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