xref: /linux/Makefile (revision df989b01b5f97dae8f9869cfacbda1308f2182c1)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 19
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Baby Opossum Posse
7
8# *DOCUMENTATION*
9# To see a list of typical targets execute "make help"
10# More info can be located in ./README
11# Comments in this file are targeted only to the developer, do not
12# expect to learn how to build the kernel reading this file.
13
14ifeq ($(filter output-sync,$(.FEATURES)),)
15$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_output := $(CURDIR)
44
45ifneq ($(sub_make_done),1)
46
47# Do not use make's built-in rules and variables
48# (this increases performance and avoids hard-to-debug behaviour)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport GREP_OPTIONS
59
60# Beautify output
61# ---------------------------------------------------------------------------
62#
63# Most of build commands in Kbuild start with "cmd_". You can optionally define
64# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
65# that command is printed by default.
66#
67# e.g.)
68#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
69#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
70#
71# A simple variant is to prefix commands with $(Q) - that's useful
72# for commands that shall be hidden in non-verbose mode.
73#
74#    $(Q)$(MAKE) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83  KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
97quiet=silent_
98override KBUILD_VERBOSE :=
99endif
100
101export quiet Q KBUILD_VERBOSE
102
103# Call a source code checker (by default, "sparse") as part of the
104# C compilation.
105#
106# Use 'make C=1' to enable checking of only re-compiled files.
107# Use 'make C=2' to enable checking of *all* source files, regardless
108# of whether they are re-compiled or not.
109#
110# See the file "Documentation/dev-tools/sparse.rst" for more details,
111# including where to get the "sparse" utility.
112
113ifeq ("$(origin C)", "command line")
114  KBUILD_CHECKSRC = $(C)
115endif
116ifndef KBUILD_CHECKSRC
117  KBUILD_CHECKSRC = 0
118endif
119
120export KBUILD_CHECKSRC
121
122# Enable "clippy" (a linter) as part of the Rust compilation.
123#
124# Use 'make CLIPPY=1' to enable it.
125ifeq ("$(origin CLIPPY)", "command line")
126  KBUILD_CLIPPY := $(CLIPPY)
127endif
128
129export KBUILD_CLIPPY
130
131# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
132# directory of external module to build. Setting M= takes precedence.
133ifeq ("$(origin M)", "command line")
134  KBUILD_EXTMOD := $(M)
135endif
136
137ifeq ("$(origin MO)", "command line")
138  KBUILD_EXTMOD_OUTPUT := $(MO)
139endif
140
141$(if $(word 2, $(KBUILD_EXTMOD)), \
142	$(error building multiple external modules is not supported))
143
144$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
145	$(error module directory path cannot contain '$x')))
146
147# Remove trailing slashes
148ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
149KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
150endif
151
152export KBUILD_EXTMOD
153
154ifeq ("$(origin W)", "command line")
155  KBUILD_EXTRA_WARN := $(W)
156endif
157
158export KBUILD_EXTRA_WARN
159
160# Kbuild will save output files in the current working directory.
161# This does not need to match to the root of the kernel source tree.
162#
163# For example, you can do this:
164#
165#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
166#
167# If you want to save output files in a different location, there are
168# two syntaxes to specify it.
169#
170# 1) O=
171# Use "make O=dir/to/store/output/files/"
172#
173# 2) Set KBUILD_OUTPUT
174# Set the environment variable KBUILD_OUTPUT to point to the output directory.
175# export KBUILD_OUTPUT=dir/to/store/output/files/; make
176#
177# The O= assignment takes precedence over the KBUILD_OUTPUT environment
178# variable.
179
180ifeq ("$(origin O)", "command line")
181  KBUILD_OUTPUT := $(O)
182endif
183
184ifdef KBUILD_EXTMOD
185    ifdef KBUILD_OUTPUT
186        objtree := $(realpath $(KBUILD_OUTPUT))
187        $(if $(objtree),,$(error specified kernel directory "$(KBUILD_OUTPUT)" does not exist))
188    else
189        objtree := $(abs_srctree)
190    endif
191    # If Make is invoked from the kernel directory (either kernel
192    # source directory or kernel build directory), external modules
193    # are built in $(KBUILD_EXTMOD) for backward compatibility,
194    # otherwise, built in the current directory.
195    output := $(or $(KBUILD_EXTMOD_OUTPUT),$(if $(filter $(CURDIR),$(objtree) $(abs_srctree)),$(KBUILD_EXTMOD)))
196    # KBUILD_EXTMOD might be a relative path. Remember its absolute path before
197    # Make changes the working directory.
198    srcroot := $(realpath $(KBUILD_EXTMOD))
199    $(if $(srcroot),,$(error specified external module directory "$(KBUILD_EXTMOD)" does not exist))
200else
201    objtree := .
202    output := $(KBUILD_OUTPUT)
203endif
204
205export objtree srcroot
206
207# Do we want to change the working directory?
208ifneq ($(output),)
209# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
210$(shell mkdir -p "$(output)")
211# $(realpath ...) resolves symlinks
212abs_output := $(realpath $(output))
213$(if $(abs_output),,$(error failed to create output directory "$(output)"))
214endif
215
216ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
217$(error source directory cannot contain spaces or colons)
218endif
219
220export sub_make_done := 1
221
222endif # sub_make_done
223
224ifeq ($(abs_output),$(CURDIR))
225# Suppress "Entering directory ..." if we are at the final work directory.
226no-print-directory := --no-print-directory
227else
228# Recursion to show "Entering directory ..."
229need-sub-make := 1
230endif
231
232ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
233# If --no-print-directory is unset, recurse once again to set it.
234# You may end up recursing into __sub-make twice. This is needed due to the
235# behavior change in GNU Make 4.4.1.
236need-sub-make := 1
237endif
238
239ifeq ($(need-sub-make),1)
240
241PHONY += $(MAKECMDGOALS) __sub-make
242
243$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
244	@:
245
246# Invoke a second make in the output directory, passing relevant variables
247__sub-make:
248	$(Q)$(MAKE) $(no-print-directory) -C $(abs_output) \
249	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
250
251else # need-sub-make
252
253# We process the rest of the Makefile if this is the final invocation of make
254
255ifndef KBUILD_EXTMOD
256srcroot := $(abs_srctree)
257endif
258
259ifeq ($(srcroot),$(CURDIR))
260building_out_of_srctree :=
261else
262export building_out_of_srctree := 1
263endif
264
265ifdef KBUILD_ABS_SRCTREE
266    # Do nothing. Use the absolute path.
267else ifeq ($(srcroot),$(CURDIR))
268    # Building in the source.
269    srcroot := .
270else ifeq ($(srcroot)/,$(dir $(CURDIR)))
271    # Building in a subdirectory of the source.
272    srcroot := ..
273endif
274
275export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot))
276
277ifdef building_out_of_srctree
278export VPATH := $(srcroot)
279else
280VPATH :=
281endif
282
283# To make sure we do not include .config for any of the *config targets
284# catch them early, and hand them over to scripts/kconfig/Makefile
285# It is allowed to specify more targets when calling make, including
286# mixing *config targets and build targets.
287# For example 'make oldconfig all'.
288# Detect when mixed targets is specified, and make a second invocation
289# of make so .config is not included in this case either (for *config).
290
291version_h := include/generated/uapi/linux/version.h
292
293clean-targets := %clean mrproper cleandocs
294no-dot-config-targets := $(clean-targets) \
295			 cscope gtags TAGS tags help% %docs check% coccicheck \
296			 $(version_h) headers headers_% archheaders archscripts \
297			 %asm-generic kernelversion %src-pkg dt_binding_check \
298			 outputmakefile rustavailable rustfmt rustfmtcheck \
299			 run-command
300no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
301			  image_name
302single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %/
303
304config-build	:=
305mixed-build	:=
306need-config	:= 1
307may-sync-config	:= 1
308single-build	:=
309
310ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
311    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
312        need-config :=
313    endif
314endif
315
316ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
317    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
318        may-sync-config :=
319    endif
320endif
321
322need-compiler := $(may-sync-config)
323
324ifneq ($(KBUILD_EXTMOD),)
325    may-sync-config :=
326endif
327
328ifeq ($(KBUILD_EXTMOD),)
329    ifneq ($(filter %config,$(MAKECMDGOALS)),)
330        config-build := 1
331        ifneq ($(words $(MAKECMDGOALS)),1)
332            mixed-build := 1
333        endif
334    endif
335endif
336
337# We cannot build single targets and the others at the same time
338ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
339    single-build := 1
340    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
341        mixed-build := 1
342    endif
343endif
344
345# For "make -j clean all", "make -j mrproper defconfig all", etc.
346ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
347    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
348        mixed-build := 1
349    endif
350endif
351
352# install and modules_install need also be processed one by one
353ifneq ($(filter install,$(MAKECMDGOALS)),)
354    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
355        mixed-build := 1
356    endif
357endif
358
359ifdef mixed-build
360# ===========================================================================
361# We're called with mixed targets (*config and build targets).
362# Handle them one by one.
363
364PHONY += $(MAKECMDGOALS) __build_one_by_one
365
366$(MAKECMDGOALS): __build_one_by_one
367	@:
368
369__build_one_by_one:
370	$(Q)set -e; \
371	for i in $(MAKECMDGOALS); do \
372		$(MAKE) -f $(srctree)/Makefile $$i; \
373	done
374
375else # !mixed-build
376
377include $(srctree)/scripts/Kbuild.include
378
379# Read KERNELRELEASE from include/config/kernel.release (if it exists)
380KERNELRELEASE = $(call read-file, $(objtree)/include/config/kernel.release)
381KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
382export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
383
384include $(srctree)/scripts/subarch.include
385
386# Cross compiling and selecting different set of gcc/bin-utils
387# ---------------------------------------------------------------------------
388#
389# When performing cross compilation for other architectures ARCH shall be set
390# to the target architecture. (See arch/* for the possibilities).
391# ARCH can be set during invocation of make:
392# make ARCH=arm64
393# Another way is to have ARCH set in the environment.
394# The default ARCH is the host where make is executed.
395
396# CROSS_COMPILE specify the prefix used for all executables used
397# during compilation. Only gcc and related bin-utils executables
398# are prefixed with $(CROSS_COMPILE).
399# CROSS_COMPILE can be set on the command line
400# make CROSS_COMPILE=aarch64-linux-gnu-
401# Alternatively CROSS_COMPILE can be set in the environment.
402# Default value for CROSS_COMPILE is not to prefix executables
403# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
404ARCH		?= $(SUBARCH)
405
406# Architecture as present in compile.h
407UTS_MACHINE 	:= $(ARCH)
408SRCARCH 	:= $(ARCH)
409
410# Additional ARCH settings for x86
411ifeq ($(ARCH),i386)
412        SRCARCH := x86
413endif
414ifeq ($(ARCH),x86_64)
415        SRCARCH := x86
416endif
417
418# Additional ARCH settings for sparc
419ifeq ($(ARCH),sparc32)
420       SRCARCH := sparc
421endif
422ifeq ($(ARCH),sparc64)
423       SRCARCH := sparc
424endif
425
426# Additional ARCH settings for parisc
427ifeq ($(ARCH),parisc64)
428       SRCARCH := parisc
429endif
430
431export cross_compiling :=
432ifneq ($(SRCARCH),$(SUBARCH))
433cross_compiling := 1
434endif
435
436KCONFIG_CONFIG	?= .config
437export KCONFIG_CONFIG
438
439# SHELL used by kbuild
440CONFIG_SHELL := sh
441
442HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
443HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
444HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
445
446ifneq ($(LLVM),)
447ifneq ($(filter %/,$(LLVM)),)
448LLVM_PREFIX := $(LLVM)
449else ifneq ($(filter -%,$(LLVM)),)
450LLVM_SUFFIX := $(LLVM)
451else ifneq ($(LLVM),1)
452$(error Invalid value for LLVM, see Documentation/kbuild/llvm.rst)
453endif
454
455HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
456HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
457else
458HOSTCC	= gcc
459HOSTCXX	= g++
460endif
461HOSTRUSTC = rustc
462HOSTPKG_CONFIG	= pkg-config
463
464# the KERNELDOC macro needs to be exported, as scripts/Makefile.build
465# has a logic to call it
466KERNELDOC       = $(srctree)/scripts/kernel-doc.py
467export KERNELDOC
468
469KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
470			 -O2 -fomit-frame-pointer -std=gnu11
471KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
472KBUILD_USERLDFLAGS := $(USERLDFLAGS)
473
474# These flags apply to all Rust code in the tree, including the kernel and
475# host programs.
476export rust_common_flags := --edition=2021 \
477			    -Zbinary_dep_depinfo=y \
478			    -Astable_features \
479			    -Dnon_ascii_idents \
480			    -Dunsafe_op_in_unsafe_fn \
481			    -Wmissing_docs \
482			    -Wrust_2018_idioms \
483			    -Wunreachable_pub \
484			    -Wclippy::all \
485			    -Wclippy::as_ptr_cast_mut \
486			    -Wclippy::as_underscore \
487			    -Wclippy::cast_lossless \
488			    -Wclippy::ignored_unit_patterns \
489			    -Wclippy::mut_mut \
490			    -Wclippy::needless_bitwise_bool \
491			    -Aclippy::needless_lifetimes \
492			    -Wclippy::no_mangle_with_rust_abi \
493			    -Wclippy::ptr_as_ptr \
494			    -Wclippy::ptr_cast_constness \
495			    -Wclippy::ref_as_ptr \
496			    -Wclippy::undocumented_unsafe_blocks \
497			    -Wclippy::unnecessary_safety_comment \
498			    -Wclippy::unnecessary_safety_doc \
499			    -Wrustdoc::missing_crate_level_docs \
500			    -Wrustdoc::unescaped_backticks
501
502KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
503		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
504KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
505		       -I $(srctree)/scripts/include
506KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
507			-Zallow-features= $(HOSTRUSTFLAGS)
508KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
509KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
510KBUILD_PROCMACROLDFLAGS := $(or $(PROCMACROLDFLAGS),$(KBUILD_HOSTLDFLAGS))
511
512# Make variables (CC, etc...)
513CPP		= $(CC) -E
514ifneq ($(LLVM),)
515CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
516LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
517AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
518NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
519OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
520OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
521READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
522STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
523else
524CC		= $(CROSS_COMPILE)gcc
525LD		= $(CROSS_COMPILE)ld
526AR		= $(CROSS_COMPILE)ar
527NM		= $(CROSS_COMPILE)nm
528OBJCOPY		= $(CROSS_COMPILE)objcopy
529OBJDUMP		= $(CROSS_COMPILE)objdump
530READELF		= $(CROSS_COMPILE)readelf
531STRIP		= $(CROSS_COMPILE)strip
532endif
533RUSTC		= rustc
534RUSTDOC		= rustdoc
535RUSTFMT		= rustfmt
536CLIPPY_DRIVER	= clippy-driver
537BINDGEN		= bindgen
538PAHOLE		= pahole
539RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
540LEX		= flex
541YACC		= bison
542AWK		= awk
543INSTALLKERNEL  := installkernel
544PERL		= perl
545PYTHON3		= python3
546CHECK		= sparse
547BASH		= bash
548KGZIP		= gzip
549KBZIP2		= bzip2
550KLZOP		= lzop
551LZMA		= lzma
552LZ4		= lz4
553XZ		= xz
554ZSTD		= zstd
555TAR		= tar
556
557CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
558		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
559NOSTDINC_FLAGS :=
560CFLAGS_MODULE   =
561RUSTFLAGS_MODULE =
562AFLAGS_MODULE   =
563LDFLAGS_MODULE  =
564CFLAGS_KERNEL	=
565RUSTFLAGS_KERNEL =
566AFLAGS_KERNEL	=
567LDFLAGS_vmlinux =
568
569# Use USERINCLUDE when you must reference the UAPI directories only.
570USERINCLUDE    := \
571		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
572		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
573		-I$(srctree)/include/uapi \
574		-I$(objtree)/include/generated/uapi \
575                -include $(srctree)/include/linux/compiler-version.h \
576                -include $(srctree)/include/linux/kconfig.h
577
578# Use LINUXINCLUDE when you must reference the include/ directory.
