Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(srcroot)/$(obj)
7
8PHONY := $(obj)/
9$(obj)/:
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-y :=
19always-m :=
20targets :=
21subdir-y :=
22subdir-m :=
23asflags-y :=
24ccflags-y :=
25rustflags-y :=
26cppflags-y :=
27ldflags-y :=
28
29subdir-asflags-y :=
30subdir-ccflags-y :=
31
32# Read auto.conf if it exists, otherwise ignore
33-include $(objtree)/include/config/auto.conf
34
35include $(srctree)/scripts/Kbuild.include
36include $(srctree)/scripts/Makefile.compiler
37include $(kbuild-file)
38include $(srctree)/scripts/Makefile.lib
39
40# flags that take effect in current and sub directories
41KBUILD_AFLAGS += $(subdir-asflags-y)
42KBUILD_CFLAGS += $(subdir-ccflags-y)
43KBUILD_RUSTFLAGS += $(subdir-rustflags-y)
44
45# Figure out what we need to build from the various variables
46# ===========================================================================
47
48# When an object is listed to be built compiled-in and modular,
49# only build the compiled-in version
50obj-m := $(filter-out $(obj-y),$(obj-m))
51
52# Libraries are always collected in one lib file.
53# Filter out objects already built-in
54lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
55
56# Subdirectories we need to descend into
57subdir-ym := $(sort $(subdir-y) $(subdir-m) \
58 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
59
60# Handle objects in subdirs:
61# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
62# foo/modules.order
63# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
64#
65# Generate modules.order to determine modorder. Unfortunately, we don't have
66# information about ordering between -y and -m subdirs. Just put -y's first.
67
68ifdef need-modorder
69obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
70else
71obj-m := $(filter-out %/, $(obj-m))
72endif
73
74ifdef need-builtin
75obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
76else
77obj-y := $(filter-out %/, $(obj-y))
78endif
79
80# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
81suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
82# List composite targets that are constructed by combining other targets
83multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
84# List primitive targets that are compiled from source files
85real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
86
87# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
88multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
89multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
90multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
91
92# Replace multi-part objects by their individual parts,
93# including built-in.a from subdirectories
94real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
95real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
96
97always-y += $(always-m)
98
99# hostprogs-always-y += foo
100# ... is a shorthand for
101# hostprogs += foo
102# always-y += foo
103hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
104always-y += $(hostprogs-always-y) $(hostprogs-always-m)
105
106# userprogs-always-y is likewise.
107userprogs += $(userprogs-always-y) $(userprogs-always-m)
108always-y += $(userprogs-always-y) $(userprogs-always-m)
109
110# Add subdir path
111
112ifneq ($(obj),.)
113extra-y := $(addprefix $(obj)/, $(extra-y))
114always-y := $(addprefix $(obj)/, $(always-y))
115targets := $(addprefix $(obj)/, $(targets))
116obj-m := $(addprefix $(obj)/, $(obj-m))
117lib-y := $(addprefix $(obj)/, $(lib-y))
118real-obj-y := $(addprefix $(obj)/, $(real-obj-y))
119real-obj-m := $(addprefix $(obj)/, $(real-obj-m))
120multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m))
121subdir-ym := $(addprefix $(obj)/, $(subdir-ym))
122endif
123
124ifndef obj
125$(warning kbuild: Makefile.build is included improperly)
126endif
127
128ifeq ($(need-modorder),)
129ifneq ($(obj-m),)
130$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
131$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
132endif
133endif
134
135# ===========================================================================
136
137# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
138subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
139subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
140
141targets-for-builtin := $(extra-y)
142
143ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
144targets-for-builtin += $(obj)/lib.a
145endif
146
147ifdef need-builtin
148targets-for-builtin += $(obj)/built-in.a
149endif
150
151targets-for-modules := $(foreach x, o mod, \
152 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
153
154ifdef need-modorder
155targets-for-modules += $(obj)/modules.order
156endif
157
158targets += $(targets-for-builtin) $(targets-for-modules)
159
160# Linus' kernel sanity checking tool
161ifeq ($(KBUILD_CHECKSRC),1)
162 quiet_cmd_checksrc = CHECK $<
163 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
164else ifeq ($(KBUILD_CHECKSRC),2)
165 quiet_cmd_force_checksrc = CHECK $<
166 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
167endif
168
169ifeq ($(KBUILD_EXTMOD),)
170ifneq ($(KBUILD_EXTRA_WARN),)
171 cmd_checkdoc = PYTHONDONTWRITEBYTECODE=1 $(PYTHON3) $(KERNELDOC) -none $(KDOCFLAGS) \
172 $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
173 $<
174endif
175endif
176
177# Compile C sources (.c)
178# ---------------------------------------------------------------------------
179
180quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
181 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
182
183$(obj)/%.s: $(obj)/%.c FORCE
184 $(call if_changed_dep,cc_s_c)
185
186quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
187cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
188
189$(obj)/%.i: $(obj)/%.c FORCE
190 $(call if_changed_dep,cpp_i_c)
191
192getexportsymbols = $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/$(1)/p'
193
194gendwarfksyms = $(objtree)/scripts/gendwarfksyms/gendwarfksyms \
195 $(if $(KBUILD_SYMTYPES), --symtypes $(@:.o=.symtypes)) \
196 $(if $(KBUILD_GENDWARFKSYMS_STABLE), --stable)
197
198genksyms = $(objtree)/scripts/genksyms/genksyms \
199 $(if $(KBUILD_SYMTYPES), -T $(@:.o=.symtypes)) \
200 $(if $(KBUILD_PRESERVE), -p) \
201 $(addprefix -r , $(wildcard $(@:.o=.symref)))
202
203# These mirror gensymtypes_S and co below, keep them in synch.
