xref: /openbmc/linux/scripts/Makefile.build (revision db30dc1a)
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-y :=
19always-m :=
20targets :=
21subdir-y :=
22subdir-m :=
23EXTRA_AFLAGS   :=
24EXTRA_CFLAGS   :=
25EXTRA_CPPFLAGS :=
26EXTRA_LDFLAGS  :=
27asflags-y  :=
28ccflags-y  :=
29cppflags-y :=
30ldflags-y  :=
31
32subdir-asflags-y :=
33subdir-ccflags-y :=
34
35# Read auto.conf if it exists, otherwise ignore
36-include include/config/auto.conf
37
38include $(srctree)/scripts/Kbuild.include
39include $(srctree)/scripts/Makefile.compiler
40
41# The filename Kbuild has precedence over Makefile
42kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
44
45include $(srctree)/scripts/Makefile.lib
46
47# Do not include hostprogs rules unless needed.
48# $(sort ...) is used here to remove duplicated words and excessive spaces.
49hostprogs := $(sort $(hostprogs))
50ifneq ($(hostprogs),)
51include $(srctree)/scripts/Makefile.host
52endif
53
54# Do not include userprogs rules unless needed.
55# $(sort ...) is used here to remove duplicated words and excessive spaces.
56userprogs := $(sort $(userprogs))
57ifneq ($(userprogs),)
58include $(srctree)/scripts/Makefile.userprogs
59endif
60
61ifndef obj
62$(warning kbuild: Makefile.build is included improperly)
63endif
64
65ifeq ($(need-modorder),)
66ifneq ($(obj-m),)
67$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
68$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
69endif
70endif
71
72# ===========================================================================
73
74# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
75subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
76subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
77
78targets-for-builtin := $(extra-y)
79
80ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
81targets-for-builtin += $(obj)/lib.a
82endif
83
84ifdef need-builtin
85targets-for-builtin += $(obj)/built-in.a
86endif
87
88targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
89				$(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
90
91ifdef need-modorder
92targets-for-modules += $(obj)/modules.order
93endif
94
95targets += $(targets-for-builtin) $(targets-for-modules)
96
97# Linus' kernel sanity checking tool
98ifeq ($(KBUILD_CHECKSRC),1)
99  quiet_cmd_checksrc       = CHECK   $<
100        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
101else ifeq ($(KBUILD_CHECKSRC),2)
102  quiet_cmd_force_checksrc = CHECK   $<
103        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
104endif
105
106ifneq ($(KBUILD_EXTRA_WARN),)
107  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
108endif
109
110# Compile C sources (.c)
111# ---------------------------------------------------------------------------
112
113quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
114      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
115
116$(obj)/%.s: $(src)/%.c FORCE
117	$(call if_changed_dep,cc_s_c)
118
119quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
120cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
121
122$(obj)/%.i: $(src)/%.c FORCE
123	$(call if_changed_dep,cpp_i_c)
124
125genksyms = scripts/genksyms/genksyms		\
126	$(if $(1), -T $(2))			\
127	$(if $(KBUILD_PRESERVE), -p)		\
128	-r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
129
130# These mirror gensymtypes_S and co below, keep them in synch.
131cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
132
133quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
134      cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
135
136$(obj)/%.symtypes : $(src)/%.c FORCE
137	$(call cmd,cc_symtypes_c)
138
139# LLVM assembly
140# Generate .ll files from .c
141quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
142      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
143
144$(obj)/%.ll: $(src)/%.c FORCE
145	$(call if_changed_dep,cc_ll_c)
146
147# C (.c) files
148# The C file is compiled and updated dependency information is generated.
149# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
150
151is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
152
153# When a module consists of a single object, there is no reason to keep LLVM IR.
154# Make $(LD) covert LLVM IR to ELF here.
155ifdef CONFIG_LTO_CLANG
156cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
157endif
158
159quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
160      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
161		$(cmd_ld_single_m) \
162		$(cmd_objtool)
163
164ifdef CONFIG_MODVERSIONS
165# When module versioning is enabled the following steps are executed:
166# o compile a <file>.o from <file>.c
167# o if <file>.o doesn't contain a __ksymtab version, i.e. does
168#   not export symbols, it's done.
169# o otherwise, we calculate symbol versions using the good old
170#   genksyms on the preprocessed source and dump them into the .cmd file.
171# o modpost will extract versions from that file and create *.c files that will
172#   be compiled and linked to the kernel and/or modules.
173
174gen_symversions =								\
175	if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then			\
176		$(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
177			>> $(dot-target).cmd;					\
178	fi
179
180cmd_gen_symversions_c =	$(call gen_symversions,c)
181
182endif
183
184ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
185# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
186ifdef BUILD_C_RECORDMCOUNT
187ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
188  RECORDMCOUNT_FLAGS = -w
189endif
190# Due to recursion, we must skip empty.o.
