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 -MMD 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 # Quote a string to pass it to C files. foo => '"foo"'
  37 stringify = $(squote)$(quote)$1$(quote)$(squote)
  38
  39 ###
  40 # Easy method for doing a status message
  41        kecho := :
  42  quiet_kecho := echo
  43 silent_kecho := :
  44 kecho := $($(quiet)kecho)
  45
  46 ###
  47 # filechk is used to check if the content of a generated file is updated.
  48 # Sample usage:
  49 #
  50 # filechk_sample = echo $(KERNELRELEASE)
  51 # version.h: FORCE
  52 #       $(call filechk,sample)
  53 #
  54 # The rule defined shall write to stdout the content of the new file.
  55 # The existing file will be compared with the new one.
  56 # - If no file exist it is created
  57 # - If the content differ the new file is used
  58 # - If they are equal no change, and no timestamp update
  59 define filechk
  60         $(Q)set -e;                                             \
  61         mkdir -p $(dir $@);                                     \
  62         trap "rm -f $(dot-target).tmp" EXIT;                    \
  63         { $(filechk_$(1)); } > $(dot-target).tmp;               \
  64         if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then   \
  65                 $(kecho) '  UPD     $@';                        \
  66                 mv -f $(dot-target).tmp $@;                     \
  67         fi
  68 endef
  69
  70 ######
  71 # gcc support functions
  72 # See documentation in Documentation/kbuild/makefiles.rst
  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>gcc is found in PATH.
  77 # If no gcc found in PATH with listed prefixes return nothing
  78 #
  79 # Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
  80 # would try to directly execute the shell builtin 'command'. This workaround
  81 # should be kept for a long time since this issue was fixed only after the
  82 # GNU Make 4.2.1 release.
  83 cc-cross-prefix = $(firstword $(foreach c, $(1), \
  84                         $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
  85
  86 # output directory for tests below
  87 TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$
  88
  89 # try-run
  90 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
  91 # Exit code chooses option. "$$TMP" serves as a temporary file and is
  92 # automatically cleaned up.
  93 try-run = $(shell set -e;               \
  94         TMP=$(TMPOUT)/tmp;              \
  95         TMPO=$(TMPOUT)/tmp.o;           \
  96         mkdir -p $(TMPOUT);             \
  97         trap "rm -rf $(TMPOUT)" EXIT;   \
  98         if ($(1)) >/dev/null 2>&1;      \
  99         then echo "$(2)";               \
 100         else echo "$(3)";               \
 101         fi)
 102
 103 # as-option
 104 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 105
 106 as-option = $(call try-run,\
 107         $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
 108
 109 # as-instr
 110 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
 111
 112 as-instr = $(call try-run,\
 113         printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
 114
 115 # __cc-option
 116 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
 117 __cc-option = $(call try-run,\
 118         $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
 119
 120 # cc-option
 121 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 122
 123 cc-option = $(call __cc-option, $(CC),\
 124         $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
 125
 126 # cc-option-yn
 127 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 128 cc-option-yn = $(call try-run,\
 129         $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 130
 131 # cc-disable-warning
 132 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 133 cc-disable-warning = $(call try-run,\
 134         $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 135
 136 # cc-ifversion
 137 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
 138 cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
 139
 140 # ld-option
 141 # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
 142 ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
 143
 144 # ld-version
 145 # Note this is mainly for HJ Lu's 3 number binutil versions
 146 ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
 147
 148 # ld-ifversion
 149 # Usage:  $(call ld-ifversion, -ge, 22252, y)
 150 ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
 151
 152 ######
 153
 154 ###
 155 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 156 # Usage:
 157 # $(Q)$(MAKE) $(build)=dir
 158 build := -f $(srctree)/scripts/Makefile.build obj
 159
 160 ###
 161 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
 162 # Usage:
 163 # $(Q)$(MAKE) $(dtbinst)=dir
 164 dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
 165
 166 ###
 167 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
 168 # Usage:
 169 # $(Q)$(MAKE) $(clean)=dir
 170 clean := -f $(srctree)/scripts/Makefile.clean obj
 171
 172 # echo command.
 173 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 174 echo-cmd = $(if $($(quiet)cmd_$(1)),\
 175         echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 176
 177 # printing commands
 178 cmd = @set -e; $(echo-cmd) $(cmd_$(1))
 179
 180 ###
 181 # if_changed      - execute command if any prerequisite is newer than
 182 #                   target, or command line has changed
 183 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 184 #                   including used config symbols
 185 # if_changed_rule - as if_changed but execute rule instead
 186 # See Documentation/kbuild/makefiles.rst for more info
 187
 188 ifneq ($(KBUILD_NOCMDDEP),1)
 189 # Check if both commands are the same including their order. Result is empty
 190 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
 191 cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
 192                          $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 193 else
 194 cmd-check = $(if $(strip $(cmd_$@)),,1)
 195 endif
 196
 197 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
 198 # (needed for make)
 199 # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
 200 # (needed for make)
 201 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
 202 # (needed for the shell)
 203 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
 204
 205 # Find any prerequisites that are newer than target or that do not exist.
