xref: /openbmc/linux/scripts/Kbuild.include (revision 1fa0a7dc) 
1####
2# kbuild: Generic definitions
3
4# Convenient variables
5comma   := ,
6quote   := "
7squote  := '
8empty   :=
9space   := $(empty) $(empty)
10space_escape := _-_SPACE_-_
11pound := \#
12
13###
14# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
15dot-target = $(dir $@).$(notdir $@)
16
17###
18# The temporary file to save gcc -MD generated dependencies must not
19# contain a comma
20depfile = $(subst $(comma),_,$(dot-target).d)
21
22###
23# filename of target with directory and extension stripped
24basetarget = $(basename $(notdir $@))
25
26###
27# real prerequisites without phony targets
28real-prereqs = $(filter-out $(PHONY), $^)
29
30###
31# Escape single quote for use in echo statements
32escsq = $(subst $(squote),'\$(squote)',$1)
33
34###
35# Easy method for doing a status message
36       kecho := :
37 quiet_kecho := echo
38silent_kecho := :
39kecho := $($(quiet)kecho)
40
41###
42# filechk is used to check if the content of a generated file is updated.
43# Sample usage:
44#
45# filechk_sample = echo $(KERNELRELEASE)
46# version.h: FORCE
47#	$(call filechk,sample)
48#
49# The rule defined shall write to stdout the content of the new file.
50# The existing file will be compared with the new one.
51# - If no file exist it is created
52# - If the content differ the new file is used
53# - If they are equal no change, and no timestamp update
54# - stdin is piped in from the first prerequisite ($<) so one has
55#   to specify a valid file as first prerequisite (often the kbuild file)
56define filechk
57	$(Q)set -e;				\
58	mkdir -p $(dir $@);			\
59	{ $(filechk_$(1)); } > $@.tmp;		\
60	if [ -r $@ ] && cmp -s $@ $@.tmp; then	\
61		rm -f $@.tmp;			\
62	else					\
63		$(kecho) '  UPD     $@';	\
64		mv -f $@.tmp $@;		\
65	fi
66endef
67
68######
69# gcc support functions
70# See documentation in Documentation/kbuild/makefiles.txt
71
72# cc-cross-prefix
73# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
74# Return first <prefix> where a <prefix>gcc is found in PATH.
75# If no gcc found in PATH with listed prefixes return nothing
76cc-cross-prefix = $(firstword $(foreach c, $(filter-out -%, $(1)), \
77					$(if $(shell which $(c)gcc), $(c))))
78
79# output directory for tests below
80TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
81
82# try-run
83# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
84# Exit code chooses option. "$$TMP" serves as a temporary file and is
85# automatically cleaned up.
86try-run = $(shell set -e;		\
87	TMP="$(TMPOUT).$$$$.tmp";	\
88	TMPO="$(TMPOUT).$$$$.o";	\
89	if ($(1)) >/dev/null 2>&1;	\
90	then echo "$(2)";		\
91	else echo "$(3)";		\
92	fi;				\
93	rm -f "$$TMP" "$$TMPO")
94
95# as-option
96# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
97
98as-option = $(call try-run,\
99	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
100
101# as-instr
102# Usage: cflags-y += $(call as-instr,instr,option1,option2)
103
104as-instr = $(call try-run,\
105	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
106
107# __cc-option
108# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
109__cc-option = $(call try-run,\
110	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
111
112# Do not attempt to build with gcc plugins during cc-option tests.
113# (And this uses delayed resolution so the flags will be up to date.)
114CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
115
116# cc-option
117# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
118
119cc-option = $(call __cc-option, $(CC),\
120	$(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
121
122# hostcc-option
123# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
124hostcc-option = $(call __cc-option, $(HOSTCC),\
125	$(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
126
127# cc-option-yn
128# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
129cc-option-yn = $(call try-run,\
130	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
131
132# cc-disable-warning
133# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
134cc-disable-warning = $(call try-run,\
135	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
136
137# cc-ifversion
138# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
139cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
140
141# cc-ldoption
142# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
143cc-ldoption = $(call try-run,\
144	$(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
145
146# ld-option
147# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
148ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
149
150# ar-option
151# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
152# Important: no spaces around options
153ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
154
155# ld-version
156# Note this is mainly for HJ Lu's 3 number binutil versions
157ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
158
159# ld-ifversion
160# Usage:  $(call ld-ifversion, -ge, 22252, y)
161ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
162
163######
164
165###
166# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
167# Usage:
168# $(Q)$(MAKE) $(build)=dir
169build := -f $(srctree)/scripts/Makefile.build obj
170
171###
172# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
173# Usage:
174# $(Q)$(MAKE) $(modbuiltin)=dir
175modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
176
177###
178# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
179# Usage:
180# $(Q)$(MAKE) $(dtbinst)=dir
181dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
182
183###
184# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
185# Usage:
186# $(Q)$(MAKE) $(clean)=dir
187clean := -f $(srctree)/scripts/Makefile.clean obj
188
189###
190# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
191# Usage:
192# $(Q)$(MAKE) $(hdr-inst)=dir
193hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
194
195# echo command.
196# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
197echo-cmd = $(if $($(quiet)cmd_$(1)),\
198	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
199
200# printing commands
201cmd = @set -e; $(echo-cmd) $(cmd_$(1))
202
203# Add $(obj)/ for paths that are not absolute
204objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
205
206###
207# if_changed      - execute command if any prerequisite is newer than
208#                   target, or command line has changed
209# if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
210#                   including used config symbols
211# if_changed_rule - as if_changed but execute rule instead
212# See Documentation/kbuild/makefiles.txt for more info
213
214ifneq ($(KBUILD_NOCMDDEP),1)
215# Check if both arguments are the same including their order. Result is empty
216# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
217arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
218                         $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
219else
220arg-check = $(if $(strip $(cmd_$@)),,1)
221endif
222
223# Replace >$< with >$$< to preserve $ when reloading the .cmd file
224# (needed for make)
225# Replace >#< with >$(pound)< to avoid starting a comment in the .cmd file
226# (needed for make)
227# Replace >'< with >'\''< to be able to enclose the whole string in '...'
228# (needed for the shell)
229make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
230
231# Find any prerequisites that is newer than target or that does not exist.
232# PHONY targets skipped in both cases.
233any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
234
235# Execute command if command has changed or prerequisite(s) are updated.
236if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
237	$(cmd);                                                              \
238	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
239
240# Execute the command and also postprocess generated .d dependencies file.
241if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)),$(cmd_and_fixdep),@:)
242
243cmd_and_fixdep =                                                             \
244	$(cmd);                                                              \
245	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
246	rm -f $(depfile)
247
248# Usage: $(call if_changed_rule,foo)
249# Will check if $(cmd_foo) or any of the prerequisites changed,
250# and if so will execute $(rule_foo).
251if_changed_rule = $(if $(strip $(any-prereq) $(arg-check)),$(rule_$(1)),@:)
252
253###
254# why - tell why a target got built
255#       enabled by make V=2
256#       Output (listed in the order they are checked):
257#          (1) - due to target is PHONY
258#          (2) - due to target missing
259#          (3) - due to: file1.h file2.h
260#          (4) - due to command line change
261#          (5) - due to missing .cmd file
262#          (6) - due to target not in $(targets)
263# (1) PHONY targets are always build
264# (2) No target, so we better build it
265# (3) Prerequisite is newer than target
266# (4) The command line stored in the file named dir/.target.cmd
267#     differed from actual command line. This happens when compiler
268#     options changes
269# (5) No dir/.target.cmd file (used to store command line)
270# (6) No dir/.target.cmd file and target not listed in $(targets)
271#     This is a good hint that there is a bug in the kbuild file
272ifeq ($(KBUILD_VERBOSE),2)
273why =                                                                        \
274    $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
275        $(if $(wildcard $@),                                                 \
276            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
277                $(if $(arg-check),                                           \
278                    $(if $(cmd_$@),- due to command line change,             \
279                        $(if $(filter $@, $(targets)),                       \
280                            - due to missing .cmd file,                      \
281                            - due to $(notdir $@) not in $$(targets)         \
282                         )                                                   \
283                     )                                                       \
284                 )                                                           \
285             ),                                                              \
286             - due to target missing                                         \
287         )                                                                   \
288     )
289
290echo-why = $(call escsq, $(strip $(why)))
291endif
292
293###############################################################################
294#
295# When a Kconfig string contains a filename, it is suitable for
296# passing to shell commands. It is surrounded by double-quotes, and
297# any double-quotes or backslashes within it are escaped by
298# backslashes.
299#
300# This is no use for dependencies or $(wildcard). We need to strip the
301# surrounding quotes and the escaping from quotes and backslashes, and
302# we *do* need to escape any spaces in the string. So, for example:
303#
304# Usage: $(eval $(call config_filename,FOO))
305#
306# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
307# transformed as described above to be suitable for use within the
308# makefile.
309#
310# Also, if the filename is a relative filename and exists in the source
311# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
312# be prefixed to *both* command invocation and dependencies.
313#
314# Note: We also print the filenames in the quiet_cmd_foo text, and
315# perhaps ought to have a version specially escaped for that purpose.
316# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
317# enough.  It'll strip the quotes in the common case where there's no
318# space and it's a simple filename, and it'll retain the quotes when
319# there's a space. There are some esoteric cases in which it'll print
320# the wrong thing, but we don't really care. The actual dependencies
321# and commands *do* get it right, with various combinations of single
322# and double quotes, backslashes and spaces in the filenames.
323#
324###############################################################################
325#
326define config_filename
327ifneq ($$(CONFIG_$(1)),"")
328$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
329ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
330else
331ifeq ($$(wildcard $$($(1)_FILENAME)),)
332ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
333$(1)_SRCPREFIX := $(srctree)/
334endif
335endif
336endif
337endif
338endef
339#
340###############################################################################
341
342# delete partially updated (i.e. corrupted) files on error
343.DELETE_ON_ERROR:
344
345# do not delete intermediate files automatically
346.SECONDARY:
347