path: root/scripts/Makefile.build (plain)
blob: d41c72a510432452e71dcad31784fdbb61a8724a

1	# ==========================================================================
2	# Building
3	# ==========================================================================
4
5	src := $(obj)
6
7	PHONY := __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
13	obj-y :=
14	obj-m :=
15	lib-y :=
16	lib-m :=
17	always :=
18	targets :=
19	subdir-y :=
20	subdir-m :=
21	EXTRA_AFLAGS :=
22	EXTRA_CFLAGS :=
23	EXTRA_CPPFLAGS :=
24	EXTRA_LDFLAGS :=
25	asflags-y :=
26	ccflags-y :=
27	cppflags-y :=
28	ldflags-y :=
29
30	subdir-asflags-y :=
31	subdir-ccflags-y :=
32
33	# Read auto.conf if it exists, otherwise ignore
34	-include include/config/auto.conf
35
36	include scripts/Kbuild.include
37
38	# For backward compatibility check that these variables do not change
39	save-cflags := $(CFLAGS)
40
41	# The filename Kbuild has precedence over Makefile
42	kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43	kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44	include $(kbuild-file)
45
46	# If the save-* variables changed error out
47	ifeq ($(KBUILD_NOPEDANTIC),)
48	ifneq ("$(save-cflags)","$(CFLAGS)")
49	$(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
50	endif
51	endif
52
53	include scripts/Makefile.lib
54
55	ifdef host-progs
56	ifneq ($(hostprogs-y),$(host-progs))
57	$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
58	hostprogs-y += $(host-progs)
59	endif
60	endif
61
62	# Do not include host rules unless needed
63	ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
64	include scripts/Makefile.host
65	endif
66
67	ifneq ($(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)))
74	endif
75
76	ifndef obj
77	$(warning kbuild: Makefile.build is included improperly)
78	endif
79
80	# ===========================================================================
81
82	ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
83	lib-target := $(obj)/lib.a
84	obj-y += $(obj)/lib-ksyms.o
85	endif
86
87	ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
88	builtin-target := $(obj)/built-in.o
89	endif
90
91	modorder-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) $(always)
98	@:
99
100	# Linus' kernel sanity checking tool
101	ifneq ($(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
109	endif
110
111	# Do section mismatch analysis for each module/built-in.o
112	ifdef CONFIG_DEBUG_SECTION_MISMATCH
113	cmd_secanalysis = ; scripts/mod/modpost $@
114	endif
115
116	# Compile C sources (.c)
117	# ---------------------------------------------------------------------------
118
119	# Default is built-in, unless we know otherwise
120	modkern_cflags = \
121	$(if $(part-of-module), \
122	$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
123	$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
124	quiet_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
139	modname = $(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
150	quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
151	cmd_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
156	quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
157	cmd_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.
163	cmd_gensymtypes_c = \
164	$(CPP) -D__GENKSYMS__ $(c_flags) $< | \
165	$(GENKSYMS) $(if $(1), -T $(2)) \
166	$(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
167	$(if $(KBUILD_PRESERVE),-p) \
168	-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
169
170	quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
171	cmd_cc_symtypes_c = \
172	set -e; \
173	$(call cmd_gensymtypes_c,true,$@) >/dev/null; \
174	test -s $@ || rm -f $@
175
176	$(obj)/%.symtypes : $(src)/%.c FORCE
177	$(call cmd,cc_symtypes_c)
178
179	# LLVM assembly
180	# Generate .ll files from .c
181	quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
182	cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
183
184	$(obj)/%.ll: $(src)/%.c FORCE
185	$(call if_changed_dep,cc_ll_c)
186
187	# C (.c) files
188	# The C file is compiled and updated dependency information is generated.
189	# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
190
191	quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
192
193	ifndef CONFIG_MODVERSIONS
194	cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
195
196	else
197	# When module versioning is enabled the following steps are executed:
198	# o compile a .tmp_<file>.o from <file>.c
199	# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
200	# not export symbols, we just rename .tmp_<file>.o to <file>.o and
201	# are done.
