Consistently enable -Wall and -Werror. Have WERROR set by default

Makefile.include

@@ -4,6 +4,10 @@ ifndef CONTIKI
   ${error CONTIKI not defined! You must specify where Contiki resides}
 endif
 
+# Enable Werror by default. To disable from command line, use make WERROR=0.
+# Setting this option is also important for tests on Cooja motes to check for warnings.
+WERROR ?= 1
+
 ifeq ($(TARGET),)
   -include Makefile.target
   ifeq ($(TARGET),)

drivers/cpu/cc2538/Makefile.cc2538

@@ -22,7 +22,7 @@ LDFLAGS += -Wl,-Map=$(@:.elf=-$(TARGET).map),--cref,--no-warn-mismatch
 OBJCOPY_FLAGS += -O binary --gap-fill 0xff
 OBJDUMP_FLAGS += --disassemble --source --disassembler-options=force-thumb
 
-ifdef WERROR
+ifeq ($(WERROR),1)
 CFLAGS += -Werror
 endif
 

drivers/cpu/cc26xx-cc13xx/Makefile.cc26xx-cc13xx

@@ -41,7 +41,7 @@ LDFLAGS += -Wl,-Map=$(@:.elf=-$(TARGET).map),--cref,--no-warn-mismatch
 OBJCOPY_FLAGS += -O binary --gap-fill 0xff
 OBJDUMP_FLAGS += --disassemble --source --disassembler-options=force-thumb
 
-ifdef WERROR
+ifeq ($(WERROR),1)
 CFLAGS += -Werror
 endif
 

drivers/cpu/msp430/Makefile.msp430

@@ -53,8 +53,8 @@ CONTIKI_SOURCEFILES        += $(CONTIKI_TARGET_SOURCEFILES)
 
 ### Compiler definitions
 
-ifdef WERROR
-CFLAGSWERROR=-Werror
+ifeq ($(WERROR),1)
+CFLAGSWERROR= -Wall -Werror
 endif
 
 ifdef IAR

drivers/cpu/native/Makefile.native

@@ -13,7 +13,7 @@ AS       ?= as
 NM       ?= nm
 OBJCOPY  ?= objcopy
 STRIP    ?= strip
-ifdef WERROR
+ifeq ($(WERROR),1)
 CFLAGSWERROR=-Werror
 endif
 CFLAGSNO = -Wall -g -I/usr/local/include $(CFLAGSWERROR)

drivers/cpu/nrf52832/Makefile.nrf52832

@@ -160,7 +160,10 @@ CFLAGS += -DCONFIG_GPIO_AS_PINRESET
 CFLAGS += -DBLE_STACK_SUPPORT_REQD
 CFLAGS += -mcpu=cortex-m4
 CFLAGS += -mthumb -mabi=aapcs --std=gnu99
-CFLAGS += -Wall -Werror
+CFLAGS += -Wall
+ifeq ($(WERROR),1)
+CFLAGS += -Werror
+endif
 CFLAGS += -ggdb
 CFLAGS += -mfloat-abi=hard -mfpu=fpv4-sp-d16
 # keep every function in separate section. This will allow linker to dump unused functions

drivers/cpu/x86/Makefile.x86_common

@@ -27,6 +27,10 @@ STRIP    = strip
 CFLAGS  += -Wall -fno-asynchronous-unwind-tables -fno-unwind-tables
 LDFLAGS += -Wl,-Map=contiki-$(TARGET).map,--build-id=none
 
+ifeq ($(WERROR),1)
+CFLAGS += -Werror
+endif
+
 ifeq ($(BUILD_RELEASE),1)
 	CFLAGS  += -Os -fno-strict-aliasing -ffunction-sections -fdata-sections
 # XXX: --gc-sections can be very tricky sometimes. If somehow the release

drivers/platform/cooja/Makefile.cooja

@@ -72,6 +72,9 @@ CONTIKI_CPU=$(CONTIKI)/drivers/cpu/x86
 ### Compiler arguments
 #CC = gcc
 CFLAGSNO = $(EXTRA_CC_ARGS) -Wall -g -I/usr/local/include -DCLASSNAME=$(CLASSNAME)
+ifeq ($(WERROR),1)
+CFLAGSNO += -Werror
+endif
 CFLAGS   += $(CFLAGSNO)
 
 MODULES += core/net core/net/mac core/net/mac/framer core/net/ip64-addr \

drivers/platform/jn516x/Makefile.jn516x

@@ -60,7 +60,7 @@ CFLAGS += -Wno-strict-aliasing
 CFLAGS += -Wno-cast-align
 
 # Warings as error
-ifdef WERROR
+ifeq ($(WERROR),1)
 CFLAGS += -Werror
 endif