kbuild: asm-offsets.h is now cleaned with O=.. builds
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / scripts / Kbuild.include
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1####
2# kbuild: Generic definitions
3
beda9f3a 4# Convenient variables
8ec4b4ff 5comma := ,
d51bfb78 6squote := '
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7empty :=
8space := $(empty) $(empty)
9
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10###
11# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
12dot-target = $(dir $@).$(notdir $@)
13
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14###
15# The temporary file to save gcc -MD generated dependencies must not
16# contain a comma
48f1f058 17depfile = $(subst $(comma),_,$(dot-target).d)
8ec4b4ff 18
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19###
20# filename of target with directory and extension stripped
21basetarget = $(basename $(notdir $@))
22
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23###
24# Escape single quote for use in echo statements
25escsq = $(subst $(squote),'\$(squote)',$1)
26
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27###
28# filechk is used to check if the content of a generated file is updated.
29# Sample usage:
30# define filechk_sample
31# echo $KERNELRELEASE
32# endef
33# version.h : Makefile
34# $(call filechk,sample)
35# The rule defined shall write to stdout the content of the new file.
36# The existing file will be compared with the new one.
37# - If no file exist it is created
38# - If the content differ the new file is used
39# - If they are equal no change, and no timestamp update
40# - stdin is piped in from the first prerequisite ($<) so one has
41# to specify a valid file as first prerequisite (often the kbuild file)
42define filechk
43 $(Q)set -e; \
44 echo ' CHK $@'; \
45 mkdir -p $(dir $@); \
46 $(filechk_$(1)) < $< > $@.tmp; \
47 if [ -r $@ ] && cmp -s $@ $@.tmp; then \
48 rm -f $@.tmp; \
49 else \
50 echo ' UPD $@'; \
51 mv -f $@.tmp $@; \
52 fi
53endef
54
20a468b5 55######
9d6e7a70 56# gcc support functions
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57# See documentation in Documentation/kbuild/makefiles.txt
58
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59# output directory for tests below
60TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
61
62# try-run
63# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
64# Exit code chooses option. "$$TMP" is can be used as temporary file and
65# is automatically cleaned up.
66try-run = $(shell set -e; \
67 TMP="$(TMPOUT).$$$$.tmp"; \
68 if ($(1)) >/dev/null 2>&1; \
69 then echo "$(2)"; \
70 else echo "$(3)"; \
71 fi; \
72 rm -f "$$TMP")
347a00fb 73
20a468b5 74# as-option
bff288c1 75# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
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76
77as-option = $(call try-run,\
78 $(CC) $(CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
20a468b5 79
e2414910 80# as-instr
bff288c1 81# Usage: cflags-y += $(call as-instr,instr,option1,option2)
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82
83as-instr = $(call try-run,\
84 echo -e "$(1)" | $(CC) $(AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))
e2414910 85
20a468b5 86# cc-option
bff288c1 87# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
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88
89cc-option = $(call try-run,\
90 $(CC) $(CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",$(1),$(2))
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91
92# cc-option-yn
bff288c1 93# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
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94cc-option-yn = $(call try-run,\
95 $(CC) $(CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",y,n)
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96
97# cc-option-align
98# Prefix align with either -falign or -malign
99cc-option-align = $(subst -functions=0,,\
beda9f3a 100 $(call cc-option,-falign-functions=0,-malign-functions=0))
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101
102# cc-version
bff288c1 103# Usage gcc-ver := $(call cc-version,$(CC))
8eb3afe0 104cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
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105
106# cc-ifversion
107# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
5de043f4 108cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
20a468b5 109
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110# ld-option
111# Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
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112ld-option = $(call try-run,\
113 $(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))
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114
115######
0b0bf7a3 116
beda9f3a 117###
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118# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
119# Usage:
120# $(Q)$(MAKE) $(build)=dir
121build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
122
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123# Prefix -I with $(srctree) if it is not an absolute path.
124addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
5de043f4 125
d9df92e2 126# Find all -I options and call addtree
beda9f3a 127flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
d9df92e2 128
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129# echo command.
130# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
bff288c1 131echo-cmd = $(if $($(quiet)cmd_$(1)),\
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132 echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
133
134# printing commands
6176aa9a 135cmd = @$(echo-cmd) $(cmd_$(1))
8ec4b4ff 136
5de043f4 137# Add $(obj)/ for paths that are not absolute
bff288c1 138objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
0a504f25 139
8ec4b4ff 140###
5de043f4 141# if_changed - execute command if any prerequisite is newer than
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142# target, or command line has changed
143# if_changed_dep - as if_changed, but uses fixdep to reveal dependencies
144# including used config symbols
145# if_changed_rule - as if_changed but execute rule instead
146# See Documentation/kbuild/makefiles.txt for more info
147
148ifneq ($(KBUILD_NOCMDDEP),1)
beda9f3a 149# Check if both arguments has same arguments. Result is empty string if equal.
8ec4b4ff 150# User may override this check using make KBUILD_NOCMDDEP=1
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151arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
152 $(filter-out $(cmd_$@), $(cmd_$(1))) )
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153endif
154
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155# >'< substitution is for echo to work,
156# >$< substitution to preserve $ when reloading .cmd file
157# note: when using inline perl scripts [perl -e '...$$t=1;...']
158# in $(cmd_xxx) double $$ your perl vars
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159make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1)))))
160
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161# Find any prerequisites that is newer than target or that does not exist.
162# PHONY targets skipped in both cases.
163any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
164
5de043f4 165# Execute command if command has changed or prerequisite(s) are updated.
4f193362 166#
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167if_changed = $(if $(strip $(any-prereq) $(arg-check)), \
168 @set -e; \
169 $(echo-cmd) $(cmd_$(1)); \
170 echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
8ec4b4ff 171
5de043f4 172# Execute the command and also postprocess generated .d dependencies file.
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173if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \
174 @set -e; \
175 $(echo-cmd) $(cmd_$(1)); \
176 scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
177 rm -f $(depfile); \
178 mv -f $(dot-target).tmp $(dot-target).cmd)
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179
180# Usage: $(call if_changed_rule,foo)
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181# Will check if $(cmd_foo) or any of the prerequisites changed,
182# and if so will execute $(rule_foo).
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183if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
184 @set -e; \
185 $(rule_$(1)))
186
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187###
188# why - tell why a a target got build
189# enabled by make V=2
190# Output (listed in the order they are checked):
191# (1) - due to target is PHONY
192# (2) - due to target missing
193# (3) - due to: file1.h file2.h
194# (4) - due to command line change
195# (5) - due to missing .cmd file
196# (6) - due to target not in $(targets)
197# (1) PHONY targets are always build
198# (2) No target, so we better build it
199# (3) Prerequisite is newer than target
200# (4) The command line stored in the file named dir/.target.cmd
201# differed from actual command line. This happens when compiler
202# options changes
203# (5) No dir/.target.cmd file (used to store command line)
204# (6) No dir/.target.cmd file and target not listed in $(targets)
205# This is a good hint that there is a bug in the kbuild file
206ifeq ($(KBUILD_VERBOSE),2)
207why = \
208 $(if $(filter $@, $(PHONY)),- due to target is PHONY, \
209 $(if $(wildcard $@), \
210 $(if $(strip $(any-prereq)),- due to: $(any-prereq), \
211 $(if $(arg-check), \
212 $(if $(cmd_$@),- due to command line change, \
213 $(if $(filter $@, $(targets)), \
214 - due to missing .cmd file, \
215 - due to $(notdir $@) not in $$(targets) \
216 ) \
217 ) \
218 ) \
219 ), \
220 - due to target missing \
221 ) \
222 )
223
224echo-why = $(call escsq, $(strip $(why)))
225endif