xref: /openbmc/linux/scripts/Makefile.build (revision 4f89e4b8) 
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
55# ===========================================================================
56
57ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
58lib-target := $(obj)/lib.a
59real-obj-y += $(obj)/lib-ksyms.o
60endif
61
62ifneq ($(strip $(real-obj-y) $(need-builtin)),)
63builtin-target := $(obj)/built-in.a
64endif
65
66ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
67modorder-target := $(obj)/modules.order
68endif
69
70mod-targets := $(patsubst %.o, %.mod, $(obj-m))
71
72__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
73	 $(if $(KBUILD_MODULES),$(obj-m) $(mod-targets) $(modorder-target)) \
74	 $(subdir-ym) $(always)
75	@:
76
77# Linus' kernel sanity checking tool
78ifeq ($(KBUILD_CHECKSRC),1)
79  quiet_cmd_checksrc       = CHECK   $<
80        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
81else ifeq ($(KBUILD_CHECKSRC),2)
82  quiet_cmd_force_checksrc = CHECK   $<
83        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
84endif
85
86ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
87  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
88endif
89
90# Compile C sources (.c)
91# ---------------------------------------------------------------------------
92
93# Default is built-in, unless we know otherwise
94$(foreach x, i ll lst o s symtypes, $(patsubst %.o,%.$(x),$(real-obj-m))): \
95	part-of-module := y
96
97modkern_cflags =                                          \
98	$(if $(part-of-module),                           \
99		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
100		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
101quiet_modtag = $(if $(part-of-module),[M],   )
102
103quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
104      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
105
106$(obj)/%.s: $(src)/%.c FORCE
107	$(call if_changed_dep,cc_s_c)
108
109quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
110cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
111
112$(obj)/%.i: $(src)/%.c FORCE
113	$(call if_changed_dep,cpp_i_c)
114
115# These mirror gensymtypes_S and co below, keep them in synch.
116cmd_gensymtypes_c =                                                         \
117    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
118    scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
119     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
120     $(if $(KBUILD_PRESERVE),-p)                                            \
121     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
122
123quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
124cmd_cc_symtypes_c =                                                         \
125    $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
126    test -s $@ || rm -f $@
127
128$(obj)/%.symtypes : $(src)/%.c FORCE
129	$(call cmd,cc_symtypes_c)
130
131# LLVM assembly
132# Generate .ll files from .c
133quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
134      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
135
136$(obj)/%.ll: $(src)/%.c FORCE
137	$(call if_changed_dep,cc_ll_c)
138
139# C (.c) files
140# The C file is compiled and updated dependency information is generated.
141# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
142
143quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
144      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
145
146ifdef CONFIG_MODVERSIONS
147# When module versioning is enabled the following steps are executed:
148# o compile a <file>.o from <file>.c
149# o if <file>.o doesn't contain a __ksymtab version, i.e. does
150#   not export symbols, it's done.
151# o otherwise, we calculate symbol versions using the good old
152#   genksyms on the preprocessed source and postprocess them in a way
153#   that they are usable as a linker script
154# o generate .tmp_<file>.o from <file>.o using the linker to
155#   replace the unresolved symbols __crc_exported_symbol with
156#   the actual value of the checksum generated by genksyms
157# o remove .tmp_<file>.o to <file>.o
158
159cmd_modversions_c =								\
160	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
161		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
162		    > $(@D)/.tmp_$(@F:.o=.ver);					\
163										\
164		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
165			-T $(@D)/.tmp_$(@F:.o=.ver);				\
166		mv -f $(@D)/.tmp_$(@F) $@;					\
167		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
168	fi
169endif
170
171ifdef CONFIG_FTRACE_MCOUNT_RECORD
172ifndef CC_USING_RECORD_MCOUNT
173# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
174ifdef BUILD_C_RECORDMCOUNT
175ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
176  RECORDMCOUNT_FLAGS = -w
177endif
178# Due to recursion, we must skip empty.o.
179# The empty.o file is created in the make process in order to determine
180# the target endianness and word size. It is made before all other C
181# files, including recordmcount.
