github.com/blixtra/rkt@v0.8.1-0.20160204105720-ab0d1add1a43/stage1/stage1.mk

# Prepare some variables, this might look strange so here goes: let's
# assume we are going to build two flavors - coreos and kvm. The
# following code is going to initialize some variables to some initial
# values. The name of the variable depends on the flavor:
# STAGE1_COPY_SO_DEPS_coreos, STAGE1_USR_STAMPS_coreos,
# STAGE1_APP_STAMPS_coreos and so on for the coreos flavor. For the
# kvm flavor the names would be STAGE1_COPY_SO_DEPS_kvm,
# STAGE1_USR_STAMPS_kvm, STAGE1_APP_STAMPS_kvm and so on.
#
# STAGE1_COPY_SO_DEPS_$(flavor) tells whether a given flavor wants to
# get missing libraries from build host before building an ACI.
#
# STAGE1_USR_STAMPS_$(flavor) is a list of stamps that say whether the
# initial /usr contents of ACI are prepared.
#
# STAGE1_SECONDARY_STAMPS_$(flavor) is a list of stamps that say
# whether the additional stuff was copied to the ACI rootfs (init,
# enter, units, net config and so on). Usually the dependencies of
# these stamps depend in turn on the stamps from
# STAGE1_USR_STAMPS_$(flavor) - which means that the additional stuff
# is copied to the ACI rootfs only after the initial /usr contents are
# already there.
#
# STAGE1_ACIDIR_$(flavor) tells where is the ACI directory for a given
# flavor. Note that this is the toplevel directory (where manifest is
# stored). Most of the time you will want the
# STAGE1_ACIROOTFSDIR_$(flavor) variable.
#
# STAGE1_ACIROOTFSDIR_$(flavor) tells where is the ACI rootfs
# directory for a given flavor.
#
# STAGE1_ACI_IMAGE_$(flavor) tells where in the build directory the
# final ACI is going to be built.
#
# STAGE1_INSTALL_FILES_$(flavor) - a list of files that can be
# installed only after all the stamps in STAGE1_USR_STAMPS_$(flavor)
# are created.
#
# STAGE1_INSTALL_SYMLINKS_$(flavor) - a list of symlinks that can be
# installed only after all the stamps in STAGE1_USR_STAMPS_$(flavor)
# are created.
#
# STAGE1_INSTALL_DIRS_$(flavor) - a list of directories that can be
# installed only after all the stamps in STAGE1_USR_STAMPS_$(flavor)
# are created.
#
# STAGE1_CREATE_DIRS_$(flavor) - a list of files that can be installed
# only after all the stamps in STAGE1_USR_STAMPS_$(flavor) are
# created. (This is less restrictive than INSTALL_DIRS counterpart,
# because an entry in CREATE_DIRS does not require the parent
# directory to exist). Please consider this as deprecated in favor of
# INSTALL_DIRS + dir-chain function.
#
# STAGE1_ENTER_CMD_$(flavor) - an enter command in stage1 to be used
# for the "rkt enter" command.

STAGE1_FLAVORS := $(call commas-to-spaces,$(RKT_STAGE1_ALL_FLAVORS))
STAGE1_BUILT_FLAVORS := $(call commas-to-spaces,$(RKT_STAGE1_FLAVORS))
# filter out the fly flavor - it is special
STAGE1_FLAVORS := $(filter-out fly,$(STAGE1_FLAVORS))
STAGE1_BUILT_FLAVORS := $(filter-out fly,$(STAGE1_BUILT_FLAVORS))

$(foreach f,$(STAGE1_FLAVORS), \
	$(eval STAGE1_COPY_SO_DEPS_$f :=) \
	$(eval STAGE1_USR_STAMPS_$f :=) \
	$(eval STAGE1_SECONDARY_STAMPS_$f :=) \
	$(eval STAGE1_ACIDIR_$f := $(BUILDDIR)/aci-for-$f-flavor) \
	$(eval STAGE1_ACIROOTFSDIR_$f := $(STAGE1_ACIDIR_$f)/rootfs) \
	$(eval STAGE1_ACI_IMAGE_$f := $(BINDIR)/stage1-$f.aci) \
	$(eval STAGE1_INSTALL_FILES_$f :=) \
	$(eval STAGE1_INSTALL_SYMLINKS_$f :=) \
	$(eval STAGE1_INSTALL_DIRS_$f :=) \
	$(eval STAGE1_CREATE_DIRS_$f :=) \
	$(eval STAGE1_ENTER_CMD_$f :=))

# Main stamp that tells whether all the ACIs have been built.
$(call setup-stamp-file,_STAGE1_BUILT_ACI_STAMP_,built_aci)

# List of all the ACIs that the build system will build
_STAGE1_ALL_ACI_ := $(foreach f,$(STAGE1_FLAVORS),$(STAGE1_ACI_IMAGE_$f))
_STAGE1_BUILT_ACI_ := $(foreach f,$(STAGE1_BUILT_FLAVORS),$(STAGE1_ACI_IMAGE_$f))

# The rootfs.mk file takes care of preparing the initial /usr contents
# of the ACI rootfs of a specific flavor. Basically fills
# STAGE1_USR_STAMPS_$(flavor) variables. Might add something to the
# STAGE1_SECONDARY_STAMPS_$(flavor) or the STAGE1_INSTALL_* variables
# too.
$(foreach flavor,$(STAGE1_FLAVORS), \
	$(eval S1_RF_FLAVOR := $(flavor)) \
	$(call inc-one,rootfs.mk))

