1#### 2# kbuild: Generic definitions 3 4# Convenient variables 5comma := , 6quote := " 7squote := ' 8empty := 9space := $(empty) $(empty) 10space_escape := _-_SPACE_-_ 11 12### 13# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 14dot-target = $(dir $@).$(notdir $@) 15 16### 17# The temporary file to save gcc -MD generated dependencies must not 18# contain a comma 19depfile = $(subst $(comma),_,$(dot-target).d) 20 21### 22# filename of target with directory and extension stripped 23basetarget = $(basename $(notdir $@)) 24 25### 26# filename of first prerequisite with directory and extension stripped 27baseprereq = $(basename $(notdir $<)) 28 29### 30# Escape single quote for use in echo statements 31escsq = $(subst $(squote),'\$(squote)',$1) 32 33### 34# Easy method for doing a status message 35 kecho := : 36 quiet_kecho := echo 37silent_kecho := : 38kecho := $($(quiet)kecho) 39 40### 41# filechk is used to check if the content of a generated file is updated. 42# Sample usage: 43# define filechk_sample 44# echo $KERNELRELEASE 45# endef 46# version.h : Makefile 47# $(call filechk,sample) 48# The rule defined shall write to stdout the content of the new file. 49# The existing file will be compared with the new one. 50# - If no file exist it is created 51# - If the content differ the new file is used 52# - If they are equal no change, and no timestamp update 53# - stdin is piped in from the first prerequisite ($<) so one has 54# to specify a valid file as first prerequisite (often the kbuild file) 55define filechk 56 $(Q)set -e; \ 57 $(kecho) ' CHK $@'; \ 58 mkdir -p $(dir $@); \ 59 $(filechk_$(1)) < $< > $@.tmp; \ 60 if [ -r $@ ] && cmp -s $@ $@.tmp; then \ 61 rm -f $@.tmp; \ 62 else \ 63 $(kecho) ' UPD $@'; \ 64 mv -f $@.tmp $@; \ 65 fi 66endef 67 68###### 69# gcc support functions 70# See documentation in Documentation/kbuild/makefiles.txt 71 72# cc-cross-prefix 73# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) 74# Return first prefix where a prefix$(CC) is found in PATH. 75# If no $(CC) found in PATH with listed prefixes return nothing 76cc-cross-prefix = \ 77 $(word 1, $(foreach c,$(1), \ 78 $(shell set -e; \ 79 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \ 80 echo $(c); \ 81 fi))) 82 83# output directory for tests below 84TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) 85 86# try-run 87# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 88# Exit code chooses option. "$$TMP" is can be used as temporary file and 89# is automatically cleaned up. 90try-run = $(shell set -e; \ 91 TMP="$(TMPOUT).$$$$.tmp"; \ 92 TMPO="$(TMPOUT).$$$$.o"; \ 93 if ($(1)) >/dev/null 2>&1; \ 94 then echo "$(2)"; \ 95 else echo "$(3)"; \ 96 fi; \ 97 rm -f "$$TMP" "$$TMPO") 98 99# as-option 100# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 101 102as-option = $(call try-run,\ 103 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 104 105# as-instr 106# Usage: cflags-y += $(call as-instr,instr,option1,option2) 107 108as-instr = $(call try-run,\ 109 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 110 111# cc-option 112# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 113 114cc-option = $(call try-run,\ 115 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 116 117# cc-option-yn 118# Usage: flag := $(call cc-option-yn,-march=winchip-c6) 119cc-option-yn = $(call try-run,\ 120 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 121 122# cc-option-align 123# Prefix align with either -falign or -malign 124cc-option-align = $(subst -functions=0,,\ 125 $(call cc-option,-falign-functions=0,-malign-functions=0)) 126 127# cc-disable-warning 128# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 129cc-disable-warning = $(call try-run,\ 130 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 131 132# cc-name 133# Expands to either gcc or clang 134cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) 135 136# cc-version 137cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) 138 139# cc-fullversion 140cc-fullversion = $(shell $(CONFIG_SHELL) \ 141 $(srctree)/scripts/gcc-version.sh -p $(CC)) 142 143# cc-ifversion 144# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 145cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4)) 146 147# cc-ldoption 148# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) 149cc-ldoption = $(call try-run,\ 150 