1# SPDX-License-Identifier: GPL-2.0 2#### 3# kbuild: Generic definitions 4 5# Convenient variables 6comma := , 7quote := " 8squote := ' 9empty := 10space := $(empty) $(empty) 11space_escape := _-_SPACE_-_ 12pound := \# 13 14### 15# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o 16dot-target = $(dir $@).$(notdir $@) 17 18### 19# The temporary file to save gcc -MMD generated dependencies must not 20# contain a comma 21depfile = $(subst $(comma),_,$(dot-target).d) 22 23### 24# filename of target with directory and extension stripped 25basetarget = $(basename $(notdir $@)) 26 27### 28# real prerequisites without phony targets 29real-prereqs = $(filter-out $(PHONY), $^) 30 31### 32# Escape single quote for use in echo statements 33escsq = $(subst $(squote),'\$(squote)',$1) 34 35### 36# Quote a string to pass it to C files. foo => '"foo"' 37stringify = $(squote)$(quote)$1$(quote)$(squote) 38 39### 40# Easy method for doing a status message 41 kecho := : 42 quiet_kecho := echo 43silent_kecho := : 44kecho := $($(quiet)kecho) 45 46### 47# filechk is used to check if the content of a generated file is updated. 48# Sample usage: 49# 50# filechk_sample = echo $(KERNELRELEASE) 51# version.h: FORCE 52# $(call filechk,sample) 53# 54# The rule defined shall write to stdout the content of the new file. 55# The existing file will be compared with the new one. 56# - If no file exist it is created 57# - If the content differ the new file is used 58# - If they are equal no change, and no timestamp update 59define filechk 60 $(Q)set -e; \ 61 mkdir -p $(dir $@); \ 62 trap "rm -f $(dot-target).tmp" EXIT; \ 63 { $(filechk_$(1)); } > $(dot-target).tmp; \ 64 if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then \ 65 $(kecho) ' UPD $@'; \ 66 mv -f $(dot-target).tmp $@; \ 67 fi 68endef 69 70### 71# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 72# Usage: 73# $(Q)$(MAKE) $(build)=dir 74build := -f $(srctree)/scripts/Makefile.build obj 75 76### 77# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= 78# Usage: 79# $(Q)$(MAKE) $(dtbinst)=dir 80dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj 81 82### 83# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj= 84# Usage: 85# $(Q)$(MAKE) $(clean)=dir 86clean := -f $(srctree)/scripts/Makefile.clean obj 87 88# echo command. 89# Short version is used, if $(quiet) equals `quiet_', otherwise full one. 90echo-cmd = $(if $($(quiet)cmd_$(1)),\ 91 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) 92 93# sink stdout for 'make -s' 94 redirect := 95 quiet_redirect := 96silent_redirect := exec >/dev/null; 97 98# printing commands 99cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(cmd_$(1)) 100 101### 102# if_changed - execute command if any prerequisite is newer than 103# target, or command line has changed 104# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies 105# including used config symbols 106# if_changed_rule - as if_changed but execute rule instead 107# See Documentation/kbuild/makefiles.rst for more info 108 109ifneq ($(KBUILD_NOCMDDEP),1) 110# Check if both commands are the same including their order. Result is empty 111# string if equal. User may override this check using make KBUILD_NOCMDDEP=1 112cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \ 113 $(subst $(space),$(space_escape),$(strip $(cmd_$1)))) 114else 115cmd-check = $(if $(strip $(cmd_$@)),,1) 116endif 117 118# Replace >$< with >$$< to preserve $ when reloading the .cmd file 119# (needed for make) 120# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file 121# (needed for make) 122# Replace >'< with >'\''< to be able to enclose the whole string in '...' 123# (needed for the shell) 124make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))) 125 126# Find any prerequisites that are newer than target or that do not exist. 127# (This is not true for now; $? should contain any non-existent prerequisites, 128# but it does not work as expected when .SECONDARY is present. This seems a bug 129# of GNU Make.) 130# PHONY targets skipped in both cases. 131newer-prereqs = $(filter-out $(PHONY),$?) 132 133# Execute command if command has changed or prerequisite(s) are updated. 