# SPDX-License-Identifier: GPL-2.0

  ###
  # Main build makefile.
  #
  #  Lots of this code have been borrowed or heavily inspired from parts
  #  of kbuild code, which is not credited, but mostly developed by:
  #
  #  Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015
  #  Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015
  #
  
  PHONY := __build
  __build:
  
  ifeq ($(V),1)
    quiet =

    Q =

  else
    quiet=quiet_

    Q=@

  endif

  ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)

    quiet=silent_
  endif

  build-dir := $(srctree)/tools/build

  # Define $(fixdep) for dep-cmd function
  ifeq ($(OUTPUT),)
    fixdep := $(build-dir)/fixdep
  else
    fixdep := $(OUTPUT)/fixdep
  endif

  # Generic definitions
  include $(build-dir)/Build.include

  # do not force detected configuration

  -include $(OUTPUT).config-detected

  # Init all relevant variables used in build files so
  # 1) they have correct type
  # 2) they do not inherit any value from the environment
  subdir-y     :=
  obj-y        :=
  subdir-y     :=
  subdir-obj-y :=
  
  # Build definitions
  build-file := $(dir)/Build

  -include $(build-file)

  quiet_cmd_flex  = FLEX     $@
  quiet_cmd_bison = BISON    $@

  # Create directory unless it exists
  quiet_cmd_mkdir = MKDIR    $(dir $@)
        cmd_mkdir = mkdir -p $(dir $@)
       rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir))

  # Compile command
  quiet_cmd_cc_o_c = CC       $@
        cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

  quiet_cmd_host_cc_o_c = HOSTCC   $@
        cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $<

  quiet_cmd_cxx_o_c = CXX      $@
        cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $<

  quiet_cmd_cpp_i_c = CPP      $@
        cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $<

  
  quiet_cmd_cc_s_c = AS       $@
        cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $<

  quiet_cmd_gen = GEN      $@

  # Link agregate command
  # If there's nothing to link, create empty $@ object.
  quiet_cmd_ld_multi = LD       $@
        cmd_ld_multi = $(if $(strip $(obj-y)),\

                       $(LD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
  
  quiet_cmd_host_ld_multi = HOSTLD   $@
        cmd_host_ld_multi = $(if $(strip $(obj-y)),\
                            $(HOSTLD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
  
  ifneq ($(filter $(obj),$(hostprogs)),)
    host = host_
  endif

  
  # Build rules
  $(OUTPUT)%.o: %.c FORCE

  	$(call rule_mkdir)

  	$(call if_changed_dep,$(host)cc_o_c)

  $(OUTPUT)%.o: %.cpp FORCE
  	$(call rule_mkdir)
  	$(call if_changed_dep,cxx_o_c)

  $(OUTPUT)%.o: %.S FORCE

  	$(call rule_mkdir)

  	$(call if_changed_dep,$(host)cc_o_c)

  $(OUTPUT)%.i: %.c FORCE
  	$(call rule_mkdir)

  	$(call if_changed_dep,cpp_i_c)

  $(OUTPUT)%.s: %.S FORCE

  	$(call rule_mkdir)

  	$(call if_changed_dep,cpp_i_c)

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

  # Gather build data:
  #   obj-y        - list of build objects
  #   subdir-y     - list of directories to nest
  #   subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'
  obj-y        := $($(obj)-y)
  subdir-y     := $(patsubst %/,%,$(filter %/, $(obj-y)))
  obj-y        := $(patsubst %/, %/$(obj)-in.o, $(obj-y))
  subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y))
  
  # '$(OUTPUT)/dir' prefix to all objects

  objprefix    := $(subst ./,,$(OUTPUT)$(dir)/)
  obj-y        := $(addprefix $(objprefix),$(obj-y))
  subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y))

  
  # Final '$(obj)-in.o' object

  in-target := $(objprefix)$(obj)-in.o

  
  PHONY += $(subdir-y)
  
  $(subdir-y):

  	$(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj)

  
  $(sort $(subdir-obj-y)): $(subdir-y) ;
  
  $(in-target): $(obj-y) FORCE
  	$(call rule_mkdir)

  	$(call if_changed,$(host)ld_multi)

  
  __build: $(in-target)
  	@:
  
  PHONY += FORCE
  FORCE:
  
  # Include all cmd files to get all the dependency rules
  # for all objects included

  targets   := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS)))

  cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
  
  ifneq ($(cmd_files),)
    include $(cmd_files)
  endif
  
  .PHONY: $(PHONY)