579# Needed to be compatible with the O= option
580LINUXINCLUDE    := \
581		-I$(srctree)/arch/$(SRCARCH)/include \
582		-I$(objtree)/arch/$(SRCARCH)/include/generated \
583		-I$(srctree)/include \
584		-I$(objtree)/include \
585		$(USERINCLUDE)
586
587KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
588
589KBUILD_CFLAGS :=
590KBUILD_CFLAGS += -std=gnu11
591KBUILD_CFLAGS += -fshort-wchar
592KBUILD_CFLAGS += -funsigned-char
593KBUILD_CFLAGS += -fno-common
594KBUILD_CFLAGS += -fno-PIE
595KBUILD_CFLAGS += -fno-strict-aliasing
596
597KBUILD_CPPFLAGS := -D__KERNEL__
598KBUILD_RUSTFLAGS := $(rust_common_flags) \
599		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
600		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
601		    -Csymbol-mangling-version=v0 \
602		    -Crelocation-model=static \
603		    -Zfunction-sections=n \
604		    -Wclippy::float_arithmetic
605
606KBUILD_AFLAGS_KERNEL :=
607KBUILD_CFLAGS_KERNEL :=
608KBUILD_RUSTFLAGS_KERNEL :=
609KBUILD_AFLAGS_MODULE  := -DMODULE
610KBUILD_CFLAGS_MODULE  := -DMODULE
611KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
612KBUILD_LDFLAGS_MODULE :=
613KBUILD_LDFLAGS :=
614CLANG_FLAGS :=
615
616ifeq ($(KBUILD_CLIPPY),1)
617	RUSTC_OR_CLIPPY_QUIET := CLIPPY
618	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
619else
620	RUSTC_OR_CLIPPY_QUIET := RUSTC
621	RUSTC_OR_CLIPPY = $(RUSTC)
622endif
623
624# Allows the usage of unstable features in stable compilers.
625export RUSTC_BOOTSTRAP := 1
626
627# Allows finding `.clippy.toml` in out-of-srctree builds.
628export CLIPPY_CONF_DIR := $(srctree)
629
630export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
631export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
632export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
633export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
634export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
635export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD TAR
636export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS KBUILD_PROCMACROLDFLAGS LDFLAGS_MODULE
637export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
638
639export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
640export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
641export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
642export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
643export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
644export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
645
646# Files to ignore in find ... statements
647
648export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
649			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
650			  -prune -o
651
652# ===========================================================================
653# Rules shared between *config targets and build targets
654
655# Basic helpers built in scripts/basic/
656PHONY += scripts_basic
657scripts_basic:
658	$(Q)$(MAKE) $(build)=scripts/basic
659
660PHONY += outputmakefile
661ifdef building_out_of_srctree
662# Before starting out-of-tree build, make sure the source tree is clean.
663# outputmakefile generates a Makefile in the output directory, if using a
664# separate output directory. This allows convenient use of make in the
665# output directory.
666# At the same time when output Makefile generated, generate .gitignore to
667# ignore whole output directory
668
669ifdef KBUILD_EXTMOD
670print_env_for_makefile = \
671	echo "export KBUILD_OUTPUT = $(objtree)"; \
672	echo "export KBUILD_EXTMOD = $(realpath $(srcroot))" ; \
673	echo "export KBUILD_EXTMOD_OUTPUT = $(CURDIR)"
674else
675print_env_for_makefile = \
676	echo "export KBUILD_OUTPUT = $(CURDIR)"
677endif
678
679quiet_cmd_makefile = GEN     Makefile
680      cmd_makefile = { \
681	echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \
682	$(print_env_for_makefile); \
683	echo "include $(abs_srctree)/Makefile"; \
684	} > Makefile
685
686outputmakefile:
687ifeq ($(KBUILD_EXTMOD),)
688	@if [ -f $(srctree)/.config -o \
689		 -d $(srctree)/include/config -o \
690		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
691		echo >&2 "***"; \
692		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
693		echo >&2 "*** in $(abs_srctree)";\
694		echo >&2 "***"; \
695		false; \
696	fi
697else
698	@if [ -f $(srcroot)/modules.order ]; then \
699		echo >&2 "***"; \
700		echo >&2 "*** The external module source tree is not clean."; \
701		echo >&2 "*** Please run 'make -C $(abs_srctree) M=$(realpath $(srcroot)) clean'"; \
702		echo >&2 "***"; \
703		false; \
704	fi
705endif
706	$(Q)ln -fsn $(srcroot) source
707	$(call cmd,makefile)
708	$(Q)test -e .gitignore || \
709	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
710endif
711
712# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
713# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
714# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
715# need export), and from include/config/auto.conf.cmd to detect the compiler
716# upgrade.
717CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
718RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
719
720ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
721include $(srctree)/scripts/Makefile.clang
722endif
723
724# Include this also for config targets because some architectures need
725# cc-cross-prefix to determine CROSS_COMPILE.
726ifdef need-compiler
727include $(srctree)/scripts/Makefile.compiler
728endif
729
730ifdef config-build
731# ===========================================================================
732# *config targets only - make sure prerequisites are updated, and descend
733# in scripts/kconfig to make the *config target
734
735# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
736# KBUILD_DEFCONFIG may point out an alternative default configuration
737# used for 'make defconfig'
738include $(srctree)/arch/$(SRCARCH)/Makefile
739export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
740
741config: outputmakefile scripts_basic FORCE
742	$(Q)$(MAKE) $(build)=scripts/kconfig $@
743
744%config: outputmakefile scripts_basic FORCE
745	$(Q)$(MAKE) $(build)=scripts/kconfig $@
746
747else #!config-build
748# ===========================================================================
749# Build targets only - this includes vmlinux, arch-specific targets, clean
750# targets and others. In general all targets except *config targets.
751
752# If building an external module we do not care about the all: rule
753# but instead __all depend on modules
754PHONY += all
755ifeq ($(KBUILD_EXTMOD),)
756__all: all
757else
758__all: modules
759endif
760
761targets :=
762
763# Decide whether to build built-in, modular, or both.
764# Normally, just do built-in.
765
766KBUILD_MODULES :=
767KBUILD_BUILTIN := y
768
769# If we have only "make modules", don't compile built-in objects.
770ifeq ($(MAKECMDGOALS),modules)
771  KBUILD_BUILTIN :=
772endif
773
774# If we have "make <whatever> modules", compile modules
775# in addition to whatever we do anyway.
776# Just "make" or "make all" shall build modules as well
777
778ifneq ($(filter all modules nsdeps compile_commands.json clang-%,$(MAKECMDGOALS)),)
779  KBUILD_MODULES := y
780endif
781
782ifeq ($(MAKECMDGOALS),)
783  KBUILD_MODULES := y
784endif
785
786export KBUILD_MODULES KBUILD_BUILTIN
787
788ifdef need-config
789include $(objtree)/include/config/auto.conf
790endif
791
792ifeq ($(KBUILD_EXTMOD),)
793# Objects we will link into vmlinux / subdirs we need to visit
794core-y		:=
795drivers-y	:=
796libs-y		:= lib/
797endif # KBUILD_EXTMOD
798
799# The all: target is the default when no target is given on the
800# command line.
801# This allow a user to issue only 'make' to build a kernel including modules
802# Defaults to vmlinux, but the arch makefile usually adds further targets
803all: vmlinux
804
805CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
806ifdef CONFIG_CC_IS_GCC
807CFLAGS_GCOV	+= -fno-tree-loop-im
808endif
809export CFLAGS_GCOV
810
811# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
812ifdef CONFIG_FUNCTION_TRACER
813  CC_FLAGS_FTRACE := -pg
814endif
815
816ifdef CONFIG_TRACEPOINTS
817# To check for unused tracepoints (tracepoints that are defined but never
818# called), run with:
819#
820# make UT=1
821#
822# Each unused tracepoints can take up to 5KB of memory in the running kernel.
823# It is best to remove any that are not used.
824#
825# This command line option will be removed when all current unused
826# tracepoints are removed.
827
828ifeq ("$(origin UT)", "command line")
829  WARN_ON_UNUSED_TRACEPOINTS := $(UT)
830endif
831endif # CONFIG_TRACEPOINTS
832
833export WARN_ON_UNUSED_TRACEPOINTS
834
835include $(srctree)/arch/$(SRCARCH)/Makefile
836
837ifdef need-config
838ifdef may-sync-config
839# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
840# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
841# because some architectures define CROSS_COMPILE there.
842include include/config/auto.conf.cmd
843
844$(KCONFIG_CONFIG):
845	@echo >&2 '***'
846	@echo >&2 '*** Configuration file "$@" not found!'
847	@echo >&2 '***'
848	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
849	@echo >&2 '*** "make menuconfig" or "make xconfig").'
850	@echo >&2 '***'
851	@/bin/false
852
853# The actual configuration files used during the build are stored in
854# include/generated/ and include/config/. Update them if .config is newer than
855# include/config/auto.conf (which mirrors .config).