# secondary-stuff.mk takes care of putting additional stuff into
# the ACI rootfs for each flavor. Basically fills the
# STAGE1_SECONDARY_STAMPS_$(flavor) and the STAGE1_INSTALL_*
# variables.
$(call inc-one,secondary-stuff.mk)

TOPLEVEL_STAMPS += $(_STAGE1_BUILT_ACI_STAMP_)
CLEAN_FILES += $(_STAGE1_ALL_ACI_)

$(call generate-stamp-rule,$(_STAGE1_BUILT_ACI_STAMP_),$(_STAGE1_BUILT_ACI_))

# A rule template for building an ACI. To build the ACI we need to
# have the /usr contents prepared and the additional stuff in place as
# well. If a flavor wants to have missing libraries copied, it is done
# here too.
#
# 1 - flavor
define _STAGE1_ACI_RULE_

STAGE1_ALL_STAMPS_$1 := $$(STAGE1_USR_STAMPS_$1) $$(STAGE1_SECONDARY_STAMPS_$1)

$$(STAGE1_SECONDARY_STAMPS_$1): $$(STAGE1_USR_STAMPS_$1)

ifeq ($$(STAGE1_COPY_SO_DEPS_$1),)

# The flavor needs no libraries from the host

$$(STAGE1_ACI_IMAGE_$1): $$(STAGE1_ALL_STAMPS_$1)

else

# The flavor requires libraries from the host, so depend on the stamp
# generated by find-so-deps.mk, which in turn will depend on the usr
# and the secondary stamps.

STAGE1_FSD_FLAVOR := $1

$$(call inc-one,find-so-deps.mk)

$$(STAGE1_ACI_IMAGE_$1): $$(STAGE1_FSD_STAMP)

endif

# The actual rule that builds the ACI. Additional dependencies are
# above.
$$(call forward-vars,$$(STAGE1_ACI_IMAGE_$1), \
	ACTOOL STAGE1_ACIDIR_$1)
$$(STAGE1_ACI_IMAGE_$1): $$(ACTOOL_STAMP) | $$(BINDIR)
	$(VQ) \
	$(call vb,vt,ACTOOL,$$(call vsp,$$@)) \
	"$$(ACTOOL)" build --overwrite --owner-root "$$(STAGE1_ACIDIR_$1)" "$$@"

endef

$(foreach f,$(STAGE1_FLAVORS), \
	$(eval $(call _STAGE1_ACI_RULE_,$f)))


# The following piece of wizardry takes the variables
# STAGE1_INSTALL_FILES_$(flavor), STAGE1_INSTALL_SYMLINKS_$(flavor),
# STAGE1_INSTALL_DIRS_$(flavor) and STAGE1_CREATE_DIRS_$(flavor),
# makes their contents to depend on STAGE1_USR_STAMPS_$(flavor) and
# appends their contents to, respectively, INSTALL_FILES,
# INSTALL_SYMLINKS, INSTALL_DIRS and CREATE_DIRS. This is to make sure
# that all the additional stuff will be installed only after the
# initial /usr contents in the ACI rootfs are prepared.


# Three fields:
# 1 - base variable name (e.g. INSTALL_FILES)
# 2 - whether it has to be split to get the created entry (elements in
# INSTALL_FILES have to be split, because the created entry is between
# source entry and mode, like src_file:created_entry:mode, elements in
# the CREATE_DIRS variable do not need to be split)
# 3 - if it has to be split, then which item is the created entry
# (index starting from 1)
_STAGE1_FILE_VARS_ := \
	INSTALL_FILES:y:2 \
	INSTALL_SYMLINKS:y:2 \
	INSTALL_DIRS:y:1 \
	CREATE_DIRS:n

# Generates dependency of a created entry on
# STAGE1_USR_STAMPS_$(flavor)
# 1 - item(s)
# 2 - flavor
define _STAGE1_GEN_DEP_
$(call add-dependency,$1,$(STAGE1_USR_STAMPS_$2))
endef

# The actual fixup - appending and "dependencing".
$(foreach v,$(_STAGE1_FILE_VARS_), \
	$(eval _S1_FX_VAR_LIST_ := $(subst :, ,$v)) \
	$(eval _S1_FX_NAME_ := $(word 1,$(_S1_FX_VAR_LIST_))) \
	$(eval _S1_FX_SPLIT_ := $(word 2,$(_S1_FX_VAR_LIST_))) \
	$(eval _S1_FX_IDX_ := $(word 3,$(_S1_FX_VAR_LIST_))) \
	$(foreach f,$(STAGE1_FLAVORS), \
		$(eval _S1_FX_VAR_NAME_ := STAGE1_$(_S1_FX_NAME_)_$f) \
		$(eval $(_S1_FX_NAME_) += $($(_S1_FX_VAR_NAME_))) \
		$(eval $(foreach i,$($(_S1_FX_VAR_NAME_)), \
			$(if $(filter y,$(_S1_FX_SPLIT_)), \
				$(eval _S1_FX_LIST_ := $(subst :, ,$i)) \
				$(eval _S1_FX_ITEM_ := $(word $(_S1_FX_IDX_),$(_S1_FX_LIST_))) \
				$(call _STAGE1_GEN_DEP_,$(_S1_FX_ITEM_),$f), \
				$(call _STAGE1_GEN_DEP_,$i,$f))))) \
	$(call undefine-namespaces,_S1_FX))

$(call undefine-namespaces,STAGE1 _STAGE1)