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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.clean obj=
118# Usage:
119# $(Q)$(MAKE) $(clean)=dir
120clean := -f $(srctree)/scripts/Makefile.clean obj
121
122# pring log
123#
124# If quiet is "silent_", print nothing and sink stdout
125# If quiet is "quiet_", print short log
126# If quiet is empty, print short log and whole command
127silent_log_print = exec >/dev/null;
128 quiet_log_print = $(if $(quiet_cmd_$1), echo ' $(call escsq,$(quiet_cmd_$1)$(why))';)
129 log_print = echo '$(pound) $(call escsq,$(or $(quiet_cmd_$1),cmd_$1 $@)$(why))'; \
130 echo ' $(call escsq,$(cmd_$1))';
131
132# Delete the target on interruption
133#
134# GNU Make automatically deletes the target if it has already been changed by
135# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make
136# will delete incomplete targets), and resume it later.
137#
138# However, this does not work when the stderr is piped to another program, like
139# $ make >&2 | tee log
140# Make dies with SIGPIPE before cleaning the targets.
141#
142# To address it, we clean the target in signal traps.
143#
144# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM.
145# So, we cover them, and also SIGPIPE just in case.
146#
147# Of course, this is unneeded for phony targets.
148delete-on-interrupt = \
149 $(if $(filter-out $(PHONY), $@), \
150 $(foreach sig, HUP INT QUIT TERM PIPE, \
151 trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);))
152
153# print and execute commands
154cmd = @$(if $(cmd_$(1)),set -e; $($(quiet)log_print) $(delete-on-interrupt) $(cmd_$(1)),:)
155
156###
157# if_changed - execute command if any prerequisite is newer than
158# target, or command line has changed
159# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
160# including used config symbols
161# if_changed_rule - as if_changed but execute rule instead
162# See Documentation/kbuild/makefiles.rst for more info
163
164ifneq ($(KBUILD_NOCMDDEP),1)
165# Check if both commands are the same including their order. Result is empty
166# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
167# If the target does not exist, the *.cmd file should not be included so
168# $(savedcmd_$@) gets empty. Then, target will be built even if $(newer-prereqs)
169# happens to become empty.
170cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(savedcmd_$@))), \
171 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
172else
173# We still need to detect missing targets.
174cmd-check = $(if $(strip $(savedcmd_$@)),,1)
175endif
176
177# Replace >$< with >$$< to preserve $ when reloading the .cmd file
178# (needed for make)
179# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
180# (needed for make)
181# Replace >'< with >'\''< to be able to enclose the whole string in '...'
182# (needed for the shell)
183make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
184
185# Find any prerequisites that are newer than target or that do not exist.
186# PHONY targets skipped in both cases.
187# If there is no prerequisite other than phony targets, $(newer-prereqs) becomes
188# empty even if the target does not exist. cmd-check saves this corner case.
189newer-prereqs = $(filter-out $(PHONY),$?)
190
191# It is a typical mistake to forget the FORCE prerequisite. Check it here so
192# no more breakage will slip in.
193check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))
194
195if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)
196
197# Execute command if command has changed or prerequisite(s) are updated.
198if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:)
199
200cmd_and_savecmd = \
201 $(cmd); \
202 printf '%s\n' 'savedcmd_$@ := $(make-cmd)' > $(dot-target).cmd
203
204# Execute the command and also postprocess generated .d dependencies file.
205if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:)
206
207cmd_and_fixdep = \
208 $(cmd); \
209 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
210 rm -f $(depfile)
211
212# Usage: $(call if_changed_rule,foo)
213# Will check if $(cmd_foo) or any of the prerequisites changed,
214# and if so will execute $(rule_foo).
215if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:)
216
217###
218# why - tell why a target got built
219# enabled by make V=2
220# Output (listed in the order they are checked):
221# (1) - due to target is PHONY
222# (2) - due to target missing
223# (3) - due to: file1.h file2.h
224# (4) - due to command line change
225# (5) - due to missing .cmd file
226# (6) - due to target not in $(targets)
227# (1) PHONY targets are always build
228# (2) No target, so we better build it
229# (3) Prerequisite is newer than target
230# (4) The command line stored in the file named dir/.target.cmd
231# differed from actual command line. This happens when compiler
232# options changes
233# (5) No dir/.target.cmd file (used to store command line)
234# (6) No dir/.target.cmd file and target not listed in $(targets)
235# This is a good hint that there is a bug in the kbuild file
236ifneq ($(findstring 2, $(KBUILD_VERBOSE)),)
237_why = \
238 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
239 $(if $(wildcard $@), \
240 $(if $(newer-prereqs),- due to: $(newer-prereqs), \
241 $(if $(cmd-check), \
242 $(if $(savedcmd_$@),- due to command line change, \
243 $(if $(filter $@, $(targets)), \
244 - due to missing .cmd file, \
245 - due to $(notdir $@) not in $$(targets) \
246 ) \
247 ) \
248 ) \
249 ), \
250 - due to target missing \
251 ) \
252 )
253
254why = $(space)$(strip $(_why))
255endif
256
257###############################################################################
258
259# delete partially updated (i.e. corrupted) files on error
260.DELETE_ON_ERROR:
261
262# do not delete intermediate files automatically
263#
264# .NOTINTERMEDIATE is more correct, but only available on newer Make versions.
