xref: /openbmc/linux/scripts/Makefile.build (revision 5a244f48) 
1# ==========================================================================
2# Building
3# ==========================================================================
4
5src := $(obj)
6
7PHONY := __build
8__build:
9
10# Init all relevant variables used in kbuild files so
11# 1) they have correct type
12# 2) they do not inherit any value from the environment
13obj-y :=
14obj-m :=
15lib-y :=
16lib-m :=
17always :=
18targets :=
19subdir-y :=
20subdir-m :=
21EXTRA_AFLAGS   :=
22EXTRA_CFLAGS   :=
23EXTRA_CPPFLAGS :=
24EXTRA_LDFLAGS  :=
25asflags-y  :=
26ccflags-y  :=
27cppflags-y :=
28ldflags-y  :=
29
30subdir-asflags-y :=
31subdir-ccflags-y :=
32
33# Read auto.conf if it exists, otherwise ignore
34-include include/config/auto.conf
35
36include scripts/Kbuild.include
37
38# For backward compatibility check that these variables do not change
39save-cflags := $(CFLAGS)
40
41# The filename Kbuild has precedence over Makefile
42kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44include $(kbuild-file)
45
46# If the save-* variables changed error out
47ifeq ($(KBUILD_NOPEDANTIC),)
48        ifneq ("$(save-cflags)","$(CFLAGS)")
49                $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
50        endif
51endif
52
53include scripts/Makefile.lib
54
55ifdef host-progs
56ifneq ($(hostprogs-y),$(host-progs))
57$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
58hostprogs-y += $(host-progs)
59endif
60endif
61
62# Do not include host rules unless needed
63ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
64include scripts/Makefile.host
65endif
66
67ifneq ($(KBUILD_SRC),)
68# Create output directory if not already present
69_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
70
71# Create directories for object files if directory does not exist
72# Needed when obj-y := dir/file.o syntax is used
73_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
74endif
75
76ifndef obj
77$(warning kbuild: Makefile.build is included improperly)
78endif
79
80# ===========================================================================
81
82ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
83lib-target := $(obj)/lib.a
84obj-y += $(obj)/lib-ksyms.o
85endif
86
87ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
88builtin-target := $(obj)/built-in.o
89endif
90
91modorder-target := $(obj)/modules.order
92
93# We keep a list of all modules in $(MODVERDIR)
94
95__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
96	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
97	 $(subdir-ym) $(always)
98	@:
99
100# Linus' kernel sanity checking tool
101ifneq ($(KBUILD_CHECKSRC),0)
102  ifeq ($(KBUILD_CHECKSRC),2)
103    quiet_cmd_force_checksrc = CHECK   $<
104          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
105  else
106      quiet_cmd_checksrc     = CHECK   $<
107            cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
108  endif
109endif
110
111# Do section mismatch analysis for each module/built-in.o
112ifdef CONFIG_DEBUG_SECTION_MISMATCH
113  cmd_secanalysis = ; scripts/mod/modpost $@
114endif
115
116# Compile C sources (.c)
117# ---------------------------------------------------------------------------
118
119# Default is built-in, unless we know otherwise
120modkern_cflags =                                          \
121	$(if $(part-of-module),                           \
122		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
123		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
124quiet_modtag := $(empty)   $(empty)
125
126$(real-objs-m)        : part-of-module := y
127$(real-objs-m:.o=.i)  : part-of-module := y
128$(real-objs-m:.o=.s)  : part-of-module := y
129$(real-objs-m:.o=.lst): part-of-module := y
130
131$(real-objs-m)        : quiet_modtag := [M]
132$(real-objs-m:.o=.i)  : quiet_modtag := [M]
133$(real-objs-m:.o=.s)  : quiet_modtag := [M]
134$(real-objs-m:.o=.lst): quiet_modtag := [M]
135
136$(obj-m)              : quiet_modtag := [M]
137
138# Default for not multi-part modules
139modname = $(basetarget)
140
141$(multi-objs-m)         : modname = $(modname-multi)
142$(multi-objs-m:.o=.i)   : modname = $(modname-multi)
143$(multi-objs-m:.o=.s)   : modname = $(modname-multi)
144$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
145$(multi-objs-y)         : modname = $(modname-multi)
146$(multi-objs-y:.o=.i)   : modname = $(modname-multi)
147$(multi-objs-y:.o=.s)   : modname = $(modname-multi)
148$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
149
150quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
151cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
152
153$(obj)/%.s: $(src)/%.c FORCE
154	$(call if_changed_dep,cc_s_c)
155
156quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
157cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
158
159$(obj)/%.i: $(src)/%.c FORCE
160	$(call if_changed_dep,cpp_i_c)
161
162# These mirror gensymtypes_S and co below, keep them in synch.