191# The empty.o file is created in the make process in order to determine
192# the target endianness and word size. It is made before all other C
193# files, including recordmcount.
194sub_cmd_record_mcount =					\
195	if [ $(@) != "scripts/mod/empty.o" ]; then	\
196		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\
197	fi;
198recordmcount_source := $(srctree)/scripts/recordmcount.c \
199		    $(srctree)/scripts/recordmcount.h
200else
201sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
202	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
203	"$(if $(CONFIG_64BIT),64,32)" \
204	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
205	"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
206	"$(if $(part-of-module),1,0)" "$(@)";
207recordmcount_source := $(srctree)/scripts/recordmcount.pl
208endif # BUILD_C_RECORDMCOUNT
209cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\
210	$(sub_cmd_record_mcount))
211endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
212
213# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
214# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
215# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
216
217is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
218
219$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
220
221ifdef CONFIG_TRIM_UNUSED_KSYMS
222cmd_gen_ksymdeps = \
223	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
224endif
225
226cmd_check_local_export = $(srctree)/scripts/check-local-export $@
227
228define rule_cc_o_c
229	$(call cmd_and_fixdep,cc_o_c)
230	$(call cmd,gen_ksymdeps)
231	$(call cmd,check_local_export)
232	$(call cmd,checksrc)
233	$(call cmd,checkdoc)
234	$(call cmd,gen_objtooldep)
235	$(call cmd,gen_symversions_c)
236	$(call cmd,record_mcount)
237endef
238
239define rule_as_o_S
240	$(call cmd_and_fixdep,as_o_S)
241	$(call cmd,gen_ksymdeps)
242	$(call cmd,check_local_export)
243	$(call cmd,gen_objtooldep)
244	$(call cmd,gen_symversions_S)
245endef
246
247# Built-in and composite module parts
248$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
249	$(call if_changed_rule,cc_o_c)
250	$(call cmd,force_checksrc)
251
252# To make this rule robust against "Argument list too long" error,
253# ensure to add $(obj)/ prefix by a shell command.
254cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
255	$(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
256
257$(obj)/%.mod: FORCE
258	$(call if_changed,mod)
259
260# List module undefined symbols
261cmd_undefined_syms = $(NM) $< | sed -n 's/^  *U //p' > $@
262
263$(obj)/%.usyms: $(obj)/%.o FORCE
264	$(call if_changed,undefined_syms)
265
266quiet_cmd_cc_lst_c = MKLST   $@
267      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
268		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
269				     System.map $(OBJDUMP) > $@
270
271$(obj)/%.lst: $(src)/%.c FORCE
272	$(call if_changed_dep,cc_lst_c)
273
274# Compile assembler sources (.S)
275# ---------------------------------------------------------------------------
276
277# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
278# or a file that it includes, in order to get versioned symbols. We build a
279# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
280# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
281#
282# This is convoluted. The .S file must first be preprocessed to run guards and
283# expand names, then the resulting exports must be constructed into plain
284# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
285# to make the genksyms input.
286#
287# These mirror gensymtypes_c and co above, keep them in synch.
288cmd_gensymtypes_S =                                                         \
289   { echo "\#include <linux/kernel.h>" ;                                    \
290     echo "\#include <asm/asm-prototypes.h>" ;                              \
291    $(CPP) $(a_flags) $< |                                                  \
292     grep "\<___EXPORT_SYMBOL\>" |                                          \
293     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
294    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
295
296quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
297      cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
298
299$(obj)/%.symtypes : $(src)/%.S FORCE
300	$(call cmd,cc_symtypes_S)
301
302
303quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
304cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
305
306$(obj)/%.s: $(src)/%.S FORCE
307	$(call if_changed_dep,cpp_s_S)
308
309quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
310      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
311
312ifdef CONFIG_ASM_MODVERSIONS
313
314# versioning matches the C process described above, with difference that
315# we parse asm-prototypes.h C header to get function definitions.
316
317cmd_gen_symversions_S = $(call gen_symversions,S)
318
319endif
320
321$(obj)/%.o: $(src)/%.S FORCE
322	$(call if_changed_rule,as_o_S)
323
324targets += $(filter-out $(subdir-builtin), $(real-obj-y))
325targets += $(filter-out $(subdir-modorder), $(real-obj-m))
326targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
327
328# Linker scripts preprocessor (.lds.S -> .lds)
329# ---------------------------------------------------------------------------
330quiet_cmd_cpp_lds_S = LDS     $@
331      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
332	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
333
334$(obj)/%.lds: $(src)/%.lds.S FORCE
335	$(call if_changed_dep,cpp_lds_S)
336
337# ASN.1 grammar
338# ---------------------------------------------------------------------------
339quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
340      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
341				$(basename $@).c $(basename $@).h
342
343$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
344	$(call cmd,asn1_compiler)
345
346# Build the compiled-in targets
347# ---------------------------------------------------------------------------
348
349# To build objects in subdirs, we need to descend into the directories
350$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
351$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
352
353#
354# Rule to compile a set of .o files into one .a file (without symbol table)
355#
356# To make this rule robust against "Argument list too long" error,
357# remove $(obj)/ prefix, and restore it by a shell command.
