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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 :=
23EXTRA_AFLAGS :=
24EXTRA_CFLAGS :=
25EXTRA_CPPFLAGS :=
26EXTRA_LDFLAGS :=
27asflags-y :=
28ccflags-y :=
29rustflags-y :=
30cppflags-y :=
31ldflags-y :=
32
33subdir-asflags-y :=
34subdir-ccflags-y :=
35
36# Read auto.conf if it exists, otherwise ignore
37-include $(objtree)/include/config/auto.conf
38
39include $(srctree)/scripts/Kbuild.include
40include $(srctree)/scripts/Makefile.compiler
41include $(kbuild-file)
42include $(srctree)/scripts/Makefile.lib
43
44ifndef obj
45$(warning kbuild: Makefile.build is included improperly)
46endif
47
48ifeq ($(need-modorder),)
49ifneq ($(obj-m),)
50$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
51$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
52endif
53endif
54
55# ===========================================================================
56
57# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
58subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
59subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
60
61targets-for-builtin := $(extra-y)
62
63ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
64targets-for-builtin += $(obj)/lib.a
65endif
66
67ifdef need-builtin
68targets-for-builtin += $(obj)/built-in.a
69endif
70
71targets-for-modules := $(foreach x, o mod, \
72 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
73
74ifdef need-modorder
75targets-for-modules += $(obj)/modules.order
76endif
77
78targets += $(targets-for-builtin) $(targets-for-modules)
79
80# Linus' kernel sanity checking tool
81ifeq ($(KBUILD_CHECKSRC),1)
82 quiet_cmd_checksrc = CHECK $<
83 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
84else ifeq ($(KBUILD_CHECKSRC),2)
85 quiet_cmd_force_checksrc = CHECK $<
86 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
87endif
88
89ifneq ($(KBUILD_EXTRA_WARN),)
90 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) \
91 $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
92 $<
93endif
94
95# Compile C sources (.c)
96# ---------------------------------------------------------------------------
97
98quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
99 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
100
101$(obj)/%.s: $(obj)/%.c FORCE
102 $(call if_changed_dep,cc_s_c)
103
104quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
105cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
106
107$(obj)/%.i: $(obj)/%.c FORCE
108 $(call if_changed_dep,cpp_i_c)
109
110genksyms = $(objtree)/scripts/genksyms/genksyms \
111 $(if $(KBUILD_SYMTYPES), -T $(@:.o=.symtypes)) \
112 $(if $(KBUILD_PRESERVE), -p) \
113 $(addprefix -r , $(wildcard $(@:.o=.symref)))
114
115# These mirror gensymtypes_S and co below, keep them in synch.
116cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
117
118# LLVM assembly
119# Generate .ll files from .c
120quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
121 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
122
123$(obj)/%.ll: $(obj)/%.c FORCE
124 $(call if_changed_dep,cc_ll_c)
125
126# C (.c) files
127# The C file is compiled and updated dependency information is generated.
128# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
129
130is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
131
132ifdef CONFIG_MODVERSIONS
133# When module versioning is enabled the following steps are executed:
134# o compile a <file>.o from <file>.c
135# o if <file>.o doesn't contain a __export_symbol_*, i.e. does
136# not export symbols, it's done.
137# o otherwise, we calculate symbol versions using the good old
138# genksyms on the preprocessed source and dump them into the .cmd file.
139# o modpost will extract versions from that file and create *.c files that will
140# be compiled and linked to the kernel and/or modules.
141
142gen_symversions = \
143 if $(NM) $@ 2>/dev/null | grep -q ' __export_symbol_'; then \
144 $(cmd_gensymtypes_$1) >> $(dot-target).cmd; \
145 fi
146
147cmd_gen_symversions_c = $(call gen_symversions,c)
148
149endif
150
151ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
152# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
153ifdef BUILD_C_RECORDMCOUNT
154ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
155 RECORDMCOUNT_FLAGS = -w
156endif
157# Due to recursion, we must skip empty.o.
158# The empty.o file is created in the make process in order to determine
159# the target endianness and word size. It is made before all other C
160# files, including recordmcount.
