672cf5bfd724198adc1e0c020ab05cdae0dac609
[muen/linux.git] / scripts / Makefile.build
1 # SPDX-License-Identifier: GPL-2.0
2 # ==========================================================================
3 # Building
4 # ==========================================================================
5
6 src := $(obj)
7
8 PHONY := __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
14 obj-y :=
15 obj-m :=
16 lib-y :=
17 lib-m :=
18 always :=
19 targets :=
20 subdir-y :=
21 subdir-m :=
22 EXTRA_AFLAGS   :=
23 EXTRA_CFLAGS   :=
24 EXTRA_CPPFLAGS :=
25 EXTRA_LDFLAGS  :=
26 asflags-y  :=
27 ccflags-y  :=
28 cppflags-y :=
29 ldflags-y  :=
30
31 subdir-asflags-y :=
32 subdir-ccflags-y :=
33
34 # Read auto.conf if it exists, otherwise ignore
35 -include include/config/auto.conf
36
37 include scripts/Kbuild.include
38
39 # For backward compatibility check that these variables do not change
40 save-cflags := $(CFLAGS)
41
42 # The filename Kbuild has precedence over Makefile
43 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
44 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
45 include $(kbuild-file)
46
47 # If the save-* variables changed error out
48 ifeq ($(KBUILD_NOPEDANTIC),)
49         ifneq ("$(save-cflags)","$(CFLAGS)")
50                 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
51         endif
52 endif
53
54 include scripts/Makefile.lib
55
56 ifdef host-progs
57 ifneq ($(hostprogs-y),$(host-progs))
58 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
59 hostprogs-y += $(host-progs)
60 endif
61 endif
62
63 # Do not include host rules unless needed
64 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
65 include scripts/Makefile.host
66 endif
67
68 ifndef obj
69 $(warning kbuild: Makefile.build is included improperly)
70 endif
71
72 # ===========================================================================
73
74 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
75 lib-target := $(obj)/lib.a
76 obj-y += $(obj)/lib-ksyms.o
77 endif
78
79 ifneq ($(strip $(obj-y) $(need-builtin)),)
80 builtin-target := $(obj)/built-in.o
81 endif
82
83 modorder-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) $(always)
90         @:
91
92 # Linus' kernel sanity checking tool
93 ifneq ($(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) $< ;
100   endif
101 endif
102
103 ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
104   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
105 endif
106
107 # Do section mismatch analysis for each module/built-in.o
108 ifdef CONFIG_DEBUG_SECTION_MISMATCH
109   cmd_secanalysis = ; scripts/mod/modpost $@
110 endif
111
112 # Compile C sources (.c)
113 # ---------------------------------------------------------------------------
114
115 # Default is built-in, unless we know otherwise
116 modkern_cflags =                                          \
117         $(if $(part-of-module),                           \
118                 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
119                 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
120 quiet_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
135 modname = $(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
146 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
147 cmd_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
152 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
153 cmd_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.
159 cmd_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
167 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
168 cmd_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
178 quiet_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
188 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
189
190 ifndef CONFIG_MODVERSIONS
191 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
192
193 else
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
206 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
207
208 cmd_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) $@;                                      \
218         fi;
219 endif
220
221 ifdef CONFIG_FTRACE_MCOUNT_RECORD
222 ifdef BUILD_C_RECORDMCOUNT
223 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
224   RECORDMCOUNT_FLAGS = -w
225 endif
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.
230 sub_cmd_record_mcount =                                 \
231         if [ $(@) != "scripts/mod/empty.o" ]; then      \
232                 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";   \
233         fi;
234 recordmcount_source := $(srctree)/scripts/recordmcount.c \
235                     $(srctree)/scripts/recordmcount.h
236 else
237 sub_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 $(part-of-module),1,0)" "$(@)";
243 recordmcount_source := $(srctree)/scripts/recordmcount.pl
244 endif # BUILD_C_RECORDMCOUNT
245 cmd_record_mcount =                                             \
246         if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" =   \
247              "$(CC_FLAGS_FTRACE)" ]; then                       \
248                 $(sub_cmd_record_mcount)                        \
249         fi;
250 endif # CONFIG_FTRACE_MCOUNT_RECORD
251
252 ifdef CONFIG_STACK_VALIDATION
253 ifneq ($(SKIP_STACK_VALIDATION),1)
254
255 __objtool_obj := $(objtree)/tools/objtool/objtool
256
257 objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
258
259 objtool_args += $(if $(part-of-module), --module,)
260
261 ifndef CONFIG_FRAME_POINTER
262 objtool_args += --no-fp
263 endif
264 ifdef CONFIG_GCOV_KERNEL
265 objtool_args += --no-unreachable
266 else
267 objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
268 endif
269 ifdef CONFIG_RETPOLINE
270 ifneq ($(RETPOLINE_CFLAGS),)
271   objtool_args += --retpoline
272 endif
273 endif
274
275
276 ifdef CONFIG_MODVERSIONS
277 objtool_o = $(@D)/.tmp_$(@F)
278 else
279 objtool_o = $(@)
280 endif
281
282 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
283 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
284 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
285 cmd_objtool = $(if $(patsubst y%,, \
286         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
287         $(__objtool_obj) $(objtool_args) "$(objtool_o)";)
288 objtool_obj = $(if $(patsubst y%,, \
289         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
290         $(__objtool_obj))
291
292 endif # SKIP_STACK_VALIDATION
293 endif # CONFIG_STACK_VALIDATION
294
295 # Rebuild all objects when objtool changes, or is enabled/disabled.
