1 #### 2 # kbuild: Generic definitions 3 4 # Convenient variables 5 comma := , 6 squote := ' 7 empty := 8 space := $(empty) $(empty) 9 10 ### 11 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 12 dot-target = $(dir $@).$(notdir $@) 13 14 ### 15 # The temporary file to save gcc -MD generated dependencies must not 16 # contain a comma 17 depfile = $(subst $(comma),_,$(dot-target).d) 18 19 ### 20 # filename of target with directory and extension stripped 21 basetarget = $(basename $(notdir $@)) 22 23 ### 24 # filename of first prerequisite with directory and extension stripped 25 baseprereq = $(basename $(notdir $<)) 26 27 ### 28 # Escape single quote for use in echo statements 29 escsq = $(subst $(squote),'\$(squote)',$1) 30 31 ### 32 # Easy method for doing a status message 33 kecho := : 34 quiet_kecho := echo 35 silent_kecho := : 36 kecho := $($(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) 53 define 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 64 endef 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 74 cc-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 82 TMPOUT := $(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 try-run = $(shell set -e; \ 89 TMP="$(TMPOUT).$$$$.tmp"; \ 90 TMPO="$(TMPOUT).$$$$.o"; \ 91 if ($(1)) >/dev/null 2>&1; \ 92 then echo "$(2)"; \ 93 else echo "$(3)"; \ 94 fi; \ 95 rm -f "$$TMP" "$$TMPO") 96 97 # as-option 98 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 99 100 as-option = $(call try-run,\ 101 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 102 103 # as-instr 104 # Usage: cflags-y += $(call as-instr,instr,option1,option2) 105 106 as-instr = $(call try-run,\ 107 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 108 109 # cc-option 110 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 111 112 cc-option = $(call try-run,\ 113 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) 114 115 # cc-option-yn 116 # Usage: flag := $(call cc-option-yn,-march=winchip-c6) 117 cc-option-yn = $(call try-run,\ 118 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 119 120 # cc-option-align 121 # Prefix align with either -falign or -malign 122 cc-option-align = $(subst -functions=0,,\ 123 $(call cc-option,-falign-functions=0,-malign-functions=0)) 124 125 # cc-disable-warning 126 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 127 cc-disable-warning = $(call try-run,\ 128 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 129 130 # cc-version 131 # Usage gcc-ver := $(call cc-version) 132 cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) 133 134 # cc-fullversion 135 # Usage gcc-ver := $(call cc-fullversion) 136 cc-fullversion = $(shell $(CONFIG_SHELL) \ 137 $(srctree)/scripts/gcc-version.sh -p $(CC)) 138 139 # cc-ifversion 140 # Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 141 cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3)) 142 143 # cc-ldoption 144 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) 145 cc-ldoption = $(call try-run,\ 146 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) 147 148 # ld-option 149 # Usage: LDFLAGS += $(call ld-option, -X) 150 ld-option = $(call try-run,\ 151 $(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) 152 153 # ar-option 154 # Usage: KBUILD_ARFLAGS := $(call ar-option,D) 155 # Important: no spaces around options 156 ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) 157 158 ###### 159 160 ### 161 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 162 # Usage: 163 # $(Q)$(MAKE) $(build)=dir 164 build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj 165 166 ### 167 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= 168 # Usage: 169 # $(Q)$(MAKE) $(modbuiltin)=dir 170 modbuiltin := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.modbuiltin obj 171 172 # Prefix -I with $(srctree) if it is not an absolute path. 173 # skip if -I has no parameter 174 addtree = $(if $(patsubst -I%,%,$(1)), \ 175 $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)) 176 177 # Find all -I options and call addtree 178 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o))) 179 180 # echo command. 181 # Short version is used, if $(quiet) equals `quiet_', otherwise full one. 182 echo-cmd = $(if $($(quiet)cmd_$(1)),\ 183 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 184 185 # printing commands 186 cmd = @$(echo-cmd) $(cmd_$(1)) 187 188 # Add $(obj)/ for paths that are not absolute 189 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) 190 191 ### 192 # if_changed - execute command if any prerequisite is newer than 193 # target, or command line has changed 194 # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 195 # including used config symbols 196 # if_changed_rule - as if_changed but execute rule instead 197 # See Documentation/kbuild/makefiles.txt for more info 198 199 ifneq ($(KBUILD_NOCMDDEP),1) 200 # Check if both arguments has same arguments. Result is empty string if equal. 201 # User may override this check using make KBUILD_NOCMDDEP=1 202 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ 203 $(filter-out $(cmd_$@), $(cmd_$(1))) ) 204 else 205 arg-check = $(if $(strip $(cmd_$@)),,1) 206 endif 207 208 # >'< substitution is for echo to work, 209 # >$< substitution to preserve $ when reloading .cmd file 210 # note: when using inline perl scripts [perl -e '...$$t=1;...'] 211 # in $(cmd_xxx) double $$ your perl vars 212 make-cmd = $(subst \\,\\\\,$(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))) 213 214 # Find any prerequisites that is newer than target or that does not exist. 215 # PHONY targets skipped in both cases. 216 any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) 217 218 # Execute command if command has changed or prerequisite(s) are updated. 219 # 220 if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ 221 @set -e; \ 222 $(echo-cmd) $(cmd_$(1)); \ 223 echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) 224 225 # Execute the command and also postprocess generated .d dependencies file. 226 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ 227 @set -e; \ 228 $(echo-cmd) $(cmd_$(1)); \ 229 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ 230 rm -f $(depfile); \ 231 mv -f $(dot-target).tmp $(dot-target).cmd) 232 233 # Usage: $(call if_changed_rule,foo) 234 # Will check if $(cmd_foo) or any of the prerequisites changed, 235 # and if so will execute $(rule_foo). 236 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \ 237 @set -e; \ 238 $(rule_$(1))) 239 240 ### 241 # why - tell why a a target got build 242 # enabled by make V=2 243 # Output (listed in the order they are checked): 244 # (1) - due to target is PHONY 245 # (2) - due to target missing 246 # (3) - due to: file1.h file2.h 247 # (4) - due to command line change 248 # (5) - due to missing .cmd file 249 # (6) - due to target not in $(targets) 250 # (1) PHONY targets are always build 251 # (2) No target, so we better build it 252 # (3) Prerequisite is newer than target 253 # (4) The command line stored in the file named dir/.target.cmd 254 # differed from actual command line. This happens when compiler 255 # options changes 256 # (5) No dir/.target.cmd file (used to store command line) 257 # (6) No dir/.target.cmd file and target not listed in $(targets) 258 # This is a good hint that there is a bug in the kbuild file 259 ifeq ($(KBUILD_VERBOSE),2) 260 why = \ 261 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 262 $(if $(wildcard $@), \ 263 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \ 264 $(if $(arg-check), \ 265 $(if $(cmd_$@),- due to command line change, \ 266 $(if $(filter $@, $(targets)), \ 267 - due to missing .cmd file, \ 268 - due to $(notdir $@) not in $$(targets) \ 269 ) \ 270 ) \ 271 ) \ 272 ), \ 273 - due to target missing \ 274 ) \ 275 ) 276 277 echo-why = $(call escsq, $(strip $(why))) 278 endif 279