xref: /openbmc/linux/scripts/Makefile.build (revision bbecb07f) 
1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(obj)
7
8PHONY := __build
9__build:
10
11# Init all relevant variables used in kbuild files so
12# 1) they have correct type
13# 2) they do not inherit any value from the environment
14obj-y :=
15obj-m :=
16lib-y :=
17lib-m :=
18always :=
19targets :=
20subdir-y :=
21subdir-m :=
22EXTRA_AFLAGS   :=
23EXTRA_CFLAGS   :=
24EXTRA_CPPFLAGS :=
25EXTRA_LDFLAGS  :=
26asflags-y  :=
27ccflags-y  :=
28cppflags-y :=
29ldflags-y  :=
30
31subdir-asflags-y :=
32subdir-ccflags-y :=
33
34# Read auto.conf if it exists, otherwise ignore
35-include include/config/auto.conf
36
37include scripts/Kbuild.include
38
39# For backward compatibility check that these variables do not change
40save-cflags := $(CFLAGS)
41
42# The filename Kbuild has precedence over Makefile
43kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
44kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
45include $(kbuild-file)
46
47# If the save-* variables changed error out
48ifeq ($(KBUILD_NOPEDANTIC),)
49        ifneq ("$(save-cflags)","$(CFLAGS)")
50                $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
51        endif
52endif
53
54include scripts/Makefile.lib
55
56ifdef host-progs
57ifneq ($(hostprogs-y),$(host-progs))
58$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
59hostprogs-y += $(host-progs)
60endif
61endif
62
63# Do not include host rules unless needed
64ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
65include scripts/Makefile.host
66endif
67
68ifndef obj
69$(warning kbuild: Makefile.build is included improperly)
70endif
71
72# ===========================================================================
73
74ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
75lib-target := $(obj)/lib.a
76obj-y += $(obj)/lib-ksyms.o
77endif
78
79ifneq ($(strip $(obj-y) $(need-builtin)),)
80builtin-target := $(obj)/built-in.o
81endif
82
83modorder-target := $(obj)/modules.order
84
85# We keep a list of all modules in $(MODVERDIR)
86
87__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
88	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
89	 $(subdir-ym) $(always)
90	@:
91
92# Linus' kernel sanity checking tool
93ifneq ($(KBUILD_CHECKSRC),0)
94  ifeq ($(KBUILD_CHECKSRC),2)
95    quiet_cmd_force_checksrc = CHECK   $<
96          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
97  else
98      quiet_cmd_checksrc     = CHECK   $<
99            cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
100  endif
101endif
102
103ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
104  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
105endif
106
107# Do section mismatch analysis for each module/built-in.o
108ifdef CONFIG_DEBUG_SECTION_MISMATCH
109  cmd_secanalysis = ; scripts/mod/modpost $@
110endif
111
112# Compile C sources (.c)
113# ---------------------------------------------------------------------------
114
115# Default is built-in, unless we know otherwise
116modkern_cflags =                                          \
117	$(if $(part-of-module),                           \
118		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
119		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
120quiet_modtag := $(empty)   $(empty)
121
122$(real-objs-m)        : part-of-module := y
123$(real-objs-m:.o=.i)  : part-of-module := y
124$(real-objs-m:.o=.s)  : part-of-module := y
125$(real-objs-m:.o=.lst): part-of-module := y
126
127$(real-objs-m)        : quiet_modtag := [M]
128$(real-objs-m:.o=.i)  : quiet_modtag := [M]
129$(real-objs-m:.o=.s)  : quiet_modtag := [M]
130$(real-objs-m:.o=.lst): quiet_modtag := [M]
131
132$(obj-m)              : quiet_modtag := [M]
133
134# Default for not multi-part modules
135modname = $(basetarget)
136
137$(multi-objs-m)         : modname = $(modname-multi)
138$(multi-objs-m:.o=.i)   : modname = $(modname-multi)
139$(multi-objs-m:.o=.s)   : modname = $(modname-multi)
140$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
141$(multi-objs-y)         : modname = $(modname-multi)
142$(multi-objs-y:.o=.i)   : modname = $(modname-multi)
143$(multi-objs-y:.o=.s)   : modname = $(modname-multi)
144$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
145
146quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
147cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
148
149$(obj)/%.s: $(src)/%.c FORCE
150	$(call if_changed_dep,cc_s_c)
151
152quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
153cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
154
155$(obj)/%.i: $(src)/%.c FORCE
156	$(call if_changed_dep,cpp_i_c)
157
158# These mirror gensymtypes_S and co below, keep them in synch.
159cmd_gensymtypes_c =                                                         \
160    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
161    $(GENKSYMS) $(if $(1), -T $(2))                                         \
162     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
163     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
164     $(if $(KBUILD_PRESERVE),-p)                                            \
165     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
166
167quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
168cmd_cc_symtypes_c =                                                         \
169    set -e;                                                                 \
170    $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
171    test -s $@ || rm -f $@
172
173$(obj)/%.symtypes : $(src)/%.c FORCE
174	$(call cmd,cc_symtypes_c)
175
176# LLVM assembly
177# Generate .ll files from .c
178quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
179      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
180
181$(obj)/%.ll: $(src)/%.c FORCE
182	$(call if_changed_dep,cc_ll_c)
183
184# C (.c) files
185# The C file is compiled and updated dependency information is generated.
186# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
187
188quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
189
190ifndef CONFIG_MODVERSIONS
191cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
192
193else
194# When module versioning is enabled the following steps are executed:
195# o compile a .tmp_<file>.o from <file>.c
196# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
197#   not export symbols, we just rename .tmp_<file>.o to <file>.o and
198#   are done.
199# o otherwise, we calculate symbol versions using the good old
200#   genksyms on the preprocessed source and postprocess them in a way
201#   that they are usable as a linker script
202# o generate <file>.o from .tmp_<file>.o using the linker to
203#   replace the unresolved symbols __crc_exported_symbol with
204#   the actual value of the checksum generated by genksyms
205
206cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
207
208cmd_modversions_c =								\
209	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
210		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
211		    > $(@D)/.tmp_$(@F:.o=.ver);					\
212										\
213		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
214			-T $(@D)/.tmp_$(@F:.o=.ver);				\
215		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
216	else									\
217		mv -f $(@D)/.tmp_$(@F) $@;					\
218	fi;
219endif
220
221ifdef CONFIG_FTRACE_MCOUNT_RECORD
222ifdef BUILD_C_RECORDMCOUNT
223ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
224  RECORDMCOUNT_FLAGS = -w
225endif
226# Due to recursion, we must skip empty.o.
227# The empty.o file is created in the make process in order to determine
228# the target endianness and word size. It is made before all other C
229# files, including recordmcount.
230sub_cmd_record_mcount =					\
231	if [ $(@) != "scripts/mod/empty.o" ]; then	\
232		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
233	fi;
234recordmcount_source := $(srctree)/scripts/recordmcount.c \
235		    $(srctree)/scripts/recordmcount.h
236else
237sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
238	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
239	"$(if $(CONFIG_64BIT),64,32)" \
240	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
241	"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
242	"$(if $(part-of-module),1,0)" "$(@)";
243recordmcount_source := $(srctree)/scripts/recordmcount.pl
244endif # BUILD_C_RECORDMCOUNT
245cmd_record_mcount =						\
246	if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" =	\
247	     "$(CC_FLAGS_FTRACE)" ]; then			\
248		$(sub_cmd_record_mcount)			\
249	fi;
250endif # CONFIG_FTRACE_MCOUNT_RECORD
251
252ifdef CONFIG_STACK_VALIDATION
253ifneq ($(SKIP_STACK_VALIDATION),1)
254
255__objtool_obj := $(objtree)/tools/objtool/objtool
256
257objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
258
259ifndef CONFIG_FRAME_POINTER
260objtool_args += --no-fp
261endif
262ifdef CONFIG_GCOV_KERNEL
263objtool_args += --no-unreachable
264else
265objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
266endif
267
268# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
269# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
270# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
271cmd_objtool = $(if $(patsubst y%,, \
272	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
273	$(__objtool_obj) $(objtool_args) "$(@)";)
274objtool_obj = $(if $(patsubst y%,, \
275	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
276	$(__objtool_obj))
277
278endif # SKIP_STACK_VALIDATION
279endif # CONFIG_STACK_VALIDATION
280
281# Rebuild all objects when objtool changes, or is enabled/disabled.