856#
857# This exploits the 'multi-target pattern rule' trick.
858# The syncconfig should be executed only once to make all the targets.
859# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
860#
861# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
862# so you cannot notice that Kconfig is waiting for the user input.
863%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
864	$(Q)$(kecho) "  SYNC    $@"
865	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
866else # !may-sync-config
867# External modules and some install targets need include/generated/autoconf.h
868# and include/config/auto.conf but do not care if they are up-to-date.
869# Use auto.conf to show the error message
870
871checked-configs := $(addprefix $(objtree)/, include/generated/autoconf.h include/generated/rustc_cfg include/config/auto.conf)
872missing-configs := $(filter-out $(wildcard $(checked-configs)), $(checked-configs))
873
874ifdef missing-configs
875PHONY += $(objtree)/include/config/auto.conf
876
877$(objtree)/include/config/auto.conf:
878	@echo   >&2 '***'
879	@echo   >&2 '***  ERROR: Kernel configuration is invalid. The following files are missing:'
880	@printf >&2 '***    - %s\n' $(missing-configs)
881	@echo   >&2 '***  Run "make oldconfig && make prepare" on kernel source to fix it.'
882	@echo   >&2 '***'
883	@/bin/false
884endif
885
886endif # may-sync-config
887endif # need-config
888
889KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
890
891ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
892KBUILD_CFLAGS += -O2
893KBUILD_RUSTFLAGS += -Copt-level=2
894else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
895KBUILD_CFLAGS += -Os
896KBUILD_RUSTFLAGS += -Copt-level=s
897endif
898
899# Always set `debug-assertions` and `overflow-checks` because their default
900# depends on `opt-level` and `debug-assertions`, respectively.
901KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
902KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
903
904# Tell gcc to never replace conditional load with a non-conditional one
905ifdef CONFIG_CC_IS_GCC
906# gcc-10 renamed --param=allow-store-data-races=0 to
907# -fno-allow-store-data-races.
908KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
909KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
910endif
911
912ifdef CONFIG_READABLE_ASM
913# Disable optimizations that make assembler listings hard to read.
914# reorder blocks reorders the control in the function
915# ipa clone creates specialized cloned functions
916# partial inlining inlines only parts of functions
917KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
918endif
919
920stackp-flags-y                                    := -fno-stack-protector
921stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
922stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
923
924KBUILD_CFLAGS += $(stackp-flags-y)
925
926ifdef CONFIG_FRAME_POINTER
927KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
928KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
929else
930# Some targets (ARM with Thumb2, for example), can't be built with frame
931# pointers.  For those, we don't have FUNCTION_TRACER automatically
932# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
933# incompatible with -fomit-frame-pointer with current GCC, so we don't use
934# -fomit-frame-pointer with FUNCTION_TRACER.
935# In the Rust target specification, "frame-pointer" is set explicitly
936# to "may-omit".
937ifndef CONFIG_FUNCTION_TRACER
938KBUILD_CFLAGS	+= -fomit-frame-pointer
939endif
940endif
941
942# Initialize all stack variables with a 0xAA pattern.
943ifdef CONFIG_INIT_STACK_ALL_PATTERN
944KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
945endif
946
947# Initialize all stack variables with a zero value.
948ifdef CONFIG_INIT_STACK_ALL_ZERO
949KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
950ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
951# https://github.com/llvm/llvm-project/issues/44842
952CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
953export CC_AUTO_VAR_INIT_ZERO_ENABLER
954KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
955endif
956endif
957
958# Explicitly clear padding bits during variable initialization
959KBUILD_CFLAGS += $(call cc-option,-fzero-init-padding-bits=all)
960
961# While VLAs have been removed, GCC produces unreachable stack probes
962# for the randomize_kstack_offset feature. Disable it for all compilers.
963KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
964
965# Get details on warnings generated due to GCC value tracking.
966KBUILD_CFLAGS	+= $(call cc-option, -fdiagnostics-show-context=2)
967
968# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
969ifdef CONFIG_ZERO_CALL_USED_REGS
970KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
971endif
972
973ifdef CONFIG_FUNCTION_TRACER
974ifdef CONFIG_FTRACE_MCOUNT_USE_CC
975  CC_FLAGS_FTRACE	+= -mrecord-mcount
976  ifdef CONFIG_HAVE_NOP_MCOUNT
977    ifeq ($(call cc-option-yn, -mnop-mcount),y)
978      CC_FLAGS_FTRACE	+= -mnop-mcount
979      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
980    endif
981  endif
982endif
983ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
984  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
985    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
986  endif
987endif
988ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
989  ifdef CONFIG_HAVE_C_RECORDMCOUNT
990    BUILD_C_RECORDMCOUNT := y
991    export BUILD_C_RECORDMCOUNT
992  endif
993endif
994ifdef CONFIG_HAVE_FENTRY
995  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
996  ifeq ($(call cc-option-yn, -mfentry),y)
997    CC_FLAGS_FTRACE	+= -mfentry
998    CC_FLAGS_USING	+= -DCC_USING_FENTRY
999  endif
1000endif
1001export CC_FLAGS_FTRACE
1002KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
1003KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
1004endif
1005
1006# We trigger additional mismatches with less inlining
1007ifdef CONFIG_DEBUG_SECTION_MISMATCH
1008KBUILD_CFLAGS += -fno-inline-functions-called-once
1009endif
1010
1011# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
1012ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
1013KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
1014KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
1015LDFLAGS_vmlinux += --gc-sections
1016endif
1017
1018ifdef CONFIG_SHADOW_CALL_STACK
1019ifndef CONFIG_DYNAMIC_SCS
1020CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
1021KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
1022KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
1023endif
1024export CC_FLAGS_SCS
1025endif
1026
1027ifdef CONFIG_LTO_CLANG
1028ifdef CONFIG_LTO_CLANG_THIN
1029CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
1030else
1031CC_FLAGS_LTO	:= -flto
1032endif
1033CC_FLAGS_LTO	+= -fvisibility=hidden
1034
1035# Limit inlining across translation units to reduce binary size
1036KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
1037endif
1038
1039ifdef CONFIG_LTO
1040KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1041KBUILD_AFLAGS	+= -fno-lto
1042export CC_FLAGS_LTO
1043endif
1044
1045ifdef CONFIG_CFI
1046CC_FLAGS_CFI	:= -fsanitize=kcfi
1047ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
1048	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
1049endif
1050ifdef CONFIG_FINEIBT_BHI
1051	CC_FLAGS_CFI	+= -fsanitize-kcfi-arity
1052endif
1053ifdef CONFIG_RUST
1054	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
1055	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
1056	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers
1057	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
1058	export RUSTC_FLAGS_CFI
1059endif
1060KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1061export CC_FLAGS_CFI
1062endif
1063
1064# Architectures can define flags to add/remove for floating-point support
1065CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
1066export CC_FLAGS_FPU
1067export CC_FLAGS_NO_FPU
1068
1069ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1070# Set the minimal function alignment. Use the newer GCC option
1071# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
1072# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
1073ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
1074KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
1075else
1076KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1077endif
1078endif
1079
1080# arch Makefile may override CC so keep this after arch Makefile is included
1081NOSTDINC_FLAGS += -nostdinc
1082
1083# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
1084# the kernel uses only C99 flexible arrays for dynamically sized trailing
1085# arrays. Enforce this for everything that may examine structure sizes and
1086# perform bounds checking.
1087KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
1088
1089# Allow including a tagged struct or union anonymously in another struct/union.
1090KBUILD_CFLAGS += -fms-extensions
1091
1092# disable invalid "can't wrap" optimizations for signed / pointers
1093KBUILD_CFLAGS	+= -fno-strict-overflow
1094
1095# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1096KBUILD_CFLAGS  += -fno-stack-check
1097
1098# conserve stack if available
1099ifdef CONFIG_CC_IS_GCC
1100KBUILD_CFLAGS   += -fconserve-stack
1101endif
1102
1103# Ensure compilers do not transform certain loops into calls to wcslen()
1104KBUILD_CFLAGS += -fno-builtin-wcslen
1105
1106# change __FILE__ to the relative path to the source directory
1107ifdef building_out_of_srctree
1108KBUILD_CPPFLAGS += -fmacro-prefix-map=$(srcroot)/=
1109endif
1110
1111# include additional Makefiles when needed
1112include-y			:= scripts/Makefile.warn
1113include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1114include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1115include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1116include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1117include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1118include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1119include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1120include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1121include-$(CONFIG_KSTACK_ERASE)	+= scripts/Makefile.kstack_erase
1122include-$(CONFIG_AUTOFDO_CLANG)	+= scripts/Makefile.autofdo
1123include-$(CONFIG_PROPELLER_CLANG)	+= scripts/Makefile.propeller
1124include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1125
1126include $(addprefix $(srctree)/, $(include-y))
1127
1128# scripts/Makefile.gcc-plugins is intentionally included last.
