scripts/Kbuild.include

   1 ####
   2 # kbuild: Generic definitions
   3
   4 # Convenient variables
   5 comma   := ,
   6 quote   := "
   7 squote  := '
   8 empty   :=
   9 space   := $(empty) $(empty)
  10 space_escape := _-_SPACE_-_
  11 pound := \#
  12 right_paren := )
  13 left_paren := (
  14
  15 ###
  16 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
  17 dot-target = $(dir $@).$(notdir $@)
  18
  19 ###
  20 # The temporary file to save gcc -MD generated dependencies must not
  21 # contain a comma
  22 depfile = $(subst $(comma),_,$(dot-target).d)
  23
  24 ###
  25 # filename of target with directory and extension stripped
  26 basetarget = $(basename $(notdir $@))
  27
  28 ###
  29 # filename of first prerequisite with directory and extension stripped
  30 baseprereq = $(basename $(notdir $<))
  31
  32 ###
  33 # Escape single quote for use in echo statements
  34 escsq = $(subst $(squote),'\$(squote)',$1)
  35
  36 ###
  37 # Easy method for doing a status message
  38        kecho := :
  39  quiet_kecho := echo
  40 silent_kecho := :
  41 kecho := $($(quiet)kecho)
  42
  43 ###
  44 # filechk is used to check if the content of a generated file is updated.
  45 # Sample usage:
  46 # define filechk_sample
  47 #       echo $KERNELRELEASE
  48 # endef
  49 # version.h : Makefile
  50 #       $(call filechk,sample)
  51 # The rule defined shall write to stdout the content of the new file.
  52 # The existing file will be compared with the new one.
  53 # - If no file exist it is created
  54 # - If the content differ the new file is used
  55 # - If they are equal no change, and no timestamp update
  56 # - stdin is piped in from the first prerequisite ($<) so one has
  57 #   to specify a valid file as first prerequisite (often the kbuild file)
  58 define filechk
  59         $(Q)set -e;                             \
  60         $(kecho) '  CHK     $@';                \
  61         mkdir -p $(dir $@);                     \
  62         $(filechk_$(1)) < $< > $@.tmp;          \
  63         if [ -r $@ ] && cmp -s $@ $@.tmp; then  \
  64                 rm -f $@.tmp;                   \
  65         else                                    \
  66                 $(kecho) '  UPD     $@';        \
  67                 mv -f $@.tmp $@;                \
  68         fi
  69 endef
  70
  71 ######
  72 # gcc support functions
  73 # See documentation in Documentation/kbuild/makefiles.txt
  74
  75 # cc-cross-prefix
  76 # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
  77 # Return first prefix where a prefix$(CC) is found in PATH.
  78 # If no $(CC) found in PATH with listed prefixes return nothing
  79 cc-cross-prefix =  \
  80         $(word 1, $(foreach c,$(1),                                   \
  81                 $(shell set -e;                                       \
  82                 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
  83                         echo $(c);                                    \
  84                 fi)))
  85
  86 # Tools for caching Makefile variables that are "expensive" to compute.
  87 #
  88 # Here we want to help deal with variables that take a long time to compute
  89 # by making it easy to store these variables in a cache.
  90 #
  91 # The canonical example here is testing for compiler flags.  On a simple system
  92 # each call to the compiler takes 10 ms, but on a system with a compiler that's
  93 # called through various wrappers it can take upwards of 100 ms.  If we have
  94 # 100 calls to the compiler this can take 1 second (on a simple system) or 10
  95 # seconds (on a complicated system).
  96 #
  97 # The "cache" will be in Makefile syntax and can be directly included.
  98 # Any time we try to reference a variable that's not in the cache we'll
  99 # calculate it and store it in the cache for next time.
 100
 101 # Include values from last time
 102 make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk
 103 $(make-cache): ;
 104 -include $(make-cache)
 105
 106 cached-data := $(filter __cached_%, $(.VARIABLES))
 107
 108 # If cache exceeds 1000 lines, shrink it down to 500.