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) 151 152# ld-option 153# Usage: LDFLAGS += $(call ld-option, -X) 154ld-option = $(call try-run,\ 155 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) 156 157# ar-option 158# Usage: KBUILD_ARFLAGS := $(call ar-option,D) 159# Important: no spaces around options 160ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) 161 162# ld-version 163# Note this is mainly for HJ Lu's 3 number binutil versions 164ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) 165 166# ld-ifversion 167# Usage: $(call ld-ifversion, -ge, 22252, y) 168ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4)) 169 170###### 171 172### 173# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 174# Usage: 175# $(Q)$(MAKE) $(build)=dir 176build := -f $(srctree)/scripts/Makefile.build obj 177 178### 179# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= 180# Usage: 181# $(Q)$(MAKE) $(modbuiltin)=dir 182modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj 183 184### 185# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= 186# Usage: 187# $(Q)$(MAKE) $(dtbinst)=dir 188dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj 189 190### 191# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= 192# Usage: 193# $(Q)$(MAKE) $(clean)=dir 194clean := -f $(srctree)/scripts/Makefile.clean obj 195 196### 197# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj= 198# Usage: 199# $(Q)$(MAKE) $(hdr-inst)=dir 200hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj 201 202# Prefix -I with $(srctree) if it is not an absolute path. 203# skip if -I has no parameter 204addtree = $(if $(patsubst -I%,%,$(1)), \ 205$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)) 206 207# Find all -I options and call addtree 208flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) 209 210# echo command. 211# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 212echo-cmd = $(if $($(quiet)cmd_$(1)),\ 213 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 214 215# printing commands 216cmd = @$(echo-cmd) $(cmd_$(1)) 217 218# Add $(obj)/ for paths that are not absolute 219objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) 220 221### 222# if_changed - execute command if any prerequisite is newer than 223# target, or command line has changed 224# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 225# including used config symbols 226# if_changed_rule - as if_changed but execute rule instead 227# See Documentation/kbuild/makefiles.txt for more info 228 229ifneq ($(KBUILD_NOCMDDEP),1) 230# Check if both arguments are the same including their order. Result is empty 231# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 232arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 233 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 234else 235arg-check = $(if $(strip $(cmd_$@)),,1) 236endif 237 238# Replace >$< with >$$< to preserve $ when reloading the .cmd file 239# (needed for make) 240# Replace >#< with >\#< to avoid starting a comment in the .cmd file 241# (needed for make) 242# Replace >'< with >'\''< to be able to enclose the whole string in '...' 243# (needed for the shell) 244make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1))))) 245 246# Find any prerequisites that is newer than target or that does not exist. 247# PHONY targets skipped in both cases. 248any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) 249 250# Execute command if command has changed or prerequisite(s) are updated. 251# 252if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 253 @set -e; \ 254 $(echo-cmd) $(cmd_$(1)); \ 255 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 256 257# Execute the command and also postprocess generated .d dependencies file. 258if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ 259 @set -e; \ 260 $(cmd_and_fixdep), @:) 261 262ifndef CONFIG_TRIM_UNUSED_KSYMS 263 264cmd_and_fixdep = \ 265 $(echo-cmd) $(cmd_$(1)); \ 266 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ 267 rm -f $(depfile); \ 268 mv -f $(dot-target).tmp $(dot-target).cmd; 269 270else 271 272# Filter out exported kernel symbol names from the preprocessor output. 273# See also __KSYM_DEPS__ in include/linux/export.h. 274# We disable the depfile generation here, so as not to overwrite the existing 275# depfile while fixdep is parsing it. 276flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1))) 277ksym_dep_filter = \ 278 case "$(1)" in \ 279 cc_*_c|cpp_i_c) \ 280 $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \ 281 as_*_S|cpp_s_S) \ 282 $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \ 283 boot*|build*|*cpp_lds_S|dtc|host*|vdso*) : ;; \ 284 *) echo "Don't know how to preprocess $(1)" >&2; false ;; \ 285 esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p' 286 287cmd_and_fixdep = \ 288 $(echo-cmd) $(cmd_$(1)); \ 289 $(ksym_dep_filter) | \ 290 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \ 291 > $(dot-target).tmp; \ 292 rm -f $(depfile); \ 293 mv -f $(dot-target).tmp $(dot-target).cmd; 294 295endif 296 297# Usage: $(call if_changed_rule,foo) 298# Will check if $(cmd_foo) or any of the prerequisites changed, 299# and if so will execute $(rule_foo). 300if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \ 301 @set -e; \ 302 $(rule_$(1)), @:) 303 304### 305# why - tell why a a target got build 306# enabled by make V=2 307# Output (listed in the order they are checked): 308# (1) - due to target is PHONY 309# (2) - due to target missing 310# (3) - due to: file1.h file2.h 311# (4) - due to command line change 312# (5) - due to missing .cmd file 313# (6) - due to target not in $(targets) 314# (1) PHONY targets are always build 315# (2) No target, so we better build it 316# (3) Prerequisite is newer than target 317# (4) The command line stored in the file named dir/.target.cmd 318# differed from actual command line. This happens when compiler 319# options changes 320# (5) No dir/.target.cmd file (used to store command line) 321# (6) No dir/.target.cmd file and target not listed in $(targets) 322# This is a good hint that there is a bug in the kbuild file 323ifeq ($(KBUILD_VERBOSE),2) 324why = \ 325 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 326 $(if $(wildcard $@), \ 327 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \ 328 $(if $(arg-check), \ 329 $(if $(cmd_$@),- due to command line change, \ 330 $(if $(filter $@, $(targets)), \ 331 - due to missing .cmd file, \ 332 - due to $(notdir $@) not in $$(targets) \ 333 ) \ 334 ) \ 335 ) \ 336 ), \ 337 - due to target missing \ 338 ) \ 339 ) 340 341echo-why = $(call escsq, $(strip $(why))) 342endif 343 344############################################################################### 345# 346# When a Kconfig string contains a filename, it is suitable for 347# passing to shell commands. It is surrounded by double-quotes, and 348# any double-quotes or backslashes within it are escaped by 349# backslashes. 350# 351# This is no use for dependencies or $(wildcard). We need to strip the 352# surrounding quotes and the escaping from quotes and backslashes, and 353# we *do* need to escape any spaces in the string. So, for example: 354# 355# Usage: $(eval $(call config_filename,FOO)) 356# 357# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 358# transformed as described above to be suitable for use within the 359# makefile. 360# 361# Also, if the filename is a relative filename and exists in the source 362# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 363# be prefixed to *both* command invocation and dependencies. 364# 365# Note: We also print the filenames in the quiet_cmd_foo text, and 366# perhaps ought to have a version specially escaped for that purpose. 367# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 368# enough. It'll strip the quotes in the common case where there's no 369# space and it's a simple filename, and it'll retain the quotes when 370# there's a space. There are some esoteric cases in which it'll print 371# the wrong thing, but we don't really care. The actual dependencies 372# and commands *do* get it right, with various combinations of single 373# and double quotes, backslashes and spaces in the filenames. 374# 375############################################################################### 376# 377define config_filename 378ifneq ($$(CONFIG_$(1)),"") 379$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 380ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 381else 382ifeq ($$(wildcard $$($(1)_FILENAME)),) 383ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 384$(1)_SRCPREFIX := $(srctree)/ 385endif 386endif 387endif 388endif 389endef 390# 391############################################################################### 392