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 # $(generic)/Kbuild lists mandatory-y. Exclude um since it is a special case.
  16 ifneq ($(SRCARCH),um)
  17 include $(srctree)/$(generic)/Kbuild
  18 endif
  19
  20 include $(srctree)/scripts/Kbuild.include
  21
  22 redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
  23 redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))
  24 redundant := $(sort $(redundant))
  25 $(if $(redundant),\
  26         $(warning redundant generic-y found in $(src)/Kbuild: $(redundant)))
  27
  28 # If arch does not implement mandatory headers, fallback to asm-generic ones.
  29 mandatory-y := $(filter-out $(generated-y), $(mandatory-y))
  30 generic-y   += $(foreach f, $(mandatory-y), $(if $(wildcard $(srctree)/$(src)/$(f)),,$(f)))
  31
  32 generic-y   := $(addprefix $(obj)/, $(generic-y))
  33 generated-y := $(addprefix $(obj)/, $(generated-y))
  34
  35 # Remove stale wrappers when the corresponding files are removed from generic-y
  36 old-headers := $(wildcard $(obj)/*.h)
  37 unwanted    := $(filter-out $(generic-y) $(generated-y),$(old-headers))
  38
  39 quiet_cmd_wrap = WRAP    $@
  40       cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
  41
  42 quiet_cmd_remove = REMOVE  $(unwanted)
  43       cmd_remove = rm -f $(unwanted)
  44
  45 all: $(generic-y)
  46         $(if $(unwanted),$(call cmd,remove))
  47         @:
  48
  49 $(obj)/%.h:
  50         $(call cmd,wrap)
  51
  52 # Create output directory. Skip it if at least one old header exists
  53 # since we know the output directory already exists.
  54 ifeq ($(old-headers),)
  55 $(shell mkdir -p $(obj))
  56 endif
  57
  58 .PHONY: $(PHONY)