202	# o otherwise, we calculate symbol versions using the good old
203	# genksyms on the preprocessed source and postprocess them in a way
204	# that they are usable as a linker script
205	# o generate <file>.o from .tmp_<file>.o using the linker to
206	# replace the unresolved symbols __crc_exported_symbol with
207	# the actual value of the checksum generated by genksyms
208
209	cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
210
211	ifdef CONFIG_LTO_CLANG
212	# Generate .o.symversions files for each .o with exported symbols, and link these
213	# to the kernel and/or modules at the end.
214	cmd_modversions_c = \
215	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) >/dev/null 2>/dev/null; then \
216	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
217	$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
218	> $(@D)/$(@F).symversions; \
219	fi; \
220	else \
221	if $(LLVM_DIS) -o=- $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
222	$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
223	> $(@D)/$(@F).symversions; \
224	fi; \
225	fi; \
226	mv -f $(@D)/.tmp_$(@F) $@;
227	else
228	cmd_modversions_c = \
229	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
230	$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
231	> $(@D)/.tmp_$(@F:.o=.ver); \
232	\
233	$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
234	-T $(@D)/.tmp_$(@F:.o=.ver); \
235	rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
236	else \
237	mv -f $(@D)/.tmp_$(@F) $@; \
238	fi;
239	endif
240	endif
241
242	ifdef CONFIG_FTRACE_MCOUNT_RECORD
243	ifdef BUILD_C_RECORDMCOUNT
244	ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
245	RECORDMCOUNT_FLAGS = -w
246	endif
247
248	ifdef CONFIG_LTO_CLANG
249	# With LTO, we postpone running recordmcount until after the LTO link step, so
250	# let's export the parameters for the link script.
251	export RECORDMCOUNT_FLAGS
252	else
253	# Due to recursion, we must skip empty.o.
254	# The empty.o file is created in the make process in order to determine
255	# the target endianness and word size. It is made before all other C
256	# files, including recordmcount.
257	sub_cmd_record_mcount = \
258	if [ $(@) != "scripts/mod/empty.o" ]; then \
259	$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
260	fi;
261	endif
262
263	recordmcount_source := $(srctree)/scripts/recordmcount.c \
264	$(srctree)/scripts/recordmcount.h
265	else # !BUILD_C_RECORDMCOUNT
266	sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
267	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
268	"$(if $(CONFIG_64BIT),64,32)" \
269	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
270	"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
271	"$(if $(part-of-module),1,0)" "$(@)";
272
273	recordmcount_source := $(srctree)/scripts/recordmcount.pl
274	endif # BUILD_C_RECORDMCOUNT
275
276	ifndef CONFIG_LTO_CLANG
277	cmd_record_mcount = \
278	if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
279	"$(CC_FLAGS_FTRACE)" ]; then \
280	$(sub_cmd_record_mcount) \
281	fi;
282	endif
283	endif # CONFIG_FTRACE_MCOUNT_RECORD
284
285	ifdef CONFIG_STACK_VALIDATION
286	ifneq ($(SKIP_STACK_VALIDATION),1)
287
288	__objtool_obj := $(objtree)/tools/objtool/objtool
289
290	objtool_args = check
291	ifndef CONFIG_FRAME_POINTER
292	objtool_args += --no-fp
293	endif
294	ifdef CONFIG_GCOV_KERNEL
295	objtool_args += --no-unreachable
296	endif
297
298	# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
299	# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
300	# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
301	cmd_objtool = $(if $(patsubst y%,, \
302	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
303	$(__objtool_obj) $(objtool_args) "$(@)";)
304	objtool_obj = $(if $(patsubst y%,, \
305	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
306	$(__objtool_obj))
307
308	endif # SKIP_STACK_VALIDATION
309	endif # CONFIG_STACK_VALIDATION
310
311	define rule_cc_o_c
312	$(call echo-cmd,checksrc) $(cmd_checksrc) \
313	$(call cmd_and_fixdep,cc_o_c) \
314	$(cmd_modversions_c) \
315	$(cmd_objtool) \
316	$(call echo-cmd,record_mcount) $(cmd_record_mcount)
317	endef
318
319	define rule_as_o_S
320	$(call cmd_and_fixdep,as_o_S) \
321	$(cmd_modversions_S) \
322	$(cmd_objtool)
323	endef
324
325	# List module undefined symbols (or empty line if not enabled)
326	ifdef CONFIG_TRIM_UNUSED_KSYMS
327	cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
328	else
329	cmd_undef_syms = echo
330	endif
331
332	# Built-in and composite module parts
333	$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
334	$(call cmd,force_checksrc)
335	$(call if_changed_rule,cc_o_c)
336
337	# Single-part modules are special since we need to mark them in $(MODVERDIR)
338
339	$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
340	$(call cmd,force_checksrc)
341	$(call if_changed_rule,cc_o_c)
342	@{ echo $(@:.o=.ko); echo $@; \
343	$(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
344
345	quiet_cmd_cc_lst_c = MKLST $@
346	cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
347	$(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
348	System.map $(OBJDUMP) > $@
349
350	$(obj)/%.lst: $(src)/%.c FORCE
351	$(call if_changed_dep,cc_lst_c)
352
353	# Compile assembler sources (.S)
354	# ---------------------------------------------------------------------------
355
356	modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
357
358	$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
359	$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
360
361	# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
362	# or a file that it includes, in order to get versioned symbols. We build a
363	# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
364	# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
365	#
366	# This is convoluted. The .S file must first be preprocessed to run guards and
367	# expand names, then the resulting exports must be constructed into plain
368	# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
369	# to make the genksyms input.
370	#
371	# These mirror gensymtypes_c and co above, keep them in synch.
372	cmd_gensymtypes_S = \
373	(echo "\#include <linux/kernel.h>" ; \
374	echo "\#include <asm/asm-prototypes.h>" ; \
375	$(CPP) $(a_flags) $< | \
376	grep "\<___EXPORT_SYMBOL\>" | \
377	sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
378	$(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
379	$(GENKSYMS) $(if $(1), -T $(2)) \
380	$(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
381	$(if $(KBUILD_PRESERVE),-p) \
382	-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
383
384	quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
385	cmd_cc_symtypes_S = \
386	set -e; \
387	$(call cmd_gensymtypes_S,true,$@) >/dev/null; \
388	test -s $@ || rm -f $@
389
390	$(obj)/%.symtypes : $(src)/%.S FORCE
391	$(call cmd,cc_symtypes_S)
392
393
394	quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
395	cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
396
397	$(obj)/%.s: $(src)/%.S FORCE
398	$(call if_changed_dep,cpp_s_S)
399
400	quiet_cmd_as_o_S = AS $(quiet_modtag) $@
401
402	ifndef CONFIG_MODVERSIONS
403	cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
404
405	else
406
407	ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
408
409	ifeq ($(ASM_PROTOTYPES),)
410	cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
411
412	else
413
414	# versioning matches the C process described above, with difference that
415	# we parse asm-prototypes.h C header to get function definitions.
416
417	cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
418
419	cmd_modversions_S = \
420	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
421	$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
422	> $(@D)/.tmp_$(@F:.o=.ver); \
423	\
424	$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
425	-T $(@D)/.tmp_$(@F:.o=.ver); \
426	rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
427	else \
428	mv -f $(@D)/.tmp_$(@F) $@; \
429	fi;
430	endif
431	endif
432
433	$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
434	$(call if_changed_rule,as_o_S)
435
436	targets += $(real-objs-y) $(real-objs-m) $(lib-y)
437	targets += $(extra-y) $(MAKECMDGOALS) $(always)
438
439	# Linker scripts preprocessor (.lds.S -> .lds)
440	# ---------------------------------------------------------------------------
441	quiet_cmd_cpp_lds_S = LDS $@
442	cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
443	-D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
444
445	$(obj)/%.lds: $(src)/%.lds.S FORCE
446	$(call if_changed_dep,cpp_lds_S)
447
448	# ASN.1 grammar
449	# ---------------------------------------------------------------------------
450	quiet_cmd_asn1_compiler = ASN.1 $@
451	cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
452	$(subst .h,.c,$@) $(subst .c,.h,$@)
453
454	.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
455
456	$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
457	$(call cmd,asn1_compiler)
458
459	# Build the compiled-in targets
460	# ---------------------------------------------------------------------------
461
462	# To build objects in subdirs, we need to descend into the directories
463	$(sort $(subdir-obj-y)): $(subdir-ym) ;
464
465	#
466	# Rule to compile a set of .o files into one .o file
467	#
468	ifdef builtin-target
469
470	ifdef CONFIG_LTO_CLANG
471	ifdef CONFIG_MODVERSIONS
472	# combine symversions for later processing
473	update_lto_symversions = \
474	rm -f $@.symversions; \
475	for i in $(filter-out FORCE,$^); do \
476	if [ -f $$i.symversions ]; then \
477	cat $$i.symversions \
478	>> $@.symversions; \
479	fi; \
480	done;
481	endif
482	# rebuild the symbol table with llvm-ar to include IR files
483	update_lto_symtable = ; \
484	mv -f $@ $@.tmp; \
485	$(LLVM_AR) rcsT$(KBUILD_ARFLAGS) $@ \
486	$$($(AR) t $@.tmp); \
487	rm -f $@.tmp
488	endif
489
490	ifdef CONFIG_THIN_ARCHIVES
491	cmd_make_builtin = $(update_lto_symversions) \
492	rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
493	cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
494	quiet_cmd_link_o_target = AR $@
495	else
496	cmd_make_builtin = $(LD) $(ld_flags) -r -o
497	cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
498	quiet_cmd_link_o_target = LD $@
499	endif
500
501	# If the list of objects to link is empty, just create an empty built-in.o
502	cmd_link_o_target = $(if $(strip $(obj-y)),\
503	$(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
504	$(cmd_secanalysis),\
505	$(cmd_make_empty_builtin) $@)
506
507	$(builtin-target): $(obj-y) FORCE
508	$(call if_changed,link_o_target)
509
510	targets += $(builtin-target)
511	endif # builtin-target
512
513	#
514	# Rule to create modules.order file
515	#
516	# Create commands to either record .ko file or cat modules.order from
517	# a subdirectory
518	modorder-cmds = \
519	$(foreach m, $(modorder), \
520	$(if $(filter %/modules.order, $m), \
521	cat $m;, echo kernel/$m;))
522
523	$(modorder-target): $(subdir-ym) FORCE
524	$(Q)(cat /dev/null; $(modorder-cmds)) > $@
525
526	#
527	# Rule to compile a set of .o files into one .a file
528	#
529	ifdef lib-target
530	quiet_cmd_link_l_target = AR $@
531
532	ifdef CONFIG_THIN_ARCHIVES
533	cmd_link_l_target = \
534	$(update_lto_symversions) \
535	rm -f $@; \
536	$(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y) \
537	$(update_lto_symtable)
538	else
539	cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
540	endif
541
542	$(lib-target): $(lib-y) FORCE
543	$(call if_changed,link_l_target)
544
545	targets += $(lib-target)
546
547	dummy-object = $(obj)/.lib_exports.o
548	ksyms-lds = $(dot-target).lds
549	ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
550	ref_prefix = EXTERN(_
551	else
552	ref_prefix = EXTERN(
553	endif
554
555	filter_export_list = sed -ne '/___ksymtab/s/.*+\([^ "]*\).*/$(ref_prefix)\1)/p'
556	link_export_list = rm -f $(dummy-object);\
557	echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
558	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
559	rm $(dummy-object) $(ksyms-lds)
560
561	quiet_cmd_export_list = EXPORTS $@
562
563	ifdef CONFIG_LTO_CLANG
564	# objdump doesn't understand IR files and llvm-dis doesn't support archives,
565	# so we'll walk through each file in the archive separately
566	cmd_export_list = \
567	rm -f $(ksyms-lds); \
568	for o in $$($(AR) t $<); do \
569	if $(OBJDUMP) -h $$o >/dev/null 2>/dev/null; then \
570	$(OBJDUMP) -h $$o | \
571	$(filter_export_list) \
572	>>$(ksyms-lds); \
573	else \
574	$(LLVM_DIS) -o=- $$o | \
575	$(filter_export_list) \
576	>>$(ksyms-lds); \
577	fi; \
578	done; \
579	$(link_export_list)
580	else
581	cmd_export_list = $(OBJDUMP) -h $< | $(filter_export_list) >$(ksyms-lds); \
582	$(link_export_list)
583	endif
584
585	$(obj)/lib-ksyms.o: $(lib-target) FORCE
586	$(call if_changed,export_list)
587
588	targets += $(obj)/lib-ksyms.o
589
590	endif
591
592	#
593	# Rule to link composite objects
594	#
595	# Composite objects are specified in kbuild makefile as follows:
596	# <composite-object>-objs := <list of .o files>
597	# or
598	# <composite-object>-y := <list of .o files>
599	# or
600	# <composite-object>-m := <list of .o files>
601	# The -m syntax only works if <composite object> is a module
602	link_multi_deps = \
603	$(filter $(addprefix $(obj)/, \
604	$($(subst $(obj)/,,$(@:.o=-objs))) \
605	$($(subst $(obj)/,,$(@:.o=-y))) \
606	$($(subst $(obj)/,,$(@:.o=-m)))), $^)
607
608	cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
609
610	ifdef CONFIG_THIN_ARCHIVES
611	quiet_cmd_link_multi-y = AR $@
612	cmd_link_multi-y = $(update_lto_symversions) \
613	rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps) \
614	$(update_lto_symtable)
615	else
616	quiet_cmd_link_multi-y = LD $@
617	cmd_link_multi-y = $(cmd_link_multi-link)
618	endif
619
620	quiet_cmd_link_multi-m = LD [M] $@
621
622	ifdef CONFIG_LTO_CLANG
623	# don't compile IR until needed
624	cmd_link_multi-m = $(cmd_link_multi-y)
625	else
626	cmd_link_multi-m = $(cmd_link_multi-link)
627	endif
628
629	$(multi-used-y): FORCE
630	$(call if_changed,link_multi-y)
631
632	$(multi-used-m): FORCE
633	$(call if_changed,link_multi-m)
634	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
635	$(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
636
637	$(call multi_depend, $(multi-used-y), .o, -objs -y)
638	$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
639
640	targets += $(multi-used-y) $(multi-used-m)
641
642
643	# Descending
644	# ---------------------------------------------------------------------------
645
646	PHONY += $(subdir-ym)
647	$(subdir-ym):
648	$(Q)$(MAKE) $(build)=$@
649
650	# Add FORCE to the prequisites of a target to force it to be always rebuilt.
651	# ---------------------------------------------------------------------------
652
653	PHONY += FORCE
654
655	FORCE:
656
657	# Read all saved command lines and dependencies for the $(targets) we
658	# may be building above, using $(if_changed{,_dep}). As an
659	# optimization, we don't need to read them if the target does not
660	# exist, we will rebuild anyway in that case.
661
662	targets := $(wildcard $(sort $(targets)))
663	cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
664
665	ifneq ($(cmd_files),)
666	include $(cmd_files)
667	endif
668
669	# Declare the contents of the .PHONY variable as phony. We keep that
670	# information in a variable se we can use it in if_changed and friends.
671
672	.PHONY: $(PHONY)
673