1 # SPDX-License-Identifier: GPL-2.0
2 ####
3 # kbuild: Generic definitions
4
5 # Convenient variables
6 comma := ,
7 quote := "
8 squote := '
9 empty :=
10 space := $(empty) $(empty)
11 space_escape := _-_SPACE_-_
12 pound := \#
13 define newline
14
15
16 endef
17
18 ###
19 # Comparison macros.
20 # Usage: $(call test-lt, $(CONFIG_LLD_VERSION)
21 #
22 # Use $(intcmp ...) if supported. (Make >= 4.4
23 # Otherwise, fall back to the 'test' shell com
24 ifeq ($(intcmp 1,0,,,y),y)
25 test-ge = $(intcmp $(strip $1)0, $(strip $2)0,
26 test-gt = $(intcmp $(strip $1)0, $(strip $2)0,
27 else
28 test-ge = $(shell test $(strip $1)0 -ge $(stri
29 test-gt = $(shell test $(strip $1)0 -gt $(stri
30 endif
31 test-le = $(call test-ge, $2, $1)
32 test-lt = $(call test-gt, $2, $1)
33
34 ###
35 # Name of target with a '.' as filename prefix
36 dot-target = $(dir $@).$(notdir $@)
37
38 ###
39 # Name of target with a '.tmp_' as filename pr
40 tmp-target = $(dir $@).tmp_$(notdir $@)
41
42 ###
43 # The temporary file to save gcc -MMD generate
44 # contain a comma
45 depfile = $(subst $(comma),_,$(dot-target).d)
46
47 ###
48 # filename of target with directory and extens
49 basetarget = $(basename $(notdir $@))
50
51 ###
52 # real prerequisites without phony targets
53 real-prereqs = $(filter-out $(PHONY), $^)
54
55 ###
56 # Escape single quote for use in echo statemen
57 escsq = $(subst $(squote),'\$(squote)',$1)
58
59 ###
60 # Quote a string to pass it to C files. foo =>
61 stringify = $(squote)$(quote)$1$(quote)$(squot
62
63 ###
64 # The path to Kbuild or Makefile. Kbuild has p
65 kbuild-file = $(or $(wildcard $(src)/Kbuild),$
66
67 ###
68 # Read a file, replacing newlines with spaces
69 #
70 # Make 4.2 or later can read a file by using i
71 ifneq ($(filter-out 4.0 4.1, $(MAKE_VERSION)),
72 read-file = $(subst $(newline),$(space),$(file
73 else
74 read-file = $(shell cat $1 2>/dev/null)
75 endif
76
77 ###
78 # Easy method for doing a status message
79 kecho := :
80 quiet_kecho := echo
81 silent_kecho := :
82 kecho := $($(quiet)kecho)
83
84 ###
85 # filechk is used to check if the content of a
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 c
93 # The existing file will be compared with the
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 timest
97 define 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-ta
104 $(kecho) ' UPD $@';
105 mv -f $(tmp-target) $@;
106 fi
107 endef
108
109 ###
110 # Shorthand for $(Q)$(MAKE) -f scripts/Makefil
111 # Usage:
112 # $(Q)$(MAKE) $(build)=dir
113 build := -f $(srctree)/scripts/Makefile.build
114
115 ###
116 # Shorthand for $(Q)$(MAKE) -f scripts/Makefil
117 # Usage:
118 # $(Q)$(MAKE) $(clean)=dir
119 clean := -f $(srctree)/scripts/Makefile.clean
120
121 # pring log
122 #
123 # If quiet is "silent_", print nothing and sin
124 # If quiet is "quiet_", print short log
125 # If quiet is empty, print short log and whole
126 silent_log_print = exec >/dev/null;
127 quiet_log_print = $(if $(quiet_cmd_$1), echo
128 log_print = echo '$(pound) $(call escsq
129 echo ' $(call escsq,$(cmd_
130
131 # Delete the target on interruption
132 #
133 # GNU Make automatically deletes the target if
134 # the interrupted recipe. So, you can safely s
135 # will delete incomplete targets), and resume
136 #
137 # However, this does not work when the stderr
138 # $ make >&2 | tee log
139 # Make dies with SIGPIPE before cleaning the t
140 #
141 # To address it, we clean the target in signal
142 #
143 # Make deletes the target when it catches SIGH
144 # So, we cover them, and also SIGPIPE just in
145 #
146 # Of course, this is unneeded for phony target
147 delete-on-interrupt = \
148 $(if $(filter-out $(PHONY), $@), \
149 $(foreach sig, HUP INT QUIT TE
150 trap 'rm -f $@; trap -
151
152 # print and execute commands
153 cmd = @$(if $(cmd_$(1)),set -e; $($(quiet)log_
154
155 ###
156 # if_changed - execute command if any pre
157 # target, or command line ha
158 # if_changed_dep - as if_changed, but uses fi
159 # including used config symb
160 # if_changed_rule - as if_changed but execute
161 # See Documentation/kbuild/makefiles.rst for m
162
163 ifneq ($(KBUILD_NOCMDDEP),1)
164 # Check if both commands are the same includin
165 # string if equal. User may override this chec
166 # If the target does not exist, the *.cmd file
167 # $(savedcmd_$@) gets empty. Then, target will
168 # happens to become empty.
