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1####
2# kbuild: Generic definitions
3
4# Convenient variables
5comma := ,
6quote := "
7squote := '
8empty :=
9space := $(empty) $(empty)
10space_escape := _-_SPACE_-_
11right_paren := )
12left_paren := (
13pound := \#
14
15###
16# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
17dot-target = $(dir $@).$(notdir $@)
18
19###
20# The temporary file to save gcc -MD generated dependencies must not
21# contain a comma
22depfile = $(subst $(comma),_,$(dot-target).d)
23
24###
25# filename of target with directory and extension stripped
26basetarget = $(basename $(notdir $@))
27
28###
29# filename of first prerequisite with directory and extension stripped
30baseprereq = $(basename $(notdir $<))
31
32###
33# Escape single quote for use in echo statements
34escsq = $(subst $(squote),'\$(squote)',$1)
35
36###
37# Easy method for doing a status message
38 kecho := :
39 quiet_kecho := echo
40silent_kecho := :
41kecho := $($(quiet)kecho)
42
43###
44# filechk is used to check if the content of a generated file is updated.
45# Sample usage:
46# define filechk_sample
47# echo $KERNELRELEASE
48# endef
49# version.h : Makefile
50# $(call filechk,sample)
51# The rule defined shall write to stdout the content of the new file.
52# The existing file will be compared with the new one.
53# - If no file exist it is created
54# - If the content differ the new file is used
55# - If they are equal no change, and no timestamp update
56# - stdin is piped in from the first prerequisite ($<) so one has
57# to specify a valid file as first prerequisite (often the kbuild file)
58define filechk
59 $(Q)set -e; \
60 $(kecho) ' CHK $@'; \
61 mkdir -p $(dir $@); \
62 $(filechk_$(1)) < $< > $@.tmp; \
63 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
64 rm -f $@.tmp; \
65 else \
66 $(kecho) ' UPD $@'; \
67 mv -f $@.tmp $@; \
68 fi
69endef
70
71######
72# gcc support functions
73# See documentation in Documentation/kbuild/makefiles.txt
74
75# cc-cross-prefix
76# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
77# Return first prefix where a prefix$(CC) is found in PATH.
78# If no $(CC) found in PATH with listed prefixes return nothing
79cc-cross-prefix = \
80 $(word 1, $(foreach c,$(1), \
81 $(shell set -e; \
82 if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
83 echo $(c); \
84 fi)))
85
86# Tools for caching Makefile variables that are "expensive" to compute.
87#
88# Here we want to help deal with variables that take a long time to compute
89# by making it easy to store these variables in a cache.
90#
91# The canonical example here is testing for compiler flags. On a simple system
92# each call to the compiler takes 10 ms, but on a system with a compiler that's
93# called through various wrappers it can take upwards of 100 ms. If we have
94# 100 calls to the compiler this can take 1 second (on a simple system) or 10
95# seconds (on a complicated system).
96#
97# The "cache" will be in Makefile syntax and can be directly included.
98# Any time we try to reference a variable that's not in the cache we'll
99# calculate it and store it in the cache for next time.
100
101# Include values from last time
102make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk
103$(make-cache): ;
104-include $(make-cache)
105
106cached-data := $(filter __cached_%, $(.VARIABLES))
107
108# If cache exceeds 1000 lines, shrink it down to 500.
109ifneq ($(word 1000,$(cached-data)),)
110$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \
111 mv $(make-cache).tmp $(make-cache))
112endif
113
114create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1))
115
116# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
117#
118# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'
119__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1)))))))))
120
121# Usage: $(call shell-cached,shell_command)
122# Example: $(call shell-cached,md5sum /usr/bin/gcc)
123#
124# If we've already seen a call to this exact shell command (even in a
125# previous invocation of make!) we'll return the value. If not, we'll
126# compute it and store the result for future runs.
127#
128# This is a bit of voodoo, but basic explanation is that if the variable
129# was undefined then we'll evaluate the shell command and store the result
130# into the variable. We'll then store that value in the cache and finally
131# output the value.
132#
133# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We
134# happen to know that the caller will have their shell command in $(2) so the
135# result of "call"ing this will produce a reference to that $(2). The reason
136# for this strangeness is to avoid an extra level of eval (and escaping) of
137# $(2).
138define __run-and-store
139ifeq ($(origin $(1)),undefined)
140 $$(eval $(1) := $$(shell $$(2)))
141ifeq ($(create-cache-dir),1)
142 $$(shell mkdir -p $(dir $(make-cache)))
143 $$(eval create-cache-dir :=)
144endif
145 $$(shell echo '$(1) := $$($(1))' >> $(make-cache))
146endif
147endef
148__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1))
149shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1))
150
151# output directory for tests below
152TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
153
154# try-run
155# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
156# Exit code chooses option. "$$TMP" serves as a temporary file and is
157# automatically cleaned up.
