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 -MD 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# Easy method for doing a status message 37 kecho := : 38 quiet_kecho := echo 39silent_kecho := : 40kecho := $($(quiet)kecho) 41 42### 43# filechk is used to check if the content of a generated file is updated. 44# Sample usage: 45# 46# filechk_sample = echo $(KERNELRELEASE) 47# version.h: FORCE 48# $(call filechk,sample) 49# 50# The rule defined shall write to stdout the content of the new file. 51# The existing file will be compared with the new one. 52# - If no file exist it is created 53# - If the content differ the new file is used 54# - If they are equal no change, and no timestamp update 55# - stdin is piped in from the first prerequisite ($<) so one has 56# to specify a valid file as first prerequisite (often the kbuild file) 57define filechk 58 $(Q)set -e; \ 59 mkdir -p $(dir $@); \ 60 trap "rm -f $(dot-target).tmp" EXIT; \ 61 { $(filechk_$(1)); } > $(dot-target).tmp; \ 62 if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then \ 63 $(kecho) ' UPD $@'; \ 64 mv -f $(dot-target).tmp $@; \ 65 fi 66endef 67 68###### 69# gcc support functions 70# See documentation in Documentation/kbuild/makefiles.rst 71 72# cc-cross-prefix 73# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) 74# Return first <prefix> where a <prefix>gcc is found in PATH. 75# If no gcc found in PATH with listed prefixes return nothing 76# 77# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it 78# would try to directly execute the shell builtin 'command'. This workaround 79# should be kept for a long time since this issue was fixed only after the 80# GNU Make 4.2.1 release. 81cc-cross-prefix = $(firstword $(foreach c, $(1), \ 82 $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) 83 84# output directory for tests below 85TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$ 86 87# try-run 88# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 89# Exit code chooses option. "$$TMP" serves as a temporary file and is 90# automatically cleaned up. 91try-run = $(shell set -e; \ 92 TMP=$(TMPOUT)/tmp; \ 93 TMPO=$(TMPOUT)/tmp.o; \ 94 mkdir -p $(TMPOUT); \ 95 trap "rm -rf $(TMPOUT)" EXIT; \ 96 if ($(1)) >/dev/null 2>&1; \ 97 then echo "$(2)"; \ 98 else echo "$(3)"; \ 99 fi) 100 101# as-option 102# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 103 104as-option = $(call try-run,\ 105 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 106 107# as-instr 108# Usage: cflags-y += $(call as-instr,instr,option1,option2) 109 110as-instr = $(call try-run,\ 111 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 112 113# __cc-option 114# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) 115__cc-option = $(call try-run,\ 116 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) 117 118# Do not attempt to build with gcc plugins during cc-option tests. 119# (And this uses delayed resolution so the flags will be up to date.) 120CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) 121 122# cc-option 123# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 124 125cc-option = $(call __cc-option, $(CC),\ 126 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2)) 127 128# cc-option-yn 129# Usage: flag := $(call cc-option-yn,-march=winchip-c6) 130cc-option-yn = $(call try-run,\ 131 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 132 133# cc-disable-warning 134# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 135cc-disable-warning = $(call try-run,\ 136 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 137 138# cc-ifversion 139# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 140cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4)) 141 142# ld-option 143# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y) 144ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3)) 145 146# ld-version 147# Note this is mainly for HJ Lu's 3 number binutil versions 148ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) 149 150# ld-ifversion 151# Usage: $(call ld-ifversion, -ge, 22252, y) 152ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4)) 153 154###### 155 156### 157# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 158# Usage: 159# $(Q)$(MAKE) $(build)=dir 160build := -f $(srctree)/scripts/Makefile.build obj 161 162### 163# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= 164# Usage: 165# $(Q)$(MAKE) $(modbuiltin)=dir 166modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj 167 168### 169# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= 170# Usage: 171# $(Q)$(MAKE) $(dtbinst)=dir 172dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj 173 174### 175# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= 176# Usage: 177# $(Q)$(MAKE) $(clean)=dir 178clean := -f $(srctree)/scripts/Makefile.clean obj 179 180# echo command. 181# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 182echo-cmd = $(if $($(quiet)cmd_$(1)),\ 183 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 184 185# sink stdout for 'make -s' 186 redirect := 187 quiet_redirect := 188silent_redirect := exec >/dev/null; 189 190# Delete the target on interruption 191# 192# GNU Make automatically deletes the target if it has already been changed by 193# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make 194# will delete incomplete targets), and resume it later. 195# 196# However, this does not work when the stderr is piped to another program, like 197# $ make >&2 | tee log 198# Make dies with SIGPIPE before cleaning the targets. 199# 200# To address it, we clean the target in signal traps. 201# 202# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM. 203# So, we cover them, and also SIGPIPE just in case. 204# 205# Of course, this is unneeded for phony targets. 