xref: /openbmc/linux/scripts/Kbuild.include (revision e6c81cce) 
1####
2# kbuild: Generic definitions
3
4# Convenient variables
5comma   := ,
6quote   := "
7squote  := '
8empty   :=
9space   := $(empty) $(empty)
10
11###
12# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
13dot-target = $(dir $@).$(notdir $@)
14
15###
16# The temporary file to save gcc -MD generated dependencies must not
17# contain a comma
18depfile = $(subst $(comma),_,$(dot-target).d)
19
20###
21# filename of target with directory and extension stripped
22basetarget = $(basename $(notdir $@))
23
24###
25# filename of first prerequisite with directory and extension stripped
26baseprereq = $(basename $(notdir $<))
27
28###
29# Escape single quote for use in echo statements
30escsq = $(subst $(squote),'\$(squote)',$1)
31
32###
33# Easy method for doing a status message
34       kecho := :
35 quiet_kecho := echo
36silent_kecho := :
37kecho := $($(quiet)kecho)
38
39###
40# filechk is used to check if the content of a generated file is updated.
41# Sample usage:
42# define filechk_sample
43#	echo $KERNELRELEASE
44# endef
45# version.h : Makefile
46#	$(call filechk,sample)
47# The rule defined shall write to stdout the content of the new file.
48# The existing file will be compared with the new one.
49# - If no file exist it is created
50# - If the content differ the new file is used
51# - If they are equal no change, and no timestamp update
52# - stdin is piped in from the first prerequisite ($<) so one has
53#   to specify a valid file as first prerequisite (often the kbuild file)
54define filechk
55	$(Q)set -e;				\
56	$(kecho) '  CHK     $@';		\
57	mkdir -p $(dir $@);			\
58	$(filechk_$(1)) < $< > $@.tmp;		\
59	if [ -r $@ ] && cmp -s $@ $@.tmp; then	\
60		rm -f $@.tmp;			\
61	else					\
62		$(kecho) '  UPD     $@';	\
63		mv -f $@.tmp $@;		\
64	fi
65endef
66
67######
68# gcc support functions
69# See documentation in Documentation/kbuild/makefiles.txt
70
71# cc-cross-prefix
72# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
73# Return first prefix where a prefix$(CC) is found in PATH.
74# If no $(CC) found in PATH with listed prefixes return nothing
75cc-cross-prefix =  \
76	$(word 1, $(foreach c,$(1),                                   \
77		$(shell set -e;                                       \
78		if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
79			echo $(c);                                    \
80		fi)))
81
82# output directory for tests below
83TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
84
85# try-run
86# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
87# Exit code chooses option. "$$TMP" is can be used as temporary file and
88# is automatically cleaned up.
89try-run = $(shell set -e;		\
90	TMP="$(TMPOUT).$$$$.tmp";	\
91	TMPO="$(TMPOUT).$$$$.o";	\
92	if ($(1)) >/dev/null 2>&1;	\
93	then echo "$(2)";		\
94	else echo "$(3)";		\
95	fi;				\
96	rm -f "$$TMP" "$$TMPO")
97
98# as-option
99# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
100
101as-option = $(call try-run,\
102	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
103
104# as-instr
105# Usage: cflags-y += $(call as-instr,instr,option1,option2)
106
107as-instr = $(call try-run,\
108	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
109
110# cc-option
111# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
112
113cc-option = $(call try-run,\
114	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
115
116# cc-option-yn
117# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
118cc-option-yn = $(call try-run,\
119	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
120
121# cc-option-align
122# Prefix align with either -falign or -malign
123cc-option-align = $(subst -functions=0,,\
124	$(call cc-option,-falign-functions=0,-malign-functions=0))
125
126# cc-disable-warning
127# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
128cc-disable-warning = $(call try-run,\
129	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
130
131# cc-version
132cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
133
134# cc-fullversion
135cc-fullversion = $(shell $(CONFIG_SHELL) \
136	$(srctree)/scripts/gcc-version.sh -p $(CC))
137
138# cc-ifversion
139# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
140cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
141
142# cc-ldoption
143# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
144cc-ldoption = $(call try-run,\
145	$(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
146
147# ld-option
148# Usage: LDFLAGS += $(call ld-option, -X)
149ld-option = $(call try-run,\
150	$(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
151
152# ar-option
153# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
154# Important: no spaces around options
155ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
156
157# ld-version
158# Note this is mainly for HJ Lu's 3 number binutil versions
159ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
160
161# ld-ifversion
162# Usage:  $(call ld-ifversion, -ge, 22252, y)
163ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
164
165######
166
167###
168# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
169# Usage:
170# $(Q)$(MAKE) $(build)=dir
171build := -f $(srctree)/scripts/Makefile.build obj
172
173###
174# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
175# Usage:
176# $(Q)$(MAKE) $(modbuiltin)=dir
177modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
178
179###
180# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
181# Usage:
182# $(Q)$(MAKE) $(dtbinst)=dir
183dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
184
185###
186# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=
187# Usage:
188# $(Q)$(MAKE) $(clean)=dir
189clean := -f $(srctree)/scripts/Makefile.clean obj
190
191###
192# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
193# Usage:
194# $(Q)$(MAKE) $(hdr-inst)=dir
195hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
196
197# Prefix -I with $(srctree) if it is not an absolute path.
198# skip if -I has no parameter
199addtree = $(if $(patsubst -I%,%,$(1)), \
200$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
201
202# Find all -I options and call addtree
203flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
204
205# echo command.
206# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
207echo-cmd = $(if $($(quiet)cmd_$(1)),\
208	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
209
210# printing commands
211cmd = @$(echo-cmd) $(cmd_$(1))
212
213# Add $(obj)/ for paths that are not absolute
214objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
215
216###
217# if_changed      - execute command if any prerequisite is newer than
218#                   target, or command line has changed
219# if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
220#                   including used config symbols
221# if_changed_rule - as if_changed but execute rule instead
222# See Documentation/kbuild/makefiles.txt for more info
223
224ifneq ($(KBUILD_NOCMDDEP),1)
225# Check if both arguments has same arguments. Result is empty string if equal.
226# User may override this check using make KBUILD_NOCMDDEP=1
227arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
228                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )
229else
230arg-check = $(if $(strip $(cmd_$@)),,1)
231endif
232
233# Replace >$< with >$$< to preserve $ when reloading the .cmd file
234# (needed for make)
235# Replace >#< with >\#< to avoid starting a comment in the .cmd file
236# (needed for make)
237# Replace >'< with >'\''< to be able to enclose the whole string in '...'
238# (needed for the shell)
239make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
240
241# Find any prerequisites that is newer than target or that does not exist.
242# PHONY targets skipped in both cases.
243any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
244
245# Execute command if command has changed or prerequisite(s) are updated.
246#
247if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
248	@set -e;                                                             \
249	$(echo-cmd) $(cmd_$(1));                                             \
250	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
251
252# Execute the command and also postprocess generated .d dependencies file.
253if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
254	@set -e;                                                             \
255	$(echo-cmd) $(cmd_$(1));                                             \
256	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
257	rm -f $(depfile);                                                    \
258	mv -f $(dot-target).tmp $(dot-target).cmd)
259
260# Usage: $(call if_changed_rule,foo)
261# Will check if $(cmd_foo) or any of the prerequisites changed,
262# and if so will execute $(rule_foo).
263if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
264	@set -e;                                                             \
265	$(rule_$(1)))
266
267###
268# why - tell why a a target got build
269#       enabled by make V=2
270#       Output (listed in the order they are checked):
271#          (1) - due to target is PHONY
272#          (2) - due to target missing
273#          (3) - due to: file1.h file2.h
274#          (4) - due to command line change
275#          (5) - due to missing .cmd file
276#          (6) - due to target not in $(targets)
277# (1) PHONY targets are always build
278# (2) No target, so we better build it
279# (3) Prerequisite is newer than target
280# (4) The command line stored in the file named dir/.target.cmd
281#     differed from actual command line. This happens when compiler
282#     options changes
283# (5) No dir/.target.cmd file (used to store command line)
284# (6) No dir/.target.cmd file and target not listed in $(targets)
285#     This is a good hint that there is a bug in the kbuild file
286ifeq ($(KBUILD_VERBOSE),2)
287why =                                                                        \
288    $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
289        $(if $(wildcard $@),                                                 \
290            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
291                $(if $(arg-check),                                           \
292                    $(if $(cmd_$@),- due to command line change,             \
293                        $(if $(filter $@, $(targets)),                       \
294                            - due to missing .cmd file,                      \
295                            - due to $(notdir $@) not in $$(targets)         \
296                         )                                                   \
297                     )                                                       \
298                 )                                                           \
299             ),                                                              \
300             - due to target missing                                         \
301         )                                                                   \
302     )
303
304echo-why = $(call escsq, $(strip $(why)))
305endif
306