161sub_cmd_record_mcount = \
162 if [ $(@) != "scripts/mod/empty.o" ]; then \
163 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
164 fi;
165recordmcount_source := $(srctree)/scripts/recordmcount.c \
166 $(srctree)/scripts/recordmcount.h
167else
168sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
169 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
170 "$(if $(CONFIG_64BIT),64,32)" \
171 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
172 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
173 "$(if $(part-of-module),1,0)" "$(@)";
174recordmcount_source := $(srctree)/scripts/recordmcount.pl
175endif # BUILD_C_RECORDMCOUNT
176cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
177 $(sub_cmd_record_mcount))
178endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
179
180# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
181# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
182# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
183
184is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),$(is-kernel-object))
185
186ifdef CONFIG_OBJTOOL
187$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
188endif
189
190ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
191cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
192endif
193
194# Built-in and composite module parts
195$(obj)/%.o: $(obj)/%.c $(recordmcount_source) FORCE
196 $(call if_changed_rule,cc_o_c)
197 $(call cmd,force_checksrc)
198
199# To make this rule robust against "Argument list too long" error,
200# ensure to add $(obj)/ prefix by a shell command.
201cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
202 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
203
204$(obj)/%.mod: FORCE
205 $(call if_changed,mod)
206
207quiet_cmd_cc_lst_c = MKLST $@
208 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
209 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
210 System.map $(OBJDUMP) > $@
211
212$(obj)/%.lst: $(obj)/%.c FORCE
213 $(call if_changed_dep,cc_lst_c)
214
215# Compile Rust sources (.rs)
216# ---------------------------------------------------------------------------
217
218rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons
219
220# `--out-dir` is required to avoid temporaries being created by `rustc` in the
221# current working directory, which may be not accessible in the out-of-tree
222# modules case.
223rust_common_cmd = \
224 OBJTREE=$(abspath $(objtree)) \
225 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
226 -Zallow-features=$(rust_allowed_features) \
227 -Zcrate-attr=no_std \
228 -Zcrate-attr='feature($(rust_allowed_features))' \
229 -Zunstable-options --extern kernel \
230 --crate-type rlib -L $(objtree)/rust/ \
231 --crate-name $(basename $(notdir $@)) \
232 --sysroot=/dev/null \
233 --out-dir $(dir $@) --emit=dep-info=$(depfile)
234
235# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
236# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
237# the compiler shows a warning if it is not 1. However, if we ever stop
238# requesting it explicitly and we start using some other `--emit` that does not
239# imply it (and for which codegen is performed), then we would be out of sync,
240# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
241# would not match each other.
242
243quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
244 cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $< $(cmd_objtool)
245
246define rule_rustc_o_rs
247 $(call cmd_and_fixdep,rustc_o_rs)
248 $(call cmd,gen_objtooldep)
249endef
250
251$(obj)/%.o: $(obj)/%.rs FORCE
252 +$(call if_changed_rule,rustc_o_rs)
253
254quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
255 cmd_rustc_rsi_rs = \
256 $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
257 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
258
259$(obj)/%.rsi: $(obj)/%.rs FORCE
260 +$(call if_changed_dep,rustc_rsi_rs)
261
262quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
263 cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
264
265$(obj)/%.s: $(obj)/%.rs FORCE
266 +$(call if_changed_dep,rustc_s_rs)
267
268quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
269 cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
270
271$(obj)/%.ll: $(obj)/%.rs FORCE
272 +$(call if_changed_dep,rustc_ll_rs)
273
274quiet_cmd_rustc_rs_rs_S = RSCPP $(quiet_modtag) $@
275 cmd_rustc_rs_rs_S = $(CPP) $(c_flags) -xc -C -P $< | sed '1,/^\/\/ Cut here.$$/d' >$@
276
277$(obj)/%.rs: $(obj)/%.rs.S FORCE
278 +$(call if_changed_dep,rustc_rs_rs_S)
279
280# Compile assembler sources (.S)
281# ---------------------------------------------------------------------------
282
283# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
284# or a file that it includes, in order to get versioned symbols. We build a
285# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
286# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
287#
288# This is convoluted. The .S file must first be preprocessed to run guards and
289# expand names, then the resulting exports must be constructed into plain
290# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
291# to make the genksyms input.
292#
293# These mirror gensymtypes_c and co above, keep them in synch.
294cmd_gensymtypes_S = \
295 { echo "\#include <linux/kernel.h>" ; \
296 echo "\#include <asm/asm-prototypes.h>" ; \
297 $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \
298 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
299
300quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
301cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
302
303$(obj)/%.s: $(obj)/%.S FORCE
304 $(call if_changed_dep,cpp_s_S)
305
306ifdef CONFIG_ASM_MODVERSIONS
307
308# versioning matches the C process described above, with difference that
309# we parse asm-prototypes.h C header to get function definitions.
310
311cmd_gen_symversions_S = $(call gen_symversions,S)
312
313endif
314
315$(obj)/%.o: $(obj)/%.S FORCE
316 $(call if_changed_rule,as_o_S)
317
318targets += $(filter-out $(subdir-builtin), $(real-obj-y))
319targets += $(filter-out $(subdir-modorder), $(real-obj-m))
320targets += $(lib-y) $(always-y)
321
322# Linker scripts preprocessor (.lds.S -> .lds)
323# ---------------------------------------------------------------------------
324quiet_cmd_cpp_lds_S = LDS $@
325 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
326 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
327
328$(obj)/%.lds: $(src)/%.lds.S FORCE
329 $(call if_changed_dep,cpp_lds_S)
330
331# ASN.1 grammar
332# ---------------------------------------------------------------------------
333quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
334 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
335 $(basename $@).c $(basename $@).h
336
337$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
338 $(call cmd,asn1_compiler)
339
340# Build the compiled-in targets
341# ---------------------------------------------------------------------------
342
343# To build objects in subdirs, we need to descend into the directories
344$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
345$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
346
347#
348# Rule to compile a set of .o files into one .a file (without symbol table)
349#
350# To make this rule robust against "Argument list too long" error,
351# remove $(obj)/ prefix, and restore it by a shell command.
352
353quiet_cmd_ar_builtin = AR $@
354 cmd_ar_builtin = rm -f $@; \
355 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
356 $(AR) cDPrST $@
357
358$(obj)/built-in.a: $(real-obj-y) FORCE
359 $(call if_changed,ar_builtin)
360
361# This is a list of build artifacts from the current Makefile and its
362# sub-directories. The timestamp should be updated when any of the member files.
363
364cmd_gen_order = { $(foreach m, $(real-prereqs), \
365 $(if $(filter %/$(notdir $@), $m), cat $m, echo $m);) :; } \
366 > $@
367
368$(obj)/modules.order: $(obj-m) FORCE
369 $(call if_changed,gen_order)
370
371#
372# Rule to compile a set of .o files into one .a file (with symbol table)
373#
374
375$(obj)/lib.a: $(lib-y) FORCE
376 $(call if_changed,ar)
377
378quiet_cmd_ld_multi_m = LD [M] $@
379 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
380
381define rule_ld_multi_m
382 $(call cmd_and_savecmd,ld_multi_m)
383 $(call cmd,gen_objtooldep)
384endef
385
386$(multi-obj-m): private objtool-enabled := $(delay-objtool)
387$(multi-obj-m): private part-of-module := y
388$(multi-obj-m): %.o: %.mod FORCE
389 $(call if_changed_rule,ld_multi_m)
390$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
391
392# Add intermediate targets:
393# When building objects with specific suffix patterns, add intermediate
394# targets that the final targets are derived from.
395intermediate_targets = $(foreach sfx, $(2), \
396 $(patsubst %$(strip $(1)),%$(sfx), \
397 $(filter %$(strip $(1)), $(targets))))
398# %.asn1.o <- %.asn1.[ch] <- %.asn1
399targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h)
400
401# Include additional build rules when necessary
402# ---------------------------------------------------------------------------
403
404# $(sort ...) is used here to remove duplicated words and excessive spaces.
405hostprogs := $(sort $(hostprogs))
406ifneq ($(hostprogs),)
407include $(srctree)/scripts/Makefile.host
408endif
409
410# $(sort ...) is used here to remove duplicated words and excessive spaces.
411userprogs := $(sort $(userprogs))
412ifneq ($(userprogs),)
413include $(srctree)/scripts/Makefile.userprogs
414endif
415
416ifneq ($(need-dtbslist)$(dtb-y)$(dtb-)$(filter %.dtb %.dtb.o %.dtbo.o,$(targets)),)
417include $(srctree)/scripts/Makefile.dtbs
418endif
419
420# Build
421# ---------------------------------------------------------------------------
422
423$(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
424 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
425 $(subdir-ym) $(always-y)
426 @:
427
428# Single targets
429# ---------------------------------------------------------------------------
430
431single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
432single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
433
434$(single-subdir-goals): $(single-subdirs)
435 @:
436
437# Descending
438# ---------------------------------------------------------------------------
439
440PHONY += $(subdir-ym)
441$(subdir-ym):
442 $(Q)$(MAKE) $(build)=$@ \
443 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
444 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
445 $(filter $@/%, $(single-subdir-goals))
446
447# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
448# ---------------------------------------------------------------------------
449
450PHONY += FORCE
451
452FORCE:
453
454targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
455targets := $(filter-out $(PHONY), $(targets))
456
457# Read all saved command lines and dependencies for the $(targets) we
458# may be building above, using $(if_changed{,_dep}). As an
459# optimization, we don't need to read them if the target does not
460# exist, we will rebuild anyway in that case.
461
462existing-targets := $(wildcard $(sort $(targets)))
463
464-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
465
466# Create directories for object files if they do not exist
467obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
468# If targets exist, their directories apparently exist. Skip mkdir.
469existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
470obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
471ifneq ($(obj-dirs),)
472$(shell mkdir -p $(obj-dirs))
473endif
474
475.PHONY: $(PHONY)
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# The filename Kbuild has precedence over Makefile
40kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
41kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
42include $(kbuild-file)
43
44include scripts/Makefile.lib
45
46# Do not include host rules unless needed
47ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
48include scripts/Makefile.host
49endif
50
51ifndef obj
52$(warning kbuild: Makefile.build is included improperly)
53endif
54
55ifeq ($(need-modorder),)
56ifneq ($(obj-m),)
57$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
58$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
59endif
60endif
61
62# ===========================================================================
63
64ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
65lib-target := $(obj)/lib.a
66real-obj-y += $(obj)/lib-ksyms.o
67endif
68
69ifneq ($(strip $(real-obj-y) $(need-builtin)),)
70builtin-target := $(obj)/built-in.a
71endif
72
73ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
74modorder-target := $(obj)/modules.order
75endif
76
77mod-targets := $(patsubst %.o, %.mod, $(obj-m))
78
79# Linus' kernel sanity checking tool
80ifeq ($(KBUILD_CHECKSRC),1)
81 quiet_cmd_checksrc = CHECK $<
82 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
83else ifeq ($(KBUILD_CHECKSRC),2)
84 quiet_cmd_force_checksrc = CHECK $<
85 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
86endif
87
88ifneq ($(KBUILD_EXTRA_WARN),)
89 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
90endif
91
92# Compile C sources (.c)
93# ---------------------------------------------------------------------------
94
95quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
96 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
97
98$(obj)/%.s: $(src)/%.c FORCE
99 $(call if_changed_dep,cc_s_c)
100
101quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
102cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
103
104$(obj)/%.i: $(src)/%.c FORCE
105 $(call if_changed_dep,cpp_i_c)
106
107# These mirror gensymtypes_S and co below, keep them in synch.
108cmd_gensymtypes_c = \
109 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
110 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
111 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
112 $(if $(KBUILD_PRESERVE),-p) \
113 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
114
115quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
116cmd_cc_symtypes_c = \
117 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
118 test -s $@ || rm -f $@
119
120$(obj)/%.symtypes : $(src)/%.c FORCE
121 $(call cmd,cc_symtypes_c)
122
123# LLVM assembly
124# Generate .ll files from .c
125quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
126 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
127
128$(obj)/%.ll: $(src)/%.c FORCE
129 $(call if_changed_dep,cc_ll_c)
130
131# C (.c) files
132# The C file is compiled and updated dependency information is generated.
133# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
134
135quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
136 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
137
138ifdef CONFIG_MODVERSIONS
139# When module versioning is enabled the following steps are executed:
140# o compile a <file>.o from <file>.c
141# o if <file>.o doesn't contain a __ksymtab version, i.e. does
142# not export symbols, it's done.
143# o otherwise, we calculate symbol versions using the good old
144# genksyms on the preprocessed source and postprocess them in a way
145# that they are usable as a linker script
146# o generate .tmp_<file>.o from <file>.o using the linker to
147# replace the unresolved symbols __crc_exported_symbol with
148# the actual value of the checksum generated by genksyms
149# o remove .tmp_<file>.o to <file>.o
150
151cmd_modversions_c = \
152 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
153 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
154 > $(@D)/.tmp_$(@F:.o=.ver); \
155 \
156 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
157 -T $(@D)/.tmp_$(@F:.o=.ver); \
158 mv -f $(@D)/.tmp_$(@F) $@; \
159 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
160 fi
161endif
162
163ifdef CONFIG_FTRACE_MCOUNT_RECORD
164ifndef CC_USING_RECORD_MCOUNT
165# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
166ifdef BUILD_C_RECORDMCOUNT
167ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
168 RECORDMCOUNT_FLAGS = -w
169endif
170# Due to recursion, we must skip empty.o.
171# The empty.o file is created in the make process in order to determine
172# the target endianness and word size. It is made before all other C
173# files, including recordmcount.
174sub_cmd_record_mcount = \
175 if [ $(@) != "scripts/mod/empty.o" ]; then \
176 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
177 fi;
178recordmcount_source := $(srctree)/scripts/recordmcount.c \
179 $(srctree)/scripts/recordmcount.h
180else
181sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
182 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
183 "$(if $(CONFIG_64BIT),64,32)" \
184 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
185 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
186 "$(if $(part-of-module),1,0)" "$(@)";
187recordmcount_source := $(srctree)/scripts/recordmcount.pl
188endif # BUILD_C_RECORDMCOUNT
189cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
190 $(sub_cmd_record_mcount))
191endif # CC_USING_RECORD_MCOUNT
192endif # CONFIG_FTRACE_MCOUNT_RECORD
193
194ifdef CONFIG_STACK_VALIDATION
195ifneq ($(SKIP_STACK_VALIDATION),1)
196
197__objtool_obj := $(objtree)/tools/objtool/objtool
198
199objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
200
201objtool_args += $(if $(part-of-module), --module,)
202
203ifndef CONFIG_FRAME_POINTER
204objtool_args += --no-fp
205endif
206ifdef CONFIG_GCOV_KERNEL
207objtool_args += --no-unreachable
208endif
209ifdef CONFIG_RETPOLINE
210 objtool_args += --retpoline
211endif
212ifdef CONFIG_X86_SMAP
213 objtool_args += --uaccess
214endif
215
216# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
217# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
218# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
219cmd_objtool = $(if $(patsubst y%,, \
220 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
221 $(__objtool_obj) $(objtool_args) $@)
222objtool_obj = $(if $(patsubst y%,, \
223 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
224 $(__objtool_obj))
225
226endif # SKIP_STACK_VALIDATION
227endif # CONFIG_STACK_VALIDATION
228
229# Rebuild all objects when objtool changes, or is enabled/disabled.
230objtool_dep = $(objtool_obj) \
231 $(wildcard include/config/orc/unwinder.h \
232 include/config/stack/validation.h)
233
234ifdef CONFIG_TRIM_UNUSED_KSYMS
235cmd_gen_ksymdeps = \
236 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
237endif
238
239define rule_cc_o_c
240 $(call cmd,checksrc)
241 $(call cmd_and_fixdep,cc_o_c)
242 $(call cmd,gen_ksymdeps)
243 $(call cmd,checkdoc)
244 $(call cmd,objtool)
245 $(call cmd,modversions_c)
246 $(call cmd,record_mcount)
247endef
248
249define rule_as_o_S
250 $(call cmd_and_fixdep,as_o_S)
251 $(call cmd,gen_ksymdeps)
252 $(call cmd,objtool)
253 $(call cmd,modversions_S)
254endef
255
256# List module undefined symbols (or empty line if not enabled)
257ifdef CONFIG_TRIM_UNUSED_KSYMS
258cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | xargs echo
259else
260cmd_undef_syms = echo
261endif
262
263# Built-in and composite module parts
264$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
265 $(call cmd,force_checksrc)
266 $(call if_changed_rule,cc_o_c)
267
268cmd_mod = { \
269 echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
270 $(cmd_undef_syms); \
271 } > $@
272
273$(obj)/%.mod: $(obj)/%.o FORCE
274 $(call if_changed,mod)
275
276targets += $(mod-targets)
277
278quiet_cmd_cc_lst_c = MKLST $@
279 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
280 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
281 System.map $(OBJDUMP) > $@
282
283$(obj)/%.lst: $(src)/%.c FORCE
284 $(call if_changed_dep,cc_lst_c)
285
286# header test (header-test-y, header-test-m target)
287# ---------------------------------------------------------------------------
288
289quiet_cmd_cc_s_h = CC $@
290 cmd_cc_s_h = $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $<
291
292$(obj)/%.h.s: $(src)/%.h FORCE
293 $(call if_changed_dep,cc_s_h)
294
295# Compile assembler sources (.S)
296# ---------------------------------------------------------------------------
297
298# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
299# or a file that it includes, in order to get versioned symbols. We build a
300# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
301# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
302#
303# This is convoluted. The .S file must first be preprocessed to run guards and
304# expand names, then the resulting exports must be constructed into plain
305# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
306# to make the genksyms input.
307#
308# These mirror gensymtypes_c and co above, keep them in synch.
309cmd_gensymtypes_S = \
310 { echo "\#include <linux/kernel.h>" ; \
311 echo "\#include <asm/asm-prototypes.h>" ; \
312 $(CPP) $(a_flags) $< | \
313 grep "\<___EXPORT_SYMBOL\>" | \
314 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
315 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
316 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
317 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
318 $(if $(KBUILD_PRESERVE),-p) \
319 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
320
321quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
322cmd_cc_symtypes_S = \
323 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
324 test -s $@ || rm -f $@
325
326$(obj)/%.symtypes : $(src)/%.S FORCE
327 $(call cmd,cc_symtypes_S)
328
329
330quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
331cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
332
333$(obj)/%.s: $(src)/%.S FORCE
334 $(call if_changed_dep,cpp_s_S)
335
336quiet_cmd_as_o_S = AS $(quiet_modtag) $@
337 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
338
339ifdef CONFIG_ASM_MODVERSIONS
340
341# versioning matches the C process described above, with difference that
342# we parse asm-prototypes.h C header to get function definitions.
343
344cmd_modversions_S = \
345 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
346 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
347 > $(@D)/.tmp_$(@F:.o=.ver); \
348 \
349 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
350 -T $(@D)/.tmp_$(@F:.o=.ver); \
351 mv -f $(@D)/.tmp_$(@F) $@; \
352 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
353 fi
354endif
355
356$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
357 $(call if_changed_rule,as_o_S)
358
359targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
360targets += $(extra-y) $(MAKECMDGOALS) $(always)
361
362# Linker scripts preprocessor (.lds.S -> .lds)
363# ---------------------------------------------------------------------------
364quiet_cmd_cpp_lds_S = LDS $@
365 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
366 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
367
368$(obj)/%.lds: $(src)/%.lds.S FORCE
369 $(call if_changed_dep,cpp_lds_S)
370
371# ASN.1 grammar
372# ---------------------------------------------------------------------------
373quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
374 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
375 $(basename $@).c $(basename $@).h
376
377$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
378 $(call cmd,asn1_compiler)
379
380# Build the compiled-in targets
381# ---------------------------------------------------------------------------
382
383# To build objects in subdirs, we need to descend into the directories
384$(sort $(subdir-obj-y)): $(subdir-ym) ;
385
386#
387# Rule to compile a set of .o files into one .a file (without symbol table)
388#
389ifdef builtin-target
390
391quiet_cmd_ar_builtin = AR $@
392 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
393
394$(builtin-target): $(real-obj-y) FORCE
395 $(call if_changed,ar_builtin)
396
397targets += $(builtin-target)
398endif # builtin-target
399
400#
401# Rule to create modules.order file
402#
403# Create commands to either record .ko file or cat modules.order from
404# a subdirectory
405$(modorder-target): $(subdir-ym) FORCE
406 $(Q){ $(foreach m, $(modorder), \
407 $(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
408 | $(AWK) '!x[$$0]++' - > $@
409
410#
411# Rule to compile a set of .o files into one .a file (with symbol table)
412#
413ifdef lib-target
414
415$(lib-target): $(lib-y) FORCE
416 $(call if_changed,ar)
417
418targets += $(lib-target)
419
420dummy-object = $(obj)/.lib_exports.o
421ksyms-lds = $(dot-target).lds
422
423quiet_cmd_export_list = EXPORTS $@
424cmd_export_list = $(OBJDUMP) -h $< | \
425 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/EXTERN(\1)/p' >$(ksyms-lds);\
426 rm -f $(dummy-object);\
427 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
428 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
429 rm $(dummy-object) $(ksyms-lds)
430
431$(obj)/lib-ksyms.o: $(lib-target) FORCE
432 $(call if_changed,export_list)
433
434targets += $(obj)/lib-ksyms.o
435
436endif
437
438# NOTE:
439# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
440# module is turned into a multi object module, $^ will contain header file
441# dependencies recorded in the .*.cmd file.
442quiet_cmd_link_multi-m = LD [M] $@
443 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
444
445$(multi-used-m): FORCE
446 $(call if_changed,link_multi-m)
447$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
448
449targets += $(multi-used-m)
450targets := $(filter-out $(PHONY), $(targets))
451
452# Add intermediate targets:
453# When building objects with specific suffix patterns, add intermediate
454# targets that the final targets are derived from.
455intermediate_targets = $(foreach sfx, $(2), \
456 $(patsubst %$(strip $(1)),%$(sfx), \
457 $(filter %$(strip $(1)), $(targets))))
458# %.asn1.o <- %.asn1.[ch] <- %.asn1
459# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
460# %.lex.o <- %.lex.c <- %.l
461# %.tab.o <- %.tab.[ch] <- %.y
462targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
463 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
464 $(call intermediate_targets, .lex.o, .lex.c) \
465 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
466
467# Build
468# ---------------------------------------------------------------------------
469
470ifdef single-build
471
472curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
473 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
474
475# Handle single targets without any rule: show "Nothing to be done for ..." or
476# "No rule to make target ..." depending on whether the target exists.
477unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
478 $(filter $(obj)/%, \
479 $(filter-out $(curdir-single), \
480 $(KBUILD_SINGLE_TARGETS))))
481
482__build: $(curdir-single) $(subdir-ym)
483ifneq ($(unknown-single),)
484 $(Q)$(MAKE) -f /dev/null $(unknown-single)
485endif
486 @:
487
488ifeq ($(curdir-single),)
489# Nothing to do in this directory. Do not include any .*.cmd file for speed-up
490targets :=
491else
492targets += $(curdir-single)
493endif
494
495else
496
497__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
498 $(if $(KBUILD_MODULES),$(obj-m) $(mod-targets) $(modorder-target)) \
499 $(subdir-ym) $(always)
500 @:
501
502endif
503
504# Descending
505# ---------------------------------------------------------------------------
506
507PHONY += $(subdir-ym)
508$(subdir-ym):
509 $(Q)$(MAKE) $(build)=$@ \
510 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
511 need-builtin=$(if $(filter $@/built-in.a, $(subdir-obj-y)),1) \
512 need-modorder=$(if $(need-modorder),$(if $(filter $@/modules.order, $(modorder)),1))
513
514# Add FORCE to the prequisites of a target to force it to be always rebuilt.
515# ---------------------------------------------------------------------------
516
517PHONY += FORCE
518
519FORCE:
520
521# Read all saved command lines and dependencies for the $(targets) we
522# may be building above, using $(if_changed{,_dep}). As an
523# optimization, we don't need to read them if the target does not
524# exist, we will rebuild anyway in that case.
525
526existing-targets := $(wildcard $(sort $(targets)))
527
528-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
529
530ifdef building_out_of_srctree
531# Create directories for object files if they do not exist
532obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
533# If targets exist, their directories apparently exist. Skip mkdir.
534existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
535obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
536ifneq ($(obj-dirs),)
537$(shell mkdir -p $(obj-dirs))
538endif
539endif
540
541.PHONY: $(PHONY)