163cmd_gensymtypes_c =                                                         \
164    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
165    $(GENKSYMS) $(if $(1), -T $(2))                                         \
166     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
167     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
168     $(if $(KBUILD_PRESERVE),-p)                                            \
169     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
170
171quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
172cmd_cc_symtypes_c =                                                         \
173    set -e;                                                                 \
174    $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
175    test -s $@ || rm -f $@
176
177$(obj)/%.symtypes : $(src)/%.c FORCE
178	$(call cmd,cc_symtypes_c)
179
180# LLVM assembly
181# Generate .ll files from .c
182quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
183      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
184
185$(obj)/%.ll: $(src)/%.c FORCE
186	$(call if_changed_dep,cc_ll_c)
187
188# C (.c) files
189# The C file is compiled and updated dependency information is generated.
190# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
191
192quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
193
194ifndef CONFIG_MODVERSIONS
195cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
196
197else
198# When module versioning is enabled the following steps are executed:
199# o compile a .tmp_<file>.o from <file>.c
200# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
201#   not export symbols, we just rename .tmp_<file>.o to <file>.o and
202#   are done.
203# o otherwise, we calculate symbol versions using the good old
204#   genksyms on the preprocessed source and postprocess them in a way
205#   that they are usable as a linker script
206# o generate <file>.o from .tmp_<file>.o using the linker to
207#   replace the unresolved symbols __crc_exported_symbol with
208#   the actual value of the checksum generated by genksyms
209
210cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
211
212cmd_modversions_c =								\
213	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
214		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
215		    > $(@D)/.tmp_$(@F:.o=.ver);					\
216										\
217		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
218			-T $(@D)/.tmp_$(@F:.o=.ver);				\
219		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
220	else									\
221		mv -f $(@D)/.tmp_$(@F) $@;					\
222	fi;
223endif
224
225ifdef CONFIG_FTRACE_MCOUNT_RECORD
226ifdef BUILD_C_RECORDMCOUNT
227ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
228  RECORDMCOUNT_FLAGS = -w
229endif
230# Due to recursion, we must skip empty.o.
231# The empty.o file is created in the make process in order to determine
232# the target endianness and word size. It is made before all other C
233# files, including recordmcount.
234sub_cmd_record_mcount =					\
235	if [ $(@) != "scripts/mod/empty.o" ]; then	\
236		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
237	fi;
238recordmcount_source := $(srctree)/scripts/recordmcount.c \
239		    $(srctree)/scripts/recordmcount.h
240else
241sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
242	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
243	"$(if $(CONFIG_64BIT),64,32)" \
244	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
245	"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
246	"$(if $(part-of-module),1,0)" "$(@)";
247recordmcount_source := $(srctree)/scripts/recordmcount.pl
248endif # BUILD_C_RECORDMCOUNT
249cmd_record_mcount =						\
250	if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" =	\
251	     "$(CC_FLAGS_FTRACE)" ]; then			\
252		$(sub_cmd_record_mcount)			\
253	fi;
254endif # CONFIG_FTRACE_MCOUNT_RECORD
255
256ifdef CONFIG_STACK_VALIDATION
257ifneq ($(SKIP_STACK_VALIDATION),1)
258
259__objtool_obj := $(objtree)/tools/objtool/objtool
260
261objtool_args = $(if $(CONFIG_ORC_UNWINDER),orc generate,check)
262
263ifndef CONFIG_FRAME_POINTER
264objtool_args += --no-fp
265endif
266ifdef CONFIG_GCOV_KERNEL
267objtool_args += --no-unreachable
268else
269objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
270endif
271
272# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
273# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
274# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
275cmd_objtool = $(if $(patsubst y%,, \
276	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
277	$(__objtool_obj) $(objtool_args) "$(@)";)
278objtool_obj = $(if $(patsubst y%,, \
279	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
280	$(__objtool_obj))
281
282endif # SKIP_STACK_VALIDATION
283endif # CONFIG_STACK_VALIDATION
284
285# Rebuild all objects when objtool changes, or is enabled/disabled.
