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