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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 := \#
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# $(call filechk,sample)
53#
54# The rule defined shall write to stdout the content of the new file.
55# The existing file will be compared with the new one.
56# - If no file exist it is created
57# - If the content differ the new file is used
58# - If they are equal no change, and no timestamp update
59# - stdin is piped in from the first prerequisite ($<) so one has
60# to specify a valid file as first prerequisite (often the kbuild file)
61define filechk
62 $(Q)set -e; \
63 mkdir -p $(dir $@); \
64 trap "rm -f $(dot-target).tmp" EXIT; \
65 { $(filechk_$(1)); } > $(dot-target).tmp; \
66 if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then \
67 $(kecho) ' UPD $@'; \
68 mv -f $(dot-target).tmp $@; \
69 fi
70endef
71
72######
73# gcc support functions
74# See documentation in Documentation/kbuild/makefiles.rst
75
76# cc-cross-prefix
77# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
78# Return first <prefix> where a <prefix>gcc is found in PATH.
79# If no gcc found in PATH with listed prefixes return nothing
80#
81# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
82# would try to directly execute the shell builtin 'command'. This workaround
83# should be kept for a long time since this issue was fixed only after the
84# GNU Make 4.2.1 release.
85cc-cross-prefix = $(firstword $(foreach c, $(1), \
86 $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
87
88# output directory for tests below
89TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$
90
91# try-run
92# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
93# Exit code chooses option. "$$TMP" serves as a temporary file and is
94# automatically cleaned up.
95try-run = $(shell set -e; \
96 TMP=$(TMPOUT)/tmp; \
97 TMPO=$(TMPOUT)/tmp.o; \
98 mkdir -p $(TMPOUT); \
99 trap "rm -rf $(TMPOUT)" EXIT; \
100 if ($(1)) >/dev/null 2>&1; \
101 then echo "$(2)"; \
102 else echo "$(3)"; \
103 fi)
104
105# as-option
106# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
107
108as-option = $(call try-run,\
109 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
110
111# as-instr
112# Usage: cflags-y += $(call as-instr,instr,option1,option2)
113
114as-instr = $(call try-run,\
115 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
116
117# __cc-option
118# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
119__cc-option = $(call try-run,\
120 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
121
122# cc-option
123# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
124
125cc-option = $(call __cc-option, $(CC),\
126 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
127
128# cc-option-yn
129# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
130cc-option-yn = $(call try-run,\
131 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
132
133# cc-disable-warning
134# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
135cc-disable-warning = $(call try-run,\
136 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
137
138# cc-ifversion
139# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
140cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
141
142# ld-option
143# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
144ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
145
146# ld-version
147# Note this is mainly for HJ Lu's 3 number binutil versions
148ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
149
150# ld-ifversion
151# Usage: $(call ld-ifversion, -ge, 22252, y)
152ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
153
154######
155
156###
157# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
158# Usage:
159# $(Q)$(MAKE) $(build)=dir
160build := -f $(srctree)/scripts/Makefile.build obj
161
162###
163# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
164# Usage:
165# $(Q)$(MAKE) $(dtbinst)=dir
166dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
167
168###
169# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
170# Usage:
171# $(Q)$(MAKE) $(clean)=dir
172clean := -f $(srctree)/scripts/Makefile.clean obj
173
174# echo command.
175# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
176echo-cmd = $(if $($(quiet)cmd_$(1)),\
177 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
178
179# printing commands
180cmd = @set -e; $(echo-cmd) $(cmd_$(1))
181
182###
183# if_changed - execute command if any prerequisite is newer than
184# target, or command line has changed
185# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
186# including used config symbols
187# if_changed_rule - as if_changed but execute rule instead
188# See Documentation/kbuild/makefiles.rst for more info
189
190ifneq ($(KBUILD_NOCMDDEP),1)
191# Check if both commands are the same including their order. Result is empty
192# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
193cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
194 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
195else
196cmd-check = $(if $(strip $(cmd_$@)),,1)
197endif
198
199# Replace >$< with >$$< to preserve $ when reloading the .cmd file
200# (needed for make)
201# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
202# (needed for make)
203# Replace >'< with >'\''< to be able to enclose the whole string in '...'
204# (needed for the shell)
205make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
206
207# Find any prerequisites that are newer than target or that do not exist.
208# (This is not true for now; $? should contain any non-existent prerequisites,
209# but it does not work as expected when .SECONDARY is present. This seems a bug
210# of GNU Make.)
211# PHONY targets skipped in both cases.
212newer-prereqs = $(filter-out $(PHONY),$?)
213
214# Execute command if command has changed or prerequisite(s) are updated.
215if_changed = $(if $(newer-prereqs)$(cmd-check), \
216 $(cmd); \
217 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
218
219# Execute the command and also postprocess generated .d dependencies file.
220if_changed_dep = $(if $(newer-prereqs)$(cmd-check),$(cmd_and_fixdep),@:)
221
222cmd_and_fixdep = \
223 $(cmd); \
224 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
225 rm -f $(depfile)
226
227# Usage: $(call if_changed_rule,foo)
228# Will check if $(cmd_foo) or any of the prerequisites changed,
229# and if so will execute $(rule_foo).
