xref: /openbmc/linux/scripts/Makefile.build (revision f5c27da4) 
1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(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 include/config/auto.conf
38
39include $(srctree)/scripts/Kbuild.include
40include $(srctree)/scripts/Makefile.compiler
41
42# The filename Kbuild has precedence over Makefile
43kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
44include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
45
46include $(srctree)/scripts/Makefile.lib
47
48# Do not include hostprogs rules unless needed.
49# $(sort ...) is used here to remove duplicated words and excessive spaces.
50hostprogs := $(sort $(hostprogs))
51ifneq ($(hostprogs),)
52include $(srctree)/scripts/Makefile.host
53endif
54
55# Do not include userprogs rules unless needed.
56# $(sort ...) is used here to remove duplicated words and excessive spaces.
57userprogs := $(sort $(userprogs))
58ifneq ($(userprogs),)
59include $(srctree)/scripts/Makefile.userprogs
60endif
61
62ifndef obj
63$(warning kbuild: Makefile.build is included improperly)
64endif
65
66ifeq ($(need-modorder),)
67ifneq ($(obj-m),)
68$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
69$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
70endif
71endif
72
73# ===========================================================================
74
75# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
76subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
77subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
78
79targets-for-builtin := $(extra-y)
80
81ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
82targets-for-builtin += $(obj)/lib.a
83endif
84
85ifdef need-builtin
86targets-for-builtin += $(obj)/built-in.a
87endif
88
89targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
90				$(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
91
92ifdef need-modorder
93targets-for-modules += $(obj)/modules.order
94endif
95
96targets += $(targets-for-builtin) $(targets-for-modules)
97
98# Linus' kernel sanity checking tool
99ifeq ($(KBUILD_CHECKSRC),1)
100  quiet_cmd_checksrc       = CHECK   $<
101        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
102else ifeq ($(KBUILD_CHECKSRC),2)
103  quiet_cmd_force_checksrc = CHECK   $<
104        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
105endif
106
107ifneq ($(KBUILD_EXTRA_WARN),)
108  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
109endif
110
111# Compile C sources (.c)
112# ---------------------------------------------------------------------------
113
114quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
115      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
116
117$(obj)/%.s: $(src)/%.c FORCE
118	$(call if_changed_dep,cc_s_c)
119
120quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
121cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
122
123$(obj)/%.i: $(src)/%.c FORCE
124	$(call if_changed_dep,cpp_i_c)
125
126genksyms = scripts/genksyms/genksyms		\
127	$(if $(1), -T $(2))			\
128	$(if $(KBUILD_PRESERVE), -p)		\
129	-r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
130
131# These mirror gensymtypes_S and co below, keep them in synch.
132cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
133
134quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
135      cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
136
137$(obj)/%.symtypes : $(src)/%.c FORCE
138	$(call cmd,cc_symtypes_c)
139
140# LLVM assembly
141# Generate .ll files from .c
142quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
143      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
144
145$(obj)/%.ll: $(src)/%.c FORCE
146	$(call if_changed_dep,cc_ll_c)
147
148# C (.c) files
149# The C file is compiled and updated dependency information is generated.
150# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
151
152is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
153
154# When a module consists of a single object, there is no reason to keep LLVM IR.
155# Make $(LD) covert LLVM IR to ELF here.
156ifdef CONFIG_LTO_CLANG
157cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
158endif
159
160quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
161      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
162		$(cmd_ld_single_m) \
163		$(cmd_objtool)
164
165ifdef CONFIG_MODVERSIONS
166# When module versioning is enabled the following steps are executed:
167# o compile a <file>.o from <file>.c
168# o if <file>.o doesn't contain a __ksymtab version, i.e. does
169#   not export symbols, it's done.
170# o otherwise, we calculate symbol versions using the good old
171#   genksyms on the preprocessed source and dump them into the .cmd file.
172# o modpost will extract versions from that file and create *.c files that will
173#   be compiled and linked to the kernel and/or modules.
174
175gen_symversions =								\
176	if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then			\
177		$(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
178			>> $(dot-target).cmd;					\
179	fi
180
181cmd_gen_symversions_c =	$(call gen_symversions,c)
182
183endif
184
185ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
186# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
187ifdef BUILD_C_RECORDMCOUNT
188ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
189  RECORDMCOUNT_FLAGS = -w
190endif
191# Due to recursion, we must skip empty.o.
192# The empty.o file is created in the make process in order to determine
193# the target endianness and word size. It is made before all other C
194# files, including recordmcount.
195sub_cmd_record_mcount =					\
196	if [ $(@) != "scripts/mod/empty.o" ]; then	\
197		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
198	fi;
199recordmcount_source := $(srctree)/scripts/recordmcount.c \
200		    $(srctree)/scripts/recordmcount.h
201else
202sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
203	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
204	"$(if $(CONFIG_64BIT),64,32)" \
205	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
206	"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
207	"$(if $(part-of-module),1,0)" "$(@)";
208recordmcount_source := $(srctree)/scripts/recordmcount.pl
209endif # BUILD_C_RECORDMCOUNT
210cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\
211	$(sub_cmd_record_mcount))
212endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
213
214# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
215# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
216# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
217
218is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
219
220$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
221
222ifdef CONFIG_TRIM_UNUSED_KSYMS
223cmd_gen_ksymdeps = \
224	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
225endif
226
227cmd_check_local_export = $(srctree)/scripts/check-local-export $@
228
229define rule_cc_o_c
230	$(call cmd_and_fixdep,cc_o_c)
231	$(call cmd,gen_ksymdeps)
232	$(call cmd,check_local_export)
233	$(call cmd,checksrc)
234	$(call cmd,checkdoc)
235	$(call cmd,gen_objtooldep)
236	$(call cmd,gen_symversions_c)
237	$(call cmd,record_mcount)
238endef
239
240define rule_as_o_S
241	$(call cmd_and_fixdep,as_o_S)
242	$(call cmd,gen_ksymdeps)
243	$(call cmd,check_local_export)
244	$(call cmd,gen_objtooldep)
245	$(call cmd,gen_symversions_S)
246endef
247
248# Built-in and composite module parts
249$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
250	$(call if_changed_rule,cc_o_c)
251	$(call cmd,force_checksrc)
252
253# To make this rule robust against "Argument list too long" error,
254# ensure to add $(obj)/ prefix by a shell command.
255cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
256	$(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
257
258$(obj)/%.mod: FORCE
259	$(call if_changed,mod)
260
261# List module undefined symbols
262cmd_undefined_syms = $(NM) $< | sed -n 's/^  *U //p' > $@
263
264$(obj)/%.usyms: $(obj)/%.o FORCE
265	$(call if_changed,undefined_syms)
266
267quiet_cmd_cc_lst_c = MKLST   $@
268      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
269		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
270				     System.map $(OBJDUMP) > $@
271
272$(obj)/%.lst: $(src)/%.c FORCE
273	$(call if_changed_dep,cc_lst_c)
274
275# Compile Rust sources (.rs)
276# ---------------------------------------------------------------------------
277
278rust_allowed_features := core_ffi_c
279
280rust_common_cmd = \
281	RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
282	-Zallow-features=$(rust_allowed_features) \
283	-Zcrate-attr=no_std \
284	-Zcrate-attr='feature($(rust_allowed_features))' \
285	--extern alloc --extern kernel \
286	--crate-type rlib --out-dir $(obj) -L $(objtree)/rust/ \
287	--crate-name $(basename $(notdir $@))
288
289rust_handle_depfile = \
290	mv $(obj)/$(basename $(notdir $@)).d $(depfile); \
291	sed -i '/^\#/d' $(depfile)
292
293# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
294# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
295# the compiler shows a warning if it is not 1. However, if we ever stop
296# requesting it explicitly and we start using some other `--emit` that does not
297# imply it (and for which codegen is performed), then we would be out of sync,
298# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
299# would not match each other.
300
301quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
302      cmd_rustc_o_rs = \
303	$(rust_common_cmd) --emit=dep-info,obj $<; \
304	$(rust_handle_depfile)
305
306$(obj)/%.o: $(src)/%.rs FORCE
307	$(call if_changed_dep,rustc_o_rs)
308
309quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
310      cmd_rustc_rsi_rs = \
311	$(rust_common_cmd) --emit=dep-info -Zunpretty=expanded $< >$@; \
312	command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@; \
313	$(rust_handle_depfile)
314
315$(obj)/%.rsi: $(src)/%.rs FORCE
316	$(call if_changed_dep,rustc_rsi_rs)
317
318quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
319      cmd_rustc_s_rs = \
320	$(rust_common_cmd) --emit=dep-info,asm $<; \
321	$(rust_handle_depfile)
322
323$(obj)/%.s: $(src)/%.rs FORCE
324	$(call if_changed_dep,rustc_s_rs)
325
326quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
327      cmd_rustc_ll_rs = \
328	$(rust_common_cmd) --emit=dep-info,llvm-ir $<; \
329	$(rust_handle_depfile)
330
331$(obj)/%.ll: $(src)/%.rs FORCE
332	$(call if_changed_dep,rustc_ll_rs)
333
334# Compile assembler sources (.S)
335# ---------------------------------------------------------------------------
336
337# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
338# or a file that it includes, in order to get versioned symbols. We build a
339# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
340# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
341#
342# This is convoluted. The .S file must first be preprocessed to run guards and
343# expand names, then the resulting exports must be constructed into plain
344# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
345# to make the genksyms input.
346#
347# These mirror gensymtypes_c and co above, keep them in synch.
348cmd_gensymtypes_S =                                                         \
349   { echo "\#include <linux/kernel.h>" ;                                    \
350     echo "\#include <asm/asm-prototypes.h>" ;                              \
351    $(CPP) $(a_flags) $< |                                                  \
352     grep "\<___EXPORT_SYMBOL\>" |                                          \
353     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
354    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
355
356quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
357      cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
358
359$(obj)/%.symtypes : $(src)/%.S FORCE
360	$(call cmd,cc_symtypes_S)
361
362
363quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
364cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
365
366$(obj)/%.s: $(src)/%.S FORCE
367	$(call if_changed_dep,cpp_s_S)
368
369quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
370      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
371
372ifdef CONFIG_ASM_MODVERSIONS
373
374# versioning matches the C process described above, with difference that
375# we parse asm-prototypes.h C header to get function definitions.
376
377cmd_gen_symversions_S = $(call gen_symversions,S)
378
379endif
380
381$(obj)/%.o: $(src)/%.S FORCE
382	$(call if_changed_rule,as_o_S)
383
384targets += $(filter-out $(subdir-builtin), $(real-obj-y))
385targets += $(filter-out $(subdir-modorder), $(real-obj-m))
386targets += $(real-dtb-y) $(lib-y) $(always-y)
387
388# Linker scripts preprocessor (.lds.S -> .lds)
389# ---------------------------------------------------------------------------
390quiet_cmd_cpp_lds_S = LDS     $@
391      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
392	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
393
394$(obj)/%.lds: $(src)/%.lds.S FORCE
395	$(call if_changed_dep,cpp_lds_S)
396
397# ASN.1 grammar
398# ---------------------------------------------------------------------------
399quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
400      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
401				$(basename $@).c $(basename $@).h
402
403$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
404	$(call cmd,asn1_compiler)
405
406# Build the compiled-in targets
407# ---------------------------------------------------------------------------
408
409# To build objects in subdirs, we need to descend into the directories
410$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
411$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
412
413#
414# Rule to compile a set of .o files into one .a file (without symbol table)
415#
416# To make this rule robust against "Argument list too long" error,
417# remove $(obj)/ prefix, and restore it by a shell command.
418
419quiet_cmd_ar_builtin = AR      $@
420      cmd_ar_builtin = rm -f $@; \
421	$(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
422	$(AR) cDPrST $@
423
424$(obj)/built-in.a: $(real-obj-y) FORCE
425	$(call if_changed,ar_builtin)
426
427#
428# Rule to create modules.order file
429#
430# Create commands to either record .ko file or cat modules.order from
431# a subdirectory
432# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
433# modules.order unless contained modules are updated.
434
435cmd_modules_order = { $(foreach m, $(real-prereqs), \
436	$(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
437	> $@
438
439$(obj)/modules.order: $(obj-m) FORCE
440	$(call if_changed,modules_order)
441
442#
443# Rule to compile a set of .o files into one .a file (with symbol table)
444#
445
446$(obj)/lib.a: $(lib-y) FORCE
447	$(call if_changed,ar)
448
449quiet_cmd_ld_multi_m = LD [M]  $@
450      cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
451
452define rule_ld_multi_m
453	$(call cmd_and_savecmd,ld_multi_m)
454	$(call cmd,gen_objtooldep)
455endef
456
457$(multi-obj-m): objtool-enabled := $(delay-objtool)
458$(multi-obj-m): part-of-module := y
459$(multi-obj-m): %.o: %.mod FORCE
460	$(call if_changed_rule,ld_multi_m)
461$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
462
463# Add intermediate targets:
464# When building objects with specific suffix patterns, add intermediate
465# targets that the final targets are derived from.
466intermediate_targets = $(foreach sfx, $(2), \
467				$(patsubst %$(strip $(1)),%$(sfx), \
468					$(filter %$(strip $(1)), $(targets))))
469# %.asn1.o <- %.asn1.[ch] <- %.asn1
470# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
471# %.lex.o <- %.lex.c <- %.l
472# %.tab.o <- %.tab.[ch] <- %.y
473targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
474	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
475	   $(call intermediate_targets, .lex.o, .lex.c) \
476	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)
477
478# Build
479# ---------------------------------------------------------------------------
480
481$(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
482	 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
483	 $(subdir-ym) $(always-y)
484	@:
485
486# Single targets
487# ---------------------------------------------------------------------------
488
489single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
490single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
491
492$(single-subdir-goals): $(single-subdirs)
493	@:
494
495# Descending
496# ---------------------------------------------------------------------------
497
498PHONY += $(subdir-ym)
499$(subdir-ym):
500	$(Q)$(MAKE) $(build)=$@ \
501	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
502	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
503	$(filter $@/%, $(single-subdir-goals))
504
505# Add FORCE to the prequisites of a target to force it to be always rebuilt.
506# ---------------------------------------------------------------------------
507
508PHONY += FORCE
509
510FORCE:
511
512targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
513targets := $(filter-out $(PHONY), $(targets))
514
515# Read all saved command lines and dependencies for the $(targets) we
516# may be building above, using $(if_changed{,_dep}). As an
517# optimization, we don't need to read them if the target does not
518# exist, we will rebuild anyway in that case.
519
520existing-targets := $(wildcard $(sort $(targets)))
521
522-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
523
524# Create directories for object files if they do not exist
525obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
526# If targets exist, their directories apparently exist. Skip mkdir.
527existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
528obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
529ifneq ($(obj-dirs),)
530$(shell mkdir -p $(obj-dirs))
531endif
532
533.PHONY: $(PHONY)
534