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         $(check-FORCE)
  61         $(Q)set -e;                                             \
  62         mkdir -p $(dir $@);                                     \
  63         trap "rm -f $(dot-target).tmp" EXIT;                    \
  64         { $(filechk_$(1)); } > $(dot-target).tmp;               \
  65         if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then   \
  66                 $(kecho) '  UPD     $@';                        \
  67                 mv -f $(dot-target).tmp $@;                     \
  68         fi
  69 endef
  70
  71 ###
  72 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
  73 # Usage:
  74 # $(Q)$(MAKE) $(build)=dir
  75 build := -f $(srctree)/scripts/Makefile.build obj
  76
  77 ###
  78 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
  79 # Usage:
  80 # $(Q)$(MAKE) $(dtbinst)=dir
  81 dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
  82
  83 ###
  84 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
  85 # Usage:
  86 # $(Q)$(MAKE) $(clean)=dir
  87 clean := -f $(srctree)/scripts/Makefile.clean obj
  88
  89 # echo command.
  90 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
  91 echo-cmd = $(if $($(quiet)cmd_$(1)),\
  92         echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
  93
  94 # sink stdout for 'make -s'
  95        redirect :=
  96  quiet_redirect :=
  97 silent_redirect := exec >/dev/null;
  98
  99 # printing commands
 100 cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(cmd_$(1))
 101
 102 ###
 103 # if_changed      - execute command if any prerequisite is newer than
 104 #                   target, or command line has changed
 105 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 106 #                   including used config symbols
 107 # if_changed_rule - as if_changed but execute rule instead
 108 # See Documentation/kbuild/makefiles.rst for more info
 109
 110 ifneq ($(KBUILD_NOCMDDEP),1)
 111 # Check if both commands are the same including their order. Result is empty
 112 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
 113 cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
 114                          $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 115 else
 116 cmd-check = $(if $(strip $(cmd_$@)),,1)
 117 endif
 118
 119 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
 120 # (needed for make)
 121 # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
 122 # (needed for make)
 123 # Replace >'< with >'\''< to be able to enclose the whole string in '...'
 124 # (needed for the shell)
 125 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
 126
 127 # Find any prerequisites that are newer than target or that do not exist.
 128 # (This is not true for now; $? should contain any non-existent prerequisites,
 129 # but it does not work as expected when .SECONDARY is present. This seems a bug
 130 # of GNU Make.)
 131 # PHONY targets skipped in both cases.
 132 newer-prereqs = $(filter-out $(PHONY),$?)
 133
 134 # It is a typical mistake to forget the FORCE prerequisite. Check it here so
 135 # no more breakage will slip in.
 136 check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))
 137
 138 if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)
 139
 140 # Execute command if command has changed or prerequisite(s) are updated.
 141 if_changed = $(if $(if-changed-cond),                                        \
 142         $(cmd);                                                              \
 143         printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 144
 145 # Execute the command and also postprocess generated .d dependencies file.
 146 if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:)
 147
 148 cmd_and_fixdep =                                                             \
 149         $(cmd);                                                              \
 150         scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
 151         rm -f $(depfile)
 152
 153 # Usage: $(call if_changed_rule,foo)
 154 # Will check if $(cmd_foo) or any of the prerequisites changed,
 155 # and if so will execute $(rule_foo).
 156 if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:)
 157
 158 ###
 159 # why - tell why a target got built
 160 #       enabled by make V=2
 161 #       Output (listed in the order they are checked):
 162 #          (1) - due to target is PHONY
 163 #          (2) - due to target missing
 164 #          (3) - due to: file1.h file2.h
 165 #          (4) - due to command line change
 166 #          (5) - due to missing .cmd file
 167 #          (6) - due to target not in $(targets)
 168 # (1) PHONY targets are always build
 169 # (2) No target, so we better build it
 170 # (3) Prerequisite is newer than target
 171 # (4) The command line stored in the file named dir/.target.cmd
 172 #     differed from actual command line. This happens when compiler
 173 #     options changes
 174 # (5) No dir/.target.cmd file (used to store command line)
 175 # (6) No dir/.target.cmd file and target not listed in $(targets)
 176 #     This is a good hint that there is a bug in the kbuild file
 177 ifeq ($(KBUILD_VERBOSE),2)
 178 why =                                                                        \
 179     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
 180         $(if $(wildcard $@),                                                 \
 181             $(if $(newer-prereqs),- due to: $(newer-prereqs),                \
 182                 $(if $(cmd-check),                                           \
 183                     $(if $(cmd_$@),- due to command line change,             \
 184                         $(if $(filter $@, $(targets)),                       \
 185                             - due to missing .cmd file,                      \
 186                             - due to $(notdir $@) not in $$(targets)         \
 187                          )                                                   \
 188                      )                                                       \
 189                  )                                                           \
 190              ),                                                              \
 191              - due to target missing                                         \
 192          )                                                                   \
 193      )
 194
 195 echo-why = $(call escsq, $(strip $(why)))
 196 endif
 197
 198 ###############################################################################
 199 #
 200 # When a Kconfig string contains a filename, it is suitable for
 201 # passing to shell commands. It is surrounded by double-quotes, and
 202 # any double-quotes or backslashes within it are escaped by
 203 # backslashes.
 204 #
 205 # This is no use for dependencies or $(wildcard). We need to strip the
 206 # surrounding quotes and the escaping from quotes and backslashes, and
 207 # we *do* need to escape any spaces in the string. So, for example:
 208 #
 209 # Usage: $(eval $(call config_filename,FOO))
 210 #
 211 # Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
 212 # transformed as described above to be suitable for use within the
 213 # makefile.
 214 #
 215 # Also, if the filename is a relative filename and exists in the source
 216 # tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
 217 # be prefixed to *both* command invocation and dependencies.
 218 #
 219 # Note: We also print the filenames in the quiet_cmd_foo text, and
 220 # perhaps ought to have a version specially escaped for that purpose.
 221 # But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
 222 # enough.  It'll strip the quotes in the common case where there's no
 223 # space and it's a simple filename, and it'll retain the quotes when
 224 # there's a space. There are some esoteric cases in which it'll print
 225 # the wrong thing, but we don't really care. The actual dependencies
 226 # and commands *do* get it right, with various combinations of single
 227 # and double quotes, backslashes and spaces in the filenames.
 228 #
 229 ###############################################################################
 230 #
 231 define config_filename
 232 ifneq ($$(CONFIG_$(1)),"")
 233 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
 234 ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
 235 else
 236 ifeq ($$(wildcard $$($(1)_FILENAME)),)
 237 ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
 238 $(1)_SRCPREFIX := $(srctree)/
 239 endif
 240 endif
 241 endif
 242 endif
 243 endef
 244 #
 245 ###############################################################################
 246
 247 # delete partially updated (i.e. corrupted) files on error
 248 .DELETE_ON_ERROR:
 249
 250 # do not delete intermediate files automatically
 251 .SECONDARY: