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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 := \#
13define newline
14
15
16endef
17
18###
19# Comparison macros.
20# Usage: $(call test-lt, $(CONFIG_LLD_VERSION), 150000)
21#
22# Use $(intcmp ...) if supported. (Make >= 4.4)
23# Otherwise, fall back to the 'test' shell command.
24ifeq ($(intcmp 1,0,,,y),y)
25test-ge = $(intcmp $(strip $1)0, $(strip $2)0,,y,y)
26test-gt = $(intcmp $(strip $1)0, $(strip $2)0,,,y)
27else
28test-ge = $(shell test $(strip $1)0 -ge $(strip $2)0 && echo y)
29test-gt = $(shell test $(strip $1)0 -gt $(strip $2)0 && echo y)
30endif
31test-le = $(call test-ge, $2, $1)
32test-lt = $(call test-gt, $2, $1)
33
34###
35# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
36dot-target = $(dir $@).$(notdir $@)
37
38###
39# Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o
40tmp-target = $(dir $@).tmp_$(notdir $@)
41
42###
43# The temporary file to save gcc -MMD generated dependencies must not
44# contain a comma
45depfile = $(subst $(comma),_,$(dot-target).d)
46
47###
48# filename of target with directory and extension stripped
49basetarget = $(basename $(notdir $@))
50
51###
52# real prerequisites without phony targets
53real-prereqs = $(filter-out $(PHONY), $^)
54
55###
56# Escape single quote for use in echo statements
57escsq = $(subst $(squote),'\$(squote)',$1)
58
59###
60# Quote a string to pass it to C files. foo => '"foo"'
61stringify = $(squote)$(quote)$1$(quote)$(squote)
62
63###
64# The path to Kbuild or Makefile. Kbuild has precedence over Makefile.
65kbuild-dir = $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
66kbuild-file = $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
67
68###
69# Read a file, replacing newlines with spaces
70#
71# Make 4.2 or later can read a file by using its builtin function.
72ifneq ($(filter-out 3.% 4.0 4.1, $(MAKE_VERSION)),)
73read-file = $(subst $(newline),$(space),$(file < $1))
74else
75read-file = $(shell cat $1 2>/dev/null)
76endif
77
78###
79# Easy method for doing a status message
80 kecho := :
81 quiet_kecho := echo
82silent_kecho := :
83kecho := $($(quiet)kecho)
84
85###
86# filechk is used to check if the content of a generated file is updated.
87# Sample usage:
88#
89# filechk_sample = echo $(KERNELRELEASE)
90# version.h: FORCE
91# $(call filechk,sample)
92#
93# The rule defined shall write to stdout the content of the new file.
94# The existing file will be compared with the new one.
95# - If no file exist it is created
96# - If the content differ the new file is used
97# - If they are equal no change, and no timestamp update
98define filechk
99 $(check-FORCE)
100 $(Q)set -e; \
101 mkdir -p $(dir $@); \
102 trap "rm -f $(tmp-target)" EXIT; \
103 { $(filechk_$(1)); } > $(tmp-target); \
104 if [ ! -r $@ ] || ! cmp -s $@ $(tmp-target); then \
105 $(kecho) ' UPD $@'; \
106 mv -f $(tmp-target) $@; \
107 fi
108endef
109
110###
111# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
112# Usage:
113# $(Q)$(MAKE) $(build)=dir
114build := -f $(srctree)/scripts/Makefile.build obj
115
116###
117# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
118# Usage:
119# $(Q)$(MAKE) $(dtbinst)=dir
120dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
121
122###
123# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
124# Usage:
125# $(Q)$(MAKE) $(clean)=dir
126clean := -f $(srctree)/scripts/Makefile.clean obj
127
128# pring log
129#
130# If quiet is "silent_", print nothing and sink stdout
131# If quiet is "quiet_", print short log
132# If quiet is empty, print short log and whole command
133silent_log_print = exec >/dev/null;
134 quiet_log_print = $(if $(quiet_cmd_$1), echo ' $(call escsq,$(quiet_cmd_$1)$(why))';)
135 log_print = echo '$(pound) $(call escsq,$(or $(quiet_cmd_$1),cmd_$1 $@)$(why))'; \
136 echo ' $(call escsq,$(cmd_$1))';
137
138# Delete the target on interruption
139#
140# GNU Make automatically deletes the target if it has already been changed by
141# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make
142# will delete incomplete targets), and resume it later.
143#
144# However, this does not work when the stderr is piped to another program, like
145# $ make >&2 | tee log
146# Make dies with SIGPIPE before cleaning the targets.
147#
148# To address it, we clean the target in signal traps.
149#
150# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM.
151# So, we cover them, and also SIGPIPE just in case.
152#
153# Of course, this is unneeded for phony targets.
154delete-on-interrupt = \
155 $(if $(filter-out $(PHONY), $@), \
156 $(foreach sig, HUP INT QUIT TERM PIPE, \
157 trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);))
158
159# print and execute commands
160cmd = @$(if $(cmd_$(1)),set -e; $($(quiet)log_print) $(delete-on-interrupt) $(cmd_$(1)),:)
161
162###
163# if_changed - execute command if any prerequisite is newer than
164# target, or command line has changed
165# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
166# including used config symbols
167# if_changed_rule - as if_changed but execute rule instead
168# See Documentation/kbuild/makefiles.rst for more info
169
170ifneq ($(KBUILD_NOCMDDEP),1)
171# Check if both commands are the same including their order. Result is empty
172# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
173# If the target does not exist, the *.cmd file should not be included so
174# $(savedcmd_$@) gets empty. Then, target will be built even if $(newer-prereqs)
175# happens to become empty.
176cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(savedcmd_$@))), \
177 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
178else
179# We still need to detect missing targets.
180cmd-check = $(if $(strip $(savedcmd_$@)),,1)
181endif
182
183# Replace >$< with >$$< to preserve $ when reloading the .cmd file
184# (needed for make)
185# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
186# (needed for make)
187# Replace >'< with >'\''< to be able to enclose the whole string in '...'
188# (needed for the shell)
189make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
190
191# Find any prerequisites that are newer than target or that do not exist.
192# PHONY targets skipped in both cases.
193# If there is no prerequisite other than phony targets, $(newer-prereqs) becomes
194# empty even if the target does not exist. cmd-check saves this corner case.
195newer-prereqs = $(filter-out $(PHONY),$?)
196
197# It is a typical mistake to forget the FORCE prerequisite. Check it here so
198# no more breakage will slip in.
199check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))
200
201if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)
202
203# Execute command if command has changed or prerequisite(s) are updated.
204if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:)
205
206cmd_and_savecmd = \
207 $(cmd); \
208 printf '%s\n' 'savedcmd_$@ := $(make-cmd)' > $(dot-target).cmd
209
210# Execute the command and also postprocess generated .d dependencies file.
211if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:)
212
213cmd_and_fixdep = \
214 $(cmd); \
215 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
216 rm -f $(depfile)
217
218# Usage: $(call if_changed_rule,foo)
219# Will check if $(cmd_foo) or any of the prerequisites changed,
220# and if so will execute $(rule_foo).
221if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:)
222
223###
224# why - tell why a target got built
225# enabled by make V=2
226# Output (listed in the order they are checked):
227# (1) - due to target is PHONY
228# (2) - due to target missing
229# (3) - due to: file1.h file2.h
230# (4) - due to command line change
231# (5) - due to missing .cmd file
232# (6) - due to target not in $(targets)
233# (1) PHONY targets are always build
234# (2) No target, so we better build it
235# (3) Prerequisite is newer than target
236# (4) The command line stored in the file named dir/.target.cmd
237# differed from actual command line. This happens when compiler
238# options changes
239# (5) No dir/.target.cmd file (used to store command line)
240# (6) No dir/.target.cmd file and target not listed in $(targets)
241# This is a good hint that there is a bug in the kbuild file
242ifneq ($(findstring 2, $(KBUILD_VERBOSE)),)
243_why = \
244 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
245 $(if $(wildcard $@), \
246 $(if $(newer-prereqs),- due to: $(newer-prereqs), \
247 $(if $(cmd-check), \
248 $(if $(savedcmd_$@),- due to command line change, \
249 $(if $(filter $@, $(targets)), \
250 - due to missing .cmd file, \
251 - due to $(notdir $@) not in $$(targets) \
252 ) \
253 ) \
254 ) \
255 ), \
256 - due to target missing \
257 ) \
258 )
259
260why = $(space)$(strip $(_why))
261endif
262
263###############################################################################
264
265# delete partially updated (i.e. corrupted) files on error
266.DELETE_ON_ERROR:
267
268# do not delete intermediate files automatically
269#
270# .NOTINTERMEDIATE is more correct, but only available on newer Make versions.
271# Make 4.4 introduced .NOTINTERMEDIATE, and it appears in .FEATURES, but the
272# global .NOTINTERMEDIATE does not work. We can use it on Make > 4.4.
273# Use .SECONDARY for older Make versions, but "newer-prereq" cannot detect
274# deleted files.
275ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),)
276.NOTINTERMEDIATE:
277else
278.SECONDARY:
279endif
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.
88try-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" "$$TMPO")
96
97# as-option
98# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
99
100as-option = $(call try-run,\
101 $(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
102
103# as-instr
104# Usage: cflags-y += $(call as-instr,instr,option1,option2)
105
106as-instr = $(call try-run,\
107 /bin/echo -e "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))
108
109# cc-option
110# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
111
112cc-option = $(call try-run,\
113 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
114
115# cc-option-yn
116# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
117cc-option-yn = $(call try-run,\
118 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
119
120# cc-option-align
121# Prefix align with either -falign or -malign
122cc-option-align = $(subst -functions=0,,\
123 $(call cc-option,-falign-functions=0,-malign-functions=0))
124
125# cc-disable-warning
126# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
127cc-disable-warning = $(call try-run,\
128 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -xc /dev/null -o "$$TMP",-Wno-$(strip $(1)))
129
130# cc-version
131# Usage gcc-ver := $(call cc-version)
132cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
133
134# cc-fullversion
135# Usage gcc-ver := $(call cc-fullversion)
136cc-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)
141cc-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)
145cc-ldoption = $(call try-run,\
146 $(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))
147
148# ld-option
149# Usage: LDFLAGS += $(call ld-option, -X)
150ld-option = $(call try-run,\
151 $(CC) /dev/null -c -o "$$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
156ar-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
164build := -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
170modbuiltin := -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
174addtree = $(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
178flags = $(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.
182echo-cmd = $(if $($(quiet)cmd_$(1)),\
183 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
184
185# printing commands
186cmd = @$(echo-cmd) $(cmd_$(1))
187
188# Add $(obj)/ for paths that are not absolute
189objectify = $(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
199ifneq ($(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
202arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
203 $(filter-out $(cmd_$@), $(cmd_$(1))) )
204else
205arg-check = $(if $(strip $(cmd_$@)),,1)
206endif
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 $$ your perl vars
212make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(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.
216any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
217
218# Execute command if command has changed or prerequisite(s) are updated.
219#
220if_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.
226if_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).
236if_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
259ifeq ($(KBUILD_VERBOSE),2)
260why = \
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
277echo-why = $(call escsq, $(strip $(why)))
278endif