 109 ifneq ($(word 1000,$(cached-data)),)
 110 $(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \
 111         mv $(make-cache).tmp $(make-cache))
 112 endif
 113
 114 create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1))
 115
 116 # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
 117 #
 118 # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'
 119 __sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1)))))))))
 120
 121 # Usage:   $(call shell-cached,shell_command)
 122 # Example: $(call shell-cached,md5sum /usr/bin/gcc)
 123 #
 124 # If we've already seen a call to this exact shell command (even in a
 125 # previous invocation of make!) we'll return the value.  If not, we'll
 126 # compute it and store the result for future runs.
 127 #
 128 # This is a bit of voodoo, but basic explanation is that if the variable
 129 # was undefined then we'll evaluate the shell command and store the result
 130 # into the variable.  We'll then store that value in the cache and finally
 131 # output the value.
 132 #
 133 # NOTE: The $$(2) here isn't actually a parameter to __run-and-store.  We
 134 # happen to know that the caller will have their shell command in $(2) so the
 135 # result of "call"ing this will produce a reference to that $(2).  The reason
 136 # for this strangeness is to avoid an extra level of eval (and escaping) of
 137 # $(2).
 138 define __run-and-store
 139 ifeq ($(origin $(1)),undefined)
 140   $$(eval $(1) := $$(shell $$(2)))
 141 ifeq ($(create-cache-dir),1)
 142   $$(shell mkdir -p $(dir $(make-cache)))
 143   $$(eval create-cache-dir :=)
 144 endif
 145   $$(shell echo '$(1) := $$($(1))' >> $(make-cache))
 146 endif
 147 endef
 148 __shell-cached = $(eval $(call __run-and-store,$(1)))$($(1))
 149 shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1))
 150
 151 # output directory for tests below
 152 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
 153
 154 # try-run
 155 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
 156 # Exit code chooses option. "$$TMP" serves as a temporary file and is
 157 # automatically cleaned up.
 158 __try-run = set -e;                     \
 159         TMP="$(TMPOUT).$$$$.tmp";       \
 160         TMPO="$(TMPOUT).$$$$.o";        \
 161         if ($(1)) >/dev/null 2>&1;      \
 162         then echo "$(2)";               \
 163         else echo "$(3)";               \
 164         fi;                             \
 165         rm -f "$$TMP" "$$TMPO"
 166
 167 try-run = $(shell $(__try-run))
 168
 169 # try-run-cached
 170 # This works like try-run, but the result is cached.
 171 try-run-cached = $(call shell-cached,$(__try-run))
 172
 173 # as-option
 174 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 175
 176 as-option = $(call try-run-cached,\
 177         $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
 178
 179 # as-instr
 180 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
 181
 182 as-instr = $(call try-run-cached,\
 183         printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
 184
 185 # __cc-option
 186 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
 187 __cc-option = $(call try-run-cached,\
 188         $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
 189
 190 # Do not attempt to build with gcc plugins during cc-option tests.
 191 # (And this uses delayed resolution so the flags will be up to date.)
 192 CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
 193
 194 # cc-option
 195 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 196
 197 cc-option = $(call __cc-option, $(CC),\
 198         $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
 199
 200 # hostcc-option
 201 # Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
 202 hostcc-option = $(call __cc-option, $(HOSTCC),\
 203         $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
 204
 205 # cc-option-yn
 206 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 207 cc-option-yn = $(call try-run-cached,\
 208         $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 209
 210 # cc-disable-warning
 211 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 212 cc-disable-warning = $(call try-run-cached,\
 213         $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 214
 215 # cc-name
 216 # Expands to either gcc or clang
 217 cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
 218
 219 # cc-version
 220 cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
 221
 222 # cc-fullversion
 223 cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \
 224         $(srctree)/scripts/gcc-version.sh -p $(CC))
 225
 226 # cc-ifversion
 227 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 228 cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
 229
 230 # cc-if-fullversion
 231 # Usage:  EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
 232 cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4))
 233
 234 # cc-ldoption
 235 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
 236 cc-ldoption = $(call try-run-cached,\
 237         $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
 238
 239 # ld-option
 240 # Usage: LDFLAGS += $(call ld-option, -X)
 241 ld-option = $(call try-run-cached,\
 242         $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \
 243         $(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
 244
 245 # ar-option
 246 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)
 247 # Important: no spaces around options
 248 ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2))
 249
 250 # ld-version
 251 # Note this is mainly for HJ Lu's 3 number binutil versions
 252 ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh)
 253
 254 # ld-ifversion
 255 # Usage:  $(call ld-ifversion, -ge, 22252, y)
 256 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
 257
 258 ######
 259
 260 ###
 261 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 262 # Usage:
 263 # $(Q)$(MAKE) $(build)=dir
 264 build := -f $(srctree)/scripts/Makefile.build obj
 265
 266 ###
 267 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
 268 # Usage:
 269 # $(Q)$(MAKE) $(modbuiltin)=dir
 270 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
 271
 272 ###
 273 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
 274 # Usage:
 275 # $(Q)$(MAKE) $(dtbinst)=dir
 276 dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
 277
 278 ###
 279 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
 280 # Usage:
 281 # $(Q)$(MAKE) $(clean)=dir
 282 clean := -f $(srctree)/scripts/Makefile.clean obj
 283
 284 ###
 285 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
 286 # Usage:
 287 # $(Q)$(MAKE) $(hdr-inst)=dir
 288 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
 289
 290 # Prefix -I with $(srctree) if it is not an absolute path.
 291 # skip if -I has no parameter
 292 addtree = $(if $(patsubst -I%,%,$(1)), \
 293 $(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
 294
 295 # Find all -I options and call addtree
 296 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
 297
 298 # echo command.
 299 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 300 echo-cmd = $(if $($(quiet)cmd_$(1)),\
 301         echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 302
 303 # printing commands
 304 cmd = @$(echo-cmd) $(cmd_$(1))
 305
 306 # Add $(obj)/ for paths that are not absolute
 307 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 308
 309 ###
 310 # if_changed      - execute command if any prerequisite is newer than
 311 #                   target, or command line has changed
 312 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 313 #                   including used config symbols
 314 # if_changed_rule - as if_changed but execute rule instead
 315 # See Documentation/kbuild/makefiles.txt for more info
 316
 317 ifneq ($(KBUILD_NOCMDDEP),1)
 318 # Check if both arguments are the same including their order. Result is empty
 319 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
 320 arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
 321                          $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 322 else
 323 arg-check = $(if $(strip $(cmd_$@)),,1)
 324 endif
 325
 326 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
 327 # (needed for make)
 328 # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
 329 # (needed for make)
 330 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
 331 # (needed for the shell)
 332 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
 333
 334 # Find any prerequisites that is newer than target or that does not exist.
 335 # PHONY targets skipped in both cases.
 336 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 337
 338 # Execute command if command has changed or prerequisite(s) are updated.
 339 if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 340         @set -e;                                                             \
 341         $(echo-cmd) $(cmd_$(1));                                             \
 342         printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 343
 344 # Execute the command and also postprocess generated .d dependencies file.
 345 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
 346         @set -e;                                                             \
 347         $(cmd_and_fixdep), @:)
 348
 349 ifndef CONFIG_TRIM_UNUSED_KSYMS
 350
 351 cmd_and_fixdep =                                                             \
 352         $(echo-cmd) $(cmd_$(1));                                             \
 353         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
 354         rm -f $(depfile);                                                    \
 355         mv -f $(dot-target).tmp $(dot-target).cmd;
 356
 357 else
 358
 359 # Filter out exported kernel symbol names from the preprocessor output.
 360 # See also __KSYM_DEPS__ in include/linux/export.h.
 361 # We disable the depfile generation here, so as not to overwrite the existing
 362 # depfile while fixdep is parsing it.
