| 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: |