 206 # (This is not true for now; $? should contain any non-existent prerequisites,
 207 # but it does not work as expected when .SECONDARY is present. This seems a bug
 208 # of GNU Make.)
 209 # PHONY targets skipped in both cases.
 210 newer-prereqs = $(filter-out $(PHONY),$?)
 211
 212 # Execute command if command has changed or prerequisite(s) are updated.
 213 if_changed = $(if $(newer-prereqs)$(cmd-check),                              \
 214         $(cmd);                                                              \
 215         printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 216
 217 # Execute the command and also postprocess generated .d dependencies file.
 218 if_changed_dep = $(if $(newer-prereqs)$(cmd-check),$(cmd_and_fixdep),@:)
 219
 220 cmd_and_fixdep =                                                             \
 221         $(cmd);                                                              \
 222         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
 223         rm -f $(depfile)
 224
 225 # Usage: $(call if_changed_rule,foo)
 226 # Will check if $(cmd_foo) or any of the prerequisites changed,
 227 # and if so will execute $(rule_foo).
 228 if_changed_rule = $(if $(newer-prereqs)$(cmd-check),$(rule_$(1)),@:)
 229
 230 ###
 231 # why - tell why a target got built
 232 #       enabled by make V=2
 233 #       Output (listed in the order they are checked):
 234 #          (1) - due to target is PHONY
 235 #          (2) - due to target missing
 236 #          (3) - due to: file1.h file2.h
 237 #          (4) - due to command line change
 238 #          (5) - due to missing .cmd file
 239 #          (6) - due to target not in $(targets)
 240 # (1) PHONY targets are always build
 241 # (2) No target, so we better build it
 242 # (3) Prerequisite is newer than target
 243 # (4) The command line stored in the file named dir/.target.cmd
 244 #     differed from actual command line. This happens when compiler
 245 #     options changes
 246 # (5) No dir/.target.cmd file (used to store command line)
 247 # (6) No dir/.target.cmd file and target not listed in $(targets)
 248 #     This is a good hint that there is a bug in the kbuild file
 249 ifeq ($(KBUILD_VERBOSE),2)
 250 why =                                                                        \
 251     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 252         $(if $(wildcard $@),                                                 \
 253             $(if $(newer-prereqs),- due to: $(newer-prereqs),                \
 254                 $(if $(cmd-check),                                           \
 255                     $(if $(cmd_$@),- due to command line change,             \
 256                         $(if $(filter $@, $(targets)),                       \
 257                             - due to missing .cmd file,                      \
 258                             - due to $(notdir $@) not in $$(targets)         \
 259                          )                                                   \
 260                      )                                                       \
 261                  )                                                           \
 262              ),                                                              \
 263              - due to target missing                                         \
 264          )                                                                   \
 265      )
 266
 267 echo-why = $(call escsq, $(strip $(why)))
 268 endif
 269
 270 ###############################################################################
 271 #
 272 # When a Kconfig string contains a filename, it is suitable for
 273 # passing to shell commands. It is surrounded by double-quotes, and
 274 # any double-quotes or backslashes within it are escaped by
 275 # backslashes.
 276 #
 277 # This is no use for dependencies or $(wildcard). We need to strip the
 278 # surrounding quotes and the escaping from quotes and backslashes, and
 279 # we *do* need to escape any spaces in the string. So, for example:
 280 #
 281 # Usage: $(eval $(call config_filename,FOO))
 282 #
 283 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
 284 # transformed as described above to be suitable for use within the
 285 # makefile.
 286 #
 287 # Also, if the filename is a relative filename and exists in the source
 288 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
 289 # be prefixed to *both* command invocation and dependencies.
 290 #
 291 # Note: We also print the filenames in the quiet_cmd_foo text, and
 292 # perhaps ought to have a version specially escaped for that purpose.
 293 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
 294 # enough.  It'll strip the quotes in the common case where there's no
 295 # space and it's a simple filename, and it'll retain the quotes when
 296 # there's a space. There are some esoteric cases in which it'll print
 297 # the wrong thing, but we don't really care. The actual dependencies
 298 # and commands *do* get it right, with various combinations of single
 299 # and double quotes, backslashes and spaces in the filenames.
 300 #
 301 ###############################################################################
 302 #
 303 define config_filename
 304 ifneq ($$(CONFIG_$(1)),"")
 305 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
 306 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
 307 else
 308 ifeq ($$(wildcard $$($(1)_FILENAME)),)
 309 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
 310 $(1)_SRCPREFIX := $(srctree)/
 311 endif
 312 endif
 313 endif
 314 endif
 315 endef
 316 #
 317 ###############################################################################
 318
 319 # delete partially updated (i.e. corrupted) files on error
 320 .DELETE_ON_ERROR:
 321
 322 # do not delete intermediate files automatically
 323 .SECONDARY: