scripts/Makefile.asm-generic

   1 # SPDX-License-Identifier: GPL-2.0
   2 # include/asm-generic contains a lot of files that are used
   3 # verbatim by several architectures.
   4 #
   5 # This Makefile reads the file arch/$(SRCARCH)/include/(uapi/)/asm/Kbuild
   6 # and for each file listed in this file with generic-y creates
   7 # a small wrapper file in arch/$(SRCARCH)/include/generated/(uapi/)/asm.
   8
   9 PHONY := all
  10 all:
  11
  12 src := $(subst /generated,,$(obj))
  13 -include $(src)/Kbuild
  14
  15 include scripts/Kbuild.include
  16
  17 # If arch does not implement mandatory headers, fallback to asm-generic ones.
  18 mandatory-y := $(filter-out $(generated-y), $(mandatory-y))
  19 generic-y   += $(foreach f, $(mandatory-y), $(if $(wildcard $(srctree)/$(src)/$(f)),,$(f)))
  20
  21 generic-y   := $(addprefix $(obj)/, $(generic-y))
  22 generated-y := $(addprefix $(obj)/, $(generated-y))
  23
  24 # Remove stale wrappers when the corresponding files are removed from generic-y
  25 old-headers := $(wildcard $(obj)/*.h)
  26 unwanted    := $(filter-out $(generic-y) $(generated-y),$(old-headers))
  27
  28 quiet_cmd_wrap = WRAP    $@
  29       cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
  30
  31 quiet_cmd_remove = REMOVE  $(unwanted)
  32       cmd_remove = rm -f $(unwanted)
  33
  34 all: $(generic-y)
  35         $(if $(unwanted),$(call cmd,remove))
  36         @:
  37
  38 $(obj)/%.h:
  39         $(call cmd,wrap)
  40
  41 # Create output directory. Skip it if at least one old header exists
  42 # since we know the output directory already exists.
  43 ifeq ($(old-headers),)
  44 $(shell mkdir -p $(obj))
  45 endif
  46
  47 .PHONY: $(PHONY)