50,7 +50,12 @@ CFLAGS += -DCONTIKI_BOARD_STRING=\"$(BOARD)\"
 endif
 
 CFLAGS += -Wno-unused-const-variable
-LDFLAGS = -Wl,--fatal-warnings
+
+LDFLAGS_WERROR ?= -Wl,--fatal-warnings
+
+ifeq ($(WERROR),1)
+ LDFLAGS += $(LDFLAGS_WERROR)
+endif
 
 MODULES += os os/sys os/dev os/lib os/services
 

arch/cpu/native/Makefile.native

@@ -22,6 +22,7 @@ CFLAGS  += $(CFLAGSNO)
 
 ifeq ($(HOST_OS),Darwin)
 AROPTS = -rc
+LDFLAGS_WERROR := -Wl,-fatal_warnings
 LDFLAGS += -Wl,-flat_namespace,-map,$(CONTIKI_NG_PROJECT_MAP)
 CFLAGS += -DHAVE_SNPRINTF=1 -U__ASSERT_USE_STDERR
 else