Bring in the WARNS directive from NetBSD, localized in a new bsd.sys.mk

to avoid polluting sys.mk.  This directive controls the addition of
compiler warning flags to CFLAGS in a relatively compiler-neutral manner.

The idea is that WARNS can be set in Makefile.inc or in individual
Makefiles as they become clean, to prevent the introduction of new
warnings in the code.  -Werror is added by default

1 files changed, 37 insertions, 0 deletions

diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
new file mode 100644
index 0000000..efb69a9
--- /dev/null
+++ b/share/mk/bsd.sys.mk
@@ -0,0 +1,37 @@
+# $FreeBSD$
+#
+# This file contains common settings used for building FreeBSD
+# sources.
+
+# Enable various levels of compiler warning checks.  These may be
+# overridden (e.g. if using a non-gcc compiler) by defining NO_WARNS.
+
+.if !defined(NO_WARNS)
+. if defined(WARNS)
+.  if ${WARNS} > 0
+CFLAGS		+=	-W -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith
+# XXX Delete -Wuninitialized by default for now -- the compiler doesn't
+# XXX always get it right.
+CFLAGS		+=	-Wno-uninitialized
+.  endif
+.  if ${WARNS} > 1
+CFLAGS		+=	-Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wshadow
+.  endif
+. endif
+
+. if defined(FORMAT_AUDIT)
+WFORMAT		=	1
+. endif
+. if defined(WFORMAT)
+.  if ${WFORMAT} > 0
+CFLAGS		+=	-Wnon-const-format -Wno-format-extra-args
+.  endif
+. endif
+
+. if !defined(NO_WERROR)
+CFLAGS		+=	-Werror
+. endif
+.endif
+
+# Allow user-specified additional warning flags
+CFLAGS		+=	${CWARNFLAGS}