Define several extra macros in bsd.sys.mk and sys/conf/kern.pre.mk, to

get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.

Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang       (disables -Werror)
- NO_WCAST_ALIGN.clang  (disables -Wcast-align)
- NO_WFORMAT.clang	(disables -Wformat and friends)
- CLANG_NO_IAS		(disables integrated assembler)
- CLANG_OPT_SMALL	(adds flags for extra small size optimizations)

As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf!  For clang, use the following:

CC=clang
CXX=clang++
CPP=clang-cpp

MFC after:	2 weeks

1 files changed, 1 insertions, 3 deletions

diff --git a/sbin/fsdb/Makefile b/sbin/fsdb/Makefile
index 038f82efd18f..5e172fd78d55 100644
--- a/sbin/fsdb/Makefile
+++ b/sbin/fsdb/Makefile
@@ -9,10 +9,8 @@ SRCS=	fsdb.c fsdbutil.c \
 	pass5.c setup.c utilities.c ffs_subr.c ffs_tables.c
 CFLAGS+= -I${.CURDIR}/../fsck_ffs
 WARNS?= 2
-.if ${CC:T:Mclang} == "clang"
 # Work around a problem with format string warnings and ntohs macros.
-NO_WFORMAT=
-.endif
+NO_WFORMAT.clang=
 LDADD=	-ledit -ltermcap
 DPADD=	${LIBEDIT} ${LIBTERMCAP}
 .PATH:	${.CURDIR}/../fsck_ffs ${.CURDIR}/../../sys/ufs/ffs