scripts/Kbuild.include

   1 # SPDX-License-Identifier: GPL-2.0
   2 ####
   3 # kbuild: Generic definitions
   4
   5 # Convenient variables
   6 comma   := ,
   7 quote   := "
   8 squote  := '
   9 empty   :=
  10 space   := $(empty) $(empty)
  11 space_escape := _-_SPACE_-_
  12 pound := \#
  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 # real prerequisites without phony targets
  29 real-prereqs = $(filter-out $(PHONY), $^)
  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 #
  46 # filechk_sample = echo $(KERNELRELEASE)
  47 # version.h: FORCE
  48 #       $(call filechk,sample)
  49 #
  50 # The rule defined shall write to stdout the content of the new file.
  51 # The existing file will be compared with the new one.
  52 # - If no file exist it is created
  53 # - If the content differ the new file is used
  54 # - If they are equal no change, and no timestamp update
  55 # - stdin is piped in from the first prerequisite ($<) so one has
  56 #   to specify a valid file as first prerequisite (often the kbuild file)
  57 define filechk
  58         $(Q)set -e;                                             \
  59         mkdir -p $(dir $@);                                     \
  60         trap "rm -f $(dot-target).tmp" EXIT;                    \
  61         { $(filechk_$(1)); } > $(dot-target).tmp;               \
  62         if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then   \
  63                 $(kecho) '  UPD     $@';                        \
  64                 mv -f $(dot-target).tmp $@;                     \
  65         fi
  66 endef
  67
  68 ######
  69 # gcc support functions
  70 # See documentation in Documentation/kbuild/makefiles.rst
  71
  72 # cc-cross-prefix
  73 # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
  74 # Return first <prefix> where a <prefix>gcc is found in PATH.
  75 # If no gcc found in PATH with listed prefixes return nothing
  76 #
  77 # Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
  78 # would try to directly execute the shell builtin 'command'. This workaround
  79 # should be kept for a long time since this issue was fixed only after the
  80 # GNU Make 4.2.1 release.
  81 cc-cross-prefix = $(firstword $(foreach c, $(1), \
  82                         $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
  83
  84 # output directory for tests below
  85 TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$
  86
  87 # try-run
  88 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
  89 # Exit code chooses option. "$$TMP" serves as a temporary file and is
  90 # automatically cleaned up.
  91 try-run = $(shell set -e;               \
  92         TMP=$(TMPOUT)/tmp;              \
  93         TMPO=$(TMPOUT)/tmp.o;           \
  94         mkdir -p $(TMPOUT);             \
  95         trap "rm -rf $(TMPOUT)" EXIT;   \
  96         if ($(1)) >/dev/null 2>&1;      \
  97         then echo "$(2)";               \
  98         else echo "$(3)";               \
  99         fi)
 100
 101 # as-option
 102 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 103
 104 as-option = $(call try-run,\
 105         $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
 106
 107 # as-instr
 108 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
 109
 110 as-instr = $(call try-run,\
 111         printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
 112
 113 # __cc-option
 114 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
 115 __cc-option = $(call try-run,\
 116         $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
 117
 118 # Do not attempt to build with gcc plugins during cc-option tests.
 119 # (And this uses delayed resolution so the flags will be up to date.)
 120 CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
 121
 122 # cc-option
 123 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 124
 125 cc-option = $(call __cc-option, $(CC),\
 126         $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
 127
 128 # cc-option-yn
 129 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 130 cc-option-yn = $(call try-run,\
 131         $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 132
 133 # cc-disable-warning
 134 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 135 cc-disable-warning = $(call try-run,\
 136         $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 137
 138 # cc-ifversion
 139 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 140 cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
 141
 142 # ld-option
 143 # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
 144 ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
 145
 146 # ld-version
 147 # Note this is mainly for HJ Lu's 3 number binutil versions
 148 ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
 149
 150 # ld-ifversion
 151 # Usage:  $(call ld-ifversion, -ge, 22252, y)
 152 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
 153
 154 ######
 155
 156 ###
 157 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 158 # Usage:
 159 # $(Q)$(MAKE) $(build)=dir
 160 build := -f $(srctree)/scripts/Makefile.build obj
 161
 162 ###
 163 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
 164 # Usage:
 165 # $(Q)$(MAKE) $(modbuiltin)=dir
 166 modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
 167
 168 ###
 169 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
 170 # Usage:
 171 # $(Q)$(MAKE) $(dtbinst)=dir
 172 dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
 173
 174 ###
 175 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
 176 # Usage:
 177 # $(Q)$(MAKE) $(clean)=dir
 178 clean := -f $(srctree)/scripts/Makefile.clean obj
 179
 180 # echo command.
 181 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 182 echo-cmd = $(if $($(quiet)cmd_$(1)),\
 183         echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 184
 185 # printing commands
 186 cmd = @set -e; $(echo-cmd) $(cmd_$(1))
 187
 188 ###
 189 # if_changed      - execute command if any prerequisite is newer than
 190 #                   target, or command line has changed
 191 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 192 #                   including used config symbols
 193 # if_changed_rule - as if_changed but execute rule instead
 194 # See Documentation/kbuild/makefiles.rst for more info
 195
 196 ifneq ($(KBUILD_NOCMDDEP),1)
 197 # Check if both commands are the same including their order. Result is empty
 198 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
 199 cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
 200                          $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 201 else
 202 cmd-check = $(if $(strip $(cmd_$@)),,1)
 203 endif
 204
 205 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
 206 # (needed for make)
 207 # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
 208 # (needed for make)
 209 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
 210 # (needed for the shell)
 211 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
 212
 213 # Find any prerequisites that is newer than target or that does not exist.
 214 # PHONY targets skipped in both cases.
 215 any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^)
 216
 217 # Execute command if command has changed or prerequisite(s) are updated.
 218 if_changed = $(if $(any-prereq)$(cmd-check),                                 \
 219         $(cmd);                                                              \
 220         printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 221
 222 # Execute the command and also postprocess generated .d dependencies file.
 223 if_changed_dep = $(if $(any-prereq)$(cmd-check),$(cmd_and_fixdep),@:)
 224
 225 cmd_and_fixdep =                                                             \
 226         $(cmd);                                                              \
 227         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
 228         rm -f $(depfile)
 229
 230 # Usage: $(call if_changed_rule,foo)
 231 # Will check if $(cmd_foo) or any of the prerequisites changed,
 232 # and if so will execute $(rule_foo).
 233 if_changed_rule = $(if $(any-prereq)$(cmd-check),$(rule_$(1)),@:)
 234
 235 ###
 236 # why - tell why a target got built
 237 #       enabled by make V=2
 238 #       Output (listed in the order they are checked):
 239 #          (1) - due to target is PHONY
 240 #          (2) - due to target missing
 241 #          (3) - due to: file1.h file2.h
 242 #          (4) - due to command line change
 243 #          (5) - due to missing .cmd file
 244 #          (6) - due to target not in $(targets)
 245 # (1) PHONY targets are always build
 246 # (2) No target, so we better build it
 247 # (3) Prerequisite is newer than target
 248 # (4) The command line stored in the file named dir/.target.cmd
 249 #     differed from actual command line. This happens when compiler
 250 #     options changes
 251 # (5) No dir/.target.cmd file (used to store command line)
 252 # (6) No dir/.target.cmd file and target not listed in $(targets)
 253 #     This is a good hint that there is a bug in the kbuild file
 254 ifeq ($(KBUILD_VERBOSE),2)
 255 why =                                                                        \
 256     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 257         $(if $(wildcard $@),                                                 \
 258             $(if $(any-prereq),- due to: $(any-prereq),                      \
 259                 $(if $(cmd-check),                                           \
 260                     $(if $(cmd_$@),- due to command line change,             \
 261                         $(if $(filter $@, $(targets)),                       \
 262                             - due to missing .cmd file,                      \
 263                             - due to $(notdir $@) not in $$(targets)         \
 264                          )                                                   \
 265                      )                                                       \
 266                  )                                                           \
 267              ),                                                              \
 268              - due to target missing                                         \
 269          )                                                                   \
 270      )
 271
 272 echo-why = $(call escsq, $(strip $(why)))
 273 endif
 274
 275 ###############################################################################
 276 #
 277 # When a Kconfig string contains a filename, it is suitable for
 278 # passing to shell commands. It is surrounded by double-quotes, and
 279 # any double-quotes or backslashes within it are escaped by
 280 # backslashes.
 281 #
 282 # This is no use for dependencies or $(wildcard). We need to strip the
 283 # surrounding quotes and the escaping from quotes and backslashes, and
 284 # we *do* need to escape any spaces in the string. So, for example:
 285 #
 286 # Usage: $(eval $(call config_filename,FOO))
 287 #
 288 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
 289 # transformed as described above to be suitable for use within the
 290 # makefile.
 291 #
 292 # Also, if the filename is a relative filename and exists in the source
 293 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
 294 # be prefixed to *both* command invocation and dependencies.
 295 #
 296 # Note: We also print the filenames in the quiet_cmd_foo text, and
 297 # perhaps ought to have a version specially escaped for that purpose.
 298 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
 299 # enough.  It'll strip the quotes in the common case where there's no
 300 # space and it's a simple filename, and it'll retain the quotes when
 301 # there's a space. There are some esoteric cases in which it'll print
 302 # the wrong thing, but we don't really care. The actual dependencies
 303 # and commands *do* get it right, with various combinations of single
 304 # and double quotes, backslashes and spaces in the filenames.
 305 #
 306 ###############################################################################
 307 #
 308 define config_filename
 309 ifneq ($$(CONFIG_$(1)),"")
 310 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
 311 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
 312 else
 313 ifeq ($$(wildcard $$($(1)_FILENAME)),)
 314 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
 315 $(1)_SRCPREFIX := $(srctree)/
 316 endif
 317 endif
 318 endif
 319 endif
 320 endef
 321 #
 322 ###############################################################################
 323
 324 # delete partially updated (i.e. corrupted) files on error
 325 .DELETE_ON_ERROR:
 326
 327 # do not delete intermediate files automatically
 328 .SECONDARY: