From e32a2cbe390f8f3bf4e24e3e2c144d967e4a7bbb Mon Sep 17 00:00:00 2001
From: Bryan Drewery <bdrewery@FreeBSD.org>
Date: Fri, 11 Mar 2016 04:09:56 +0000
Subject: [PATCH] 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
---
 Makefile              | 2 ++
 share/mk/bsd.dep.mk   | 6 ++++++
 sys/conf/kern.post.mk | 9 ++++++++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index bc191e15c9c2..49fe0ab6dfa7 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
diff --git a/share/mk/bsd.dep.mk b/share/mk/bsd.dep.mk
index 19ab9e558aa1..92c10a4a90b4 100644
--- a/share/mk/bsd.dep.mk
+++ b/share/mk/bsd.dep.mk
@@ -176,7 +176,9 @@ ${_D}.po: ${_DSRC} ${POBJS:S/^${_D}.po$//}
 _meta_filemon=	1
 .endif
 .if ${MK_FAST_DEPEND} == "yes"
+.if ${MAKE_VERSION} < 20160220
 DEPEND_MP?=	-MP
+.endif
 # Handle OBJS=../somefile.o hacks.  Just replace '/' rather than use :T to
 # avoid collisions.
 DEPEND_FILTER=	C,/,_,g
@@ -200,7 +202,11 @@ CFLAGS+=	${DEPEND_CFLAGS}
 .endif
 .if !defined(_SKIP_READ_DEPEND)
 .for __depend_obj in ${DEPENDFILES_OBJS}
+.if ${MAKE_VERSION} < 20160220
 .sinclude "${.OBJDIR}/${__depend_obj}"
+.else
+.dinclude "${.OBJDIR}/${__depend_obj}"
+.endif
 .endfor
 .endif	# !defined(_SKIP_READ_DEPEND)
 .endif	# !defined(_meta_filemon)
diff --git a/sys/conf/kern.post.mk b/sys/conf/kern.post.mk
index ba2c7928fbe3..d5047a840344 100644
--- a/sys/conf/kern.post.mk
+++ b/sys/conf/kern.post.mk
@@ -231,7 +231,10 @@ _meta_filemon=	1
 .if ${MK_FAST_DEPEND} == "yes"
 DEPENDOBJS+=	${SYSTEM_OBJS} genassym.o
 DEPENDFILES_OBJS=	${DEPENDOBJS:O:u:C/^/.depend./}
-DEPEND_CFLAGS+=	-MD -MP -MF.depend.${.TARGET}
+.if ${MAKE_VERSION} < 20160220
+DEPEND_MP?=	-MP
+.endif
+DEPEND_CFLAGS+=	-MD ${DEPEND_MP} -MF.depend.${.TARGET}
 DEPEND_CFLAGS+=	-MT${.TARGET}
 .if !defined(_meta_filemon)
 .if defined(.PARSEDIR)
@@ -244,7 +247,11 @@ CFLAGS+=	${DEPEND_CFLAGS}
 .endif
 .if !defined(_SKIP_READ_DEPEND)
 .for __depend_obj in ${DEPENDFILES_OBJS}
+.if ${MAKE_VERSION} < 20160220
 .sinclude "${.OBJDIR}/${__depend_obj}"
+.else
+.dinclude "${.OBJDIR}/${__depend_obj}"
+.endif
 .endfor
 .endif	# !defined(_SKIP_READ_DEPEND)
 .endif	# !defined(_meta_filemon)