282objtool_dep = $(objtool_obj)					\
283	      $(wildcard include/config/orc/unwinder.h		\
284			 include/config/stack/validation.h)
285
286define rule_cc_o_c
287	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
288	$(call cmd_and_fixdep,cc_o_c)					  \
289	$(cmd_modversions_c)						  \
290	$(cmd_checkdoc)							  \
291	$(call echo-cmd,objtool) $(cmd_objtool)				  \
292	$(call echo-cmd,record_mcount) $(cmd_record_mcount)
293endef
294
295define rule_as_o_S
296	$(call cmd_and_fixdep,as_o_S)					  \
297	$(cmd_modversions_S)						  \
298	$(call echo-cmd,objtool) $(cmd_objtool)
299endef
300
301# List module undefined symbols (or empty line if not enabled)
302ifdef CONFIG_TRIM_UNUSED_KSYMS
303cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
304else
305cmd_undef_syms = echo
306endif
307
308# Built-in and composite module parts
309$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
310	$(call cmd,force_checksrc)
311	$(call if_changed_rule,cc_o_c)
312
313# Single-part modules are special since we need to mark them in $(MODVERDIR)
314
315$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
316	$(call cmd,force_checksrc)
317	$(call if_changed_rule,cc_o_c)
318	@{ echo $(@:.o=.ko); echo $@; \
319	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
320
321quiet_cmd_cc_lst_c = MKLST   $@
322      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
323		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
324				     System.map $(OBJDUMP) > $@
325
326$(obj)/%.lst: $(src)/%.c FORCE
327	$(call if_changed_dep,cc_lst_c)
328
329# Compile assembler sources (.S)
330# ---------------------------------------------------------------------------
331
332modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
333
334$(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
335$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
336
337# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
338# or a file that it includes, in order to get versioned symbols. We build a
339# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
340# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
341#
342# This is convoluted. The .S file must first be preprocessed to run guards and
343# expand names, then the resulting exports must be constructed into plain
344# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
345# to make the genksyms input.
346#
347# These mirror gensymtypes_c and co above, keep them in synch.
348cmd_gensymtypes_S =                                                         \
349    (echo "\#include <linux/kernel.h>" ;                                    \
350     echo "\#include <asm/asm-prototypes.h>" ;                              \
351    $(CPP) $(a_flags) $< |                                                  \
352     grep "\<___EXPORT_SYMBOL\>" |                                          \
353     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
354    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
355    $(GENKSYMS) $(if $(1), -T $(2))                                         \
356     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
357     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
358     $(if $(KBUILD_PRESERVE),-p)                                            \
359     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
360
361quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
362cmd_cc_symtypes_S =                                                         \
363    set -e;                                                                 \
364    $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
365    test -s $@ || rm -f $@
366
367$(obj)/%.symtypes : $(src)/%.S FORCE
368	$(call cmd,cc_symtypes_S)
369
370
371quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
372cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
373
374$(obj)/%.s: $(src)/%.S FORCE
375	$(call if_changed_dep,cpp_s_S)
376
377quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
378
379ifndef CONFIG_MODVERSIONS
380cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
381
382else
383
384ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
385
386ifeq ($(ASM_PROTOTYPES),)
387cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
388
389else
390
391# versioning matches the C process described above, with difference that
392# we parse asm-prototypes.h C header to get function definitions.
393
394cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
395
396cmd_modversions_S =								\
397	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
398		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
399		    > $(@D)/.tmp_$(@F:.o=.ver);					\
400										\
401		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
402			-T $(@D)/.tmp_$(@F:.o=.ver);				\
403		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
404	else									\
405		mv -f $(@D)/.tmp_$(@F) $@;					\
406	fi;
407endif
408endif
409
410$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
411	$(call if_changed_rule,as_o_S)
412
413targets += $(real-objs-y) $(real-objs-m) $(lib-y)
414targets += $(extra-y) $(MAKECMDGOALS) $(always)
415
416# Linker scripts preprocessor (.lds.S -> .lds)
417# ---------------------------------------------------------------------------
418quiet_cmd_cpp_lds_S = LDS     $@
419      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
420	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
421
422$(obj)/%.lds: $(src)/%.lds.S FORCE
423	$(call if_changed_dep,cpp_lds_S)
424
425# ASN.1 grammar
426# ---------------------------------------------------------------------------
427quiet_cmd_asn1_compiler = ASN.1   $@
