scripts/Kbuild.include

   1 ####
   2 # kbuild: Generic definitions
   3
   4 # Convinient variables
   5 comma   := ,
   6 squote  := '
   7 empty   :=
   8 space   := $(empty) $(empty)
   9
  10 ###
  11 # The temporary file to save gcc -MD generated dependencies must not
  12 # contain a comma
  13 depfile = $(subst $(comma),_,$(@D)/.$(@F).d)
  14
  15 ###
  16 # filename of target with directory and extension stripped
  17 basetarget = $(basename $(notdir $@))
  18
  19 ###
  20 # Escape single quote for use in echo statements
  21 escsq = $(subst $(squote),'\$(squote)',$1)
  22
  23 ###
  24 # filechk is used to check if the content of a generated file is updated.
  25 # Sample usage:
  26 # define filechk_sample
  27 #       echo $KERNELRELEASE
  28 # endef
  29 # version.h : Makefile
  30 #       $(call filechk,sample)
  31 # The rule defined shall write to stdout the content of the new file.
  32 # The existing file will be compared with the new one.
  33 # - If no file exist it is created
  34 # - If the content differ the new file is used
  35 # - If they are equal no change, and no timestamp update
  36 # - stdin is piped in from the first prerequisite ($<) so one has
  37 #   to specify a valid file as first prerequisite (often the kbuild file)
  38 define filechk
  39         $(Q)set -e;                             \
  40         echo '  CHK     $@';                    \
  41         mkdir -p $(dir $@);                     \
  42         $(filechk_$(1)) < $< > $@.tmp;          \
  43         if [ -r $@ ] && cmp -s $@ $@.tmp; then  \
  44                 rm -f $@.tmp;                   \
  45         else                                    \
  46                 echo '  UPD     $@';            \
  47                 mv -f $@.tmp $@;                \
  48         fi
  49 endef
  50
  51 ######
  52 # gcc support functions
  53 # See documentation in Documentation/kbuild/makefiles.txt
  54
  55 # as-option
  56 # Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,)
  57
  58 as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
  59              -xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \
  60              else echo "$(2)"; fi ;)
  61
  62 # cc-option
  63 # Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
  64
  65 cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
  66              > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
  67
  68 # cc-option-yn
  69 # Usage: flag := $(call cc-option-yn, -march=winchip-c6)
  70 cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
  71                 > /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
  72
  73 # cc-option-align
  74 # Prefix align with either -falign or -malign
  75 cc-option-align = $(subst -functions=0,,\
  76         $(call cc-option,-falign-functions=0,-malign-functions=0))
  77
  78 # cc-version
  79 # Usage gcc-ver := $(call cc-version, $(CC))
  80 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
  81
  82 # cc-ifversion
  83 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
  84 cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
  85                        echo $(3); fi;)
  86
  87 # ld-option
  88 # Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
  89 ld-option = $(shell if $(CC) $(1) \
  90                              -nostdlib -o ldtest$$$$.out -xc /dev/null \
  91              > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi; \
  92              rm -f ldtest$$$$.out)
  93
  94 ###
  95 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
  96 # Usage:
  97 # $(Q)$(MAKE) $(build)=dir
  98 build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
  99
 100 # Prefix -I with $(srctree) if it is not an absolute path
 101 addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
 102 # Find all -I options and call addtree
 103 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
 104
 105 # If quiet is set, only print short version of command
 106 cmd = @$(echo-cmd) $(cmd_$(1))
 107
 108 # Add $(obj)/ for paths that is not absolute
 109 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 110
 111 ###
 112 # if_changed      - execute command if any prerequisite is newer than
 113 #                   target, or command line has changed
 114 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 115 #                   including used config symbols
 116 # if_changed_rule - as if_changed but execute rule instead
 117 # See Documentation/kbuild/makefiles.txt for more info
 118
 119 ifneq ($(KBUILD_NOCMDDEP),1)
 120 # Check if both arguments has same arguments. Result in empty string if equal
 121 # User may override this check using make KBUILD_NOCMDDEP=1
 122 arg-check = $(strip $(filter-out $(1), $(2)) $(filter-out $(2), $(1)) )
 123 endif
 124
 125 # echo command. Short version is $(quiet) equals quiet, otherwise full command
 126 echo-cmd = $(if $($(quiet)cmd_$(1)), \
 127         echo '  $(call escsq,$($(quiet)cmd_$(1)))';)
 128
 129 make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
 130
 131 # function to only execute the passed command if necessary
 132 # >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file
 133 # note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars
 134 #
 135 if_changed = $(if $(strip $(filter-out $(PHONY),$?)          \
 136                 $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \
 137         @set -e; \
 138         $(echo-cmd) $(cmd_$(1)); \
 139         echo 'cmd_$@ := $(make-cmd)' > $(@D)/.$(@F).cmd)
 140
 141 # execute the command and also postprocess generated .d dependencies
 142 # file
 143 if_changed_dep = $(if $(strip $(filter-out $(PHONY),$?)  \
 144                 $(filter-out FORCE $(wildcard $^),$^)    \
 145         $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),     \
 146         @set -e; \
 147         $(echo-cmd) $(cmd_$(1)); \
 148         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(@D)/.$(@F).tmp; \
 149         rm -f $(depfile); \
 150         mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd)
 151
 152 # Usage: $(call if_changed_rule,foo)
 153 # will check if $(cmd_foo) changed, or any of the prequisites changed,
 154 # and if so will execute $(rule_foo)
 155 if_changed_rule = $(if $(strip $(filter-out $(PHONY),$?)            \
 156                         $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\
 157                         @set -e; \
 158                         $(rule_$(1)))