265# Make 4.4 introduced .NOTINTERMEDIATE, and it appears in .FEATURES, but the
266# global .NOTINTERMEDIATE does not work. We can use it on Make > 4.4.
267# Use .SECONDARY for older Make versions, but "newer-prereq" cannot detect
268# deleted files.
269ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),)
270.NOTINTERMEDIATE:
271else
272.SECONDARY:
273endif
1####
2# kbuild: Generic definitions
3
4# Convenient variables
5comma := ,
6quote := "
7squote := '
8empty :=
9space := $(empty) $(empty)
10
11###
12# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
13dot-target = $(dir $@).$(notdir $@)
14
15###
16# The temporary file to save gcc -MD generated dependencies must not
17# contain a comma
18depfile = $(subst $(comma),_,$(dot-target).d)
19
20###
21# filename of target with directory and extension stripped
22basetarget = $(basename $(notdir $@))
23
24###
25# filename of first prerequisite with directory and extension stripped
26baseprereq = $(basename $(notdir $<))
27
28###
29# Escape single quote for use in echo statements
30escsq = $(subst $(squote),'\$(squote)',$1)
31
32###
33# Easy method for doing a status message
34 kecho := :
35 quiet_kecho := echo
36silent_kecho := :
37kecho := $($(quiet)kecho)
38
39###
40# filechk is used to check if the content of a generated file is updated.
41# Sample usage:
42# define filechk_sample
43# echo $KERNELRELEASE
44# endef
45# version.h : Makefile
46# $(call filechk,sample)
47# The rule defined shall write to stdout the content of the new file.
48# The existing file will be compared with the new one.
49# - If no file exist it is created
50# - If the content differ the new file is used
51# - If they are equal no change, and no timestamp update
52# - stdin is piped in from the first prerequisite ($<) so one has
53# to specify a valid file as first prerequisite (often the kbuild file)
54define filechk
55 $(Q)set -e; \
56 $(kecho) ' CHK $@'; \
57 mkdir -p $(dir $@); \
58 $(filechk_$(1)) < $< > $@.tmp; \
59 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
60 rm -f $@.tmp; \
61 else \
62 $(kecho) ' UPD $@'; \
63 mv -f $@.tmp $@; \
64 fi
65endef
66
67######
68# gcc support functions
69# See documentation in Documentation/kbuild/makefiles.txt
70
71# cc-cross-prefix
72# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
73# Return first prefix where a prefix$(CC) is found in PATH.
74# If no $(CC) found in PATH with listed prefixes return nothing
75cc-cross-prefix = \
76 $(word 1, $(foreach c,$(1), \
77 $(shell set -e; \
78 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
79 echo $(c); \
80 fi)))
81
82# output directory for tests below
83TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
84
85# try-run
86# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
87# Exit code chooses option. "$$TMP" is can be used as temporary file and
88# is automatically cleaned up.
