- Remove include links only when .depend is also removed, so that

"make depend; make clean; make -n" works.

- Preseve kernel's .depend if it already exists and its creation
  is interrupted.

Reported/reviewed by:	bde

sys/conf/kern.post.mk

@@ -121,7 +121,7 @@ kernel-clean:
 	    linterrs makelinks tags vers.c \
 	    vnode_if.c vnode_if.h vnode_if_newproto.h vnode_if_typedef.h \
 	    ${MFILES:T:S/.m$/.c/} ${MFILES:T:S/.m$/.h/} \
-	    ${CLEAN} ${_ILINKS}
+	    ${CLEAN}
 
 lint: ${LNFILES}
 	${LINT} ${LINTKERNFLAGS} ${CFLAGS:M-[DILU]*} ${.ALLSRC} 2>&1 | \
@@ -153,7 +153,7 @@ kernel-depend: .depend
 SRCS=	assym.s vnode_if.h ${BEFORE_DEPEND} ${CFILES} \
 	${SYSTEM_CFILES} ${GEN_CFILES} ${SFILES} \
 	${MFILES:T:S/.m$/.h/}
-.depend: ${SRCS}
+.depend: .PRECIOUS ${SRCS}
 	rm -f .newdep
 	${MAKE} -V CFILES -V SYSTEM_CFILES -V GEN_CFILES | \
 	    MKDEP_CPP="${CC} -E" CC="${CC}" xargs mkdep -a -f .newdep ${CFLAGS}
@@ -184,8 +184,9 @@ ${_ILINKS}:
 	${ECHO} ${.TARGET} "->" $$path ; \
 	ln -s $$path ${.TARGET}
 
+# .depend needs include links so we remove them only together.
 kernel-cleandepend:
-	rm -f .depend
+	rm -f .depend ${_ILINKS}
 
 links:
 	egrep '#if' ${CFILES} | sed -f $S/conf/defines | \

sys/conf/kmod.mk

@@ -246,7 +246,7 @@ ${_ILINKS}:
 	${ECHO} ${.TARGET} "->" $$path ; \
 	ln -sf $$path ${.TARGET}
 
-CLEANFILES+= ${PROG} ${KMOD}.kld ${OBJS} ${_ILINKS}
+CLEANFILES+= ${PROG} ${KMOD}.kld ${OBJS}
 
 .if defined(DEBUG_FLAGS)
 CLEANFILES+= ${FULLPROG} ${PROG}.symbols
@@ -435,6 +435,11 @@ lint: ${SRCS}
 
 .include <bsd.dep.mk>
 
+cleandepend: cleanilinks
+# .depend needs include links so we remove them only together.
+cleanilinks:
+	rm -f ${_ILINKS}
+
 .if !exists(${.OBJDIR}/${DEPENDFILE})
 ${OBJS}: ${SRCS:M*.h}
 .endif