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