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.
89# modifed for U-Boot: prevent cc-option from leaving .*.su files
90try-run = $(shell set -e;		\
91	TMP="$(TMPOUT).$$$$.tmp";	\
92	TMPO="$(TMPOUT).$$$$.o";	\
93	TMPSU="$(TMPOUT).$$$$.su";	\
94	if ($(1)) >/dev/null 2>&1;	\
95	then echo "$(2)";		\
96	else echo "$(3)";		\
97	fi;				\
98	rm -f "$$TMP" "$$TMPO" "$$TMPSU")
99
100# as-option
101# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
102
103as-option = $(call try-run,\
104	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
105
106# as-instr
107# Usage: cflags-y += $(call as-instr,instr,option1,option2)
108
109as-instr = $(call try-run,\
110	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
111
112# cc-option
113# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
114
115cc-option = $(call try-run,\
116	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
117
118# cc-option-yn
119# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
120cc-option-yn = $(call try-run,\
121	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
122
123# cc-option-align
124# Prefix align with either -falign or -malign
125cc-option-align = $(subst -functions=0,,\
126	$(call cc-option,-falign-functions=0,-malign-functions=0))
127
128# cc-disable-warning
129# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
130cc-disable-warning = $(call try-run,\
131	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
132
133# cc-version
134# Usage gcc-ver := $(call cc-version)
135cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
136
137# cc-fullversion
138# Usage gcc-ver := $(call cc-fullversion)
139cc-fullversion = $(shell $(CONFIG_SHELL) \
140	$(srctree)/scripts/gcc-version.sh -p $(CC))
141
142# cc-ifversion
143# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
144cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
145
146# added for U-Boot
147binutils-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/binutils-version.sh $(AS))
148dtc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/dtc-version.sh $(DTC))
149
150# cc-ldoption
151# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
152cc-ldoption = $(call try-run,\
153	$(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
154
155# ld-option
156# Usage: LDFLAGS += $(call ld-option, -X)
157ld-option = $(call try-run,\
158	$(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
159
160# ar-option
161# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
162# Important: no spaces around options
163ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
164
165# ld-version
166# Usage: $(call ld-version)
167# Note this is mainly for HJ Lu's 3 number binutil versions
168ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
169
170# ld-ifversion
171# Usage:  $(call ld-ifversion, -ge, 22252, y)
172ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3))
173
174######
175
176###
177# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
178# Usage:
179# $(Q)$(MAKE) $(build)=dir
180build := -f $(srctree)/scripts/Makefile.build obj
181
182###
183# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
184# Usage:
185# $(Q)$(MAKE) $(modbuiltin)=dir
186modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
187
188# Prefix -I with $(srctree) if it is not an absolute path.
189# skip if -I has no parameter
190addtree = $(if $(patsubst -I%,%,$(1)), \
191$(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1))
192
193# Find all -I options and call addtree
194flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
195
196# echo command.
197# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
198echo-cmd = $(if $($(quiet)cmd_$(1)),\
199	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
200
201# printing commands
202cmd = @$(echo-cmd) $(cmd_$(1))
203
204# Add $(obj)/ for paths that are not absolute
205objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
206
207###
208# if_changed      - execute command if any prerequisite is newer than
209#                   target, or command line has changed
210# if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
211#                   including used config symbols
212# if_changed_rule - as if_changed but execute rule instead
213# See Documentation/kbuild/makefiles.txt for more info
214
215ifneq ($(KBUILD_NOCMDDEP),1)
216# Check if both arguments has same arguments. Result is empty string if equal.
217# User may override this check using make KBUILD_NOCMDDEP=1
218arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
219                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )
220else
221arg-check = $(if $(strip $(cmd_$@)),,1)
222endif
223
224# Replace >$< with >$$< to preserve $ when reloading the .cmd file
225# (needed for make)
226# Replace >#< with >\#< to avoid starting a comment in the .cmd file
227# (needed for make)
228# Replace >'< with >'\''< to be able to enclose the whole string in '...'
229# (needed for the shell)
230make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
231
232# Find any prerequisites that is newer than target or that does not exist.
233# PHONY targets skipped in both cases.
234any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
235
236# Execute command if command has changed or prerequisite(s) are updated.
237#
238if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
239	@set -e;                                                             \
240	$(echo-cmd) $(cmd_$(1));                                             \
241	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
242
243# Execute the command and also postprocess generated .d dependencies file.
244if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
245	@set -e;                                                             \
246	$(echo-cmd) $(cmd_$(1));                                             \
247	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
248	rm -f $(depfile);                                                    \
249	mv -f $(dot-target).tmp $(dot-target).cmd)
250
251# Usage: $(call if_changed_rule,foo)
252# Will check if $(cmd_foo) or any of the prerequisites changed,
253# and if so will execute $(rule_foo).
254if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
255	@set -e;                                                             \
256	$(rule_$(1)))
257
258###
259# why - tell why a a target got build
260#       enabled by make V=2
261#       Output (listed in the order they are checked):
262#          (1) - due to target is PHONY
263#          (2) - due to target missing
264#          (3) - due to: file1.h file2.h
265#          (4) - due to command line change
266#          (5) - due to missing .cmd file
267#          (6) - due to target not in $(targets)
268# (1) PHONY targets are always build
269# (2) No target, so we better build it
270# (3) Prerequisite is newer than target
271# (4) The command line stored in the file named dir/.target.cmd
272#     differed from actual command line. This happens when compiler
273#     options changes
274# (5) No dir/.target.cmd file (used to store command line)
275# (6) No dir/.target.cmd file and target not listed in $(targets)
276#     This is a good hint that there is a bug in the kbuild file
277ifeq ($(KBUILD_VERBOSE),2)
278why =                                                                        \
279    $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
280        $(if $(wildcard $@),                                                 \
281            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
282                $(if $(arg-check),                                           \
283                    $(if $(cmd_$@),- due to command line change,             \
284                        $(if $(filter $@, $(targets)),                       \
285                            - due to missing .cmd file,                      \
286                            - due to $(notdir $@) not in $$(targets)         \
287                         )                                                   \
288                     )                                                       \
289                 )                                                           \
290             ),                                                              \
291             - due to target missing                                         \
292         )                                                                   \
293     )
294
295echo-why = $(call escsq, $(strip $(why)))
296endif
297