158__try-run = set -e; \
159 TMP="$(TMPOUT).$$$$.tmp"; \
160 TMPO="$(TMPOUT).$$$$.o"; \
161 if ($(1)) >/dev/null 2>&1; \
162 then echo "$(2)"; \
163 else echo "$(3)"; \
164 fi; \
165 rm -f "$$TMP" "$$TMPO"
166
167try-run = $(shell $(__try-run))
168
169# try-run-cached
170# This works like try-run, but the result is cached.
171try-run-cached = $(call shell-cached,$(__try-run))
172
173# as-option
174# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
175
176as-option = $(call try-run-cached,\
177 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
178
179# as-instr
180# Usage: cflags-y += $(call as-instr,instr,option1,option2)
181
182as-instr = $(call try-run-cached,\
183 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
184
185# __cc-option
186# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
187__cc-option = $(call try-run-cached,\
188 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
189
190# Do not attempt to build with gcc plugins during cc-option tests.
191# (And this uses delayed resolution so the flags will be up to date.)
192CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
193
194# cc-option
195# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
196
197cc-option = $(call __cc-option, $(CC),\
198 $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
199
200# hostcc-option
201# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
202hostcc-option = $(call __cc-option, $(HOSTCC),\
203 $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
204
205# cc-option-yn
206# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
207cc-option-yn = $(call try-run-cached,\
208 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
209
210# cc-disable-warning
211# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
212cc-disable-warning = $(call try-run-cached,\
213 $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
214
215# cc-name
216# Expands to either gcc or clang
217cc-name = $(call shell-cached,$(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
218
219# cc-version
220cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
221
222# cc-fullversion
223cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \
224 $(srctree)/scripts/gcc-version.sh -p $(CC))
225
226# cc-ifversion
227# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
228cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
229
230# cc-if-fullversion
231# Usage: EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
232cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4))
233
234# cc-ldoption
235# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
236cc-ldoption = $(call try-run-cached,\
237 $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
238
239# ld-option
240# Usage: LDFLAGS += $(call ld-option, -X)
241ld-option = $(call try-run-cached, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2))
242
243# ar-option
244# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
245# Important: no spaces around options
246ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2))
247
248# ld-version
249# Note this is mainly for HJ Lu's 3 number binutil versions
250ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh)
251
252# ld-ifversion
253# Usage: $(call ld-ifversion, -ge, 22252, y)
254ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
255
256######
257
258###
259# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
260# Usage:
261# $(Q)$(MAKE) $(build)=dir
262build := -f $(srctree)/scripts/Makefile.build obj
263
264###
265# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
266# Usage:
267# $(Q)$(MAKE) $(modbuiltin)=dir
268modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
269
270###
271# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
272# Usage:
273# $(Q)$(MAKE) $(dtbinst)=dir
274dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
275
276###
277# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
278# Usage:
279# $(Q)$(MAKE) $(clean)=dir
280clean := -f $(srctree)/scripts/Makefile.clean obj
281
282###
283# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
284# Usage:
285# $(Q)$(MAKE) $(hdr-inst)=dir
286hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
287
288# Prefix -I with $(srctree) if it is not an absolute path.
289# skip if -I has no parameter
290addtree = $(if $(patsubst -I%,%,$(1)), \
291$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
292
293# Find all -I options and call addtree
294flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
295
296# echo command.
297# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
298echo-cmd = $(if $($(quiet)cmd_$(1)),\
299 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
300
301# printing commands
302cmd = @$(echo-cmd) $(cmd_$(1))
303
304# Add $(obj)/ for paths that are not absolute
305objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
306
307###
308# if_changed - execute command if any prerequisite is newer than
309# target, or command line has changed
310# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
311# including used config symbols
312# if_changed_rule - as if_changed but execute rule instead
313# See Documentation/kbuild/makefiles.txt for more info
314
315ifneq ($(KBUILD_NOCMDDEP),1)
316# Check if both arguments are the same including their order. Result is empty
317# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
318arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
319 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
320else
321arg-check = $(if $(strip $(cmd_$@)),,1)
322endif
323
324# Replace >$< with >$$< to preserve $ when reloading the .cmd file
325# (needed for make)
326# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
327# (needed for make)
328# Replace >'< with >'\''< to be able to enclose the whole string in '...'
329# (needed for the shell)
330make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
331
332# Find any prerequisites that is newer than target or that does not exist.
333# PHONY targets skipped in both cases.
334any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
335
336# Execute command if command has changed or prerequisite(s) are updated.