182sub_cmd_record_mcount =					\
183	if [ $(@) != "scripts/mod/empty.o" ]; then	\
184		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
185	fi;
186recordmcount_source := $(srctree)/scripts/recordmcount.c \
187		    $(srctree)/scripts/recordmcount.h
188else
189sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
190	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
191	"$(if $(CONFIG_64BIT),64,32)" \
192	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
193	"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
194	"$(if $(part-of-module),1,0)" "$(@)";
195recordmcount_source := $(srctree)/scripts/recordmcount.pl
196endif # BUILD_C_RECORDMCOUNT
197cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\
198	$(sub_cmd_record_mcount))
199endif # CC_USING_RECORD_MCOUNT
200endif # CONFIG_FTRACE_MCOUNT_RECORD
201
202ifdef CONFIG_STACK_VALIDATION
203ifneq ($(SKIP_STACK_VALIDATION),1)
204
205__objtool_obj := $(objtree)/tools/objtool/objtool
206
207objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
208
209objtool_args += $(if $(part-of-module), --module,)
210
211ifndef CONFIG_FRAME_POINTER
212objtool_args += --no-fp
213endif
214ifdef CONFIG_GCOV_KERNEL
215objtool_args += --no-unreachable
216endif
217ifdef CONFIG_RETPOLINE
218  objtool_args += --retpoline
219endif
220ifdef CONFIG_X86_SMAP
221  objtool_args += --uaccess
222endif
223
224# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
225# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
226# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
227cmd_objtool = $(if $(patsubst y%,, \
228	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
229	$(__objtool_obj) $(objtool_args) $@)
230objtool_obj = $(if $(patsubst y%,, \
231	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
232	$(__objtool_obj))
233
234endif # SKIP_STACK_VALIDATION
235endif # CONFIG_STACK_VALIDATION
236
237# Rebuild all objects when objtool changes, or is enabled/disabled.
238objtool_dep = $(objtool_obj)					\
239	      $(wildcard include/config/orc/unwinder.h		\
240			 include/config/stack/validation.h)
241
242ifdef CONFIG_TRIM_UNUSED_KSYMS
243cmd_gen_ksymdeps = \
244	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
245endif
246
247define rule_cc_o_c
248	$(call cmd,checksrc)
249	$(call cmd_and_fixdep,cc_o_c)
250	$(call cmd,gen_ksymdeps)
251	$(call cmd,checkdoc)
252	$(call cmd,objtool)
253	$(call cmd,modversions_c)
254	$(call cmd,record_mcount)
255endef
256
257define rule_as_o_S
258	$(call cmd_and_fixdep,as_o_S)
259	$(call cmd,gen_ksymdeps)
260	$(call cmd,objtool)
261	$(call cmd,modversions_S)
262endef
263
264# List module undefined symbols (or empty line if not enabled)
265ifdef CONFIG_TRIM_UNUSED_KSYMS
266cmd_undef_syms = $(NM) $< | sed -n 's/^  *U //p' | xargs echo
267else
268cmd_undef_syms = echo
269endif
270
271# Built-in and composite module parts
272$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
273	$(call cmd,force_checksrc)
274	$(call if_changed_rule,cc_o_c)
275
276cmd_mod = { \
277	echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
278	$(cmd_undef_syms); \
279	} > $@
280
281$(obj)/%.mod: $(obj)/%.o FORCE
282	$(call if_changed,mod)
283
284targets += $(mod-targets)
285
286quiet_cmd_cc_lst_c = MKLST   $@
287      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
288		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
289				     System.map $(OBJDUMP) > $@
290
291$(obj)/%.lst: $(src)/%.c FORCE
292	$(call if_changed_dep,cc_lst_c)
293
294# header test (header-test-y, header-test-m target)
295# ---------------------------------------------------------------------------
296
297quiet_cmd_cc_s_h = CC      $@
298      cmd_cc_s_h = $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $<
299
300$(obj)/%.h.s: $(src)/%.h FORCE
301	$(call if_changed_dep,cc_s_h)
302
303# Compile assembler sources (.S)
304# ---------------------------------------------------------------------------
305
306modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
307
308$(real-obj-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
309$(real-obj-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
310
311# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
312# or a file that it includes, in order to get versioned symbols. We build a
313# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
314# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
315#
316# This is convoluted. The .S file must first be preprocessed to run guards and
317# expand names, then the resulting exports must be constructed into plain
318# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
319# to make the genksyms input.
320#
321# These mirror gensymtypes_c and co above, keep them in synch.
322cmd_gensymtypes_S =                                                         \
323   { echo "\#include <linux/kernel.h>" ;                                    \
324     echo "\#include <asm/asm-prototypes.h>" ;                              \
325    $(CPP) $(a_flags) $< |                                                  \
326     grep "\<___EXPORT_SYMBOL\>" |                                          \
327     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
328    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
329    scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
330     $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
331     $(if $(KBUILD_PRESERVE),-p)                                            \
332     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
333
334quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
335cmd_cc_symtypes_S =                                                         \
336    $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
337    test -s $@ || rm -f $@
338
339$(obj)/%.symtypes : $(src)/%.S FORCE
340	$(call cmd,cc_symtypes_S)
341
342
343quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
344cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
345
346$(obj)/%.s: $(src)/%.S FORCE
347	$(call if_changed_dep,cpp_s_S)
348
349quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
350      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
351
352ifdef CONFIG_MODVERSIONS
353
354ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
355
356ifneq ($(ASM_PROTOTYPES),)
357
358# versioning matches the C process described above, with difference that
359# we parse asm-prototypes.h C header to get function definitions.
