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 { $(filechk_$(1)); } > $@.tmp; \ 61 if [ -r $@ ] && cmp -s $@ $@.tmp; then \ 62 rm -f $@.tmp; \ 63 else \ 64 $(kecho) ' UPD $@'; \ 65 mv -f $@.tmp $@; \ 66 fi 67endef 68 69###### 70# gcc support functions 71# See documentation in Documentation/kbuild/makefiles.rst 72 73# cc-cross-prefix 74# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) 75# Return first <prefix> where a <prefix>gcc is found in PATH. 76# If no gcc found in PATH with listed prefixes return nothing 77# 78# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it 79# would try to directly execute the shell builtin 'command'. This workaround 80# should be kept for a long time since this issue was fixed only after the 81# GNU Make 4.2.1 release. 82cc-cross-prefix = $(firstword $(foreach c, $(1), \ 83 $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) 84 85# output directory for tests below 86TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) 87 88# try-run 89# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 90# Exit code chooses option. "$$TMP" serves as a temporary file and is 91# automatically cleaned up. 92try-run = $(shell set -e; \ 93 TMP="$(TMPOUT).$$$$.tmp"; \ 94 TMPO="$(TMPOUT).$$$$.o"; \ 95 if ($(1)) >/dev/null 2>&1; \ 96 then echo "$(2)"; \ 97 else echo "$(3)"; \ 98 fi; \ 99 rm -f "$$TMP" "$$TMPO") 100 101# as-option 102# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 103 104as-option = $(call try-run,\ 105 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$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# printing commands 186cmd = @set -e; $(echo-cmd) $(cmd_$(1)) 187 188### 189# if_changed - execute command if any prerequisite is newer than 190# target, or command line has changed 191# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 192# including used config symbols 193# if_changed_rule - as if_changed but execute rule instead 194# See Documentation/kbuild/makefiles.rst for more info 195 196ifneq ($(KBUILD_NOCMDDEP),1) 197# Check if both commands are the same including their order. Result is empty 198# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 199cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 200 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 201else 202cmd-check = $(if $(strip $(cmd_$@)),,1) 203endif 204 205# Replace >$< with >$$< to preserve $ when reloading the .cmd file 206# (needed for make) 207# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 208# (needed for make) 209# Replace >'< with >'\''< to be able to enclose the whole string in '...' 210# (needed for the shell) 211make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 212 213# Find any prerequisites that is newer than target or that does not exist. 214# PHONY targets skipped in both cases. 215any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^) 216 217# Execute command if command has changed or prerequisite(s) are updated. 218if_changed = $(if $(any-prereq)$(cmd-check), \ 219 $(cmd); \ 220 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 221 222# Execute the command and also postprocess generated .d dependencies file. 223if_changed_dep = $(if $(any-prereq)$(cmd-check),$(cmd_and_fixdep),@:) 224 225cmd_and_fixdep = \ 226 $(cmd); \ 227 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ 228 rm -f $(depfile) 229 230# Usage: $(call if_changed_rule,foo) 231# Will check if $(cmd_foo) or any of the prerequisites changed, 232# and if so will execute $(rule_foo). 233if_changed_rule = $(if $(any-prereq)$(cmd-check),$(rule_$(1)),@:) 234 235### 236# why - tell why a target got built 237# enabled by make V=2 238# Output (listed in the order they are checked): 239# (1) - due to target is PHONY 240# (2) - due to target missing 241# (3) - due to: file1.h file2.h 242# (4) - due to command line change 243# (5) - due to missing .cmd file 244# (6) - due to target not in $(targets) 245# (1) PHONY targets are always build 246# (2) No target, so we better build it 247# (3) Prerequisite is newer than target 248# (4) The command line stored in the file named dir/.target.cmd 249# differed from actual command line. This happens when compiler 250# options changes 251# (5) No dir/.target.cmd file (used to store command line) 252# (6) No dir/.target.cmd file and target not listed in $(targets) 253# This is a good hint that there is a bug in the kbuild file 254ifeq ($(KBUILD_VERBOSE),2) 255why = \ 256 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 257 $(if $(wildcard $@), \ 258 $(if $(any-prereq),- due to: $(any-prereq), \ 259 $(if $(cmd-check), \ 260 $(if $(cmd_$@),- due to command line change, \ 261 $(if $(filter $@, $(targets)), \ 262 - due to missing .cmd file, \ 263 - due to $(notdir $@) not in $$(targets) \ 264 ) \ 265 ) \ 266 ) \ 267 ), \ 268 - due to target missing \ 269 ) \ 270 ) 271 272echo-why = $(call escsq, $(strip $(why))) 273endif 274 275############################################################################### 276# 277# When a Kconfig string contains a filename, it is suitable for 278# passing to shell commands. It is surrounded by double-quotes, and 279# any double-quotes or backslashes within it are escaped by 280# backslashes. 281# 282# This is no use for dependencies or $(wildcard). We need to strip the 283# surrounding quotes and the escaping from quotes and backslashes, and 284# we *do* need to escape any spaces in the string. So, for example: 285# 286# Usage: $(eval $(call config_filename,FOO)) 287# 288# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 289# transformed as described above to be suitable for use within the 290# makefile. 291# 292# Also, if the filename is a relative filename and exists in the source 293# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 294# be prefixed to *both* command invocation and dependencies. 295# 296# Note: We also print the filenames in the quiet_cmd_foo text, and 297# perhaps ought to have a version specially escaped for that purpose. 298# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 299# enough. It'll strip the quotes in the common case where there's no 300# space and it's a simple filename, and it'll retain the quotes when 301# there's a space. There are some esoteric cases in which it'll print 302# the wrong thing, but we don't really care. The actual dependencies 303# and commands *do* get it right, with various combinations of single 304# and double quotes, backslashes and spaces in the filenames. 305# 306############################################################################### 307# 308define config_filename 309ifneq ($$(CONFIG_$(1)),"") 310$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 311ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 312else 313ifeq ($$(wildcard $$($(1)_FILENAME)),) 314ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 315$(1)_SRCPREFIX := $(srctree)/ 316endif 317endif 318endif 319endif 320endef 321# 322############################################################################### 323 324# delete partially updated (i.e. corrupted) files on error 325.DELETE_ON_ERROR: 326 327# do not delete intermediate files automatically 328.SECONDARY: 329
