pkgbase: Add incremental packages

This adds a new target update-packages which will create the new packages
compared to the last run.

This is how to use it:
At this point we cut a release
$ make buildworld ...
$ make buildkernel
$ make packages

    There is now a PKG_VERSION directory with latest link pointing to it
    Distribute the packages to server

$ something something that update the source tree
$ make buildworld ...
$ make buildkernel
$ make update-packages
You know have a PKG_VERSION directory in the REPODIR and latest link pointing to it.
In PKG_VERSION dir only the packages which differs from the latest run are
named PKG_VERSION, otherwise the old packages are there.

The process is :
Build the new packages in the PKG_VERSION directory
Compare the internal data with the PKG_VERSION_FROM version. The comparison is done
by checking the internal hash of the packages.
By default PKG_VERSION_FROM is set to what the latest link points to.
If the old and new version matches, we rm the new package and cp the old one.

Differential Revision:	https://reviews.freebsd.org/D25984

Makefile

@@ -162,8 +162,8 @@ TGTS=	all all-man buildenv buildenvvars buildkernel buildworld \
 	xdev-links native-xtools native-xtools-install stageworld stagekernel \
 	stage-packages stage-packages-kernel stage-packages-world \
 	create-packages-world create-packages-kernel create-packages \
-	packages installconfig real-packages sign-packages package-pkg \
+	update-packages packages installconfig real-packages real-update-packages \
-	print-dir test-system-compiler test-system-linker
+	sign-packages package-pkg print-dir test-system-compiler test-system-linker
 
 # These targets require a TARGET and TARGET_ARCH be defined.
 XTGTS=	native-xtools native-xtools-install xdev xdev-build xdev-install \

Makefile.inc1

@@ -568,12 +568,12 @@ EXTRA_REVISION= _${_BRANCH:C/-PRERELEASE/.p/}
 .elif ${_BRANCH:M*-p*}
 EXTRA_REVISION=	_${_BRANCH:C/.*-p([0-9]+$)/\1/}
 .endif
-PKG_VERSION=	${_REVISION}${EXTRA_REVISION}
+PKG_VERSION:=	${_REVISION}${EXTRA_REVISION}
 .endif
 .endif	# !defined(PKG_VERSION)
 
 .if !defined(PKG_TIMESTAMP)
-TIMEEPOCHNOW=	%s
+TIMEEPOCHNOW=		%s
 SOURCE_DATE_EPOCH=	${TIMEEPOCHNOW:gmtime}
 .else
 SOURCE_DATE_EPOCH=	${PKG_TIMESTAMP}
@@ -1855,9 +1855,22 @@ _pkgbootstrap: .PHONY
 	@env ASSUME_ALWAYS_YES=YES pkg bootstrap
 .endif
 
+.if make(create-world-packages-jobs) || make(create-kernel-packages*) || make(real-update-packages)
+PKG_ABI!=${PKG_CMD} -o ABI_FILE=${WSTAGEDIR}/usr/bin/uname config ABI
+.endif
+
+.if !defined(PKG_VERSION_FROM)
+.if defined(PKG_ABI)
+PKG_VERSION_FROM!=/usr/bin/readlink ${REPODIR}/${PKG_ABI}/latest
+.endif
+.endif
+
 packages: .PHONY
 	${_+_}${MAKE} -C ${.CURDIR} PKG_VERSION=${PKG_VERSION} real-packages
 
+update-packages: .PHONY
+	${_+_}${MAKE} -C ${.CURDIR} PKG_VERSION=${PKG_VERSION} real-update-packages
+
 package-pkg: .PHONY
 	rm -rf /tmp/ports.${TARGET} || :
 	env ${WMAKEENV:Q} SRCDIR=${.CURDIR} PORTSDIR=${PORTSDIR} REVISION=${_REVISION} \
@@ -1867,6 +1880,28 @@ package-pkg: .PHONY
 
 real-packages:	stage-packages create-packages sign-packages .PHONY
 
+real-update-packages: stage-packages .PHONY
+	${_+_}${MAKE} -C ${.CURDIR} PKG_VERSION=${PKG_VERSION} create-packages
+	@echo "==> Checking for new packages (comparing ${PKG_VERSION} to ${PKG_VERSION_FROM})"
+	@for pkg in ${REPODIR}/${PKG_ABI}/${PKG_VERSION_FROM}/${PKG_NAME_PREFIX}-*; do \
+	  pkgname=$$(pkg query -F $${pkg} '%n' | sed 's/${PKG_NAME_PREFIX}-\(.*\)/\1/') ; \
+	  newpkgname=${PKG_NAME_PREFIX}-$${pkgname}-${PKG_VERSION}.${PKG_FORMAT} ; \
+	  oldsum=$$(pkg query -F $${pkg} '%X') ; \
+	  if [ ! -f ${REPODIR}/${PKG_ABI}/${PKG_VERSION}/$${newpkgname} ]; then \
+	    continue; \
+	  fi ; \
+	  newsum=$$(pkg query -F ${REPODIR}/${PKG_ABI}/${PKG_VERSION}/$${newpkgname} '%X') ; \
+	  if [ "$${oldsum}" == "$${newsum}" ]; then \
+	   echo "==> Keeping old ${PKG_NAME_PREFIX}-$${pkgname}-${PKG_VERSION_FROM}.${PKG_FORMAT}" ; \
+	   rm ${REPODIR}/${PKG_ABI}/${PKG_VERSION}/$${newpkgname} ; \
+	   cp $${pkg} ${REPODIR}/${PKG_ABI}/${PKG_VERSION} ; \
+	  else \
+	    echo "==> New package $${newpkgname}" ; \
+	  fi ; \
+	done
+	${_+_}@cd ${.CURDIR}; \
+		${MAKE} -f Makefile.inc1 PKG_VERSION=${PKG_VERSION} sign-packages
+
 stage-packages-world: .PHONY
 	@mkdir -p ${WSTAGEDIR}
 	${_+_}@cd ${.CURDIR}; \
@@ -1917,10 +1952,6 @@ create-world-packages:	_pkgbootstrap .PHONY
 .include "${WSTAGEDIR}/packages.mk"
 .endif
 
-.if make(create-world-packages-jobs) || make(create-kernel-packages*)
-PKG_ABI!=${PKG_CMD} -o ABI_FILE=${WSTAGEDIR}/usr/bin/uname config ABI
-.endif
-
 create-world-packages-jobs: .PHONY
 .for pkgname in ${_PKGS}
 create-world-packages-jobs: create-world-package-${pkgname}