286objtool_dep = $(objtool_obj)					\
287	      $(wildcard include/config/orc/unwinder.h		\
288			 include/config/stack/validation.h)
289
290define rule_cc_o_c
291	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
292	$(call cmd_and_fixdep,cc_o_c)					  \
293	$(cmd_modversions_c)						  \
294	$(call echo-cmd,objtool) $(cmd_objtool)				  \
295	$(call echo-cmd,record_mcount) $(cmd_record_mcount)
296endef
297
298define rule_as_o_S
299	$(call cmd_and_fixdep,as_o_S)					  \
300	$(cmd_modversions_S)						  \
301	$(call echo-cmd,objtool) $(cmd_objtool)
302endef
303
304# List module undefined symbols (or empty line if not enabled)
305ifdef CONFIG_TRIM_UNUSED_KSYMS
306cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
307else
308cmd_undef_syms = echo
309endif
310
311# Built-in and composite module parts
312$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
313	$(call cmd,force_checksrc)
314	$(call if_changed_rule,cc_o_c)
315
316# Single-part modules are special since we need to mark them in $(MODVERDIR)
317
318$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
319	$(call cmd,force_checksrc)
320	$(call if_changed_rule,cc_o_c)
321	@{ echo $(@:.o=.ko); echo $@; \
322	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
323
324quiet_cmd_cc_lst_c = MKLST   $@
325      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
326		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
327				     System.map $(OBJDUMP) > $@
328
329$(obj)/%.lst: $(src)/%.c FORCE
330	$(call if_changed_dep,cc_lst_c)
331
332# Compile assembler sources (.S)
333# ---------------------------------------------------------------------------
334
335modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
336
337$(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
338$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
339
340# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
341# or a file that it includes, in order to get versioned symbols. We build a
342# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
343# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
344#
345# This is convoluted. The .S file must first be preprocessed to run guards and
346# expand names, then the resulting exports must be constructed into plain
347# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
348# to make the genksyms input.
349#
350# These mirror gensymtypes_c and co above, keep them in synch.
351cmd_gensymtypes_S =                                                         \
352    (echo "\#include <linux/kernel.h>" ;                                    \
353     echo "\#include <asm/asm-prototypes.h>" ;                              \
354    $(CPP) $(a_flags) $< |                                                  \
355     grep "\<___EXPORT_SYMBOL\>" |                                          \
356     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
357    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
358    $(GENKSYMS) $(if $(1), -T $(2))                                         \
359     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
360     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
361     $(if $(KBUILD_PRESERVE),-p)                                            \
362     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
363
364quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
365cmd_cc_symtypes_S =                                                         \
366    set -e;                                                                 \
367    $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
368    test -s $@ || rm -f $@
369
370$(obj)/%.symtypes : $(src)/%.S FORCE
371	$(call cmd,cc_symtypes_S)
372
373
374quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
375cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
376
377$(obj)/%.s: $(src)/%.S FORCE
378	$(call if_changed_dep,cpp_s_S)
379
380quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
381
382ifndef CONFIG_MODVERSIONS
383cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
384
385else
386
387ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
388
389ifeq ($(ASM_PROTOTYPES),)
390cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
391
392else
393
394# versioning matches the C process described above, with difference that
395# we parse asm-prototypes.h C header to get function definitions.
396
397cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
398
399cmd_modversions_S =								\
400	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
401		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
402		    > $(@D)/.tmp_$(@F:.o=.ver);					\
403										\
404		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
405			-T $(@D)/.tmp_$(@F:.o=.ver);				\
406		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
407	else									\
408		mv -f $(@D)/.tmp_$(@F) $@;					\
409	fi;
410endif
411endif
412
413$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
414	$(call if_changed_rule,as_o_S)
415
416targets += $(real-objs-y) $(real-objs-m) $(lib-y)
417targets += $(extra-y) $(MAKECMDGOALS) $(always)
418
419# Linker scripts preprocessor (.lds.S -> .lds)
420# ---------------------------------------------------------------------------
421quiet_cmd_cpp_lds_S = LDS     $@
422      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
423	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
424
425$(obj)/%.lds: $(src)/%.lds.S FORCE
426	$(call if_changed_dep,cpp_lds_S)
427
428# ASN.1 grammar
429# ---------------------------------------------------------------------------
430quiet_cmd_asn1_compiler = ASN.1   $@
431      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
432				$(subst .h,.c,$@) $(subst .c,.h,$@)
433
434.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
435
436$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
437	$(call cmd,asn1_compiler)
438
439# Build the compiled-in targets
440# ---------------------------------------------------------------------------
441
442# To build objects in subdirs, we need to descend into the directories
443$(sort $(subdir-obj-y)): $(subdir-ym) ;
444
445#
446# Rule to compile a set of .o files into one .o file
447#
448ifdef builtin-target
449
450ifdef CONFIG_THIN_ARCHIVES
451  cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
452  cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
453  quiet_cmd_link_o_target = AR      $@
454else
455  cmd_make_builtin = $(LD) $(ld_flags) -r -o
456  cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
457  quiet_cmd_link_o_target = LD      $@
458endif
459
460# If the list of objects to link is empty, just create an empty built-in.o
461cmd_link_o_target = $(if $(strip $(obj-y)),\
462		      $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
463		      $(cmd_secanalysis),\
464		      $(cmd_make_empty_builtin) $@)
465
466$(builtin-target): $(obj-y) FORCE
467	$(call if_changed,link_o_target)
468
469targets += $(builtin-target)
470endif # builtin-target
471
472#
473# Rule to create modules.order file
474#
475# Create commands to either record .ko file or cat modules.order from
476# a subdirectory
477modorder-cmds =						\
478	$(foreach m, $(modorder),			\
479		$(if $(filter %/modules.order, $m),	\
480			cat $m;, echo kernel/$m;))
481
482$(modorder-target): $(subdir-ym) FORCE
483	$(Q)(cat /dev/null; $(modorder-cmds)) > $@
484
485#
486# Rule to compile a set of .o files into one .a file
487#
488ifdef lib-target
489quiet_cmd_link_l_target = AR      $@
490
491ifdef CONFIG_THIN_ARCHIVES
492  cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
493else
494  cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
495endif
496
497$(lib-target): $(lib-y) FORCE
498	$(call if_changed,link_l_target)
499
500targets += $(lib-target)
501
502dummy-object = $(obj)/.lib_exports.o
503ksyms-lds = $(dot-target).lds
504ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
505ref_prefix = EXTERN(_
506else
507ref_prefix = EXTERN(
508endif
509
510quiet_cmd_export_list = EXPORTS $@
511cmd_export_list = $(OBJDUMP) -h $< | \
512	sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
513	rm -f $(dummy-object);\
514	echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
515	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
516	rm $(dummy-object) $(ksyms-lds)
517
518$(obj)/lib-ksyms.o: $(lib-target) FORCE
519	$(call if_changed,export_list)
520
521targets += $(obj)/lib-ksyms.o
522
523endif
524
525#
526# Rule to link composite objects
527#
528#  Composite objects are specified in kbuild makefile as follows:
529#    <composite-object>-objs := <list of .o files>
530#  or
531#    <composite-object>-y    := <list of .o files>
532#  or
533#    <composite-object>-m    := <list of .o files>
534#  The -m syntax only works if <composite object> is a module
535link_multi_deps =                     \
536$(filter $(addprefix $(obj)/,         \
537$($(subst $(obj)/,,$(@:.o=-objs)))    \
538$($(subst $(obj)/,,$(@:.o=-y)))       \
539$($(subst $(obj)/,,$(@:.o=-m)))), $^)
540
541cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
542
543ifdef CONFIG_THIN_ARCHIVES
544  quiet_cmd_link_multi-y = AR      $@
545  cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
546else
547  quiet_cmd_link_multi-y = LD      $@
548  cmd_link_multi-y = $(cmd_link_multi-link)
549endif
550
551quiet_cmd_link_multi-m = LD [M]  $@
552cmd_link_multi-m = $(cmd_link_multi-link)
553
554$(multi-used-y): FORCE
555	$(call if_changed,link_multi-y)
556$(call multi_depend, $(multi-used-y), .o, -objs -y)
557
558$(multi-used-m): FORCE
559	$(call if_changed,link_multi-m)
560	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
561	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
562$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
563
564targets += $(multi-used-y) $(multi-used-m)
565
566
567# Descending
568# ---------------------------------------------------------------------------
569
570PHONY += $(subdir-ym)
571$(subdir-ym):
572	$(Q)$(MAKE) $(build)=$@
573
574# Add FORCE to the prequisites of a target to force it to be always rebuilt.
575# ---------------------------------------------------------------------------
576
577PHONY += FORCE
578
579FORCE:
580
581# Read all saved command lines and dependencies for the $(targets) we
582# may be building above, using $(if_changed{,_dep}). As an
583# optimization, we don't need to read them if the target does not
584# exist, we will rebuild anyway in that case.
585
586targets := $(wildcard $(sort $(targets)))
587cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
588
589ifneq ($(cmd_files),)
590  include $(cmd_files)
591endif
592
593# Declare the contents of the .PHONY variable as phony.  We keep that
594# information in a variable se we can use it in if_changed and friends.
595
596.PHONY: $(PHONY)
597