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-ifversion 145# Usage: $(call ld-ifversion, -ge, 22252, y) 146ld-ifversion = $(shell [ $(CONFIG_LD_VERSION)0 $(1) $(2)0 ] && echo $(3) || echo $(4)) 147 148###### 149 150### 151# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 152# Usage: 153# $(Q)$(MAKE) $(build)=dir 154build := -f $(srctree)/scripts/Makefile.build obj 155 156### 157# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= 158# Usage: 159# $(Q)$(MAKE) $(dtbinst)=dir 160dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj 161 162### 163# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= 164# Usage: 165# $(Q)$(MAKE) $(clean)=dir 166clean := -f $(srctree)/scripts/Makefile.clean obj 167 168# echo command. 169# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 170echo-cmd = $(if $($(quiet)cmd_$(1)),\ 171 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 172 173# printing commands 174cmd = @set -e; $(echo-cmd) $(cmd_$(1)) 175 176### 177# if_changed - execute command if any prerequisite is newer than 178# target, or command line has changed 179# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 180# including used config symbols 181# if_changed_rule - as if_changed but execute rule instead 182# See Documentation/kbuild/makefiles.rst for more info 183 184ifneq ($(KBUILD_NOCMDDEP),1) 185# Check if both commands are the same including their order. Result is empty 186# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 187cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 188 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 189else 190cmd-check = $(if $(strip $(cmd_$@)),,1) 191endif 192 193# Replace >$< with >$$< to preserve $ when reloading the .cmd file 194# (needed for make) 195# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 196# (needed for make) 197# Replace >'< with >'\''< to be able to enclose the whole string in '...' 198# (needed for the shell) 199make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 200 201# Find any prerequisites that are newer than target or that do not exist. 202# (This is not true for now; $? should contain any non-existent prerequisites, 203# but it does not work as expected when .SECONDARY is present. This seems a bug 204# of GNU Make.) 205# PHONY targets skipped in both cases. 206newer-prereqs = $(filter-out $(PHONY),$?) 207 208# Execute command if command has changed or prerequisite(s) are updated. 209if_changed = $(if $(newer-prereqs)$(cmd-check), \ 210 $(cmd); \ 211 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 212 213# Execute the command and also postprocess generated .d dependencies file. 214if_changed_dep = $(if $(newer-prereqs)$(cmd-check),$(cmd_and_fixdep),@:) 215 216cmd_and_fixdep = \ 217 $(cmd); \ 218 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ 219 rm -f $(depfile) 220 221# Usage: $(call if_changed_rule,foo) 222# Will check if $(cmd_foo) or any of the prerequisites changed, 223# and if so will execute $(rule_foo). 224if_changed_rule = $(if $(newer-prereqs)$(cmd-check),$(rule_$(1)),@:) 225 226### 227# why - tell why a target got built 228# enabled by make V=2 229# Output (listed in the order they are checked): 230# (1) - due to target is PHONY 231# (2) - due to target missing 232# (3) - due to: file1.h file2.h 233# (4) - due to command line change 234# (5) - due to missing .cmd file 235# (6) - due to target not in $(targets) 236# (1) PHONY targets are always build 237# (2) No target, so we better build it 238# (3) Prerequisite is newer than target 239# (4) The command line stored in the file named dir/.target.cmd 240# differed from actual command line. This happens when compiler 241# options changes 242# (5) No dir/.target.cmd file (used to store command line) 243# (6) No dir/.target.cmd file and target not listed in $(targets) 244# This is a good hint that there is a bug in the kbuild file 245ifeq ($(KBUILD_VERBOSE),2) 246why = \ 247 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 248 $(if $(wildcard $@), \ 249 $(if $(newer-prereqs),- due to: $(newer-prereqs), \ 250 $(if $(cmd-check), \ 251 $(if $(cmd_$@),- due to command line change, \ 252 $(if $(filter $@, $(targets)), \ 253 - due to missing .cmd file, \ 254 - due to $(notdir $@) not in $$(targets) \ 255 ) \ 256 ) \ 257 ) \ 258 ), \ 259 - due to target missing \ 260 ) \ 261 ) 262 263echo-why = $(call escsq, $(strip $(why))) 264endif 265 266############################################################################### 267# 268# When a Kconfig string contains a filename, it is suitable for 269# passing to shell commands. It is surrounded by double-quotes, and 270# any double-quotes or backslashes within it are escaped by 271# backslashes. 272# 273# This is no use for dependencies or $(wildcard). We need to strip the 274# surrounding quotes and the escaping from quotes and backslashes, and 275# we *do* need to escape any spaces in the string. So, for example: 276# 277# Usage: $(eval $(call config_filename,FOO)) 278# 279# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 280# transformed as described above to be suitable for use within the 281# makefile. 282# 283# Also, if the filename is a relative filename and exists in the source 284# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 285# be prefixed to *both* command invocation and dependencies. 286# 287# Note: We also print the filenames in the quiet_cmd_foo text, and 288# perhaps ought to have a version specially escaped for that purpose. 289# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 290# enough. It'll strip the quotes in the common case where there's no 291# space and it's a simple filename, and it'll retain the quotes when 292# there's a space. There are some esoteric cases in which it'll print 293# the wrong thing, but we don't really care. The actual dependencies 294# and commands *do* get it right, with various combinations of single 295# and double quotes, backslashes and spaces in the filenames. 296# 297############################################################################### 298# 299define config_filename 300ifneq ($$(CONFIG_$(1)),"") 301$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 302ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 303else 304ifeq ($$(wildcard $$($(1)_FILENAME)),) 305ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 306$(1)_SRCPREFIX := $(srctree)/ 307endif 308endif 309endif 310endif 311endef 312# 313############################################################################### 314 315# delete partially updated (i.e. corrupted) files on error 316.DELETE_ON_ERROR: 317 318# do not delete intermediate files automatically 319.SECONDARY: 320