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 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
  12 dot-target = $(dir $@).$(notdir $@)
  13
  14 ###
  15 # The temporary file to save gcc -MD generated dependencies must not
  16 # contain a comma
  17 depfile = $(subst $(comma),_,$(dot-target).d)
  18
  19 ###
  20 # filename of target with directory and extension stripped
  21 basetarget = $(basename $(notdir $@))
  22
  23 ###
  24 # Escape single quote for use in echo statements
  25 escsq = $(subst $(squote),'\$(squote)',$1)
  26
  27 ###
  28 # filechk is used to check if the content of a generated file is updated.
  29 # Sample usage:
  30 # define filechk_sample
  31 #       echo $KERNELRELEASE
  32 # endef
  33 # version.h : Makefile
  34 #       $(call filechk,sample)
  35 # The rule defined shall write to stdout the content of the new file.
  36 # The existing file will be compared with the new one.
  37 # - If no file exist it is created
  38 # - If the content differ the new file is used
  39 # - If they are equal no change, and no timestamp update
  40 # - stdin is piped in from the first prerequisite ($<) so one has
  41 #   to specify a valid file as first prerequisite (often the kbuild file)
  42 define filechk
  43         $(Q)set -e;                             \
  44         echo '  CHK     $@';                    \
  45         mkdir -p $(dir $@);                     \
  46         $(filechk_$(1)) < $< > $@.tmp;          \
  47         if [ -r $@ ] && cmp -s $@ $@.tmp; then  \
  48                 rm -f $@.tmp;                   \
  49         else                                    \
  50                 echo '  UPD     $@';            \
  51                 mv -f $@.tmp $@;                \
  52         fi
  53 endef
  54
  55 ######
  56 # gcc support functions
  57 # See documentation in Documentation/kbuild/makefiles.txt
  58
  59 # output directory for tests below
  60 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
  61
  62 # as-option
  63 # Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,)
  64
  65 as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
  66              -xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \
  67              else echo "$(2)"; fi ;)
  68
  69 # as-instr
  70 # Usage: cflags-y += $(call as-instr, instr, option1, option2)
  71
  72 as-instr = $(shell if echo -e "$(1)" | \
  73                       $(CC) $(AFLAGS) -c -xassembler - \
  74                             -o $(TMPOUT)astest$$$$.out > /dev/null 2>&1; \
  75                    then rm $(TMPOUT)astest$$$$.out; echo "$(2)"; \
  76                    else echo "$(3)"; fi)
  77
  78 # cc-option
  79 # Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
  80
  81 cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
  82              > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
  83
  84 # cc-option-yn
  85 # Usage: flag := $(call cc-option-yn, -march=winchip-c6)
  86 cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
  87                 > /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
  88
  89 # cc-option-align
  90 # Prefix align with either -falign or -malign
  91 cc-option-align = $(subst -functions=0,,\
  92         $(call cc-option,-falign-functions=0,-malign-functions=0))
  93
  94 # cc-version
  95 # Usage gcc-ver := $(call cc-version, $(CC))
  96 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
  97
  98 # cc-ifversion
  99 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 100 cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
 101                        echo $(3); fi;)
 102
 103 # ld-option
 104 # Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
 105 ld-option = $(shell if $(CC) $(1) -nostdlib -xc /dev/null \
 106                              -o $(TMPOUT)ldtest$$$$.out > /dev/null 2>&1; \
 107              then rm $(TMPOUT)ldtest$$$$.out; echo "$(1)"; \
 108              else echo "$(2)"; fi)
 109
 110 ###
 111 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 112 # Usage:
 113 # $(Q)$(MAKE) $(build)=dir
 114 build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
 115
 116 # Prefix -I with $(srctree) if it is not an absolute path
 117 addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
 118 # Find all -I options and call addtree
 119 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
 120
 121 # If quiet is set, only print short version of command
 122 cmd = @$(echo-cmd) $(cmd_$(1))
 123
 124 # Add $(obj)/ for paths that is not absolute
 125 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 126
 127 ###
 128 # if_changed      - execute command if any prerequisite is newer than
 129 #                   target, or command line has changed
 130 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 131 #                   including used config symbols
 132 # if_changed_rule - as if_changed but execute rule instead
 133 # See Documentation/kbuild/makefiles.txt for more info
 134
 135 ifneq ($(KBUILD_NOCMDDEP),1)
 136 # Check if both arguments has same arguments. Result in empty string if equal
 137 # User may override this check using make KBUILD_NOCMDDEP=1
 138 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
 139                     $(filter-out $(cmd_$@),   $(cmd_$(1))) )
 140 endif
 141
 142 # echo command. Short version is $(quiet) equals quiet, otherwise full command
 143 echo-cmd = $(if $($(quiet)cmd_$(1)), \
 144         echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 145
 146 # >'< substitution is for echo to work,
 147 # >$< substitution to preserve $ when reloading .cmd file
 148 # note: when using inline perl scripts [perl -e '...$$t=1;...']
 149 # in $(cmd_xxx) double $$ your perl vars
 150 make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
 151
 152 # Find any prerequisites that is newer than target or that does not exist.
 153 # PHONY targets skipped in both cases.
 154 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 155
 156 # Execute command if command has changed or prerequisitei(s) are updated
 157 #
 158 if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 159         @set -e;                                                             \
 160         $(echo-cmd) $(cmd_$(1));                                             \
 161         echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
 162
 163 # execute the command and also postprocess generated .d dependencies
 164 # file
 165 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
 166         @set -e;                                                             \
 167         $(echo-cmd) $(cmd_$(1));                                             \
 168         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
 169         rm -f $(depfile);                                                    \
 170         mv -f $(dot-target).tmp $(dot-target).cmd)
 171
 172 # Usage: $(call if_changed_rule,foo)
 173 # will check if $(cmd_foo) changed, or any of the prequisites changed,
 174 # and if so will execute $(rule_foo)
 175 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
 176         @set -e;                                                             \
 177         $(rule_$(1)))
 178
 179 ###
 180 # why - tell why a a target got build
 181 #       enabled by make V=2
 182 #       Output (listed in the order they are checked):
 183 #          (1) - due to target is PHONY
 184 #          (2) - due to target missing
 185 #          (3) - due to: file1.h file2.h
 186 #          (4) - due to command line change
 187 #          (5) - due to missing .cmd file
 188 #          (6) - due to target not in $(targets)
 189 # (1) PHONY targets are always build
 190 # (2) No target, so we better build it
 191 # (3) Prerequisite is newer than target
 192 # (4) The command line stored in the file named dir/.target.cmd
 193 #     differed from actual command line. This happens when compiler
 194 #     options changes
 195 # (5) No dir/.target.cmd file (used to store command line)
 196 # (6) No dir/.target.cmd file and target not listed in $(targets)
 197 #     This is a good hint that there is a bug in the kbuild file
 198 ifeq ($(KBUILD_VERBOSE),2)
 199 why =                                                                        \
 200     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 201         $(if $(wildcard $@),                                                 \
 202             $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
 203                 $(if $(arg-check),                                           \
 204                     $(if $(cmd_$@),- due to command line change,             \
 205                         $(if $(filter $@, $(targets)),                       \
 206                             - due to missing .cmd file,                      \
 207                             - due to $(notdir $@) not in $$(targets)         \
 208                          )                                                   \
 209                      )                                                       \
 210                  )                                                           \
 211              ),                                                              \
 212              - due to target missing                                         \
 213          )                                                                   \
 214      )
 215
 216 echo-why = $(call escsq, $(strip $(why)))
 217 endif