358
359quiet_cmd_ar_builtin = AR      $@
360      cmd_ar_builtin = rm -f $@; \
361		echo $(patsubst $(obj)/%,%,$(real-prereqs)) | \
362		sed -E 's:([^ ]+):$(obj)/\1:g' | \
363		xargs $(AR) cDPrST $@
364
365$(obj)/built-in.a: $(real-obj-y) FORCE
366	$(call if_changed,ar_builtin)
367
368#
369# Rule to create modules.order file
370#
371# Create commands to either record .ko file or cat modules.order from
372# a subdirectory
373# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
374# modules.order unless contained modules are updated.
375
376cmd_modules_order = { $(foreach m, $(real-prereqs), \
377	$(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
378	| $(AWK) '!x[$$0]++' - > $@
379
380$(obj)/modules.order: $(obj-m) FORCE
381	$(call if_changed,modules_order)
382
383#
384# Rule to compile a set of .o files into one .a file (with symbol table)
385#
386
387$(obj)/lib.a: $(lib-y) FORCE
388	$(call if_changed,ar)
389
390quiet_cmd_ld_multi_m = LD [M]  $@
391      cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
392
393define rule_ld_multi_m
394	$(call cmd_and_savecmd,ld_multi_m)
395	$(call cmd,gen_objtooldep)
396endef
397
398$(multi-obj-m): objtool-enabled := $(delay-objtool)
399$(multi-obj-m): part-of-module := y
400$(multi-obj-m): %.o: %.mod FORCE
401	$(call if_changed_rule,ld_multi_m)
402$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
403
404targets := $(filter-out $(PHONY), $(targets))
405
406# Add intermediate targets:
407# When building objects with specific suffix patterns, add intermediate
408# targets that the final targets are derived from.
409intermediate_targets = $(foreach sfx, $(2), \
410				$(patsubst %$(strip $(1)),%$(sfx), \
411					$(filter %$(strip $(1)), $(targets))))
412# %.asn1.o <- %.asn1.[ch] <- %.asn1
413# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
414# %.lex.o <- %.lex.c <- %.l
415# %.tab.o <- %.tab.[ch] <- %.y
416targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
417	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
418	   $(call intermediate_targets, .lex.o, .lex.c) \
419	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)
420
421# Build
422# ---------------------------------------------------------------------------
423
424ifdef single-build
425
426KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
427
428curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
429			$(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
430
431# Handle single targets without any rule: show "Nothing to be done for ..." or
432# "No rule to make target ..." depending on whether the target exists.
433unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
434			$(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
435
436single-subdirs := $(foreach d, $(subdir-ym), \
437			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
438
439__build: $(curdir-single) $(single-subdirs)
440ifneq ($(unknown-single),)
441	$(Q)$(MAKE) -f /dev/null $(unknown-single)
442endif
443	@:
444
445ifeq ($(curdir-single),)
446# Nothing to do in this directory. Do not include any .*.cmd file for speed-up
447targets :=
448else
449targets += $(curdir-single)
450endif
451
452else
453
454__build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
455	 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
456	 $(subdir-ym) $(always-y)
457	@:
458
459endif
460
461# Descending
462# ---------------------------------------------------------------------------
463
464PHONY += $(subdir-ym)
465$(subdir-ym):
466	$(Q)$(MAKE) $(build)=$@ \
467	$(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
468	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
469	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
470
471# Add FORCE to the prequisites of a target to force it to be always rebuilt.
472# ---------------------------------------------------------------------------
473
474PHONY += FORCE
475
476FORCE:
477
478# Read all saved command lines and dependencies for the $(targets) we
479# may be building above, using $(if_changed{,_dep}). As an
480# optimization, we don't need to read them if the target does not
481# exist, we will rebuild anyway in that case.
482
483existing-targets := $(wildcard $(sort $(targets)))
484
485-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
486
487# Create directories for object files if they do not exist
488obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
489# If targets exist, their directories apparently exist. Skip mkdir.
490existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
491obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
492ifneq ($(obj-dirs),)
493$(shell mkdir -p $(obj-dirs))
494endif
495
496.PHONY: $(PHONY)
497