1#### 2# kbuild: Generic definitions 3 4# Convenient variables 5comma := , 6quote := " 7squote := ' 8empty := 9space := $(empty) $(empty) 10 11### 12# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 13dot-target = $(dir $@).$(notdir $@) 14 15### 16# The temporary file to save gcc -MD generated dependencies must not 17# contain a comma 18depfile = $(subst $(comma),_,$(dot-target).d) 19 20### 21# filename of target with directory and extension stripped 22basetarget = $(basename $(notdir $@)) 23 24### 25# filename of first prerequisite with directory and extension stripped 26baseprereq = $(basename $(notdir $<)) 27 28### 29# Escape single quote for use in echo statements 30escsq = $(subst $(squote),'\$(squote)',$1) 31 32### 33# Easy method for doing a status message 34 kecho := : 35 quiet_kecho := echo 36silent_kecho := : 37kecho := $($(quiet)kecho) 38 39### 40# filechk is used to check if the content of a generated file is updated. 41# Sample usage: 42# define filechk_sample 43# echo $KERNELRELEASE 44# endef 45# version.h : Makefile 46# $(call filechk,sample) 47# The rule defined shall write to stdout the content of the new file. 48# The existing file will be compared with the new one. 49# - If no file exist it is created 50# - If the content differ the new file is used 51# - If they are equal no change, and no timestamp update 52# - stdin is piped in from the first prerequisite ($<) so one has 53# to specify a valid file as first prerequisite (often the kbuild file) 54define filechk 55 $(Q)set -e; \ 56 $(kecho) ' CHK $@'; \ 57 mkdir -p $(dir $@); \ 58 $(filechk_$(1)) < $< > $@.tmp; \ 59 if [ -r $@ ] && cmp -s $@ $@.tmp; then \ 60 rm -f $@.tmp; \ 61 else \ 62 $(kecho) ' UPD $@'; \ 63 mv -f $@.tmp $@; \ 64 fi 65endef 66 67###### 68# gcc support functions 69# See documentation in Documentation/kbuild/makefiles.txt 70 71# cc-cross-prefix 72# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) 73# Return first prefix where a prefix$(CC) is found in PATH. 74# If no $(CC) found in PATH with listed prefixes return nothing 75cc-cross-prefix = \ 76 $(word 1, $(foreach c,$(1), \ 77 $(shell set -e; \ 78 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \ 79 echo $(c); \ 80 fi))) 81 82# output directory for tests below 83TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) 84 85# try-run 86# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 87# Exit code chooses option. "$$TMP" is can be used as temporary file and 88# is automatically cleaned up. 89# modifed for U-Boot: prevent cc-option from leaving .*.su files 90try-run = $(shell set -e; \ 91 TMP="$(TMPOUT).$$$$.tmp"; \ 92 TMPO="$(TMPOUT).$$$$.o"; \ 93 TMPSU="$(TMPOUT).$$$$.su"; \ 94 if ($(1)) >/dev/null 2>&1; \ 95 then echo "$(2)"; \ 96 else echo "$(3)"; \ 97 fi; \ 98 rm -f "$$TMP" "$$TMPO" "$$TMPSU") 99 100# as-option 101# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 102 103as-option = $(call try-run,\ 104 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 105 106# as-instr 107# Usage: cflags-y += $(call as-instr,instr,option1,option2) 108 109as-instr = $(call try-run,\ 110 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 111 112# cc-option 113# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 114 115cc-option = $(call try-run,\ 116 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 117 118# cc-option-yn 119# Usage: flag := $(call cc-option-yn,-march=winchip-c6) 120cc-option-yn = $(call try-run,\ 121 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 122 123# cc-option-align 124# Prefix align with either -falign or -malign 125cc-option-align = $(subst -functions=0,,\ 126 $(call cc-option,-falign-functions=0,-malign-functions=0)) 127 128# cc-disable-warning 129# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 130cc-disable-warning = $(call try-run,\ 131 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 132 133# cc-version 134# Usage gcc-ver := $(call cc-version) 135cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) 136 137# cc-fullversion 138# Usage gcc-ver := $(call cc-fullversion) 139cc-fullversion = $(shell $(CONFIG_SHELL) \ 140 $(srctree)/scripts/gcc-version.sh -p $(CC)) 141 142# cc-ifversion 143# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 144cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3)) 145 146# added for U-Boot 147binutils-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/binutils-version.sh $(AS)) 148dtc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/dtc-version.sh $(DTC)) 149 150# cc-ldoption 151# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) 152cc-ldoption = $(call try-run,\ 153 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) 154 155# ld-option 156# Usage: LDFLAGS += $(call ld-option, -X) 157ld-option = $(call try-run,\ 158 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) 159 160# ar-option 161# Usage: KBUILD_ARFLAGS := $(call ar-option,D) 162# Important: no spaces around options 163ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) 164 165# ld-version 166# Usage: $(call ld-version) 167# Note this is mainly for HJ Lu's 3 number binutil versions 168ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) 169 170# ld-ifversion 171# Usage: $(call ld-ifversion, -ge, 22252, y) 172ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3)) 173 174###### 175 176### 177# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 178# Usage: 179# $(Q)$(MAKE) $(build)=dir 180build := -f $(srctree)/scripts/Makefile.build obj 181 182### 183# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= 184# Usage: 185# $(Q)$(MAKE) $(modbuiltin)=dir 186modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj 187 188# Prefix -I with $(srctree) if it is not an absolute path. 189# skip if -I has no parameter 190addtree = $(if $(patsubst -I%,%,$(1)), \ 191$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)) 192 193# Find all -I options and call addtree 194flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) 195 196# echo command. 197# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 198echo-cmd = $(if $($(quiet)cmd_$(1)),\ 199 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 200 201# printing commands 202cmd = @$(echo-cmd) $(cmd_$(1)) 203 204# Add $(obj)/ for paths that are not absolute 205objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) 206 207### 208# if_changed - execute command if any prerequisite is newer than 209# target, or command line has changed 210# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 211# including used config symbols 212# if_changed_rule - as if_changed but execute rule instead 213# See Documentation/kbuild/makefiles.txt for more info 214 215ifneq ($(KBUILD_NOCMDDEP),1) 216# Check if both arguments has same arguments. Result is empty string if equal. 217# User may override this check using make KBUILD_NOCMDDEP=1 218arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ 219 $(filter-out $(cmd_$@), $(cmd_$(1))) ) 220else 221arg-check = $(if $(strip $(cmd_$@)),,1) 222endif 223 224# Replace >$< with >$$< to preserve $ when reloading the .cmd file 225# (needed for make) 226# Replace >#< with >\#< to avoid starting a comment in the .cmd file 227# (needed for make) 228# Replace >'< with >'\''< to be able to enclose the whole string in '...' 229# (needed for the shell) 230make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1))))) 231 232# Find any prerequisites that is newer than target or that does not exist. 233# PHONY targets skipped in both cases. 234any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) 235 236# Execute command if command has changed or prerequisite(s) are updated. 237# 238if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 239 @set -e; \ 240 $(echo-cmd) $(cmd_$(1)); \ 241 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) 242 243# Execute the command and also postprocess generated .d dependencies file. 244if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ 245 @set -e; \ 246 $(echo-cmd) $(cmd_$(1)); \ 247 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ 248 rm -f $(depfile); \ 249 mv -f $(dot-target).tmp $(dot-target).cmd) 250 251# Usage: $(call if_changed_rule,foo) 252# Will check if $(cmd_foo) or any of the prerequisites changed, 253# and if so will execute $(rule_foo). 254if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \ 255 @set -e; \ 256 $(rule_$(1))) 257 258### 259# why - tell why a a target got build 260# enabled by make V=2 261# Output (listed in the order they are checked): 262# (1) - due to target is PHONY 263# (2) - due to target missing 264# (3) - due to: file1.h file2.h 265# (4) - due to command line change 266# (5) - due to missing .cmd file 267# (6) - due to target not in $(targets) 268# (1) PHONY targets are always build 269# (2) No target, so we better build it 270# (3) Prerequisite is newer than target 271# (4) The command line stored in the file named dir/.target.cmd 272# differed from actual command line. This happens when compiler 273# options changes 274# (5) No dir/.target.cmd file (used to store command line) 275# (6) No dir/.target.cmd file and target not listed in $(targets) 276# This is a good hint that there is a bug in the kbuild file 277ifeq ($(KBUILD_VERBOSE),2) 278why = \ 279 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 280 $(if $(wildcard $@), \ 281 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \ 282 $(if $(arg-check), \ 283 $(if $(cmd_$@),- due to command line change, \ 284 $(if $(filter $@, $(targets)), \ 285 - due to missing .cmd file, \ 286 - due to $(notdir $@) not in $$(targets) \ 287 ) \ 288 ) \ 289 ) \ 290 ), \ 291 - due to target missing \ 292 ) \ 293 ) 294 295echo-why = $(call escsq, $(strip $(why))) 296endif 297