337if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
338 @set -e; \
339 $(echo-cmd) $(cmd_$(1)); \
340 printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
341
342# Execute the command and also postprocess generated .d dependencies file.
343if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
344 @set -e; \
345 $(cmd_and_fixdep), @:)
346
347ifndef CONFIG_TRIM_UNUSED_KSYMS
348
349cmd_and_fixdep = \
350 $(echo-cmd) $(cmd_$(1)); \
351 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
352 rm -f $(depfile); \
353 mv -f $(dot-target).tmp $(dot-target).cmd;
354
355else
356
357# Filter out exported kernel symbol names from the preprocessor output.
358# See also __KSYM_DEPS__ in include/linux/export.h.
359# We disable the depfile generation here, so as not to overwrite the existing
360# depfile while fixdep is parsing it.
361flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
362ksym_dep_filter = \
363 case "$(1)" in \
364 cc_*_c|cpp_i_c) \
365 $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;; \
366 as_*_S|cpp_s_S) \
367 $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \
368 boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;; \
369 *) echo "Don't know how to preprocess $(1)" >&2; false ;; \
370 esac | tr ";" "\n" | sed -n 's/^.*=== __KSYM_\(.*\) ===.*$$/_\1/p'
371
372cmd_and_fixdep = \
373 $(echo-cmd) $(cmd_$(1)); \
374 $(ksym_dep_filter) | \
375 scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)' \
376 > $(dot-target).tmp; \
377 rm -f $(depfile); \
378 mv -f $(dot-target).tmp $(dot-target).cmd;
379
380endif
381
382# Usage: $(call if_changed_rule,foo)
383# Will check if $(cmd_foo) or any of the prerequisites changed,
384# and if so will execute $(rule_foo).
385if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
386 @set -e; \
387 $(rule_$(1)), @:)
388
389###
390# why - tell why a target got built
391# enabled by make V=2
392# Output (listed in the order they are checked):
393# (1) - due to target is PHONY
394# (2) - due to target missing
395# (3) - due to: file1.h file2.h
396# (4) - due to command line change
397# (5) - due to missing .cmd file
398# (6) - due to target not in $(targets)
399# (1) PHONY targets are always build
400# (2) No target, so we better build it
401# (3) Prerequisite is newer than target
402# (4) The command line stored in the file named dir/.target.cmd
403# differed from actual command line. This happens when compiler
404# options changes
405# (5) No dir/.target.cmd file (used to store command line)
406# (6) No dir/.target.cmd file and target not listed in $(targets)
407# This is a good hint that there is a bug in the kbuild file
408ifeq ($(KBUILD_VERBOSE),2)
409why = \
410 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
411 $(if $(wildcard $@), \
412 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
413 $(if $(arg-check), \
414 $(if $(cmd_$@),- due to command line change, \
415 $(if $(filter $@, $(targets)), \
416 - due to missing .cmd file, \
417 - due to $(notdir $@) not in $$(targets) \
418 ) \
419 ) \
420 ) \
421 ), \
422 - due to target missing \
423 ) \
424 )
425
426echo-why = $(call escsq, $(strip $(why)))
427endif
428
429###############################################################################
430#
431# When a Kconfig string contains a filename, it is suitable for
432# passing to shell commands. It is surrounded by double-quotes, and
433# any double-quotes or backslashes within it are escaped by
434# backslashes.
435#
436# This is no use for dependencies or $(wildcard). We need to strip the
437# surrounding quotes and the escaping from quotes and backslashes, and
438# we *do* need to escape any spaces in the string. So, for example:
439#
440# Usage: $(eval $(call config_filename,FOO))
441#
442# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
443# transformed as described above to be suitable for use within the
444# makefile.
445#
446# Also, if the filename is a relative filename and exists in the source
447# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
448# be prefixed to *both* command invocation and dependencies.
449#
450# Note: We also print the filenames in the quiet_cmd_foo text, and
451# perhaps ought to have a version specially escaped for that purpose.
452# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
453# enough. It'll strip the quotes in the common case where there's no
454# space and it's a simple filename, and it'll retain the quotes when
455# there's a space. There are some esoteric cases in which it'll print
456# the wrong thing, but we don't really care. The actual dependencies
457# and commands *do* get it right, with various combinations of single
458# and double quotes, backslashes and spaces in the filenames.
459#
460###############################################################################
461#
462define config_filename
463ifneq ($$(CONFIG_$(1)),"")
464$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
465ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
466else
467ifeq ($$(wildcard $$($(1)_FILENAME)),)
468ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
469$(1)_SRCPREFIX := $(srctree)/
470endif
471endif
472endif
473endif
474endef
475#
476###############################################################################
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