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# printing commands 178cmd = @set -e; $(echo-cmd) $(cmd_$(1)) 179 180### 181# if_changed - execute command if any prerequisite is newer than 182# target, or command line has changed 183# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 184# including used config symbols 185# if_changed_rule - as if_changed but execute rule instead 186# See Documentation/kbuild/makefiles.rst for more info 187 188ifneq ($(KBUILD_NOCMDDEP),1) 189# Check if both commands are the same including their order. Result is empty 190# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 191cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 192 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 193else 194cmd-check = $(if $(strip $(cmd_$@)),,1) 195endif 196 197# Replace >$< with >$$< to preserve $ when reloading the .cmd file 198# (needed for make) 199# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 200# (needed for make) 201# Replace >'< with >'\''< to be able to enclose the whole string in '...' 202# (needed for the shell) 203make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 204 205# Find any prerequisites that are newer than target or that do not exist. 206# (This is not true for now; $? should contain any non-existent prerequisites, 207# but it does not work as expected when .SECONDARY is present. This seems a bug 208# of GNU Make.) 209# PHONY targets skipped in both cases. 210newer-prereqs = $(filter-out $(PHONY),$?) 211 212# Execute command if command has changed or prerequisite(s) are updated. 213if_changed = $(if $(newer-prereqs)$(cmd-check), \ 214 $(cmd); \ 215 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 216 217# Execute the command and also postprocess generated .d dependencies file. 218if_changed_dep = $(if $(newer-prereqs)$(cmd-check),$(cmd_and_fixdep),@:) 219 220cmd_and_fixdep = \ 221 $(cmd); \ 222 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ 223 rm -f $(depfile) 224 225# Usage: $(call if_changed_rule,foo) 226# Will check if $(cmd_foo) or any of the prerequisites changed, 227# and if so will execute $(rule_foo). 228if_changed_rule = $(if $(newer-prereqs)$(cmd-check),$(rule_$(1)),@:) 229 230### 231# why - tell why a target got built 232# enabled by make V=2 233# Output (listed in the order they are checked): 234# (1) - due to target is PHONY 235# (2) - due to target missing 236# (3) - due to: file1.h file2.h 237# (4) - due to command line change 238# (5) - due to missing .cmd file 239# (6) - due to target not in $(targets) 240# (1) PHONY targets are always build 241# (2) No target, so we better build it 242# (3) Prerequisite is newer than target 243# (4) The command line stored in the file named dir/.target.cmd 244# differed from actual command line. This happens when compiler 245# options changes 246# (5) No dir/.target.cmd file (used to store command line) 247# (6) No dir/.target.cmd file and target not listed in $(targets) 248# This is a good hint that there is a bug in the kbuild file 249ifeq ($(KBUILD_VERBOSE),2) 250why = \ 251 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 252 $(if $(wildcard $@), \ 253 $(if $(newer-prereqs),- due to: $(newer-prereqs), \ 254 $(if $(cmd-check), \ 255 $(if $(cmd_$@),- due to command line change, \ 256 $(if $(filter $@, $(targets)), \ 257 - due to missing .cmd file, \ 258 - due to $(notdir $@) not in $$(targets) \ 259 ) \ 260 ) \ 261 ) \ 262 ), \ 263 - due to target missing \ 264 ) \ 265 ) 266 267echo-why = $(call escsq, $(strip $(why))) 268endif 269 270############################################################################### 271# 272# When a Kconfig string contains a filename, it is suitable for 273# passing to shell commands. It is surrounded by double-quotes, and 274# any double-quotes or backslashes within it are escaped by 275# backslashes. 276# 277# This is no use for dependencies or $(wildcard). We need to strip the 278# surrounding quotes and the escaping from quotes and backslashes, and 279# we *do* need to escape any spaces in the string. So, for example: 280# 281# Usage: $(eval $(call config_filename,FOO)) 282# 283# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 284# transformed as described above to be suitable for use within the 285# makefile. 286# 287# Also, if the filename is a relative filename and exists in the source 288# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 289# be prefixed to *both* command invocation and dependencies. 290# 291# Note: We also print the filenames in the quiet_cmd_foo text, and 292# perhaps ought to have a version specially escaped for that purpose. 293# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 294# enough. It'll strip the quotes in the common case where there's no 295# space and it's a simple filename, and it'll retain the quotes when 296# there's a space. There are some esoteric cases in which it'll print 297# the wrong thing, but we don't really care. The actual dependencies 298# and commands *do* get it right, with various combinations of single 299# and double quotes, backslashes and spaces in the filenames. 300# 301############################################################################### 302# 303define config_filename 304ifneq ($$(CONFIG_$(1)),"") 305$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 306ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 307else 308ifeq ($$(wildcard $$($(1)_FILENAME)),) 309ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 310$(1)_SRCPREFIX := $(srctree)/ 311endif 312endif 313endif 314endif 315endef 316# 317############################################################################### 318 319# delete partially updated (i.e. corrupted) files on error 320.DELETE_ON_ERROR: 321 322# do not delete intermediate files automatically 323.SECONDARY: 324