1129# Do not add $(call cc-option,...) below this line. When you build the kernel
1130# from the clean source tree, the GCC plugins do not exist at this point.
1131
1132# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1133KBUILD_CPPFLAGS += $(KCPPFLAGS)
1134KBUILD_AFLAGS   += $(KAFLAGS)
1135KBUILD_CFLAGS   += $(KCFLAGS)
1136KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1137
1138KBUILD_LDFLAGS_MODULE += --build-id=sha1
1139LDFLAGS_vmlinux += --build-id=sha1
1140
1141KBUILD_LDFLAGS	+= -z noexecstack
1142ifeq ($(CONFIG_LD_IS_BFD),y)
1143KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1144endif
1145
1146ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1147LDFLAGS_vmlinux	+= -X
1148endif
1149
1150ifeq ($(CONFIG_RELR),y)
1151# ld.lld before 15 did not support -z pack-relative-relocs.
1152LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1153endif
1154
1155# We never want expected sections to be placed heuristically by the
1156# linker. All sections should be explicitly named in the linker script.
1157ifdef CONFIG_LD_ORPHAN_WARN
1158LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1159endif
1160
1161ifneq ($(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS),)
1162LDFLAGS_vmlinux	+= --emit-relocs --discard-none
1163endif
1164
1165# Align the architecture of userspace programs with the kernel
1166USERFLAGS_FROM_KERNEL := --target=%
1167
1168ifdef CONFIG_ARCH_USERFLAGS
1169KBUILD_USERCFLAGS += $(CONFIG_ARCH_USERFLAGS)
1170KBUILD_USERLDFLAGS += $(CONFIG_ARCH_USERFLAGS)
1171else
1172# If not overridden also inherit the bit size
1173USERFLAGS_FROM_KERNEL += -m32 -m64
1174endif
1175
1176KBUILD_USERCFLAGS  += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1177KBUILD_USERLDFLAGS += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1178
1179# userspace programs are linked via the compiler, use the correct linker
1180ifdef CONFIG_CC_IS_CLANG
1181KBUILD_USERLDFLAGS += --ld-path=$(LD)
1182endif
1183
1184# make the checker run with the right architecture
1185CHECKFLAGS += --arch=$(ARCH)
1186
1187# insure the checker run with the right endianness
1188CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1189
1190# the checker needs the correct machine size
1191CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1192
1193# Default kernel image to build when no specific target is given.
1194# KBUILD_IMAGE may be overruled on the command line or
1195# set in the environment
1196# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1197# this default value
1198export KBUILD_IMAGE ?= vmlinux
1199
1200#
1201# INSTALL_PATH specifies where to place the updated kernel and system map
1202# images. Default is /boot, but you can set it to other values
1203export	INSTALL_PATH ?= /boot
1204
1205#
1206# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1207# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1208# an argument if needed. Otherwise it defaults to the kernel install path
1209#
1210export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1211
1212#
1213# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1214# relocations required by build roots.  This is not defined in the
1215# makefile but the argument can be passed to make if needed.
1216#
1217
1218MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1219export MODLIB
1220
1221PHONY += prepare0
1222
1223ifeq ($(KBUILD_EXTMOD),)
1224
1225build-dir	:= .
1226clean-dirs	:= $(sort . Documentation \
1227		     $(patsubst %/,%,$(filter %/, $(core-) \
1228			$(drivers-) $(libs-))))
1229
1230export ARCH_CORE	:= $(core-y)
1231export ARCH_LIB		:= $(filter %/, $(libs-y))
1232export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1233# Externally visible symbols (used by link-vmlinux.sh)
1234
1235KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1236KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1237
1238export KBUILD_VMLINUX_LIBS
1239export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1240
1241ifdef CONFIG_TRIM_UNUSED_KSYMS
1242# For the kernel to actually contain only the needed exported symbols,
1243# we have to build modules as well to determine what those symbols are.
1244KBUILD_MODULES := y
1245endif
1246
1247# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1248quiet_cmd_ar_vmlinux.a = AR      $@
1249      cmd_ar_vmlinux.a = \
1250	rm -f $@; \
1251	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1252	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1253
1254targets += vmlinux.a
1255vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1256	$(call if_changed,ar_vmlinux.a)
1257
1258PHONY += vmlinux_o
1259vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1260	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1261
1262vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1263	@:
1264
1265PHONY += vmlinux
1266# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1267# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1268# unrelated; the decompressors just happen to have the same base name,
1269# arch/*/boot/compressed/vmlinux.
1270# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1271#
1272# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1273#   https://savannah.gnu.org/bugs/?61463
1274# For Make > 4.4, the following simple code will work:
1275#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1276vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1277vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1278vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1279	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1280
1281# The actual objects are generated when descending,
1282# make sure no implicit rule kicks in
1283$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1284
1285ifeq ($(origin KERNELRELEASE),file)
1286filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1287else
1288filechk_kernel.release = echo $(KERNELRELEASE)
1289endif
1290
1291# Store (new) KERNELRELEASE string in include/config/kernel.release
1292include/config/kernel.release: FORCE
1293	$(call filechk,kernel.release)
1294
1295# Additional helpers built in scripts/
1296# Carefully list dependencies so we do not try to build scripts twice
1297# in parallel
1298PHONY += scripts
1299scripts: scripts_basic scripts_dtc
1300	$(Q)$(MAKE) $(build)=$(@)
1301
1302# Things we need to do before we recursively start building the kernel
1303# or the modules are listed in "prepare".
1304# A multi level approach is used. prepareN is processed before prepareN-1.
1305# archprepare is used in arch Makefiles and when processed asm symlink,
1306# version.h and scripts_basic is processed / created.
1307
1308PHONY += prepare archprepare
1309
1310archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1311	asm-generic $(version_h) include/generated/utsrelease.h \
1312	include/generated/compile.h include/generated/autoconf.h \
1313	include/generated/rustc_cfg remove-stale-files
1314
1315prepare0: archprepare
1316	$(Q)$(MAKE) $(build)=scripts/mod
1317	$(Q)$(MAKE) $(build)=. prepare
1318
1319# All the preparing..
1320prepare: prepare0
1321ifdef CONFIG_RUST
1322	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1323	$(Q)$(MAKE) $(build)=rust
1324endif
1325
1326PHONY += remove-stale-files
1327remove-stale-files:
1328	$(Q)$(srctree)/scripts/remove-stale-files
1329
1330# Support for using generic headers in asm-generic
1331asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1332
1333PHONY += asm-generic uapi-asm-generic
1334asm-generic: uapi-asm-generic
1335	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1336	generic=include/asm-generic
1337uapi-asm-generic:
1338	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1339	generic=include/uapi/asm-generic
1340
1341# Generate some files
1342# ---------------------------------------------------------------------------
1343
1344# KERNELRELEASE can change from a few different places, meaning version.h
1345# needs to be updated, so this check is forced on all builds
1346
1347uts_len := 64
1348define filechk_utsrelease.h
1349	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1350	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1351	  exit 1;                                                         \
1352	fi;                                                               \
1353	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1354endef
1355
1356define filechk_version.h
1357	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1358		echo \#define LINUX_VERSION_CODE $(shell                 \
1359		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1360	else                                                             \
1361		echo \#define LINUX_VERSION_CODE $(shell                 \
1362		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1363	fi;                                                              \
1364	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1365	((c) > 255 ? 255 : (c)))';                                       \
1366	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1367	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1368	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1369endef
1370
1371$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1372$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1373$(version_h): FORCE
1374	$(call filechk,version.h)
1375
1376include/generated/utsrelease.h: include/config/kernel.release FORCE
1377	$(call filechk,utsrelease.h)
1378
1379filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1380	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1381
1382include/generated/compile.h: FORCE
1383	$(call filechk,compile.h)
1384
1385PHONY += headerdep
1386headerdep:
1387	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1388	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1389
1390# ---------------------------------------------------------------------------
1391# Kernel headers
1392
1393#Default location for installed headers
1394export INSTALL_HDR_PATH = $(objtree)/usr
1395
1396quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1397      cmd_headers_install = \
1398	mkdir -p $(INSTALL_HDR_PATH); \
1399	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1400	usr/include $(INSTALL_HDR_PATH)
1401
1402PHONY += headers_install
1403headers_install: headers
1404	$(call cmd,headers_install)
1405
1406PHONY += archheaders archscripts
1407
1408hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1409
1410PHONY += headers
1411headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders
1412ifdef HEADER_ARCH
1413	$(Q)$(MAKE) -f $(srctree)/Makefile HEADER_ARCH= SRCARCH=$(HEADER_ARCH) headers
1414else
1415	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1416	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1417endif
1418
1419ifdef CONFIG_HEADERS_INSTALL
1420prepare: headers
1421endif
1422
1423PHONY += usr_gen_init_cpio
1424usr_gen_init_cpio: scripts_basic
1425	$(Q)$(MAKE) $(build)=usr usr/gen_init_cpio
1426
1427PHONY += scripts_unifdef
1428scripts_unifdef: scripts_basic
1429	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1430
1431PHONY += scripts_gen_packed_field_checks
1432scripts_gen_packed_field_checks: scripts_basic
1433	$(Q)$(MAKE) $(build)=scripts scripts/gen_packed_field_checks
1434
1435# ---------------------------------------------------------------------------
1436# Install
1437
1438# Many distributions have the custom install script, /sbin/installkernel.
1439# If DKMS is installed, 'make install' will eventually recurse back
1440# to this Makefile to build and install external modules.
1441# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1442
1443quiet_cmd_install = INSTALL $(INSTALL_PATH)
1444      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1445
1446# ---------------------------------------------------------------------------
1447# vDSO install
1448
1449PHONY += vdso_install
1450vdso_install: export INSTALL_FILES = $(vdso-install-y)
1451vdso_install:
1452	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1453
1454# ---------------------------------------------------------------------------
1455# Tools
1456
1457ifdef CONFIG_OBJTOOL
1458prepare: tools/objtool
1459endif
1460
1461ifdef CONFIG_BPF
1462ifdef CONFIG_DEBUG_INFO_BTF
1463prepare: tools/bpf/resolve_btfids
1464endif
1465endif
1466
1467# The tools build system is not a part of Kbuild and tends to introduce
1468# its own unique issues. If you need to integrate a new tool into Kbuild,
1469# please consider locating that tool outside the tools/ tree and using the
1470# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1471# here. See Documentation/kbuild/makefiles.rst for details.
1472
1473PHONY += resolve_btfids_clean
1474
1475resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1476
1477# tools/bpf/resolve_btfids directory might not exist
1478# in output directory, skip its clean in that case
1479resolve_btfids_clean:
1480ifneq ($(wildcard $(resolve_btfids_O)),)
1481	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1482endif
1483
1484tools/: FORCE
1485	$(Q)mkdir -p $(objtree)/tools
1486	$(Q)$(MAKE) O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1487
1488tools/%: FORCE
1489	$(Q)mkdir -p $(objtree)/tools
1490	$(Q)$(MAKE) O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1491
1492# ---------------------------------------------------------------------------
1493# Kernel selftest
1494
1495PHONY += kselftest
1496kselftest: headers
1497	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1498
1499kselftest-%: headers FORCE
1500	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1501
1502PHONY += kselftest-merge
1503kselftest-merge:
1504	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1505	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1506		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1507	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1508
1509# ---------------------------------------------------------------------------
1510# Devicetree files
1511
1512ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1513dtstree := arch/$(SRCARCH)/boot/dts
1514endif
1515
1516ifneq ($(dtstree),)
1517
1518%.dtb: dtbs_prepare
1519	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1520
1521%.dtbo: dtbs_prepare
1522	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1523
1524PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1525dtbs: dtbs_prepare
1526	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1527
1528# include/config/kernel.release is actually needed when installing DTBs because
1529# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1530# dtbs_install depend on it as dtbs_install may run as root.
1531dtbs_prepare: include/config/kernel.release scripts_dtc
1532
1533ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1534export CHECK_DTBS=y
1535endif
1536
1537ifneq ($(CHECK_DTBS),)
1538dtbs_prepare: dt_binding_schemas
1539endif
1540
1541dtbs_check: dtbs
1542
1543dtbs_install:
1544	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1545
1546ifdef CONFIG_OF_EARLY_FLATTREE
1547all: dtbs
1548endif
1549
1550ifdef CONFIG_GENERIC_BUILTIN_DTB
1551vmlinux: dtbs
1552endif
1553
1554endif
1555
1556PHONY += scripts_dtc
1557scripts_dtc: scripts_basic
1558	$(Q)$(MAKE) $(build)=scripts/dtc
1559
1560ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1561export CHECK_DTBS=y
1562endif
1563
1564PHONY += dt_binding_check dt_binding_schemas
1565dt_binding_check: dt_binding_schemas scripts_dtc
1566	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1567
1568dt_binding_schemas:
1569	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1570
1571PHONY += dt_compatible_check
1572dt_compatible_check: dt_binding_schemas
1573	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1574
1575# ---------------------------------------------------------------------------
1576# Modules
1577
1578ifdef CONFIG_MODULES
1579
1580# By default, build modules as well
1581
1582all: modules
1583
1584# When we're building modules with modversions, we need to consider
1585# the built-in objects during the descend as well, in order to
1586# make sure the checksums are up to date before we record them.
1587ifdef CONFIG_MODVERSIONS
1588  KBUILD_BUILTIN := y
1589endif
1590
1591# Build modules
1592#
1593
1594# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1595# is an exception.
1596ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1597KBUILD_BUILTIN := y
1598modules: vmlinux
1599endif
1600
1601modules: modules_prepare
1602
1603# Target to prepare building external modules
1604modules_prepare: prepare
1605	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1606
1607endif # CONFIG_MODULES
1608
1609###
1610# Cleaning is done on three levels.
1611# make clean     Delete most generated files
1612#                Leave enough to build external modules
1613# make mrproper  Delete the current configuration, and all generated files
1614# make distclean Remove editor backup files, patch leftover files and the like
1615
1616# Directories & files removed with 'make clean'
1617CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1618	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1619	       modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \
1620	       compile_commands.json rust/test \
1621	       rust-project.json .vmlinux.objs .vmlinux.export.c \
1622               .builtin-dtbs-list .builtin-dtb.S
1623
1624# Directories & files removed with 'make mrproper'
1625MRPROPER_FILES += include/config include/generated          \
1626		  arch/$(SRCARCH)/include/generated .objdiff \
1627		  debian snap tar-install PKGBUILD pacman \
1628		  .config .config.old .version \
1629		  Module.symvers \
1630		  certs/signing_key.pem \
1631		  certs/x509.genkey \
1632		  vmlinux-gdb.py \
1633		  rpmbuild \
1634		  rust/libmacros.so rust/libmacros.dylib \
1635		  rust/libpin_init_internal.so rust/libpin_init_internal.dylib
1636
1637# clean - Delete most, but leave enough to build external modules
1638#
1639clean: private rm-files := $(CLEAN_FILES)
1640
1641PHONY += archclean vmlinuxclean
1642
1643vmlinuxclean:
1644	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1645	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1646
1647clean: archclean vmlinuxclean resolve_btfids_clean
1648
1649# mrproper - Delete all generated files, including .config
1650#
1651mrproper: private rm-files := $(MRPROPER_FILES)
1652mrproper-dirs      := $(addprefix _mrproper_,scripts)
1653
1654PHONY += $(mrproper-dirs) mrproper
1655$(mrproper-dirs):
1656	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1657
1658mrproper: clean $(mrproper-dirs)
1659	$(call cmd,rmfiles)
1660	@find . $(RCS_FIND_IGNORE) \
1661		\( -name '*.rmeta' \) \
1662		-type f -print | xargs rm -f
1663
1664# distclean
1665#
1666PHONY += distclean
1667
1668distclean: mrproper
1669	@find . $(RCS_FIND_IGNORE) \
1670		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1671		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1672		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1673		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1674		-type f -print | xargs rm -f
1675
1676
1677# Packaging of the kernel to various formats
1678# ---------------------------------------------------------------------------
1679
1680modules-cpio-pkg: usr_gen_init_cpio
1681
1682%src-pkg: FORCE
1683	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1684%pkg: include/config/kernel.release FORCE
1685	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1686
1687# Brief documentation of the typical targets used
1688# ---------------------------------------------------------------------------
1689
1690boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1691boards := $(sort $(notdir $(boards)))
1692board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1693board-dirs := $(sort $(notdir $(board-dirs:/=)))
1694
1695PHONY += help
1696help:
1697	@echo  'Cleaning targets:'
1698	@echo  '  clean		  - Remove most generated files but keep the config and'
1699	@echo  '                    enough build support to build external modules'
1700	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1701	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1702	@echo  ''
1703	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1704	@echo  ''
1705	@echo  'Other generic targets:'
1706	@echo  '  all		  - Build all targets marked with [*]'
1707	@echo  '* vmlinux	  - Build the bare kernel'
1708	@echo  '* modules	  - Build all modules'
1709	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1710	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1711	@echo  '  dir/            - Build all files in dir and below'
1712	@echo  '  dir/file.[ois]  - Build specified target only'
1713	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1714	@echo  '                    (requires compiler support for LLVM assembly generation)'
1715	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1716	@echo  '                    (requires a recent binutils and recent build (System.map))'
1717	@echo  '  dir/file.ko     - Build module including final link'
1718	@echo  '  modules_prepare - Set up for building external modules'
1719	@echo  '  tags/TAGS	  - Generate tags file for editors'
1720	@echo  '  cscope	  - Generate cscope index'
1721	@echo  '  gtags           - Generate GNU GLOBAL index'
1722	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1723	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1724	@echo  '  image_name	  - Output the image name (use with make -s)'
1725	@echo  '  headers	  - Build ready-to-install UAPI headers in usr/include'
1726	@echo  '  headers_install - Install sanitised kernel UAPI headers to INSTALL_HDR_PATH'; \
1727	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1728	 echo  ''
1729	@echo  'Static analysers:'
1730	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1731	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1732	@echo  '  versioncheck    - Sanity check on version.h usage'
1733	@echo  '  includecheck    - Check for duplicate included header files'
1734	@echo  '  headerdep       - Detect inclusion cycles in headers'
1735	@echo  '  coccicheck      - Check with Coccinelle'
1736	@echo  '  clang-analyzer  - Check with clang static analyzer'
1737	@echo  '  clang-tidy      - Check with clang-tidy'
1738	@echo  ''
1739	@echo  'Tools:'
1740	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1741	@echo  ''
1742	@echo  'Kernel selftest:'
1743	@echo  '  kselftest         - Build and run kernel selftest'
1744	@echo  '                      Build, install, and boot kernel before'
1745	@echo  '                      running kselftest on it'
1746	@echo  '                      Run as root for full coverage'
1747	@echo  '  kselftest-all     - Build kernel selftest'
1748	@echo  '  kselftest-install - Build and install kernel selftest'
1749	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1750	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1751	@echo  '		      kselftest to existing .config.'
1752	@echo  ''
1753	@echo  'Rust targets:'
1754	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1755	@echo  '		    available and, if not, explains why.'
1756	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1757	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1758	@echo  '		    is formatted, printing a diff otherwise.'
1759	@echo  '  rustdoc	  - Generate Rust documentation'
1760	@echo  '		    (requires kernel .config)'
1761	@echo  '  rusttest        - Runs the Rust tests'
1762	@echo  '                    (requires kernel .config; downloads external repos)'
1763	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1764	@echo  '		    (requires kernel .config)'
1765	@echo  '  dir/file.[os]   - Build specified target only'
1766	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1767	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1768	@echo  '                    The output is not intended to be compilable.'
1769	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1770	@echo  ''
1771	@$(if $(dtstree), \
1772		echo 'Devicetree:'; \
1773		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1774		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1775		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1776		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1777		echo '  dtbs_check         - Validate device tree source files';\
1778		echo '')
1779
1780	@echo 'Userspace tools targets:'
1781	@echo '  use "make tools/help"'
1782	@echo '  or  "cd tools; make help"'
1783	@echo  ''
1784	@echo  'Kernel packaging:'
1785	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1786	@echo  ''
1787	@echo  'Documentation targets:'
1788	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1789	@echo  ''
1790	@echo  'Architecture-specific targets ($(SRCARCH)):'
1791	@$(or $(archhelp),\
1792		echo '  No architecture-specific help defined for $(SRCARCH)')
1793	@echo  ''
1794	@$(if $(boards), \
1795		$(foreach b, $(boards), \
1796		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1797		echo '')
1798	@$(if $(board-dirs), \
1799		$(foreach b, $(board-dirs), \
1800		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1801		printf "  %-16s - Show all of the above\\n" help-boards; \
1802		echo '')
1803
1804	@echo  '  make V=n   [targets] 1: verbose build'
1805	@echo  '                       2: give reason for rebuild of target'
1806	@echo  '                       V=1 and V=2 can be combined with V=12'
1807	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1808	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1809	@echo  '                       (sparse by default)'
1810	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1811	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1812	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1813	@echo  '		1: warnings which may be relevant and do not occur too often'
1814	@echo  '		2: warnings which occur quite often but may still be relevant'
1815	@echo  '		3: more obscure warnings, can most likely be ignored'
1816	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1817	@echo  '		e: warnings are being treated as errors'
1818	@echo  '		Multiple levels can be combined with W=12 or W=123'
1819	@echo  '  make UT=1   [targets] Warn if a tracepoint is defined but not used.'
1820	@echo  '          [ This will be removed when all current unused tracepoints are eliminated. ]'
1821	@$(if $(dtstree), \
1822		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1823		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1824		)
1825	@echo  ''
1826	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1827	@echo  'For further info see the ./README file'
1828
1829
1830help-board-dirs := $(addprefix help-,$(board-dirs))
1831
1832help-boards: $(help-board-dirs)
1833
1834boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1835
1836$(help-board-dirs): help-%:
1837	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1838	@$(if $(boards-per-dir), \
1839		$(foreach b, $(boards-per-dir), \
1840		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1841		echo '')
1842
1843
1844# Documentation targets
1845# ---------------------------------------------------------------------------
1846DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1847	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs mandocs \
1848	       htmldocs-redirects
1849
1850PHONY += $(DOC_TARGETS)
1851$(DOC_TARGETS):
1852	$(Q)$(MAKE) $(build)=Documentation $@
1853
1854
1855# Rust targets
1856# ---------------------------------------------------------------------------
1857
1858# "Is Rust available?" target
1859PHONY += rustavailable
1860rustavailable:
1861	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1862
1863# Documentation target
1864#
1865# Using the singular to avoid running afoul of `no-dot-config-targets`.
1866PHONY += rustdoc
1867rustdoc: prepare
1868	$(Q)$(MAKE) $(build)=rust $@
1869
1870# Testing target
1871PHONY += rusttest
1872rusttest: prepare
1873	$(Q)$(MAKE) $(build)=rust $@
1874
1875# Formatting targets
1876#
1877# Generated files as well as vendored crates are skipped.
1878PHONY += rustfmt rustfmtcheck
1879
1880rustfmt:
1881	$(Q)find $(srctree) $(RCS_FIND_IGNORE) \
1882		\( \
1883			-path $(srctree)/rust/proc-macro2 \
1884			-o -path $(srctree)/rust/quote \
1885			-o -path $(srctree)/rust/syn \
1886		\) -prune -o \
1887		-type f -a -name '*.rs' -a ! -name '*generated*' -print \
1888		| xargs $(RUSTFMT) $(rustfmt_flags)
1889
1890rustfmtcheck: rustfmt_flags = --check
1891rustfmtcheck: rustfmt
1892
1893# Misc
1894# ---------------------------------------------------------------------------
1895
1896PHONY += misc-check
1897misc-check:
1898	$(Q)$(srctree)/scripts/misc-check
1899
1900all: misc-check
1901
1902PHONY += scripts_gdb
1903scripts_gdb: prepare0
1904	$(Q)$(MAKE) $(build)=scripts/gdb
1905	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1906
1907ifdef CONFIG_GDB_SCRIPTS
1908all: scripts_gdb
1909endif
1910
1911else # KBUILD_EXTMOD
1912
1913filechk_kernel.release = echo $(KERNELRELEASE)
1914
1915###
1916# External module support.
1917# When building external modules the kernel used as basis is considered
1918# read-only, and no consistency checks are made and the make
1919# system is not used on the basis kernel. If updates are required
1920# in the basis kernel ordinary make commands (without M=...) must be used.
1921
1922# We are always building only modules.
1923KBUILD_BUILTIN :=
1924KBUILD_MODULES := y
1925
1926build-dir := .
1927
1928clean-dirs := .
1929clean: private rm-files := Module.symvers modules.nsdeps compile_commands.json
1930
1931PHONY += prepare
1932# now expand this into a simple variable to reduce the cost of shell evaluations
1933prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1934prepare:
1935	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1936		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1937		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1938		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1939	fi
1940
1941PHONY += help
1942help:
1943	@echo  '  Building external modules.'
1944	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1945	@echo  ''
1946	@echo  '  modules         - default target, build the module(s)'
1947	@echo  '  modules_install - install the module'
1948	@echo  '  clean           - remove generated files in module directory only'
1949	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1950	@echo  ''
1951
1952ifndef CONFIG_MODULES
1953modules modules_install: __external_modules_error
1954__external_modules_error:
1955	@echo >&2 '***'
1956	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1957	@echo >&2 '*** You cannot build or install external modules.'
1958	@echo >&2 '***'
1959	@false
1960endif
1961
1962endif # KBUILD_EXTMOD
1963
1964# ---------------------------------------------------------------------------
1965# Modules
1966
1967PHONY += modules modules_install modules_sign modules_prepare
1968
1969modules_install:
1970	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1971	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1972
1973ifeq ($(CONFIG_MODULE_SIG),y)
1974# modules_sign is a subset of modules_install.
1975# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1976modules_sign: modules_install
1977	@:
1978else
1979modules_sign:
1980	@echo >&2 '***'
1981	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1982	@echo >&2 '***'
1983	@false
1984endif
1985
1986ifdef CONFIG_MODULES
1987
1988modules.order: $(build-dir)
1989	@:
1990
1991# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1992# This is solely useful to speed up test compiles.
1993modules: modpost
1994ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1995	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1996endif
1997
1998PHONY += modules_check
1999modules_check: modules.order
2000	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
2001
2002else # CONFIG_MODULES
2003
2004modules:
2005	@:
2006
2007KBUILD_MODULES :=
2008
2009endif # CONFIG_MODULES
2010
2011PHONY += modpost
2012modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
2013	 $(if $(KBUILD_MODULES), modules_check)
2014	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2015
2016# Single targets
2017# ---------------------------------------------------------------------------
2018# To build individual files in subdirectories, you can do like this:
2019#
2020#   make foo/bar/baz.s
2021#
2022# The supported suffixes for single-target are listed in 'single-targets'
2023#
2024# To build only under specific subdirectories, you can do like this:
2025#
2026#   make foo/bar/baz/
2027
2028ifdef single-build
2029
2030# .ko is special because modpost is needed
2031single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
2032single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
2033		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
2034
2035$(single-ko): single_modules
2036	@:
2037$(single-no-ko): $(build-dir)
2038	@:
2039
2040# Remove modules.order when done because it is not the real one.
2041PHONY += single_modules
2042single_modules: $(single-no-ko) modules_prepare
2043	$(Q){ $(foreach m, $(single-ko), echo $(m:%.ko=%.o);) } > modules.order
2044	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2045ifneq ($(KBUILD_MODPOST_NOFINAL),1)
2046	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
2047endif
2048	$(Q)rm -f modules.order
2049
2050single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
2051
2052KBUILD_MODULES := y
2053
2054endif
2055
2056prepare: outputmakefile
2057
2058# Preset locale variables to speed up the build process. Limit locale
2059# tweaks to this spot to avoid wrong language settings when running
2060# make menuconfig etc.
2061# Error messages still appears in the original language
2062PHONY += $(build-dir)
2063$(build-dir): prepare
2064	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2065
2066clean-dirs := $(addprefix _clean_, $(clean-dirs))
2067PHONY += $(clean-dirs) clean
2068$(clean-dirs):
2069	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2070
2071clean: $(clean-dirs)
2072	$(call cmd,rmfiles)
2073	@find . $(RCS_FIND_IGNORE) \
2074		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2075		-o -name '*.ko.*' \
2076		-o -name '*.dtb' -o -name '*.dtbo' \
2077		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2078		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
2079		-o -name '*.dwo' -o -name '*.lst' \
2080		-o -name '*.su' -o -name '*.mod' \
2081		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2082		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2083		-o -name '*.asn1.[ch]' \
2084		-o -name '*.symtypes' -o -name 'modules.order' \
2085		-o -name '*.c.[012]*.*' \
2086		-o -name '*.ll' \
2087		-o -name '*.gcno' \
2088		\) -type f -print \
2089		-o -name '.tmp_*' -print \
2090		| xargs rm -rf
2091
2092# Generate tags for editors
2093# ---------------------------------------------------------------------------
2094quiet_cmd_tags = GEN     $@
2095      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2096
2097tags TAGS cscope gtags: FORCE
2098	$(call cmd,tags)
2099
2100# Generate rust-project.json (a file that describes the structure of non-Cargo
2101# Rust projects) for rust-analyzer (an implementation of the Language Server
2102# Protocol).
2103PHONY += rust-analyzer
2104rust-analyzer:
2105	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
2106ifdef KBUILD_EXTMOD
2107# FIXME: external modules must not descend into a sub-directory of the kernel
2108	$(Q)$(MAKE) $(build)=$(objtree)/rust src=$(srctree)/rust $@
2109else
2110	$(Q)$(MAKE) $(build)=rust $@
2111endif
2112
2113# Script to generate missing namespace dependencies
2114# ---------------------------------------------------------------------------
2115
2116PHONY += nsdeps
2117nsdeps: export KBUILD_NSDEPS=1
2118nsdeps: modules
2119	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2120
2121# Clang Tooling
2122# ---------------------------------------------------------------------------
2123
2124quiet_cmd_gen_compile_commands = GEN     $@
2125      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2126
2127compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2128	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2129	$(if $(CONFIG_MODULES), modules.order) FORCE
2130	$(call if_changed,gen_compile_commands)
2131
2132targets += compile_commands.json
2133
2134PHONY += clang-tidy clang-analyzer
2135
2136ifdef CONFIG_CC_IS_CLANG
2137quiet_cmd_clang_tools = CHECK   $<
2138      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2139
2140clang-tidy clang-analyzer: compile_commands.json
2141	$(call cmd,clang_tools)
2142else
2143clang-tidy clang-analyzer:
2144	@echo "$@ requires CC=clang" >&2
2145	@false
2146endif
2147
2148# Scripts to check various things for consistency
2149# ---------------------------------------------------------------------------
2150
2151PHONY += includecheck versioncheck coccicheck
2152
2153includecheck:
2154	find $(srctree)/* $(RCS_FIND_IGNORE) \
2155		-name '*.[hcS]' -type f -print | sort \
2156		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2157
2158versioncheck:
2159	find $(srctree)/* $(RCS_FIND_IGNORE) \
2160		-name '*.[hcS]' -type f -print | sort \
2161		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2162
2163coccicheck:
2164	$(Q)$(BASH) $(srctree)/scripts/$@
2165
2166PHONY += checkstack kernelrelease kernelversion image_name
2167
2168# UML needs a little special treatment here.  It wants to use the host
2169# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2170# else wants $(ARCH), including people doing cross-builds, which means
2171# that $(SUBARCH) doesn't work here.
2172ifeq ($(ARCH), um)
2173CHECKSTACK_ARCH := $(SUBARCH)
2174else
2175CHECKSTACK_ARCH := $(ARCH)
2176endif
2177MINSTACKSIZE	?= 100
2178checkstack:
2179	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2180	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2181
2182kernelrelease:
2183	@$(filechk_kernel.release)
2184
2185kernelversion:
2186	@echo $(KERNELVERSION)
2187
2188image_name:
2189	@echo $(KBUILD_IMAGE)
2190
2191PHONY += run-command
2192run-command:
2193	$(Q)$(KBUILD_RUN_COMMAND)
2194
2195quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2196      cmd_rmfiles = rm -rf $(rm-files)
2197
2198# read saved command lines for existing targets
2199existing-targets := $(wildcard $(sort $(targets)))
2200
2201-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2202
2203endif # config-build
2204endif # mixed-build
2205endif # need-sub-make
2206
2207PHONY += FORCE
2208FORCE:
2209
2210# Declare the contents of the PHONY variable as phony.  We keep that
2211# information in a variable so we can use it in if_changed and friends.
2212.PHONY: $(PHONY)
2213