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8ec4b4ff SR |
1 | #### |
2 | # kbuild: Generic definitions | |
3 | ||
4 | # Convinient variables | |
5 | comma := , | |
6 | empty := | |
7 | space := $(empty) $(empty) | |
8 | ||
9 | ### | |
10 | # The temporary file to save gcc -MD generated dependencies must not | |
11 | # contain a comma | |
12 | depfile = $(subst $(comma),_,$(@D)/.$(@F).d) | |
13 | ||
14 | ### | |
15 | # filechk is used to check if the content of a generated file is updated. | |
16 | # Sample usage: | |
17 | # define filechk_sample | |
18 | # echo $KERNELRELEASE | |
19 | # endef | |
20 | # version.h : Makefile | |
21 | # $(call filechk,sample) | |
22 | # The rule defined shall write to stdout the content of the new file. | |
23 | # The existing file will be compared with the new one. | |
24 | # - If no file exist it is created | |
25 | # - If the content differ the new file is used | |
26 | # - If they are equal no change, and no timestamp update | |
27 | # - stdin is piped in from the first prerequisite ($<) so one has | |
28 | # to specify a valid file as first prerequisite (often the kbuild file) | |
29 | define filechk | |
30 | $(Q)set -e; \ | |
31 | echo ' CHK $@'; \ | |
32 | mkdir -p $(dir $@); \ | |
33 | $(filechk_$(1)) < $< > $@.tmp; \ | |
34 | if [ -r $@ ] && cmp -s $@ $@.tmp; then \ | |
35 | rm -f $@.tmp; \ | |
36 | else \ | |
37 | echo ' UPD $@'; \ | |
38 | mv -f $@.tmp $@; \ | |
39 | fi | |
40 | endef | |
41 | ||
42 | ### | |
43 | # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= | |
44 | # Usage: | |
45 | # $(Q)$(MAKE) $(build)=dir | |
46 | build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj | |
47 | ||
48 | # If quiet is set, only print short version of command | |
49 | cmd = @$(if $($(quiet)cmd_$(1)),\ | |
50 | echo ' $(subst ','\'',$($(quiet)cmd_$(1)))' &&) $(cmd_$(1)) | |
51 | ||
0a504f25 SR |
52 | # Add $(obj)/ for paths that is not absolute |
53 | objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o))) | |
54 | ||
8ec4b4ff SR |
55 | ### |
56 | # if_changed - execute command if any prerequisite is newer than | |
57 | # target, or command line has changed | |
58 | # if_changed_dep - as if_changed, but uses fixdep to reveal dependencies | |
59 | # including used config symbols | |
60 | # if_changed_rule - as if_changed but execute rule instead | |
61 | # See Documentation/kbuild/makefiles.txt for more info | |
62 | ||
63 | ifneq ($(KBUILD_NOCMDDEP),1) | |
64 | # Check if both arguments has same arguments. Result in empty string if equal | |
65 | # User may override this check using make KBUILD_NOCMDDEP=1 | |
66 | arg-check = $(strip $(filter-out $(1), $(2)) $(filter-out $(2), $(1)) ) | |
67 | endif | |
68 | ||
69 | # echo command. Short version is $(quiet) equals quiet, otherwise full command | |
70 | echo-cmd = $(if $($(quiet)cmd_$(1)), \ | |
71 | echo ' $(subst ','\'',$($(quiet)cmd_$(1)))';) | |
72 | ||
73 | # function to only execute the passed command if necessary | |
74 | # >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file | |
75 | # note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars | |
76 | # | |
77 | if_changed = $(if $(strip $? $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \ | |
78 | @set -e; \ | |
79 | $(echo-cmd) \ | |
80 | $(cmd_$(1)); \ | |
81 | echo 'cmd_$@ := $(subst $$,$$$$,$(subst ','\'',$(cmd_$(1))))' > $(@D)/.$(@F).cmd) | |
82 | ||
83 | # execute the command and also postprocess generated .d dependencies | |
84 | # file | |
85 | if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\ | |
86 | $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \ | |
87 | @set -e; \ | |
88 | $(echo-cmd) \ | |
89 | $(cmd_$(1)); \ | |
90 | scripts/basic/fixdep $(depfile) $@ '$(subst $$,$$$$,$(subst ','\'',$(cmd_$(1))))' > $(@D)/.$(@F).tmp; \ | |
91 | rm -f $(depfile); \ | |
92 | mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd) | |
93 | ||
94 | # Usage: $(call if_changed_rule,foo) | |
95 | # will check if $(cmd_foo) changed, or any of the prequisites changed, | |
96 | # and if so will execute $(rule_foo) | |
97 | if_changed_rule = $(if $(strip $? $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\ | |
98 | @set -e; \ | |
99 | $(rule_$(1))) |