360
361cmd_modversions_S =								\
362	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
363		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
364		    > $(@D)/.tmp_$(@F:.o=.ver);					\
365										\
366		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
367			-T $(@D)/.tmp_$(@F:.o=.ver);				\
368		mv -f $(@D)/.tmp_$(@F) $@;					\
369		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
370	fi
371endif
372endif
373
374$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
375	$(call if_changed_rule,as_o_S)
376
377targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
378targets += $(extra-y) $(MAKECMDGOALS) $(always)
379
380# Linker scripts preprocessor (.lds.S -> .lds)
381# ---------------------------------------------------------------------------
382quiet_cmd_cpp_lds_S = LDS     $@
383      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
384	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
385
386$(obj)/%.lds: $(src)/%.lds.S FORCE
387	$(call if_changed_dep,cpp_lds_S)
388
389# ASN.1 grammar
390# ---------------------------------------------------------------------------
391quiet_cmd_asn1_compiler = ASN.1   $@
392      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
393				$(subst .h,.c,$@) $(subst .c,.h,$@)
394
395$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
396	$(call cmd,asn1_compiler)
397
398# Build the compiled-in targets
399# ---------------------------------------------------------------------------
400
401# To build objects in subdirs, we need to descend into the directories
402$(sort $(subdir-obj-y)): $(subdir-ym) ;
403
404#
405# Rule to compile a set of .o files into one .a file (without symbol table)
406#
407ifdef builtin-target
408
409quiet_cmd_ar_builtin = AR      $@
410      cmd_ar_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)
411
412$(builtin-target): $(real-obj-y) FORCE
413	$(call if_changed,ar_builtin)
414
415targets += $(builtin-target)
416endif # builtin-target
417
418#
419# Rule to create modules.order file
420#
421# Create commands to either record .ko file or cat modules.order from
422# a subdirectory
423$(modorder-target): $(subdir-ym) FORCE
424	$(Q){ $(foreach m, $(modorder), \
425	$(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
426	| $(AWK) '!x[$$0]++' - > $@
427
428#
429# Rule to compile a set of .o files into one .a file (with symbol table)
430#
431ifdef lib-target
432
433$(lib-target): $(lib-y) FORCE
434	$(call if_changed,ar)
435
436targets += $(lib-target)
437
438dummy-object = $(obj)/.lib_exports.o
439ksyms-lds = $(dot-target).lds
440
441quiet_cmd_export_list = EXPORTS $@
442cmd_export_list = $(OBJDUMP) -h $< | \
443	sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/EXTERN(\1)/p' >$(ksyms-lds);\
444	rm -f $(dummy-object);\
445	echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
446	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
447	rm $(dummy-object) $(ksyms-lds)
448
449$(obj)/lib-ksyms.o: $(lib-target) FORCE
450	$(call if_changed,export_list)
451
452targets += $(obj)/lib-ksyms.o
453
454endif
455
456# NOTE:
457# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
458# module is turned into a multi object module, $^ will contain header file
459# dependencies recorded in the .*.cmd file.
460quiet_cmd_link_multi-m = LD [M]  $@
461      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
462
463$(multi-used-m): FORCE
464	$(call if_changed,link_multi-m)
465$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
466
467targets += $(multi-used-m)
468targets := $(filter-out $(PHONY), $(targets))
469
470# Add intermediate targets:
471# When building objects with specific suffix patterns, add intermediate
472# targets that the final targets are derived from.
473intermediate_targets = $(foreach sfx, $(2), \
474				$(patsubst %$(strip $(1)),%$(sfx), \
475					$(filter %$(strip $(1)), $(targets))))
476# %.asn1.o <- %.asn1.[ch] <- %.asn1
477# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
478# %.lex.o <- %.lex.c <- %.l
479# %.tab.o <- %.tab.[ch] <- %.y
480targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
481	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
482	   $(call intermediate_targets, .lex.o, .lex.c) \
483	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)
484
485# Descending
486# ---------------------------------------------------------------------------
487
488PHONY += $(subdir-ym)
489$(subdir-ym):
490	$(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
491
492# Add FORCE to the prequisites of a target to force it to be always rebuilt.
493# ---------------------------------------------------------------------------
494
495PHONY += FORCE
496
497FORCE:
498
499# Read all saved command lines and dependencies for the $(targets) we
500# may be building above, using $(if_changed{,_dep}). As an
501# optimization, we don't need to read them if the target does not
502# exist, we will rebuild anyway in that case.
503
504existing-targets := $(wildcard $(sort $(targets)))
505
506-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
507
508ifdef building_out_of_srctree
509# Create directories for object files if they do not exist
510obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
511# If targets exist, their directories apparently exist. Skip mkdir.
512existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
513obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
514ifneq ($(obj-dirs),)
515$(shell mkdir -p $(obj-dirs))
516endif
517endif
518
519.PHONY: $(PHONY)
520