428      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
429				$(subst .h,.c,$@) $(subst .c,.h,$@)
430
431.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
432
433$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
434	$(call cmd,asn1_compiler)
435
436# Build the compiled-in targets
437# ---------------------------------------------------------------------------
438
439# To build objects in subdirs, we need to descend into the directories
440$(sort $(subdir-obj-y)): $(subdir-ym) ;
441
442#
443# Rule to compile a set of .o files into one .o file
444#
445ifdef builtin-target
446
447ifdef CONFIG_THIN_ARCHIVES
448  cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
449  cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
450  quiet_cmd_link_o_target = AR      $@
451else
452  cmd_make_builtin = $(LD) $(ld_flags) -r -o
453  cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
454  quiet_cmd_link_o_target = LD      $@
455endif
456
457# If the list of objects to link is empty, just create an empty built-in.o
458cmd_link_o_target = $(if $(strip $(obj-y)),\
459		      $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
460		      $(cmd_secanalysis),\
461		      $(cmd_make_empty_builtin) $@)
462
463$(builtin-target): $(obj-y) FORCE
464	$(call if_changed,link_o_target)
465
466targets += $(builtin-target)
467endif # builtin-target
468
469#
470# Rule to create modules.order file
471#
472# Create commands to either record .ko file or cat modules.order from
473# a subdirectory
474modorder-cmds =						\
475	$(foreach m, $(modorder),			\
476		$(if $(filter %/modules.order, $m),	\
477			cat $m;, echo kernel/$m;))
478
479$(modorder-target): $(subdir-ym) FORCE
480	$(Q)(cat /dev/null; $(modorder-cmds)) > $@
481
482#
483# Rule to compile a set of .o files into one .a file
484#
485ifdef lib-target
486quiet_cmd_link_l_target = AR      $@
487
488ifdef CONFIG_THIN_ARCHIVES
489  cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
490else
491  cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
492endif
493
494$(lib-target): $(lib-y) FORCE
495	$(call if_changed,link_l_target)
496
497targets += $(lib-target)
498
499dummy-object = $(obj)/.lib_exports.o
500ksyms-lds = $(dot-target).lds
501ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
502ref_prefix = EXTERN(_
503else
504ref_prefix = EXTERN(
505endif
506
507quiet_cmd_export_list = EXPORTS $@
508cmd_export_list = $(OBJDUMP) -h $< | \
509	sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
510	rm -f $(dummy-object);\
511	echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
512	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
513	rm $(dummy-object) $(ksyms-lds)
514
515$(obj)/lib-ksyms.o: $(lib-target) FORCE
516	$(call if_changed,export_list)
517
518targets += $(obj)/lib-ksyms.o
519
520endif
521
522#
523# Rule to link composite objects
524#
525#  Composite objects are specified in kbuild makefile as follows:
526#    <composite-object>-objs := <list of .o files>
527#  or
528#    <composite-object>-y    := <list of .o files>
529#  or
530#    <composite-object>-m    := <list of .o files>
531#  The -m syntax only works if <composite object> is a module
532link_multi_deps =                     \
533$(filter $(addprefix $(obj)/,         \
534$($(subst $(obj)/,,$(@:.o=-objs)))    \
535$($(subst $(obj)/,,$(@:.o=-y)))       \
536$($(subst $(obj)/,,$(@:.o=-m)))), $^)
537
538cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
539
540ifdef CONFIG_THIN_ARCHIVES
541  quiet_cmd_link_multi-y = AR      $@
542  cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
543else
544  quiet_cmd_link_multi-y = LD      $@
545  cmd_link_multi-y = $(cmd_link_multi-link)
546endif
547
548quiet_cmd_link_multi-m = LD [M]  $@
549cmd_link_multi-m = $(cmd_link_multi-link)
550
551$(multi-used-y): FORCE
552	$(call if_changed,link_multi-y)
553$(call multi_depend, $(multi-used-y), .o, -objs -y)
554
555$(multi-used-m): FORCE
556	$(call if_changed,link_multi-m)
557	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
558	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
559$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
560
561targets += $(multi-used-y) $(multi-used-m)
562targets := $(filter-out $(PHONY), $(targets))
563
564# Descending
565# ---------------------------------------------------------------------------
566
567PHONY += $(subdir-ym)
568$(subdir-ym):
569	$(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
570
571# Add FORCE to the prequisites of a target to force it to be always rebuilt.
572# ---------------------------------------------------------------------------
573
574PHONY += FORCE
575
576FORCE:
577
578# Read all saved command lines and dependencies for the $(targets) we
579# may be building above, using $(if_changed{,_dep}). As an
580# optimization, we don't need to read them if the target does not
581# exist, we will rebuild anyway in that case.
582
583cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
584
585ifneq ($(cmd_files),)
586  include $(cmd_files)
587endif
588
589ifneq ($(KBUILD_SRC),)
590# Create directories for object files if they do not exist
591obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
592# If cmd_files exist, their directories apparently exist.  Skip mkdir.
593exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files))))
594obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs)))
595ifneq ($(obj-dirs),)
596$(shell mkdir -p $(obj-dirs))
597endif
598endif
599
600# Declare the contents of the .PHONY variable as phony.  We keep that
601# information in a variable se we can use it in if_changed and friends.
602
603.PHONY: $(PHONY)
604