# ==========================================================================
# Building
# ==========================================================================

src := $(obj)

PHONY := __build
__build:

# Init all relevant variables used in kbuild files so
# 1) they have correct type
# 2) they do not inherit any value from the environment
obj-y :=
obj-m :=
lib-y :=
lib-m :=
pbl-y :=
always :=
always-y :=
always-m :=
targets :=
subdir-y :=
subdir-m :=
EXTRA_AFLAGS   :=
EXTRA_CFLAGS   :=
EXTRA_CPPFLAGS :=
EXTRA_LDFLAGS  :=
asflags-y  :=
ccflags-y  :=
cppflags-y :=
ldflags-y  :=

subdir-asflags-y :=
subdir-ccflags-y :=

# Read auto.conf if it exists, otherwise ignore
-include include/config/auto.conf

include scripts/Kbuild.include

# The filename Kbuild has precedence over Makefile
kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile)

include scripts/Makefile.lib

# Do not include host rules unless needed
ifneq ($(hostprogs),)
include scripts/Makefile.host
endif

# Do not include userprogs rules unless needed.
userprogs := $(sort $(userprogs))
ifneq ($(userprogs),)
include scripts/Makefile.userprogs
endif

ifndef obj
$(warning kbuild: Makefile.build is included improperly)
endif

# ===========================================================================

ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
lib-target := $(obj)/lib.a
endif

ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(lib-target) $(pbl-y)),)
builtin-target := $(obj)/built-in.a
endif

ifeq ($(CONFIG_PBL_IMAGE), y)
ifneq ($(strip $(pbl-y) $(builtin-target)),)
pbl-target := $(obj)/built-in.pbl.a
endif
endif

# We keep a list of all modules in $(MODVERDIR)

__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(pbl-target) $(extra-y)) \
	 $(if $(KBUILD_MODULES),$(obj-m)) \
	 $(subdir-ym) $(always-y)
	@:

# Linus' kernel sanity checking tool
ifeq ($(KBUILD_CHECKSRC),1)
  quiet_cmd_checksrc       = CHECK   $<
        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
else ifeq ($(KBUILD_CHECKSRC),2)
  quiet_cmd_force_checksrc = CHECK   $<
        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
endif

# Compile C sources (.c)
# ---------------------------------------------------------------------------

# Default for not multi-part modules
modname = $(basetarget)

$(multi-objs-m)         : modname = $(modname-multi)
$(multi-objs-m:.o=.i)   : modname = $(modname-multi)
$(multi-objs-m:.o=.s)   : modname = $(modname-multi)
$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
$(multi-objs-y)         : modname = $(modname-multi)
$(multi-objs-y:.o=.i)   : modname = $(modname-multi)
$(multi-objs-y:.o=.s)   : modname = $(modname-multi)
$(multi-objs-y:.o=.lst) : modname = $(modname-multi)

quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
cmd_cc_s_c       = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<

%.s: %.c FORCE
	$(call if_changed_dep,cc_s_c)

quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
cmd_cc_i_c       = $(CPP) $(c_flags)   -o $@ $<

%.i: %.c FORCE
	$(call if_changed_dep,cc_i_c)

# C (.c) files
# The C file is compiled and updated dependency information is generated.
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)

quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

define rule_cc_o_c
	$(call cmd,checksrc)
	$(call cmd_and_fixdep,cc_o_c)
endef

# Built-in and composite module parts

%.pbl.o: %.c FORCE
	$(call cmd,force_checksrc)
	$(call if_changed_rule,cc_o_c)

%.o: %.c FORCE
	$(call cmd,force_checksrc)
	$(call if_changed_rule,cc_o_c)

# Single-part modules are special since we need to mark them in $(MODVERDIR)

$(single-used-m): %.o: %.c FORCE
	$(call cmd,force_checksrc)
	$(call if_changed_rule,cc_o_c)
	@{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)

quiet_cmd_cc_lst_c = MKLST   $@
      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
				     System.map $(OBJDUMP) > $@

%.lst: %.c FORCE
	$(call if_changed_dep,cc_lst_c)

# Compile assembler sources (.S)
# ---------------------------------------------------------------------------

quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
cmd_as_s_S       = $(CPP) $(a_flags)   -o $@ $<