206delete-on-interrupt = \ 207 $(if $(filter-out $(PHONY), $@), \ 208 $(foreach sig, HUP INT QUIT TERM PIPE, \ 209 trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);)) 210 211# printing commands 212cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(1)) 213 214### 215# if_changed - execute command if any prerequisite is newer than 216# target, or command line has changed 217# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 218# including used config symbols 219# if_changed_rule - as if_changed but execute rule instead 220# See Documentation/kbuild/makefiles.rst for more info 221 222ifneq ($(KBUILD_NOCMDDEP),1) 223# Check if both commands are the same including their order. Result is empty 224# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 225cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 226 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 227else 228cmd-check = $(if $(strip $(cmd_$@)),,1) 229endif 230 231# Replace >$< with >$$< to preserve $ when reloading the .cmd file 232# (needed for make) 233# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 234# (needed for make) 235# Replace >'< with >'\''< to be able to enclose the whole string in '...' 236# (needed for the shell) 237make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 238 239# Find any prerequisites that is newer than target or that does not exist. 240# PHONY targets skipped in both cases. 241any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^) 242 243# Execute command if command has changed or prerequisite(s) are updated. 244if_changed = $(if $(any-prereq)$(cmd-check), \ 245 $(cmd); \ 246 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 247 248# Execute the command and also postprocess generated .d dependencies file. 249if_changed_dep = $(if $(any-prereq)$(cmd-check),$(cmd_and_fixdep),@:) 250 251cmd_and_fixdep = \ 252 $(cmd); \ 253 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ 254 rm -f $(depfile) 255 256# Usage: $(call if_changed_rule,foo) 257# Will check if $(cmd_foo) or any of the prerequisites changed, 258# and if so will execute $(rule_foo). 259if_changed_rule = $(if $(any-prereq)$(cmd-check),$(rule_$(1)),@:) 260 261### 262# why - tell why a target got built 263# enabled by make V=2 264# Output (listed in the order they are checked): 265# (1) - due to target is PHONY 266# (2) - due to target missing 267# (3) - due to: file1.h file2.h 268# (4) - due to command line change 269# (5) - due to missing .cmd file 270# (6) - due to target not in $(targets) 271# (1) PHONY targets are always build 272# (2) No target, so we better build it 273# (3) Prerequisite is newer than target 274# (4) The command line stored in the file named dir/.target.cmd 275# differed from actual command line. This happens when compiler 276# options changes 277# (5) No dir/.target.cmd file (used to store command line) 278# (6) No dir/.target.cmd file and target not listed in $(targets) 279# This is a good hint that there is a bug in the kbuild file 280ifeq ($(KBUILD_VERBOSE),2) 281why = \ 282 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 283 $(if $(wildcard $@), \ 284 $(if $(any-prereq),- due to: $(any-prereq), \ 285 $(if $(cmd-check), \ 286 $(if $(cmd_$@),- due to command line change, \ 287 $(if $(filter $@, $(targets)), \ 288 - due to missing .cmd file, \ 289 - due to $(notdir $@) not in $$(targets) \ 290 ) \ 291 ) \ 292 ) \ 293 ), \ 294 - due to target missing \ 295 ) \ 296 ) 297 298echo-why = $(call escsq, $(strip $(why))) 299endif 300 301############################################################################### 302# 303# When a Kconfig string contains a filename, it is suitable for 304# passing to shell commands. It is surrounded by double-quotes, and 305# any double-quotes or backslashes within it are escaped by 306# backslashes. 307# 308# This is no use for dependencies or $(wildcard). We need to strip the 309# surrounding quotes and the escaping from quotes and backslashes, and 310# we *do* need to escape any spaces in the string. So, for example: 311# 312# Usage: $(eval $(call config_filename,FOO)) 313# 314# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 315# transformed as described above to be suitable for use within the 316# makefile. 317# 318# Also, if the filename is a relative filename and exists in the source 319# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 320# be prefixed to *both* command invocation and dependencies. 321# 322# Note: We also print the filenames in the quiet_cmd_foo text, and 323# perhaps ought to have a version specially escaped for that purpose. 324# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 325# enough. It'll strip the quotes in the common case where there's no 326# space and it's a simple filename, and it'll retain the quotes when 327# there's a space. There are some esoteric cases in which it'll print 328# the wrong thing, but we don't really care. The actual dependencies 329# and commands *do* get it right, with various combinations of single 330# and double quotes, backslashes and spaces in the filenames. 331# 332############################################################################### 333# 334define config_filename 335ifneq ($$(CONFIG_$(1)),"") 336$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 337ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 338else 339ifeq ($$(wildcard $$($(1)_FILENAME)),) 340ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 341$(1)_SRCPREFIX := $(srctree)/ 342endif 343endif 344endif 345endif 346endef 347# 348############################################################################### 349 350# delete partially updated (i.e. corrupted) files on error 351.DELETE_ON_ERROR: 352 353# do not delete intermediate files automatically 354.SECONDARY: 355