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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-file = $(or $(wildcard $(src)/Kbuild),$(src)/Makefile)
66
67###
68# Read a file, replacing newlines with spaces
69#
70# Make 4.2 or later can read a file by using its builtin function.
71ifneq ($(filter-out 4.0 4.1, $(MAKE_VERSION)),)
72read-file = $(subst $(newline),$(space),$(file < $1))
73else
74read-file = $(shell cat $1 2>/dev/null)
75endif
76
77###
78# Easy method for doing a status message
79 kecho := :
80 quiet_kecho := echo
81silent_kecho := :
82kecho := $($(quiet)kecho)
83
84###
85# filechk is used to check if the content of a generated file is updated.
86# Sample usage:
87#
88# filechk_sample = echo $(KERNELRELEASE)
89# version.h: FORCE
90# $(call filechk,sample)
91#
92# The rule defined shall write to stdout the content of the new file.
93# The existing file will be compared with the new one.
94# - If no file exist it is created
95# - If the content differ the new file is used
96# - If they are equal no change, and no timestamp update
97define filechk
98 $(check-FORCE)
99 $(Q)set -e; \
100 mkdir -p $(dir $@); \
101 trap "rm -f $(tmp-target)" EXIT; \
102 { $(filechk_$(1)); } > $(tmp-target); \
103 if [ ! -r $@ ] || ! cmp -s $@ $(tmp-target); then \
104 $(kecho) ' UPD $@'; \
105 mv -f $(tmp-target) $@; \
106 fi
107endef
108
109###
110# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
111# Usage:
112# $(Q)$(MAKE) $(build)=dir
113build := -f $(srctree)/scripts/Makefile.build obj
114
115###
116# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
117# Usage:
118# $(Q)$(MAKE) $(clean)=dir
119clean := -f $(srctree)/scripts/Makefile.clean obj
120
121# pring log
122#
123# If quiet is "silent_", print nothing and sink stdout
124# If quiet is "quiet_", print short log
125# If quiet is empty, print short log and whole command
126silent_log_print = exec >/dev/null;
127 quiet_log_print = $(if $(quiet_cmd_$1), echo ' $(call escsq,$(quiet_cmd_$1)$(why))';)
128 log_print = echo '$(pound) $(call escsq,$(or $(quiet_cmd_$1),cmd_$1 $@)$(why))'; \
129 echo ' $(call escsq,$(cmd_$1))';
130
131# Delete the target on interruption
132#
133# GNU Make automatically deletes the target if it has already been changed by
134# the interrupted recipe. So, you can safely stop the build by Ctrl-C (Make
135# will delete incomplete targets), and resume it later.
136#
137# However, this does not work when the stderr is piped to another program, like
138# $ make >&2 | tee log
139# Make dies with SIGPIPE before cleaning the targets.
140#
141# To address it, we clean the target in signal traps.
142#
143# Make deletes the target when it catches SIGHUP, SIGINT, SIGQUIT, SIGTERM.
144# So, we cover them, and also SIGPIPE just in case.
145#
146# Of course, this is unneeded for phony targets.
147delete-on-interrupt = \
148 $(if $(filter-out $(PHONY), $@), \
149 $(foreach sig, HUP INT QUIT TERM PIPE, \
150 trap 'rm -f $@; trap - $(sig); kill -s $(sig) $$$$' $(sig);))
151
152# print and execute commands
153cmd = @$(if $(cmd_$(1)),set -e; $($(quiet)log_print) $(delete-on-interrupt) $(cmd_$(1)),:)
154
155###
156# if_changed - execute command if any prerequisite is newer than
157# target, or command line has changed
158# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
159# including used config symbols
160# if_changed_rule - as if_changed but execute rule instead
161# See Documentation/kbuild/makefiles.rst for more info
162
163ifneq ($(KBUILD_NOCMDDEP),1)
164# Check if both commands are the same including their order. Result is empty
165# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
166# If the target does not exist, the *.cmd file should not be included so
167# $(savedcmd_$@) gets empty. Then, target will be built even if $(newer-prereqs)
168# happens to become empty.
169cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(savedcmd_$@))), \
170 $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
171else
172# We still need to detect missing targets.
173cmd-check = $(if $(strip $(savedcmd_$@)),,1)
174endif
175
176# Replace >$< with >$$< to preserve $ when reloading the .cmd file
177# (needed for make)
178# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
179# (needed for make)
180# Replace >'< with >'\''< to be able to enclose the whole string in '...'
181# (needed for the shell)
182make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
183
184# Find any prerequisites that are newer than target or that do not exist.
185# PHONY targets skipped in both cases.
186# If there is no prerequisite other than phony targets, $(newer-prereqs) becomes
187# empty even if the target does not exist. cmd-check saves this corner case.
188newer-prereqs = $(filter-out $(PHONY),$?)
189
190# It is a typical mistake to forget the FORCE prerequisite. Check it here so
191# no more breakage will slip in.
192check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))
193
194if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)
195
196# Execute command if command has changed or prerequisite(s) are updated.
197if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:)
198
199cmd_and_savecmd = \
200 $(cmd); \
201 printf '%s\n' 'savedcmd_$@ := $(make-cmd)' > $(dot-target).cmd
202
203# Execute the command and also postprocess generated .d dependencies file.
204if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:)
205
206cmd_and_fixdep = \
207 $(cmd); \
208 $(objtree)/scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
209 rm -f $(depfile)
210
211# Usage: $(call if_changed_rule,foo)
212# Will check if $(cmd_foo) or any of the prerequisites changed,
213# and if so will execute $(rule_foo).
214if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:)
215
216###
217# why - tell why a target got built
218# enabled by make V=2
219# Output (listed in the order they are checked):
220# (1) - due to target is PHONY
221# (2) - due to target missing
222# (3) - due to: file1.h file2.h
223# (4) - due to command line change
224# (5) - due to missing .cmd file
225# (6) - due to target not in $(targets)
226# (1) PHONY targets are always build
227# (2) No target, so we better build it
228# (3) Prerequisite is newer than target
229# (4) The command line stored in the file named dir/.target.cmd
230# differed from actual command line. This happens when compiler
231# options changes
232# (5) No dir/.target.cmd file (used to store command line)
233# (6) No dir/.target.cmd file and target not listed in $(targets)
234# This is a good hint that there is a bug in the kbuild file
235ifneq ($(findstring 2, $(KBUILD_VERBOSE)),)
236_why = \
237 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
238 $(if $(wildcard $@), \
239 $(if $(newer-prereqs),- due to: $(newer-prereqs), \
240 $(if $(cmd-check), \
241 $(if $(savedcmd_$@),- due to command line change, \
242 $(if $(filter $@, $(targets)), \
243 - due to missing .cmd file, \
244 - due to $(notdir $@) not in $$(targets) \
245 ) \
246 ) \
247 ) \
248 ), \
249 - due to target missing \
250 ) \
251 )
252
253why = $(space)$(strip $(_why))
254endif
255
256###############################################################################
257
258# delete partially updated (i.e. corrupted) files on error
259.DELETE_ON_ERROR:
260
261# do not delete intermediate files automatically
262#
263# .NOTINTERMEDIATE is more correct, but only available on newer Make versions.
264# Make 4.4 introduced .NOTINTERMEDIATE, and it appears in .FEATURES, but the
265# global .NOTINTERMEDIATE does not work. We can use it on Make > 4.4.
266# Use .SECONDARY for older Make versions, but "newer-prereq" cannot detect
267# deleted files.
268ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),)
269.NOTINTERMEDIATE:
270else
271.SECONDARY:
272endif