%.s: %.S FORCE
	$(call if_changed_dep,as_s_S)

quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<

%.pbl.o: %.S FORCE
	$(call if_changed_dep,as_o_S)

%.o: %.S FORCE
	$(call if_changed_dep,as_o_S)

targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
targets += $(pbl-y)
targets += $(extra-y) $(always-y) $(MAKECMDGOALS)

# Linker scripts preprocessor (.lds.S -> .lds)
# ---------------------------------------------------------------------------
quiet_cmd_cpp_lds_S = LDS     $@
      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -D__ASSEMBLY__ -o $@ $<

%.lds: %.lds.S FORCE
	$(call if_changed_dep,cpp_lds_S)

# Build the compiled-in targets
# ---------------------------------------------------------------------------

# To build objects in subdirs, we need to descend into the directories
$(sort $(subdir-obj-y)): $(subdir-ym) ;

#
# Rule to compile a set of .o files into one .a file (without symbol table)
#
quiet_cmd_ar_builtin = AR $(quiet_modtag)  $@
      cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)

$(builtin-target): $(real-obj-y) FORCE
	$(call if_changed,ar_builtin)

targets += $(builtin-target)

$(pbl-target): $(pbl-y) FORCE
	$(call if_changed,ar_builtin)

targets += $(pbl-target)

#
# Rule to compile a set of .o files into one .a file
#
ifdef lib-target
quiet_cmd_link_l_target = AR      $@
cmd_link_l_target = rm -f $@; $(AR) rcs $@ $(lib-y)

$(lib-target): $(lib-y) FORCE
	$(call if_changed,link_l_target)

targets += $(lib-target)
endif

#
# Rule to link composite objects
#
#  Composite objects are specified in kbuild makefile as follows:
#    <composite-object>-objs := <list of .o files>
#  or
#    <composite-object>-y    := <list of .o files>
link_multi_deps =                     \
$(filter $(addprefix $(obj)/,         \
$($(subst $(obj)/,,$(@:.o=-objs)))    \
$($(subst $(obj)/,,$(@:.o=-y)))), $^)

quiet_cmd_link_multi-y = LD      $@
cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps)

quiet_cmd_link_multi-m = LD [M]  $@
cmd_link_multi-m = $(LD) $(ld_flags) $(LDFLAGS_MODULE) -o $@ $(link_multi_deps)

$(multi-used-y): FORCE
	$(call if_changed,link_multi-y)
$(call multi_depend, $(multi-used-y), .o, -objs -y)

$(multi-used-m): FORCE
	$(call if_changed,link_multi-m)
	@{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
$(call multi_depend, $(multi-used-m), .o, -objs -y)

targets += $(multi-used-y) $(multi-used-m)
targets := $(filter-out $(PHONY), $(targets))

# Add intermediate targets:
# When building objects with specific suffix patterns, add intermediate
# targets that the final targets are derived from.
intermediate_targets = $(foreach sfx, $(2), \
				$(patsubst %$(strip $(1)),%$(sfx), \
					$(filter %$(strip $(1)), $(targets))))
# %.asn1.o <- %.asn1.[ch] <- %.asn1
# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
# %.dtb.pbl.o <- %.dtb.S <- %.dtb <- %.dts (Barebox only)
# %.lex.o <- %.lex.c <- %.l
# %.tab.o <- %.tab.[ch] <- %.y
targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
	   $(call intermediate_targets, .dtb.pbl.o, .dtb.S .dtb) \
	   $(call intermediate_targets, .lex.o, .lex.c) \
	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)

# Descending
# ---------------------------------------------------------------------------

PHONY += $(subdir-ym)
$(subdir-ym):
	$(Q)$(MAKE) $(build)=$@

# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------

PHONY += FORCE

FORCE:

# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.

existing-targets := $(wildcard $(sort $(targets)))

-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)

ifdef building_out_of_srctree
# Create directories for object files if they do not exist
obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
# If targets exist, their directories apparently exist. Skip mkdir.
existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
ifneq ($(obj-dirs),)
$(shell mkdir -p $(obj-dirs))
endif
endif

.PHONY: $(PHONY)