296 objtool_dep = $(objtool_obj)                                    \
297               $(wildcard include/config/orc/unwinder.h          \
298                          include/config/stack/validation.h)
299
300 define rule_cc_o_c
301         $(call echo-cmd,checksrc) $(cmd_checksrc)                         \
302         $(call cmd_and_fixdep,cc_o_c)                                     \
303         $(cmd_checkdoc)                                                   \
304         $(call echo-cmd,objtool) $(cmd_objtool)                           \
305         $(cmd_modversions_c)                                              \
306         $(call echo-cmd,record_mcount) $(cmd_record_mcount)
307 endef
308
309 define rule_as_o_S
310         $(call cmd_and_fixdep,as_o_S)                                     \
311         $(call echo-cmd,objtool) $(cmd_objtool)                           \
312         $(cmd_modversions_S)
313 endef
314
315 # List module undefined symbols (or empty line if not enabled)
316 ifdef CONFIG_TRIM_UNUSED_KSYMS
317 cmd_undef_syms = $(NM) $@ | sed -n 's/^  *U //p' | xargs echo
318 else
319 cmd_undef_syms = echo
320 endif
321
322 # Built-in and composite module parts
323 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
324         $(call cmd,force_checksrc)
325         $(call if_changed_rule,cc_o_c)
326
327 # Single-part modules are special since we need to mark them in $(MODVERDIR)
328
329 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
330         $(call cmd,force_checksrc)
331         $(call if_changed_rule,cc_o_c)
332         @{ echo $(@:.o=.ko); echo $@; \
333            $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
334
335 quiet_cmd_cc_lst_c = MKLST   $@
336       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
337                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
338                                      System.map $(OBJDUMP) > $@
339
340 $(obj)/%.lst: $(src)/%.c FORCE
341         $(call if_changed_dep,cc_lst_c)
342
343 # Compile assembler sources (.S)
344 # ---------------------------------------------------------------------------
345
346 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
347
348 $(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
349 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
350
351 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
352 # or a file that it includes, in order to get versioned symbols. We build a
353 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
354 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
355 #
356 # This is convoluted. The .S file must first be preprocessed to run guards and
357 # expand names, then the resulting exports must be constructed into plain
358 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
359 # to make the genksyms input.
360 #
361 # These mirror gensymtypes_c and co above, keep them in synch.
362 cmd_gensymtypes_S =                                                         \
363     (echo "\#include <linux/kernel.h>" ;                                    \
364      echo "\#include <asm/asm-prototypes.h>" ;                              \
365     $(CPP) $(a_flags) $< |                                                  \
366      grep "\<___EXPORT_SYMBOL\>" |                                          \
367      sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
368     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
369     $(GENKSYMS) $(if $(1), -T $(2))                                         \
370      $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
371      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
372      $(if $(KBUILD_PRESERVE),-p)                                            \
373      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
374
375 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
376 cmd_cc_symtypes_S =                                                         \
377     set -e;                                                                 \
378     $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
379     test -s $@ || rm -f $@
380
381 $(obj)/%.symtypes : $(src)/%.S FORCE
382         $(call cmd,cc_symtypes_S)
383
384
385 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
386 cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
387
388 $(obj)/%.s: $(src)/%.S FORCE
389         $(call if_changed_dep,cpp_s_S)
390
391 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
392
393 ifndef CONFIG_MODVERSIONS
394 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
395
396 else
397
398 ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
399
400 ifeq ($(ASM_PROTOTYPES),)
401 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
402
403 else
404
405 # versioning matches the C process described above, with difference that
406 # we parse asm-prototypes.h C header to get function definitions.
407
408 cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
409
410 cmd_modversions_S =                                                             \
411         if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then             \
412                 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
413                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
414                                                                                 \
415                 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F)                      \
416                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
417                 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);                \
418         else                                                                    \
419                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
420         fi;
421 endif
422 endif
423
424 $(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
425         $(call if_changed_rule,as_o_S)
426
427 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
428 targets += $(extra-y) $(MAKECMDGOALS) $(always)
429
430 # Linker scripts preprocessor (.lds.S -> .lds)
431 # ---------------------------------------------------------------------------
432 quiet_cmd_cpp_lds_S = LDS     $@
433       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
434                              -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
435
436 $(obj)/%.lds: $(src)/%.lds.S FORCE
437         $(call if_changed_dep,cpp_lds_S)
438
439 # ASN.1 grammar
440 # ---------------------------------------------------------------------------
441 quiet_cmd_asn1_compiler = ASN.1   $@
442       cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
443                                 $(subst .h,.c,$@) $(subst .c,.h,$@)
444
445 .PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
446
447 $(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
448         $(call cmd,asn1_compiler)
449
450 # Build the compiled-in targets
451 # ---------------------------------------------------------------------------
452
453 # To build objects in subdirs, we need to descend into the directories
454 $(sort $(subdir-obj-y)): $(subdir-ym) ;
455
456 #
457 # Rule to compile a set of .o files into one .o file
458 #
459 ifdef builtin-target
460
461 # built-in.o archives are made with no symbol table or index which
462 # makes them small and fast, but unable to be used by the linker.
463 # scripts/link-vmlinux.sh builds an aggregate built-in.o with a symbol
464 # table and index.
465 cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
466 cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
467 quiet_cmd_link_o_target = AR      $@
468
469 # If the list of objects to link is empty, just create an empty built-in.o
470 cmd_link_o_target = $(if $(strip $(obj-y)),\
471                       $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
472                       $(cmd_secanalysis),\
473                       $(cmd_make_empty_builtin) $@)
474
475 $(builtin-target): $(obj-y) FORCE
476         $(call if_changed,link_o_target)
477
478 targets += $(builtin-target)
479 endif # builtin-target
480
481 #
482 # Rule to create modules.order file
483 #
484 # Create commands to either record .ko file or cat modules.order from
485 # a subdirectory
486 modorder-cmds =                                         \
487         $(foreach m, $(modorder),                       \
488                 $(if $(filter %/modules.order, $m),     \
489                         cat $m;, echo kernel/$m;))
490
491 $(modorder-target): $(subdir-ym) FORCE
492         $(Q)(cat /dev/null; $(modorder-cmds)) > $@
493
494 #
495 # Rule to compile a set of .o files into one .a file
496 #
497 ifdef lib-target
498 quiet_cmd_link_l_target = AR      $@
499
500 # lib target archives do get a symbol table and index
501 cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
502
503 $(lib-target): $(lib-y) FORCE
504         $(call if_changed,link_l_target)
505
506 targets += $(lib-target)
507
508 dummy-object = $(obj)/.lib_exports.o
509 ksyms-lds = $(dot-target).lds
510 ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
511 ref_prefix = EXTERN(_
512 else
513 ref_prefix = EXTERN(
514 endif
515
516 quiet_cmd_export_list = EXPORTS $@
517 cmd_export_list = $(OBJDUMP) -h $< | \
518         sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
519         rm -f $(dummy-object);\
520         echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
521         $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
522         rm $(dummy-object) $(ksyms-lds)
523
524 $(obj)/lib-ksyms.o: $(lib-target) FORCE
525         $(call if_changed,export_list)
526
527 targets += $(obj)/lib-ksyms.o
528
529 endif
530
531 #
532 # Rule to link composite objects
533 #
534 #  Composite objects are specified in kbuild makefile as follows:
535 #    <composite-object>-objs := <list of .o files>
536 #  or
537 #    <composite-object>-y    := <list of .o files>
538 #  or
539 #    <composite-object>-m    := <list of .o files>
540 #  The -m syntax only works if <composite object> is a module
541 link_multi_deps =                     \
542 $(filter $(addprefix $(obj)/,         \
543 $($(subst $(obj)/,,$(@:.o=-objs)))    \
544 $($(subst $(obj)/,,$(@:.o=-y)))       \
545 $($(subst $(obj)/,,$(@:.o=-m)))), $^)
546
547 cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
548
549 quiet_cmd_link_multi-y = AR      $@
550 cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
551
552 quiet_cmd_link_multi-m = LD [M]  $@
553 cmd_link_multi-m = $(cmd_link_multi-link)
554
555 $(multi-used-y): FORCE
556         $(call if_changed,link_multi-y)
557 $(call multi_depend, $(multi-used-y), .o, -objs -y)
558
559 $(multi-used-m): FORCE
560         $(call if_changed,link_multi-m)
561         @{ echo $(@:.o=.ko); echo $(link_multi_deps); \
562            $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
563 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
564
565 targets += $(multi-used-y) $(multi-used-m)
566 targets := $(filter-out $(PHONY), $(targets))
567
568 # Descending
569 # ---------------------------------------------------------------------------
570
571 PHONY += $(subdir-ym)
572 $(subdir-ym):
573         $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
574
575 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
576 # ---------------------------------------------------------------------------
577
578 PHONY += FORCE
579
580 FORCE:
581
582 # Read all saved command lines and dependencies for the $(targets) we
583 # may be building above, using $(if_changed{,_dep}). As an
584 # optimization, we don't need to read them if the target does not
585 # exist, we will rebuild anyway in that case.
586
587 cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
588
589 ifneq ($(cmd_files),)
590   include $(cmd_files)
591 endif
592
593 ifneq ($(KBUILD_SRC),)
594 # Create directories for object files if they do not exist
595 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
596 # If cmd_files exist, their directories apparently exist.  Skip mkdir.
597 exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files))))
598 obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs)))
599 ifneq ($(obj-dirs),)
600 $(shell mkdir -p $(obj-dirs))
601 endif
602 endif
603
604 # Declare the contents of the .PHONY variable as phony.  We keep that
605 # information in a variable se we can use it in if_changed and friends.
606
607 .PHONY: $(PHONY)