230if_changed_rule = $(if $(newer-prereqs)$(cmd-check),$(rule_$(1)),@:)
231
232###
233# why - tell why a target got built
234# enabled by make V=2
235# Output (listed in the order they are checked):
236# (1) - due to target is PHONY
237# (2) - due to target missing
238# (3) - due to: file1.h file2.h
239# (4) - due to command line change
240# (5) - due to missing .cmd file
241# (6) - due to target not in $(targets)
242# (1) PHONY targets are always build
243# (2) No target, so we better build it
244# (3) Prerequisite is newer than target
245# (4) The command line stored in the file named dir/.target.cmd
246# differed from actual command line. This happens when compiler
247# options changes
248# (5) No dir/.target.cmd file (used to store command line)
249# (6) No dir/.target.cmd file and target not listed in $(targets)
250# This is a good hint that there is a bug in the kbuild file
251ifeq ($(KBUILD_VERBOSE),2)
252why = \
253 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
254 $(if $(wildcard $@), \
255 $(if $(newer-prereqs),- due to: $(newer-prereqs), \
256 $(if $(cmd-check), \
257 $(if $(cmd_$@),- due to command line change, \
258 $(if $(filter $@, $(targets)), \
259 - due to missing .cmd file, \
260 - due to $(notdir $@) not in $$(targets) \
261 ) \
262 ) \
263 ) \
264 ), \
265 - due to target missing \
266 ) \
267 )
268
269echo-why = $(call escsq, $(strip $(why)))
270endif
271
272###############################################################################
273#
274# When a Kconfig string contains a filename, it is suitable for
275# passing to shell commands. It is surrounded by double-quotes, and
276# any double-quotes or backslashes within it are escaped by
277# backslashes.
278#
279# This is no use for dependencies or $(wildcard). We need to strip the
280# surrounding quotes and the escaping from quotes and backslashes, and
281# we *do* need to escape any spaces in the string. So, for example:
282#
283# Usage: $(eval $(call config_filename,FOO))
284#
285# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
286# transformed as described above to be suitable for use within the
287# makefile.
288#
289# Also, if the filename is a relative filename and exists in the source
290# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
291# be prefixed to *both* command invocation and dependencies.
292#
293# Note: We also print the filenames in the quiet_cmd_foo text, and
294# perhaps ought to have a version specially escaped for that purpose.
295# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
296# enough. It'll strip the quotes in the common case where there's no
297# space and it's a simple filename, and it'll retain the quotes when
298# there's a space. There are some esoteric cases in which it'll print
299# the wrong thing, but we don't really care. The actual dependencies
300# and commands *do* get it right, with various combinations of single
301# and double quotes, backslashes and spaces in the filenames.
302#
303###############################################################################
304#
305define config_filename
306ifneq ($$(CONFIG_$(1)),"")
307$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
308ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
309else
310ifeq ($$(wildcard $$($(1)_FILENAME)),)
311ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
312$(1)_SRCPREFIX := $(srctree)/
313endif
314endif
315endif
316endif
317endef
318#
319###############################################################################
320
321# delete partially updated (i.e. corrupted) files on error
322.DELETE_ON_ERROR:
323
324# do not delete intermediate files automatically
325.SECONDARY:
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 $(dot-target).tmp" EXIT; \
103 { $(filechk_$(1)); } > $(dot-target).tmp; \
104 if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then \
105 $(kecho) ' UPD $@'; \
106 mv -f $(dot-target).tmp $@; \
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# echo command.
129# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
130echo-cmd = $(if $($(quiet)cmd_$(1)),\
131 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
132
133# sink stdout for 'make -s'
134 redirect :=
135 quiet_redirect :=
136silent_redirect := exec >/dev/null;
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) $$$$' $(sig);))
158
159# printing commands
160cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(delete-on-interrupt) $(cmd_$(1))
161
162###
163# if_changed - execute command if any prerequisite is newer than
164# target, or command line has changed
165# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
166# including used config symbols
167# if_changed_rule - as if_changed but execute rule instead
168# See Documentation/kbuild/makefiles.rst for more info
169
170ifneq ($(KBUILD_NOCMDDEP),1)
171# Check if both commands are the same including their order. Result is empty
172# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
173cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
174 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
175else
176cmd-check = $(if $(strip $(cmd_$@)),,1)
177endif
178
179# Replace >$< with >$$< to preserve $ when reloading the .cmd file
180# (needed for make)
181# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
182# (needed for make)
183# Replace >'< with >'\''< to be able to enclose the whole string in '...'
184# (needed for the shell)
185make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
186
187# Find any prerequisites that are newer than target or that do not exist.
188# PHONY targets skipped in both cases.
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' 'cmd_$@ := $(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
236ifeq ($(KBUILD_VERBOSE),2)
237why = \
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 $(cmd_$@),- 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
254echo-why = $(call escsq, $(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