89try-run = $(shell set -e; \
90 TMP="$(TMPOUT).$$$$.tmp"; \
91 TMPO="$(TMPOUT).$$$$.o"; \
92 if ($(1)) >/dev/null 2>&1; \
93 then echo "$(2)"; \
94 else echo "$(3)"; \
95 fi; \
96 rm -f "$$TMP" "$$TMPO")
97
98# as-option
99# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
100
101as-option = $(call try-run,\
102 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
103
104# as-instr
105# Usage: cflags-y += $(call as-instr,instr,option1,option2)
106
107as-instr = $(call try-run,\
108 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
109
110# cc-option
111# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
112
113cc-option = $(call try-run,\
114 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
115
116# cc-option-yn
117# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
118cc-option-yn = $(call try-run,\
119 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
120
121# cc-option-align
122# Prefix align with either -falign or -malign
123cc-option-align = $(subst -functions=0,,\
124 $(call cc-option,-falign-functions=0,-malign-functions=0))
125
126# cc-disable-warning
127# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
128cc-disable-warning = $(call try-run,\
129 $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
130
131# cc-version
132# Usage gcc-ver := $(call cc-version)
133cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
134
135# cc-fullversion
136# Usage gcc-ver := $(call cc-fullversion)
137cc-fullversion = $(shell $(CONFIG_SHELL) \
138 $(srctree)/scripts/gcc-version.sh -p $(CC))
139
140# cc-ifversion
141# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
142cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
143
144# cc-ldoption
145# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
146cc-ldoption = $(call try-run,\
147 $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
148
149# ld-option
150# Usage: LDFLAGS += $(call ld-option, -X)
151ld-option = $(call try-run,\
152 $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
153
154# ar-option
155# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
156# Important: no spaces around options
157ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
158
159# ld-version
160# Usage: $(call ld-version)
161# Note this is mainly for HJ Lu's 3 number binutil versions
162ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
163
164# ld-ifversion
165# Usage: $(call ld-ifversion, -ge, 22252, y)
166ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3))
167
168######
169
170###
171# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
172# Usage:
173# $(Q)$(MAKE) $(build)=dir
174build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
175
176###
177# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
178# Usage:
179# $(Q)$(MAKE) $(modbuiltin)=dir
180modbuiltin := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.modbuiltin obj
181
182# Prefix -I with $(srctree) if it is not an absolute path.
183# skip if -I has no parameter
184addtree = $(if $(patsubst -I%,%,$(1)), \
185$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
186
187# Find all -I options and call addtree
188flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
189
190# echo command.
191# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
192echo-cmd = $(if $($(quiet)cmd_$(1)),\
193 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
194
195# printing commands
196cmd = @$(echo-cmd) $(cmd_$(1))
197
198# Add $(obj)/ for paths that are not absolute
199objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
200
201###
202# if_changed - execute command if any prerequisite is newer than
203# target, or command line has changed
204# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
205# including used config symbols
206# if_changed_rule - as if_changed but execute rule instead
207# See Documentation/kbuild/makefiles.txt for more info
208
209ifneq ($(KBUILD_NOCMDDEP),1)
210# Check if both arguments has same arguments. Result is empty string if equal.
211# User may override this check using make KBUILD_NOCMDDEP=1
212arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
213 $(filter-out $(cmd_$@), $(cmd_$(1))) )
214else
215arg-check = $(if $(strip $(cmd_$@)),,1)
216endif
217
218# >'< substitution is for echo to work,
219# >$< substitution to preserve $ when reloading .cmd file
220# note: when using inline perl scripts [perl -e '...$$t=1;...']
221# in $(cmd_xxx) double $$ your perl vars
222make-cmd = $(subst \\,\\\\,$(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))))
223
224# Find any prerequisites that is newer than target or that does not exist.
225# PHONY targets skipped in both cases.
226any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
227
228# Execute command if command has changed or prerequisite(s) are updated.
229#
230if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
231 @set -e; \
232 $(echo-cmd) $(cmd_$(1)); \
233 echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
234
235# Execute the command and also postprocess generated .d dependencies file.
236if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
237 @set -e; \
238 $(echo-cmd) $(cmd_$(1)); \
239 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
240 rm -f $(depfile); \
241 mv -f $(dot-target).tmp $(dot-target).cmd)
242
243# Usage: $(call if_changed_rule,foo)
244# Will check if $(cmd_foo) or any of the prerequisites changed,
245# and if so will execute $(rule_foo).
246if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
247 @set -e; \
248 $(rule_$(1)))
249
250###
251# why - tell why a a target got build
252# enabled by make V=2
253# Output (listed in the order they are checked):
254# (1) - due to target is PHONY
255# (2) - due to target missing
256# (3) - due to: file1.h file2.h
257# (4) - due to command line change
258# (5) - due to missing .cmd file
259# (6) - due to target not in $(targets)
260# (1) PHONY targets are always build
261# (2) No target, so we better build it
262# (3) Prerequisite is newer than target
263# (4) The command line stored in the file named dir/.target.cmd
264# differed from actual command line. This happens when compiler
265# options changes
266# (5) No dir/.target.cmd file (used to store command line)
267# (6) No dir/.target.cmd file and target not listed in $(targets)
268# This is a good hint that there is a bug in the kbuild file
269ifeq ($(KBUILD_VERBOSE),2)
270why = \
271 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
272 $(if $(wildcard $@), \
273 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
274 $(if $(arg-check), \
275 $(if $(cmd_$@),- due to command line change, \
276 $(if $(filter $@, $(targets)), \
277 - due to missing .cmd file, \
278 - due to $(notdir $@) not in $$(targets) \
279 ) \
280 ) \
281 ) \
282 ), \
283 - due to target missing \
284 ) \
285 )
286
287echo-why = $(call escsq, $(strip $(why)))
288endif