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