 363 flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
 364 ksym_dep_filter =                                                            \
 365         case "$(1)" in                                                       \
 366           cc_*_c|cpp_i_c)                                                    \
 367             $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;;        \
 368           as_*_S|cpp_s_S)                                                    \
 369             $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;;        \
 370           boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;;            \
 371           *) echo "Don't know how to preprocess $(1)" >&2; false ;;          \
 372         esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
 373
 374 cmd_and_fixdep =                                                             \
 375         $(echo-cmd) $(cmd_$(1));                                             \
 376         $(ksym_dep_filter) |                                                 \
 377                 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)'          \
 378                         > $(dot-target).tmp;                                 \
 379         rm -f $(depfile);                                                    \
 380         mv -f $(dot-target).tmp $(dot-target).cmd;
 381
 382 endif
 383
 384 # Usage: $(call if_changed_rule,foo)
 385 # Will check if $(cmd_foo) or any of the prerequisites changed,
 386 # and if so will execute $(rule_foo).
 387 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
 388         @set -e;                                                             \
 389         $(rule_$(1)), @:)
 390
 391 ###
 392 # why - tell why a target got built
 393 #       enabled by make V=2
 394 #       Output (listed in the order they are checked):
 395 #          (1) - due to target is PHONY
 396 #          (2) - due to target missing
 397 #          (3) - due to: file1.h file2.h
 398 #          (4) - due to command line change
 399 #          (5) - due to missing .cmd file
 400 #          (6) - due to target not in $(targets)
 401 # (1) PHONY targets are always build
 402 # (2) No target, so we better build it
 403 # (3) Prerequisite is newer than target
 404 # (4) The command line stored in the file named dir/.target.cmd
 405 #     differed from actual command line. This happens when compiler
 406 #     options changes
 407 # (5) No dir/.target.cmd file (used to store command line)
 408 # (6) No dir/.target.cmd file and target not listed in $(targets)
 409 #     This is a good hint that there is a bug in the kbuild file
 410 ifeq ($(KBUILD_VERBOSE),2)
 411 why =                                                                        \
 412     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 413         $(if $(wildcard $@),                                                 \
 414             $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
 415                 $(if $(arg-check),                                           \
 416                     $(if $(cmd_$@),- due to command line change,             \
 417                         $(if $(filter $@, $(targets)),                       \
 418                             - due to missing .cmd file,                      \
 419                             - due to $(notdir $@) not in $$(targets)         \
 420                          )                                                   \
 421                      )                                                       \
 422                  )                                                           \
 423              ),                                                              \
 424              - due to target missing                                         \
 425          )                                                                   \
 426      )
 427
 428 echo-why = $(call escsq, $(strip $(why)))
 429 endif
 430
 431 ###############################################################################
 432 #
 433 # When a Kconfig string contains a filename, it is suitable for
 434 # passing to shell commands. It is surrounded by double-quotes, and
 435 # any double-quotes or backslashes within it are escaped by
 436 # backslashes.
 437 #
 438 # This is no use for dependencies or $(wildcard). We need to strip the
 439 # surrounding quotes and the escaping from quotes and backslashes, and
 440 # we *do* need to escape any spaces in the string. So, for example:
 441 #
 442 # Usage: $(eval $(call config_filename,FOO))
 443 #
 444 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
 445 # transformed as described above to be suitable for use within the
 446 # makefile.
 447 #
 448 # Also, if the filename is a relative filename and exists in the source
 449 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
 450 # be prefixed to *both* command invocation and dependencies.
 451 #
 452 # Note: We also print the filenames in the quiet_cmd_foo text, and
 453 # perhaps ought to have a version specially escaped for that purpose.
 454 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
 455 # enough.  It'll strip the quotes in the common case where there's no
 456 # space and it's a simple filename, and it'll retain the quotes when
 457 # there's a space. There are some esoteric cases in which it'll print
 458 # the wrong thing, but we don't really care. The actual dependencies
 459 # and commands *do* get it right, with various combinations of single
 460 # and double quotes, backslashes and spaces in the filenames.
 461 #
 462 ###############################################################################
 463 #
 464 define config_filename
 465 ifneq ($$(CONFIG_$(1)),"")
 466 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
 467 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
 468 else
 469 ifeq ($$(wildcard $$($(1)_FILENAME)),)
 470 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
 471 $(1)_SRCPREFIX := $(srctree)/
 472 endif
 473 endif
 474 endif
 475 endif
 476 endef
 477 #
 478 ###############################################################################