204ifdef CONFIG_GENDWARFKSYMS
205cmd_gensymtypes_c = $(if $(skip_gendwarfksyms),, \
206 $(call getexportsymbols,\1) | $(gendwarfksyms) $@)
207else
208cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
209endif # CONFIG_GENDWARFKSYMS
210
211# LLVM assembly
212# Generate .ll files from .c
213quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
214 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
215
216$(obj)/%.ll: $(obj)/%.c FORCE
217 $(call if_changed_dep,cc_ll_c)
218
219# C (.c) files
220# The C file is compiled and updated dependency information is generated.
221# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
222
223is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
224
225ifdef CONFIG_MODVERSIONS
226# When module versioning is enabled the following steps are executed:
227# o compile a <file>.o from <file>.c
228# o if <file>.o doesn't contain a __export_symbol_*, i.e. does
229# not export symbols, it's done.
230# o otherwise, we calculate symbol versions using the good old
231# genksyms on the preprocessed source and dump them into the .cmd file.
232# o modpost will extract versions from that file and create *.c files that will
233# be compiled and linked to the kernel and/or modules.
234
235gen_symversions = \
236 if $(NM) $@ 2>/dev/null | grep -q ' __export_symbol_'; then \
237 $(cmd_gensymtypes_$1) >> $(dot-target).cmd; \
238 fi
239
240cmd_gen_symversions_c = $(call gen_symversions,c)
241
242endif
243
244ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
245# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
246ifdef BUILD_C_RECORDMCOUNT
247ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
248 RECORDMCOUNT_FLAGS = -w
249endif
250# Due to recursion, we must skip empty.o.
251# The empty.o file is created in the make process in order to determine
252# the target endianness and word size. It is made before all other C
253# files, including recordmcount.
254sub_cmd_record_mcount = \
255 if [ $(@) != "scripts/mod/empty.o" ]; then \
256 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
257 fi;
258recordmcount_source := $(srctree)/scripts/recordmcount.c \
259 $(srctree)/scripts/recordmcount.h
260else
261sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
262 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
263 "$(if $(CONFIG_64BIT),64,32)" \
264 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
265 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
266 "$(if $(part-of-module),1,0)" "$(@)";
267recordmcount_source := $(srctree)/scripts/recordmcount.pl
268endif # BUILD_C_RECORDMCOUNT
269cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
270 $(sub_cmd_record_mcount))
271endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
272
273# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
274# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
275# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
276
277is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),$(is-kernel-object))
278
279ifdef CONFIG_OBJTOOL
280$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
281endif
282
283ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
284cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
285endif
286
287# Built-in and composite module parts
288$(obj)/%.o: $(obj)/%.c $(recordmcount_source) FORCE
289 $(call if_changed_rule,cc_o_c)
290 $(call cmd,force_checksrc)
291
292# To make this rule robust against "Argument list too long" error,
293# ensure to add $(obj)/ prefix by a shell command.
294cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
295 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
296
297$(obj)/%.mod: FORCE
298 $(call if_changed,mod)
299
300quiet_cmd_cc_lst_c = MKLST $@
301 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
302 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
303 System.map $(OBJDUMP) > $@
304
305$(obj)/%.lst: $(obj)/%.c FORCE
306 $(call if_changed_dep,cc_lst_c)
307
308# Compile Rust sources (.rs)
309# ---------------------------------------------------------------------------
310
311# The features in this list are the ones allowed for non-`rust/` code.
312#
313# - Stable since Rust 1.81.0: `feature(lint_reasons)`.
314# - Stable since Rust 1.82.0: `feature(asm_const)`,
315# `feature(offset_of_nested)`, `feature(raw_ref_op)`.
316# - Stable since Rust 1.87.0: `feature(asm_goto)`.
317# - Expected to become stable: `feature(arbitrary_self_types)`.
318# - To be determined: `feature(used_with_arg)`.
319#
320# Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on
321# the unstable features in use.
322rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,offset_of_nested,raw_ref_op,used_with_arg
323
324# `--out-dir` is required to avoid temporaries being created by `rustc` in the
325# current working directory, which may be not accessible in the out-of-tree
326# modules case.
327rust_common_cmd = \
328 OBJTREE=$(abspath $(objtree)) \
329 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
330 -Zallow-features=$(rust_allowed_features) \
331 -Zcrate-attr=no_std \
332 -Zcrate-attr='feature($(rust_allowed_features))' \
333 -Zunstable-options --extern pin_init --extern kernel \
334 --crate-type rlib -L $(objtree)/rust/ \
335 --crate-name $(basename $(notdir $@)) \
336 --sysroot=/dev/null \
337 --out-dir $(dir $@) --emit=dep-info=$(depfile)
338
339# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
340# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
341# the compiler shows a warning if it is not 1. However, if we ever stop
342# requesting it explicitly and we start using some other `--emit` that does not
343# imply it (and for which codegen is performed), then we would be out of sync,
344# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
345# would not match each other.
346
347quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
348 cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $< $(cmd_objtool)
349
350define rule_rustc_o_rs
351 $(call cmd_and_fixdep,rustc_o_rs)
352 $(call cmd,gen_objtooldep)
353endef
354
355$(obj)/%.o: $(obj)/%.rs FORCE
356 +$(call if_changed_rule,rustc_o_rs)
357
358quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
359 cmd_rustc_rsi_rs = \
360 $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
361 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) --config-path $(srctree)/.rustfmt.toml $@
362
363$(obj)/%.rsi: $(obj)/%.rs FORCE
364 +$(call if_changed_dep,rustc_rsi_rs)
365
366quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
367 cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
368
369$(obj)/%.s: $(obj)/%.rs FORCE
370 +$(call if_changed_dep,rustc_s_rs)
371
372quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
373 cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
374
375$(obj)/%.ll: $(obj)/%.rs FORCE
376 +$(call if_changed_dep,rustc_ll_rs)
377
378quiet_cmd_rustc_rs_rs_S = RSCPP $(quiet_modtag) $@
379 cmd_rustc_rs_rs_S = $(CPP) $(c_flags) -xc -C -P $< | sed '1,/^\/\/ Cut here.$$/d' >$@
380
381$(obj)/%.rs: $(obj)/%.rs.S FORCE
382 +$(call if_changed_dep,rustc_rs_rs_S)
383
384# Compile assembler sources (.S)
385# ---------------------------------------------------------------------------
386
387# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
388# or a file that it includes, in order to get versioned symbols. We build a
389# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
390# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
391#
392# This is convoluted. The .S file must first be preprocessed to run guards and
393# expand names, then the resulting exports must be constructed into plain
394# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
395# to make the genksyms input or compiled into an object for gendwarfksyms.
396#
397# These mirror gensymtypes_c and co above, keep them in synch.
398getasmexports = \
399 { echo "\#include <linux/kernel.h>" ; \
400 echo "\#include <linux/string.h>" ; \
401 echo "\#include <asm/asm-prototypes.h>" ; \
402 $(call getexportsymbols,EXPORT_SYMBOL(\1);) ; }
403
404ifdef CONFIG_GENDWARFKSYMS
405cmd_gensymtypes_S = \
406 $(getasmexports) | \
407 $(CC) $(c_flags) -c -o $(@:.o=.gendwarfksyms.o) -xc -; \
408 $(call getexportsymbols,\1) | \
409 $(gendwarfksyms) $(@:.o=.gendwarfksyms.o)
410else
411cmd_gensymtypes_S = \
412 $(getasmexports) | \
413 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
414endif # CONFIG_GENDWARFKSYMS
415
416quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
417cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
418
419$(obj)/%.s: $(obj)/%.S FORCE
420 $(call if_changed_dep,cpp_s_S)
421
422ifdef CONFIG_ASM_MODVERSIONS
423
424# versioning matches the C process described above, with difference that
425# we parse asm-prototypes.h C header to get function definitions.
426
427cmd_gen_symversions_S = $(call gen_symversions,S)
428
429endif
430
431$(obj)/%.o: $(obj)/%.S FORCE
432 $(call if_changed_rule,as_o_S)
433
434targets += $(filter-out $(subdir-builtin), $(real-obj-y))
435targets += $(filter-out $(subdir-modorder), $(real-obj-m))
436targets += $(lib-y) $(always-y)
437
438# Linker scripts preprocessor (.lds.S -> .lds)
439# ---------------------------------------------------------------------------
440quiet_cmd_cpp_lds_S = LDS $@
441 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
442 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
443
444$(obj)/%.lds: $(src)/%.lds.S FORCE
445 $(call if_changed_dep,cpp_lds_S)
446
447# ASN.1 grammar
448# ---------------------------------------------------------------------------
449quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
450 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
451 $(basename $@).c $(basename $@).h
452
453$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
454 $(call cmd,asn1_compiler)
455
456# Build the compiled-in targets
457# ---------------------------------------------------------------------------
458
459# To build objects in subdirs, we need to descend into the directories
460$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
461$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
462
463#
464# Rule to compile a set of .o files into one .a file (without symbol table)
465#
466# To make this rule robust against "Argument list too long" error,
467# remove $(obj)/ prefix, and restore it by a shell command.
468
469quiet_cmd_ar_builtin = AR $@
470 cmd_ar_builtin = rm -f $@; \
471 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
472 $(AR) cDPrST $@
473
474$(obj)/built-in.a: $(real-obj-y) FORCE
475 $(call if_changed,ar_builtin)
476
477# This is a list of build artifacts from the current Makefile and its
478# sub-directories. The timestamp should be updated when any of the member files.
479
480cmd_gen_order = { $(foreach m, $(real-prereqs), \
481 $(if $(filter %/$(notdir $@), $m), cat $m, echo $m);) :; } \
482 > $@
483
484$(obj)/modules.order: $(obj-m) FORCE
485 $(call if_changed,gen_order)
486
487#
488# Rule to compile a set of .o files into one .a file (with symbol table)
489#
490
491$(obj)/lib.a: $(lib-y) FORCE
492 $(call if_changed,ar)
493
494quiet_cmd_ld_multi_m = LD [M] $@
495 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
496
497define rule_ld_multi_m
498 $(call cmd_and_savecmd,ld_multi_m)
499 $(call cmd,gen_objtooldep)
500endef
501
502$(multi-obj-m): private objtool-enabled := $(delay-objtool)
503$(multi-obj-m): private part-of-module := y
504$(multi-obj-m): %.o: %.mod FORCE
505 $(call if_changed_rule,ld_multi_m)
506$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
507
508# Add intermediate targets:
509# When building objects with specific suffix patterns, add intermediate
510# targets that the final targets are derived from.
511intermediate_targets = $(foreach sfx, $(2), \
512 $(patsubst %$(strip $(1)),%$(sfx), \
513 $(filter %$(strip $(1)), $(targets))))
514# %.asn1.o <- %.asn1.[ch] <- %.asn1
515targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h)
516
517# Include additional build rules when necessary
518# ---------------------------------------------------------------------------
519
520# $(sort ...) is used here to remove duplicated words and excessive spaces.
521hostprogs := $(sort $(hostprogs))
522ifneq ($(hostprogs),)
523include $(srctree)/scripts/Makefile.host
524endif
525
526# $(sort ...) is used here to remove duplicated words and excessive spaces.
527userprogs := $(sort $(userprogs))
528ifneq ($(userprogs),)
529include $(srctree)/scripts/Makefile.userprogs
530endif
531
532# Single targets
533# ---------------------------------------------------------------------------
534
535single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
536single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
537
538$(single-subdir-goals): $(single-subdirs)
539 @:
540
541# Descending
542# ---------------------------------------------------------------------------
543
544PHONY += $(subdir-ym)
545$(subdir-ym):
546 $(Q)$(MAKE) $(build)=$@ \
547 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
548 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
549 $(filter $@/%, $(single-subdir-goals))
550
551# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
552# ---------------------------------------------------------------------------
553
554PHONY += FORCE
555
556FORCE:
557
558targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
559targets := $(filter-out $(PHONY), $(targets))
560
561# Now that targets is fully known, include dtb rules if needed
562ifneq ($(need-dtbslist)$(dtb-y)$(dtb-)$(filter %.dtb %.dtb.o %.dtbo.o,$(targets)),)
563include $(srctree)/scripts/Makefile.dtbs
564endif
565
566# Build
567# Needs to be after the include of Makefile.dtbs, which updates always-y
568# ---------------------------------------------------------------------------
569
570$(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
571 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
572 $(subdir-ym) $(always-y)
573 @:
574
575# Read all saved command lines and dependencies for the $(targets) we
576# may be building above, using $(if_changed{,_dep}). As an
577# optimization, we don't need to read them if the target does not
578# exist, we will rebuild anyway in that case.
579
580existing-targets := $(wildcard $(sort $(targets)))
581
582-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
583
584# Create directories for object files if they do not exist
585obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
586# If targets exist, their directories apparently exist. Skip mkdir.
587existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
588obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
589ifneq ($(obj-dirs),)
590$(shell mkdir -p $(obj-dirs))
591endif
592
593.PHONY: $(PHONY)