FAST_DEPEND: Use .dinclude to enable full .depend logic in bmake.

The inclusion of .MAKE.DEPENDFILE (.depend) has special logic in make
to ignore stale/missing dependencies.  bmake 20160220 added a '.dinclude'
directive that uses the special logic for .depend when including the file.

This fixes a build error when a file is moved or deleted that exists in a
.depend.OBJ file.  This happened in r292782 when sha512c.c "moved" and an
incremental build of lib/libmd would fail with:
  make: don't know how to make /usr/src/lib/libcrypt/../libmd/sha512c.c. Stop

Now this will just be seen as a stale dependency and cause a rebuild:
  make: /usr/obj/usr/src/lib/libmd/.depend.sha512c.o, 13: ignoring stale .depend for /usr/src/lib/libcrypt/../libmd/sha512c.c
  --- sha512c.o ---
  ...
This rebuild will only be done once since the .depend.sha512c.o will
be updated on the build with the -MF flags.

This also removes -MP being passed for the .depend.OBJ generation (which
would create fake targets for system headers) since the logic is no
longer needed to protect from missing files.

Sponsored by:	EMC / Isilon Storage Division

1 files changed, 2 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index bc191e15c9c29..49fe0ab6dfa7d 100644
--- a/Makefile
+++ b/Makefile
@@ -159,6 +159,8 @@ _MAKEOBJDIRPREFIX!= /usr/bin/env -i PATH=${PATH} MK_AUTO_OBJ=no ${MAKE} \
 # We cannot blindly use a make which may not be the one we want
 # so be exlicit - until all choice is removed.
 WANT_MAKE=	bmake
+# 20160220 - support .dinclude for FAST_DEPEND.
+WANT_MAKE_VERSION= 20160220
 MYMAKE=		${MAKEOBJDIRPREFIX}${.CURDIR}/make.${MACHINE}/${WANT_MAKE}
 .if defined(.PARSEDIR)
 HAVE_MAKE=	bmake