| Tom Rini | 614edd8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 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 |