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