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