effectively kill depend as an independant target (there are a few corners

where a separate depend step is still needed, mostly gcc3 and mesa).

Use of BUILDFIRST is mostly enough to make sure important stuff is built
first.

Otherwise, this makes use of -M* compiler options to generate dependencies
on the fly.  There is a bit of behind-the-scene for targets with several
steps (like yacc and/or libraries) and the compiler needs extra hand-holding
with assembler files (don't know why, don't care).

Idea based on guenther@'s initial kernel work, loads of input from
drahn, aoyama, tb, etc.

okay tb@

"why wait" deraadt@

5 files changed, 70 insertions, 65 deletions

diff --git a/share/mk/bsd.dep.mk b/share/mk/bsd.dep.mk
index bbbe61b2673..f6f39dde98f 100644
--- a/share/mk/bsd.dep.mk
+++ b/share/mk/bsd.dep.mk
@@ -1,42 +1,24 @@
-#	$OpenBSD: bsd.dep.mk,v 1.15 2017/06/16 10:20:52 espie Exp $
+#	$OpenBSD: bsd.dep.mk,v 1.16 2017/07/01 14:41:54 espie Exp $
 #	$NetBSD: bsd.dep.mk,v 1.12 1995/09/27 01:15:09 christos Exp $
 
-# some of the rules involve .h sources, so remove them from mkdep line
 .if !target(depend)
-depend: beforedepend .depend realdepend afterdepend
-.ORDER: beforedepend .depend realdepend afterdepend
-realdepend: _SUBDIRUSE
+depend:
+	@:
+.endif
 
-.  if defined(SRCS) && !empty(SRCS)
-.depend: ${SRCS} ${_LEXINTM} ${_YACCINTM}
-	@rm -f .depend
-	@files="${.ALLSRC:M*.s} ${.ALLSRC:M*.S}"; \
-	if [ "$$files" != " " ]; then \
-	  echo mkdep -a ${MKDEP} ${CFLAGS:M-std=*} ${CFLAGS:M-[ID]*} ${CPPFLAGS} ${AINC} $$files;\
-	  mkdep -a ${MKDEP} ${CFLAGS:M-std=*} ${CFLAGS:M-[ID]*} ${CPPFLAGS} ${AINC} $$files; \
-	fi
-	@files="${.ALLSRC:M*.c}"; \
-	if [ "$$files" != "" ]; then \
-	  echo mkdep -a ${MKDEP} ${CFLAGS:M-std=*} ${CFLAGS:M-[ID]*} ${CPPFLAGS} $$files; \
-	  mkdep -a ${MKDEP} ${CFLAGS:M-[ID]*} ${CPPFLAGS} $$files; \
-	fi
-	@files="${.ALLSRC:M*.cc} ${.ALLSRC:M*.C} ${.ALLSRC:M*.cpp}"; \
-	files="$$files ${.ALLSRC:M*.cxx}"; \
-	if [ "$$files" != "   " ]; then \
-	  echo CC=${CXX:Q} mkdep -a ${MKDEP} ${CXXFLAGS:M-std=*} ${CXXFLAGS:M-[ID]*} ${CPPFLAGS} $$files; \
-	  CC=${CXX:Q} mkdep -a ${MKDEP} ${CXXFLAGS:M-std=*} ${CXXFLAGS:M-[ID]*} ${CPPFLAGS} $$files; \
-	fi
-.  else
-.depend:
-.  endif
-.  if !target(beforedepend)
-beforedepend:
-.  endif
-.  if !target(afterdepend)
-afterdepend:
-.  endif
+# relies on DEPS defined by bsd.lib.mk and bsd.prog.mk
+.if defined(DEPS) && !empty(DEPS)
+.  for o in ${DEPS}
+     sinclude $o
+.  endfor
 .endif
 
+CFLAGS += -MD -MP
+CXXFLAGS += -MD -MP
+
+# libraries need some special love
+DFLAGS = -MT $*.o -MT $*.po -MT $*.so -MT $*.do
+
 .if !target(tags)
 .  if defined(SRCS)
 tags: ${SRCS} _SUBDIRUSE
@@ -47,16 +29,10 @@ tags:
 .  endif
 .endif
 
-.if defined(SRCS)
-cleandir: cleandepend
-cleandepend:
-	rm -f .depend ${.CURDIR}/tags
-.endif
 
+CLEANFILES += ${DEPS} .depend
 BUILDFIRST ?=
 BUILDAFTER ?=
 .if !empty(BUILDFIRST) && !empty(BUILDAFTER)
 ${BUILDAFTER}: ${BUILDFIRST}
 .endif
-
-.PHONY: beforedepend depend afterdepend cleandepend realdepend
diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index cf7cbeed237..cf439c88082 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -1,4 +1,4 @@
-#	$OpenBSD: bsd.lib.mk,v 1.84 2017/06/16 10:20:52 espie Exp $
+#	$OpenBSD: bsd.lib.mk,v 1.85 2017/07/01 14:41:54 espie Exp $
 #	$NetBSD: bsd.lib.mk,v 1.67 1996/01/17 20:39:26 mycroft Exp $
 #	@(#)bsd.lib.mk	5.26 (Berkeley) 5/2/91
 
@@ -38,92 +38,107 @@ DIST_CFLAGS+=	-Os
 
 .c.o:
 	@echo "${COMPILE.c} ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.c} ${.IMPSRC}  -o ${.TARGET}.o
+	@${COMPILE.c} ${DFLAGS} ${.IMPSRC}  -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .c.po:
 	@echo "${COMPILE.c} -p ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.c} -p ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.c} ${DFLAGS} -p ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .c.so:
 	@echo "${COMPILE.c} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.c} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.c} ${DFLAGS} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .c.do:
 	@echo "${COMPILE.c} ${DIST_CFLAGS} ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.c} ${DIST_CFLAGS} ${.IMPSRC}  -o ${.TARGET}.o
+	@${COMPILE.c} ${DFLAGS} ${DIST_CFLAGS} ${.IMPSRC}  -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .cc.o .cpp.o .C.o .cxx.o:
 	@echo "${COMPILE.cc} ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.cc} ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.cc} ${DFLAGS} ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .cc.po .cpp.po .C.po .cxx.po:
 	@echo "${COMPILE.cc} -p ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.cc} -p ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.cc} ${DFLAGS} -p ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .cc.so .cpp.so .C.so .cxx.so:
 	@echo "${COMPILE.cc} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.cc} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.cc} ${DFLAGS} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 # Fortran 77
 .f.o:
 	@echo "${COMPILE.f} ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.f} ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.f} ${DFLAGS} ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .f.po:
 	@echo "${COMPILE.f} -p ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.f} -p ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.f} ${DFLAGS} -p ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .f.so:
 	@echo "${COMPILE.f} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.f} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.f} ${DFLAGS} ${PICFLAG} -DPIC ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .S.o .s.o:
 	@echo "${COMPILE.S} ${CFLAGS:M-[ID]*} ${AINC} ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.S} ${CFLAGS:M-[ID]*} ${AINC} ${.IMPSRC} -o ${.TARGET}.o
+	@${COMPILE.S} ${DFLAGS} -MF $@.d ${CFLAGS:M-[IDM]*} ${AINC} \
+	    ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .S.po .s.po:
 	@echo "${COMPILE.S} -DPROF ${CFLAGS:M-[ID]*} ${AINC} ${.IMPSRC} \
 	    -o ${.TARGET}"
-	@${COMPILE.S} -DPROF ${CFLAGS:M-[ID]*} ${AINC} ${.IMPSRC} \
-	    -o ${.TARGET}.o
+	@${COMPILE.S} ${DFLAGS} -MF $@.d -DPROF ${CFLAGS:M-[IDM]*} ${AINC} \
+	    ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .S.so .s.so:
 	@echo "${COMPILE.S} ${PICFLAG} ${CFLAGS:M-[ID]*} ${AINC} ${.IMPSRC} \
 	    -o ${.TARGET}"
-	@${COMPILE.S} ${PICFLAG} ${CFLAGS:M-[ID]*} ${AINC} ${.IMPSRC} \
-	    -o ${.TARGET}.o
+	@${COMPILE.S} ${DFLAGS} -MF $@.d ${PICFLAG} ${CFLAGS:M-[IDM]*} \
+	    ${AINC} ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
 .S.do .s.do:
 	@echo "${COMPILE.S} ${CFLAGS:M-[ID]*} ${AINC} ${DIST_CFLAGS} \
 	    ${.IMPSRC} -o ${.TARGET}"
-	@${COMPILE.S} ${CFLAGS:M-[ID]*} ${AINC} ${DIST_CFLAGS} ${.IMPSRC} \
-	    -o ${.TARGET}.o
+	@${COMPILE.S} ${DFLAGS} -MF $@.d ${CFLAGS:M-[IDM]*} ${AINC} \
+	    ${DIST_CFLAGS} ${.IMPSRC} -o ${.TARGET}.o
+	@-mv $@.d $*.d
 	@${LD} -X -r ${.TARGET}.o -o ${.TARGET}
 	@rm -f ${.TARGET}.o
 
@@ -167,6 +182,7 @@ all: ${_LIBS} _SUBDIRUSE
 BUILDAFTER += ${_LIBS}
 
 OBJS+=	${SRCS:N*.h:R:S/$/.o/}
+DEPS+=	${OBJS:S/$/.d/}
 BUILDAFTER += ${OBJS}
 
 lib${LIB}.a: ${OBJS}
@@ -177,6 +193,7 @@ lib${LIB}.a: ${OBJS}
 
 POBJS+=	${OBJS:.o=.po}
 BUILDAFTER += ${POBJS}
+
 lib${LIB}_p.a: ${POBJS}
 	@echo building profiled ${LIB} library
 	@rm -f lib${LIB}_p.a
@@ -185,6 +202,7 @@ lib${LIB}_p.a: ${POBJS}
 
 SOBJS+=	${OBJS:.o=.so}
 BUILDAFTER += ${SOBJS}
+
 ${FULLSHLIBNAME}: ${SOBJS} ${DPADD}
 	@echo building shared ${LIB} library \(version ${SHLIB_MAJOR}.${SHLIB_MINOR}\)
 	@rm -f ${.TARGET}
@@ -237,10 +255,6 @@ clean: _SUBDIRUSE
 
 cleandir: _SUBDIRUSE clean
 
-.if defined(SRCS)
-afterdepend: .depend
-	@sed -i 's/^\([^\.]*\).o[ ]*:/\1.o \1.po \1.so \1.do:/' .depend
-.endif
 
 .if !target(install)
 .if !target(beforeinstall)
diff --git a/share/mk/bsd.prog.mk b/share/mk/bsd.prog.mk
index 49f3c5b16e6..c86512e4409 100644
--- a/share/mk/bsd.prog.mk
+++ b/share/mk/bsd.prog.mk
@@ -1,4 +1,4 @@
-#	$OpenBSD: bsd.prog.mk,v 1.71 2017/06/16 10:20:52 espie Exp $
+#	$OpenBSD: bsd.prog.mk,v 1.72 2017/07/01 14:41:54 espie Exp $
 #	$NetBSD: bsd.prog.mk,v 1.55 1996/04/08 21:19:26 jtc Exp $
 #	@(#)bsd.prog.mk	5.26 (Berkeley) 6/25/91
 
@@ -72,6 +72,8 @@ LIBARCH?=
 SRCS?=	${PROG}.c
 .  if !empty(SRCS:N*.h:N*.sh)
 OBJS+=	${SRCS:N*.h:N*.sh:R:S/$/.o/}
+DEPS+=	${OBJS:R:S/$/.d/}
+
 _LEXINTM+=${SRCS:M*.l:.l=.c}
 _YACCINTM+=${SRCS:M*.y:.y=.c}
 .  endif
@@ -141,6 +143,15 @@ realinstall: beforeinstall
 .include <bsd.man.mk>
 .endif
 
+# if we already got bsd.lib.mk we don't want to wreck that
+.if !defined(_LIBS)
+.s.o:
+	${COMPILE.S} -MD -MF ${.TARGET:R}.d -o $@ ${.IMPSRC}
+
+.S.o:
+	${COMPILE.S} -MD -MF ${.TARGET:R}.d -o $@ ${.IMPSRC}
+.endif
+
 .include <bsd.obj.mk>
 .include <bsd.dep.mk>
 .include <bsd.subdir.mk>
diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
index 7fd2d00185c..b1af201eb65 100644
--- a/share/mk/bsd.sys.mk
+++ b/share/mk/bsd.sys.mk
@@ -1,4 +1,4 @@
-#	$OpenBSD: bsd.sys.mk,v 1.10 2012/04/08 15:56:28 jsg Exp $
+#	$OpenBSD: bsd.sys.mk,v 1.11 2017/07/01 14:41:54 espie Exp $
 #	$NetBSD: bsd.sys.mk,v 1.2 1995/12/13 01:25:07 cgd Exp $
 #
 # Overrides used for OpenBSD source tree builds.
@@ -22,6 +22,7 @@ CXXFLAGS+= -idirafter ${DESTDIR}/usr/include/g++
 	${LEX.l} -o${.TARGET:R}.yy.c ${.IMPSRC}
 	${COMPILE.c} -o ${.TARGET} ${.TARGET:R}.yy.c 
 	rm -f ${.TARGET:R}.yy.c
+	if test -f ${.TARGET:R}.d; then sed -i -e 's,${.TARGET:R}.yy.c,${.IMPSRC},' ${.TARGET:R}.d; fi
 
 # Yacc
 .y:
@@ -35,4 +36,5 @@ CXXFLAGS+= -idirafter ${DESTDIR}/usr/include/g++
 	${YACC.y} -b ${.TARGET:R} ${.IMPSRC}
 	${COMPILE.c} -o ${.TARGET} ${.TARGET:R}.tab.c
 	rm -f ${.TARGET:R}.tab.c
+	if test -f ${.TARGET:R}.d; then sed -i -e 's,${.TARGET:R}.tab.c,${.IMPSRC},' ${.TARGET:R}.d; fi
 .endif
diff --git a/share/mk/sys.mk b/share/mk/sys.mk
index fc59aec15f6..c72a44d8eb1 100644
--- a/share/mk/sys.mk
+++ b/share/mk/sys.mk
@@ -1,4 +1,4 @@
-#	$OpenBSD: sys.mk,v 1.77 2017/03/04 16:52:47 deraadt Exp $
+#	$OpenBSD: sys.mk,v 1.78 2017/07/01 14:41:54 espie Exp $
 #	$NetBSD: sys.mk,v 1.27 1996/04/10 05:47:19 mycroft Exp $
 #	@(#)sys.mk	5.11 (Berkeley) 3/13/91
 
@@ -195,6 +195,7 @@ CTAGS?=		/usr/bin/ctags
 	${LEX.l} ${.IMPSRC}
 	${COMPILE.c} -o ${.TARGET} lex.yy.c 
 	rm -f lex.yy.c
+	if test -f ${.TARGET:R}.d; then sed -i -e 's,lex.yy.c,${.IMPSRC},' ${.TARGET:R}.d; fi
 
 # Yacc
 .y:
@@ -208,6 +209,7 @@ CTAGS?=		/usr/bin/ctags
 	${YACC.y} ${.IMPSRC}
 	${COMPILE.c} -o ${.TARGET} y.tab.c
 	rm -f y.tab.c
+	if test -f ${.TARGET:R}.d; then sed -i -e 's,y.tab.c,${.IMPSRC},' ${.TARGET:R}.d; fi
 
 # Shell
 .sh: