xref: /openbmc/linux/scripts/Makefile.build (revision a44e4f3a) 
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)
542