Index: ../../../conf/kern.mk
===================================================================
--- ../../../conf/kern.mk	(wersja 188288)
+++ ../../../conf/kern.mk	(kopia robocza)
@@ -12,14 +12,21 @@
 .else
 CWARNFLAGS?=	-Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
 		-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \
-		${_wundef} ${_Wno_pointer_sign} -fformat-extensions
+		${_wundef} ${_Wno_pointer_sign} -fformat-extensions \
+		${_Wunreachable_code}
 .if !defined(WITH_GCC3)
 _Wno_pointer_sign=-Wno-pointer-sign
+_Werror_no_pointer_sign=-Werror=pointer-sign
 .endif
 .if !defined(NO_UNDEF)
 _wundef=	-Wundef
+_werror_undef=-Werror=undef
 .endif
+.if defined(UNREACHABLE_CODE)
+_Wunreachable_code=-Wunreachable-code -Wno-error=unreachable-code 
 .endif
+.endif
+
 #
 # The following flags are next up for working on:
 #	-W
Index: ../../../conf/kern.pre.mk
===================================================================
--- ../../../conf/kern.pre.mk	(wersja 188292)
+++ ../../../conf/kern.pre.mk	(kopia robocza)
@@ -93,8 +93,16 @@
 CFLAGS+= -fno-common -finline-limit=${INLINE_LIMIT}
 CFLAGS+= --param inline-unit-growth=100
 CFLAGS+= --param large-function-growth=1000
+.if defined(UNREACHABLE_CODE)
+# Keep this list synchronized with list of warnings present in kern.mk
+WERROR?= -Werror=all -Werror=redundant-decls -Werror=nested-externs \
+	 -Werror=missing-prototypes -Werror=pointer-arith \
+	 -Werror=inline -Werror=cast-qual ${_Werror_no_pointer_sign} \
+	 ${_werror_undef}
+.else
 WERROR?= -Werror
 .endif
+.endif
 
 # XXX LOCORE means "don't declare C stuff" not "for locore.s".
 ASM_CFLAGS= -x assembler-with-cpp -DLOCORE ${CFLAGS}