xref: /linux/scripts/Kbuild.include (revision fcc8487d477a3452a1d0ccbdd4c5e0e1e3cb8bed)
1####
2# kbuild: Generic definitions
3
4# Convenient variables
5comma   := ,
6quote   := "
7squote  := '
8empty   :=
9space   := $(empty) $(empty)
10space_escape := _-_SPACE_-_
11
12###
13# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
14dot-target = $(dir $@).$(notdir $@)
15
16###
17# The temporary file to save gcc -MD generated dependencies must not
18# contain a comma
19depfile = $(subst $(comma),_,$(dot-target).d)
20
21###
22# filename of target with directory and extension stripped
23basetarget = $(basename $(notdir $@))
24
25###
26# filename of first prerequisite with directory and extension stripped
27baseprereq = $(basename $(notdir $<))
28
29###
30# Escape single quote for use in echo statements
31escsq = $(subst $(squote),'\$(squote)',$1)
32
33###
34# Easy method for doing a status message
35       kecho := :
36 quiet_kecho := echo
37silent_kecho := :
38kecho := $($(quiet)kecho)
39
40###
41# filechk is used to check if the content of a generated file is updated.
42# Sample usage:
43# define filechk_sample
44#	echo $KERNELRELEASE
45# endef
46# version.h : Makefile
47#	$(call filechk,sample)
48# The rule defined shall write to stdout the content of the new file.
49# The existing file will be compared with the new one.
50# - If no file exist it is created
51# - If the content differ the new file is used
52# - If they are equal no change, and no timestamp update
53# - stdin is piped in from the first prerequisite ($<) so one has
54#   to specify a valid file as first prerequisite (often the kbuild file)
55define filechk
56	$(Q)set -e;				\
57	$(kecho) '  CHK     $@';		\
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 := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
74# Return first prefix where a prefix$(CC) is found in PATH.
75# If no $(CC) found in PATH with listed prefixes return nothing
76cc-cross-prefix =  \
77	$(word 1, $(foreach c,$(1),                                   \
78		$(shell set -e;                                       \
79		if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
80			echo $(c);                                    \
81		fi)))
82
83# output directory for tests below
84TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
85
86# try-run
87# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
88# Exit code chooses option. "$$TMP" is can be used as temporary file and
89# is automatically cleaned up.
90try-run = $(shell set -e;		\
91	TMP="$(TMPOUT).$$$$.tmp";	\
92	TMPO="$(TMPOUT).$$$$.o";	\
93	if ($(1)) >/dev/null 2>&1;	\
94	then echo "$(2)";		\
95	else echo "$(3)";		\
96	fi;				\
97	rm -f "$$TMP" "$$TMPO")
98
99# as-option
100# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
101
102as-option = $(call try-run,\
103	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
104
105# as-instr
106# Usage: cflags-y += $(call as-instr,instr,option1,option2)
107
108as-instr = $(call try-run,\
109	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
110
111# Do not attempt to build with gcc plugins during cc-option tests.
112# (And this uses delayed resolution so the flags will be up to date.)
113CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
114
115# cc-option
116# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
117
118cc-option = $(call try-run,\
119	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
120
121# cc-option-yn
122# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
123cc-option-yn = $(call try-run,\
124	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
125
126# cc-option-align
127# Prefix align with either -falign or -malign
128cc-option-align = $(subst -functions=0,,\
129	$(call cc-option,-falign-functions=0,-malign-functions=0))
130
131# cc-disable-warning
132# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
133cc-disable-warning = $(call try-run,\
134	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
135
136# cc-name
137# Expands to either gcc or clang
138cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
139
140# cc-version
141cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
142
143# cc-fullversion
144cc-fullversion = $(shell $(CONFIG_SHELL) \
145	$(srctree)/scripts/gcc-version.sh -p $(CC))
146
147# cc-ifversion
148# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
149cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
150
151# cc-if-fullversion
152# Usage:  EXTRA_CFLAGS += $(call cc-if-fullversion, -lt, 040502, -O1)
153cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo $(4))
154
155# cc-ldoption
156# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
157cc-ldoption = $(call try-run,\
158	$(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
159
160# ld-option
161# Usage: LDFLAGS += $(call ld-option, -X)
162ld-option = $(call try-run,\
163	$(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
164
165# ar-option
166# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
167# Important: no spaces around options
168ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
169
170# ld-version
171# Note this is mainly for HJ Lu's 3 number binutil versions
172ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
173
174# ld-ifversion
175# Usage:  $(call ld-ifversion, -ge, 22252, y)
176ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
177
178######
179
180###
181# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
182# Usage:
183# $(Q)$(MAKE) $(build)=dir
184build := -f $(srctree)/scripts/Makefile.build obj
185
186###
187# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
188# Usage:
189# $(Q)$(MAKE) $(modbuiltin)=dir
190modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
191
192###
193# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
194# Usage:
195# $(Q)$(MAKE) $(dtbinst)=dir
196dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
197
198###
199# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
200# Usage:
201# $(Q)$(MAKE) $(clean)=dir
202clean := -f $(srctree)/scripts/Makefile.clean obj
203
204###
205# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
206# Usage:
207# $(Q)$(MAKE) $(hdr-inst)=dir
208hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
209
210# Prefix -I with $(srctree) if it is not an absolute path.
211# skip if -I has no parameter
212addtree = $(if $(patsubst -I%,%,$(1)), \
213$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
214
215# Find all -I options and call addtree
216flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
217
218# echo command.
219# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
220echo-cmd = $(if $($(quiet)cmd_$(1)),\
221	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
222
223# printing commands
224cmd = @$(echo-cmd) $(cmd_$(1))
225
226# Add $(obj)/ for paths that are not absolute
227objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
228
229###
230# if_changed      - execute command if any prerequisite is newer than
231#                   target, or command line has changed
232# if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
233#                   including used config symbols
234# if_changed_rule - as if_changed but execute rule instead
235# See Documentation/kbuild/makefiles.txt for more info
236
237ifneq ($(KBUILD_NOCMDDEP),1)
238# Check if both arguments are the same including their order. Result is empty
239# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
240arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
241                         $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
242else
243arg-check = $(if $(strip $(cmd_$@)),,1)
244endif
245
246# Replace >$< with >$$< to preserve $ when reloading the .cmd file
247# (needed for make)
248# Replace >#< with >\#< to avoid starting a comment in the .cmd file
249# (needed for make)
250# Replace >'< with >'\''< to be able to enclose the whole string in '...'
251# (needed for the shell)
252make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
253
254# Find any prerequisites that is newer than target or that does not exist.
255# PHONY targets skipped in both cases.
256any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
257
258# Execute command if command has changed or prerequisite(s) are updated.
259#
260if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
261	@set -e;                                                             \
262	$(echo-cmd) $(cmd_$(1));                                             \
263	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
264
265# Execute the command and also postprocess generated .d dependencies file.
266if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
267	@set -e;                                                             \
268	$(cmd_and_fixdep), @:)
269
270ifndef CONFIG_TRIM_UNUSED_KSYMS
271
272cmd_and_fixdep =                                                             \
273	$(echo-cmd) $(cmd_$(1));                                             \
274	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
275	rm -f $(depfile);                                                    \
276	mv -f $(dot-target).tmp $(dot-target).cmd;
277
278else
279
280# Filter out exported kernel symbol names from the preprocessor output.
281# See also __KSYM_DEPS__ in include/linux/export.h.
282# We disable the depfile generation here, so as not to overwrite the existing
283# depfile while fixdep is parsing it.
284flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
285ksym_dep_filter =                                                            \
286	case "$(1)" in                                                       \
287	  cc_*_c|cpp_i_c)                                                    \
288	    $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;;        \
289	  as_*_S|cpp_s_S)                                                    \
290	    $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;;        \
291	  boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;;            \
292	  *) echo "Don't know how to preprocess $(1)" >&2; false ;;          \
293	esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
294
295cmd_and_fixdep =                                                             \
296	$(echo-cmd) $(cmd_$(1));                                             \
297	$(ksym_dep_filter) |                                                 \
298		scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)'          \
299			> $(dot-target).tmp;	                             \
300	rm -f $(depfile);                                                    \
301	mv -f $(dot-target).tmp $(dot-target).cmd;
302
303endif
304
305# Usage: $(call if_changed_rule,foo)
306# Will check if $(cmd_foo) or any of the prerequisites changed,
307# and if so will execute $(rule_foo).
308if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
309	@set -e;                                                             \
310	$(rule_$(1)), @:)
311
312###
313# why - tell why a a target got build
314#       enabled by make V=2
315#       Output (listed in the order they are checked):
316#          (1) - due to target is PHONY
317#          (2) - due to target missing
318#          (3) - due to: file1.h file2.h
319#          (4) - due to command line change
320#          (5) - due to missing .cmd file
321#          (6) - due to target not in $(targets)
322# (1) PHONY targets are always build
323# (2) No target, so we better build it
324# (3) Prerequisite is newer than target
325# (4) The command line stored in the file named dir/.target.cmd
326#     differed from actual command line. This happens when compiler
327#     options changes
328# (5) No dir/.target.cmd file (used to store command line)
329# (6) No dir/.target.cmd file and target not listed in $(targets)
330#     This is a good hint that there is a bug in the kbuild file
331ifeq ($(KBUILD_VERBOSE),2)
332why =                                                                        \
333    $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
334        $(if $(wildcard $@),                                                 \
335            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
336                $(if $(arg-check),                                           \
337                    $(if $(cmd_$@),- due to command line change,             \
338                        $(if $(filter $@, $(targets)),                       \
339                            - due to missing .cmd file,                      \
340                            - due to $(notdir $@) not in $$(targets)         \
341                         )                                                   \
342                     )                                                       \
343                 )                                                           \
344             ),                                                              \
345             - due to target missing                                         \
346         )                                                                   \
347     )
348
349echo-why = $(call escsq, $(strip $(why)))
350endif
351
352###############################################################################
353#
354# When a Kconfig string contains a filename, it is suitable for
355# passing to shell commands. It is surrounded by double-quotes, and
356# any double-quotes or backslashes within it are escaped by
357# backslashes.
358#
359# This is no use for dependencies or $(wildcard). We need to strip the
360# surrounding quotes and the escaping from quotes and backslashes, and
361# we *do* need to escape any spaces in the string. So, for example:
362#
363# Usage: $(eval $(call config_filename,FOO))
364#
365# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
366# transformed as described above to be suitable for use within the
367# makefile.
368#
369# Also, if the filename is a relative filename and exists in the source
370# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
371# be prefixed to *both* command invocation and dependencies.
372#
373# Note: We also print the filenames in the quiet_cmd_foo text, and
374# perhaps ought to have a version specially escaped for that purpose.
375# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
376# enough.  It'll strip the quotes in the common case where there's no
377# space and it's a simple filename, and it'll retain the quotes when
378# there's a space. There are some esoteric cases in which it'll print
379# the wrong thing, but we don't really care. The actual dependencies
380# and commands *do* get it right, with various combinations of single
381# and double quotes, backslashes and spaces in the filenames.
382#
383###############################################################################
384#
385define config_filename
386ifneq ($$(CONFIG_$(1)),"")
387$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
388ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
389else
390ifeq ($$(wildcard $$($(1)_FILENAME)),)
391ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
392$(1)_SRCPREFIX := $(srctree)/
393endif
394endif
395endif
396endif
397endef
398#
399###############################################################################
400