1# SPDX-License-Identifier: GPL-2.0 2#### 3# kbuild: Generic definitions 4 5# Convenient variables 6comma := , 7quote := " 8squote := ' 9empty := 10space := $(empty) $(empty) 11space_escape := _-_SPACE_-_ 12pound := \# 13 14### 15# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 16dot-target = $(dir $@).$(notdir $@) 17 18### 19# The temporary file to save gcc -MMD generated dependencies must not 20# contain a comma 21depfile = $(subst $(comma),_,$(dot-target).d) 22 23### 24# filename of target with directory and extension stripped 25basetarget = $(basename $(notdir $@)) 26 27### 28# real prerequisites without phony targets 29real-prereqs = $(filter-out $(PHONY), $^) 30 31### 32# Escape single quote for use in echo statements 33escsq = $(subst $(squote),'\$(squote)',$1) 34 35### 36# Quote a string to pass it to C files. foo => '"foo"' 37stringify = $(squote)$(quote)$1$(quote)$(squote) 38 39### 40# Easy method for doing a status message 41 kecho := : 42 quiet_kecho := echo 43silent_kecho := : 44kecho := $($(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 59define 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 69endef 70 71### 72# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 73# Usage: 74# $(Q)$(MAKE) $(build)=dir 75build := -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 81dtbinst := -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 87clean := -f $(srctree)/scripts/Makefile.clean obj 88 89# echo command. 90# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 91echo-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 := 97silent_redirect := exec >/dev/null; 98 99# Delete the target on interruption 100# 101# GNU Make automatically deletes the target if it has already been changed by 102# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make 103# will delete incomplete targets), and resume it later. 104# 105# However, this does not work when the stderr is piped to another program, like 106# $ make >&2 | tee log 107# Make dies with SIGPIPE before cleaning the targets. 108# 109# To address it, we clean the target in signal traps. 110# 111# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM. 112# So, we cover them, and also SIGPIPE just in case. 113# 114# Of course, this is unneeded for phony targets. 115delete-on-interrupt = \ 116 $(if $(filter-out $(PHONY), $@), \ 117 $(foreach sig, HUP INT QUIT TERM PIPE, \ 118 trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);)) 119 120# printing commands 121cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(1)) 122 123### 124# if_changed - execute command if any prerequisite is newer than 125# target, or command line has changed 126# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 127# including used config symbols 128# if_changed_rule - as if_changed but execute rule instead 129# See Documentation/kbuild/makefiles.rst for more info 130 131ifneq ($(KBUILD_NOCMDDEP),1) 132# Check if both commands are the same including their order. Result is empty 133# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 134cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 135 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 136else 137cmd-check = $(if $(strip $(cmd_$@)),,1) 138endif 139 140# Replace >$< with >$$< to preserve $ when reloading the .cmd file 141# (needed for make) 142# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 143# (needed for make) 144# Replace >'< with >'\''< to be able to enclose the whole string in '...' 145# (needed for the shell) 146make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 147 148# Find any prerequisites that are newer than target or that do not exist. 149# (This is not true for now; $? should contain any non-existent prerequisites, 150# but it does not work as expected when .SECONDARY is present. This seems a bug 151# of GNU Make.) 152# PHONY targets skipped in both cases. 153newer-prereqs = $(filter-out $(PHONY),$?) 154 155# It is a typical mistake to forget the FORCE prerequisite. Check it here so 156# no more breakage will slip in. 157check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing)) 158 159if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE) 160 161# Execute command if command has changed or prerequisite(s) are updated. 162if_changed = $(if $(if-changed-cond), \ 163 $(cmd); \ 164 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 165 166# Execute the command and also postprocess generated .d dependencies file. 167if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:) 168 169cmd_and_fixdep = \ 170 $(cmd); \ 171 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ 172 rm -f $(depfile) 173 174# Usage: $(call if_changed_rule,foo) 175# Will check if $(cmd_foo) or any of the prerequisites changed, 176# and if so will execute $(rule_foo). 177if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:) 178 179### 180# why - tell why a target got built 181# enabled by make V=2 182# Output (listed in the order they are checked): 183# (1) - due to target is PHONY 184# (2) - due to target missing 185# (3) - due to: file1.h file2.h 186# (4) - due to command line change 187# (5) - due to missing .cmd file 188# (6) - due to target not in $(targets) 189# (1) PHONY targets are always build 190# (2) No target, so we better build it 191# (3) Prerequisite is newer than target 192# (4) The command line stored in the file named dir/.target.cmd 193# differed from actual command line. This happens when compiler 194# options changes 195# (5) No dir/.target.cmd file (used to store command line) 196# (6) No dir/.target.cmd file and target not listed in $(targets) 197# This is a good hint that there is a bug in the kbuild file 198ifeq ($(KBUILD_VERBOSE),2) 199why = \ 200 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 201 $(if $(wildcard $@), \ 202 $(if $(newer-prereqs),- due to: $(newer-prereqs), \ 203 $(if $(cmd-check), \ 204 $(if $(cmd_$@),- due to command line change, \ 205 $(if $(filter $@, $(targets)), \ 206 - due to missing .cmd file, \ 207 - due to $(notdir $@) not in $$(targets) \ 208 ) \ 209 ) \ 210 ) \ 211 ), \ 212 - due to target missing \ 213 ) \ 214 ) 215 216echo-why = $(call escsq, $(strip $(why))) 217endif 218 219############################################################################### 220# 221# When a Kconfig string contains a filename, it is suitable for 222# passing to shell commands. It is surrounded by double-quotes, and 223# any double-quotes or backslashes within it are escaped by 224# backslashes. 225# 226# This is no use for dependencies or $(wildcard). We need to strip the 227# surrounding quotes and the escaping from quotes and backslashes, and 228# we *do* need to escape any spaces in the string. So, for example: 229# 230# Usage: $(eval $(call config_filename,FOO)) 231# 232# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 233# transformed as described above to be suitable for use within the 234# makefile. 235# 236# Also, if the filename is a relative filename and exists in the source 237# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 238# be prefixed to *both* command invocation and dependencies. 239# 240# Note: We also print the filenames in the quiet_cmd_foo text, and 241# perhaps ought to have a version specially escaped for that purpose. 242# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 243# enough. It'll strip the quotes in the common case where there's no 244# space and it's a simple filename, and it'll retain the quotes when 245# there's a space. There are some esoteric cases in which it'll print 246# the wrong thing, but we don't really care. The actual dependencies 247# and commands *do* get it right, with various combinations of single 248# and double quotes, backslashes and spaces in the filenames. 249# 250############################################################################### 251# 252define config_filename 253ifneq ($$(CONFIG_$(1)),"") 254$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 255ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 256else 257ifeq ($$(wildcard $$($(1)_FILENAME)),) 258ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 259$(1)_SRCPREFIX := $(srctree)/ 260endif 261endif 262endif 263endif 264endef 265# 266############################################################################### 267 268# delete partially updated (i.e. corrupted) files on error 269.DELETE_ON_ERROR: 270 271# do not delete intermediate files automatically 272.SECONDARY: 273