134if_changed = $(if $(newer-prereqs)$(cmd-check), \ 135 $(cmd); \ 136 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) 137 138# Execute the command and also postprocess generated .d dependencies file. 139if_changed_dep = $(if $(newer-prereqs)$(cmd-check),$(cmd_and_fixdep),@:) 140 141cmd_and_fixdep = \ 142 $(cmd); \ 143 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\ 144 rm -f $(depfile) 145 146# Usage: $(call if_changed_rule,foo) 147# Will check if $(cmd_foo) or any of the prerequisites changed, 148# and if so will execute $(rule_foo). 149if_changed_rule = $(if $(newer-prereqs)$(cmd-check),$(rule_$(1)),@:) 150 151### 152# why - tell why a target got built 153# enabled by make V=2 154# Output (listed in the order they are checked): 155# (1) - due to target is PHONY 156# (2) - due to target missing 157# (3) - due to: file1.h file2.h 158# (4) - due to command line change 159# (5) - due to missing .cmd file 160# (6) - due to target not in $(targets) 161# (1) PHONY targets are always build 162# (2) No target, so we better build it 163# (3) Prerequisite is newer than target 164# (4) The command line stored in the file named dir/.target.cmd 165# differed from actual command line. This happens when compiler 166# options changes 167# (5) No dir/.target.cmd file (used to store command line) 168# (6) No dir/.target.cmd file and target not listed in $(targets) 169# This is a good hint that there is a bug in the kbuild file 170ifeq ($(KBUILD_VERBOSE),2) 171why = \ 172 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \ 173 $(if $(wildcard $@), \ 174 $(if $(newer-prereqs),- due to: $(newer-prereqs), \ 175 $(if $(cmd-check), \ 176 $(if $(cmd_$@),- due to command line change, \ 177 $(if $(filter $@, $(targets)), \ 178 - due to missing .cmd file, \ 179 - due to $(notdir $@) not in $$(targets) \ 180 ) \ 181 ) \ 182 ) \ 183 ), \ 184 - due to target missing \ 185 ) \ 186 ) 187 188echo-why = $(call escsq, $(strip $(why))) 189endif 190 191############################################################################### 192# 193# When a Kconfig string contains a filename, it is suitable for 194# passing to shell commands. It is surrounded by double-quotes, and 195# any double-quotes or backslashes within it are escaped by 196# backslashes. 197# 198# This is no use for dependencies or $(wildcard). We need to strip the 199# surrounding quotes and the escaping from quotes and backslashes, and 200# we *do* need to escape any spaces in the string. So, for example: 201# 202# Usage: $(eval $(call config_filename,FOO)) 203# 204# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option, 205# transformed as described above to be suitable for use within the 206# makefile. 207# 208# Also, if the filename is a relative filename and exists in the source 209# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to 210# be prefixed to *both* command invocation and dependencies. 211# 212# Note: We also print the filenames in the quiet_cmd_foo text, and 213# perhaps ought to have a version specially escaped for that purpose. 214# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good 215# enough. It'll strip the quotes in the common case where there's no 216# space and it's a simple filename, and it'll retain the quotes when 217# there's a space. There are some esoteric cases in which it'll print 218# the wrong thing, but we don't really care. The actual dependencies 219# and commands *do* get it right, with various combinations of single 220# and double quotes, backslashes and spaces in the filenames. 221# 222############################################################################### 223# 224define config_filename 225ifneq ($$(CONFIG_$(1)),"") 226$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1))))))) 227ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME))) 228else 229ifeq ($$(wildcard $$($(1)_FILENAME)),) 230ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),) 231$(1)_SRCPREFIX := $(srctree)/ 232endif 233endif 234endif 235endif 236endef 237# 238############################################################################### 239 240# delete partially updated (i.e. corrupted) files on error 241.DELETE_ON_ERROR: 242 243# do not delete intermediate files automatically 244.SECONDARY: 245