169 cmd-check = $(filter-out $(subst $(space),$(sp
170 $(subst $(space),$(sp
171 else
172 # We still need to detect missing targets.
173 cmd-check = $(if $(strip $(savedcmd_$@)),,1)
174 endif
175
176 # Replace >$< with >$$< to preserve $ when rel
177 # (needed for make)
178 # Replace >#< with >$(pound)< to avoid startin
179 # (needed for make)
180 # Replace >'< with >'\''< to be able to enclos
181 # (needed for the shell)
182 make-cmd = $(call escsq,$(subst $(pound),$$(po
183
184 # Find any prerequisites that are newer than t
185 # PHONY targets skipped in both cases.
186 # If there is no prerequisite other than phony
187 # empty even if the target does not exist. cmd
188 newer-prereqs = $(filter-out $(PHONY),$?)
189
190 # It is a typical mistake to forget the FORCE
191 # no more breakage will slip in.
192 check-FORCE = $(if $(filter FORCE, $^),,$(warn
193
194 if-changed-cond = $(newer-prereqs)$(cmd-check)
195
196 # Execute command if command has changed or pr
197 if_changed = $(if $(if-changed-cond),$(cmd_and
198
199 cmd_and_savecmd =
200 $(cmd);
201 printf '%s\n' 'savedcmd_$@ := $(make-c
202
203 # Execute the command and also postprocess gen
204 if_changed_dep = $(if $(if-changed-cond),$(cmd
205
206 cmd_and_fixdep =
207 $(cmd);
208 scripts/basic/fixdep $(depfile) $@ '$(
209 rm -f $(depfile)
210
211 # Usage: $(call if_changed_rule,foo)
212 # Will check if $(cmd_foo) or any of the prere
213 # and if so will execute $(rule_foo).
214 if_changed_rule = $(if $(if-changed-cond),$(ru
215
216 ###
217 # why - tell why a target got built
218 # enabled by make V=2
219 # Output (listed in the order they are c
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 $(target
226 # (1) PHONY targets are always build
227 # (2) No target, so we better build it
228 # (3) Prerequisite is newer than target
229 # (4) The command line stored in the file name
230 # differed from actual command line. This
231 # options changes
232 # (5) No dir/.target.cmd file (used to store c
233 # (6) No dir/.target.cmd file and target not l
234 # This is a good hint that there is a bug
235 ifneq ($(findstring 2, $(KBUILD_VERBOSE)),)
236 _why =
237 $(if $(filter $@, $(PHONY)),- due to targe
238 $(if $(wildcard $@),
239 $(if $(newer-prereqs),- due to: $(
240 $(if $(cmd-check),
241 $(if $(savedcmd_$@),- due
242 $(if $(filter $@, $(ta
243 - due to missing .
244 - due to $(notdir
245 )
246 )
247 )
248 ),
249 - due to target missing
250 )
251 )
252
253 why = $(space)$(strip $(_why))
254 endif
255
256 ##############################################
257
258 # delete partially updated (i.e. corrupted) fi
259 .DELETE_ON_ERROR:
260
261 # do not delete intermediate files automatical
262 #
263 # .NOTINTERMEDIATE is more correct, but only a
264 # Make 4.4 introduced .NOTINTERMEDIATE, and it
265 # global .NOTINTERMEDIATE does not work. We ca
266 # Use .SECONDARY for older Make versions, but
267 # deleted files.
268 ifneq ($(and $(filter notintermediate, $(.FEAT
269 .NOTINTERMEDIATE:
270 else
271 .SECONDARY:
272 endif
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