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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 | # SPDX-License-Identifier: GPL-2.0 #### # kbuild: Generic definitions # Convenient variables comma := , quote := " squote := ' empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ pound := \# ### # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o dot-target = $(dir $@).$(notdir $@) ### # Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o tmp-target = $(dir $@).tmp_$(notdir $@) ### # The temporary file to save gcc -MMD generated dependencies must not # contain a comma depfile = $(subst $(comma),_,$(dot-target).d) ### # filename of target with directory and extension stripped basetarget = $(basename $(notdir $@)) ### # real prerequisites without phony targets real-prereqs = $(filter-out $(PHONY), $^) ### # Escape single quote for use in echo statements escsq = $(subst $(squote),'\$(squote)',$1) ### # Quote a string to pass it to C files. foo => '"foo"' stringify = $(squote)$(quote)$1$(quote)$(squote) ### # Easy method for doing a status message kecho := : quiet_kecho := echo silent_kecho := : kecho := $($(quiet)kecho) ### # filechk is used to check if the content of a generated file is updated. # Sample usage: # # filechk_sample = echo $(KERNELRELEASE) # version.h: FORCE # $(call filechk,sample) # # The rule defined shall write to stdout the content of the new file. # The existing file will be compared with the new one. # - If no file exist it is created # - If the content differ the new file is used # - If they are equal no change, and no timestamp update define filechk $(check-FORCE) $(Q)set -e; \ mkdir -p $(dir $@); \ trap "rm -f $(dot-target).tmp" EXIT; \ { $(filechk_$(1)); } > $(dot-target).tmp; \ if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then \ $(kecho) ' UPD $@'; \ mv -f $(dot-target).tmp $@; \ fi endef ### # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= # Usage: # $(Q)$(MAKE) $(build)=dir build := -f $(srctree)/scripts/Makefile.build obj ### # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= # Usage: # $(Q)$(MAKE) $(dtbinst)=dir dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj ### # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= # Usage: # $(Q)$(MAKE) $(clean)=dir clean := -f $(srctree)/scripts/Makefile.clean obj # echo command. # Short version is used, if $(quiet) equals `quiet_', otherwise full one. echo-cmd = $(if $($(quiet)cmd_$(1)),\ echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) # sink stdout for 'make -s' redirect := quiet_redirect := silent_redirect := exec >/dev/null; # Delete the target on interruption # # GNU Make automatically deletes the target if it has already been changed by # the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make # will delete incomplete targets), and resume it later. # # However, this does not work when the stderr is piped to another program, like # $ make >&2 | tee log # Make dies with SIGPIPE before cleaning the targets. # # To address it, we clean the target in signal traps. # # Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM. # So, we cover them, and also SIGPIPE just in case. # # Of course, this is unneeded for phony targets. delete-on-interrupt = \ $(if $(filter-out $(PHONY), $@), \ $(foreach sig, HUP INT QUIT TERM PIPE, \ trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);)) # printing commands cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(1)) ### # if_changed - execute command if any prerequisite is newer than # target, or command line has changed # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies # including used config symbols # if_changed_rule - as if_changed but execute rule instead # See Documentation/kbuild/makefiles.rst for more info ifneq ($(KBUILD_NOCMDDEP),1) # Check if both commands are the same including their order. Result is empty # string if equal. User may override this check using make KBUILD_NOCMDDEP=1 cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) else cmd-check = $(if $(strip $(cmd_$@)),,1) endif # Replace >$< with >$$< to preserve $ when reloading the .cmd file # (needed for make) # Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file # (needed for make) # Replace >'< with >'\''< to be able to enclose the whole string in '...' # (needed for the shell) make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) # Find any prerequisites that are newer than target or that do not exist. # (This is not true for now; $? should contain any non-existent prerequisites, # but it does not work as expected when .SECONDARY is present. This seems a bug # of GNU Make.) # PHONY targets skipped in both cases. newer-prereqs = $(filter-out $(PHONY),$?) # It is a typical mistake to forget the FORCE prerequisite. Check it here so # no more breakage will slip in. check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing)) if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE) # Execute command if command has changed or prerequisite(s) are updated. if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:) cmd_and_savecmd = \ $(cmd); \ printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd # Execute the command and also postprocess generated .d dependencies file. if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:) cmd_and_fixdep = \ $(cmd); \ scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ rm -f $(depfile) # Usage: $(call if_changed_rule,foo) # Will check if $(cmd_foo) or any of the prerequisites changed, # and if so will execute $(rule_foo). if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:) ### # why - tell why a target got built # enabled by make V=2 # Output (listed in the order they are checked): # (1) - due to target is PHONY # (2) - due to target missing # (3) - due to: file1.h file2.h # (4) - due to command line change # (5) - due to missing .cmd file # (6) - due to target not in $(targets) # (1) PHONY targets are always build # (2) No target, so we better build it # (3) Prerequisite is newer than target # (4) The command line stored in the file named dir/.target.cmd # differed from actual command line. This happens when compiler # options changes # (5) No dir/.target.cmd file (used to store command line) # (6) No dir/.target.cmd file and target not listed in $(targets) # This is a good hint that there is a bug in the kbuild file ifeq ($(KBUILD_VERBOSE),2) why = \ $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ $(if $(wildcard $@), \ $(if $(newer-prereqs),- due to: $(newer-prereqs), \ $(if $(cmd-check), \ $(if $(cmd_$@),- due to command line change, \ $(if $(filter $@, $(targets)), \ - due to missing .cmd file, \ - due to $(notdir $@) not in $$(targets) \ ) \ ) \ ) \ ), \ - due to target missing \ ) \ ) echo-why = $(call escsq, $(strip $(why))) endif ############################################################################### # delete partially updated (i.e. corrupted) files on error .DELETE_ON_ERROR: # do not delete intermediate files automatically .SECONDARY: |