linux/scripts/Makefile.lib
Linus Torvalds 79db4d2293 clang-lto series for v5.12-rc1
- Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen)
 - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmA0OEYACgkQiXL039xt
 wCYGJw/8CcyvQUGmXYEZVDLMahKz93RYijiGuSTVnhl0pNAyfOojaZ8Z//eD1VNA
 s82azW1XybbA6RnPGD7YQzYz27cSF2qUFDmplwVfE4mwBnPXzRxtVBDLSxksP1HS
 77sCOu91QhbovPCWET4dSHLJB3DVc78FiW4lVlRgrglyAz+dut1iXYar5e7VNoS0
 S4MwnqwteHC6YXP619rubhpdDoj7njuw1uxRIaodt9S/zRSpl5MCUgHmzQusgezs
 yWDdPHPWHnF7xxKgwSvE7AKZPdOnIxKxRi6Yd6vUIyrYB3qLZkFe75nUsgMroAhs
 /Bgrn69U2McMiJsOdh0ERzP2VNYfvMacBQ308nb45j83Bgv5l6uj8QOZU4ZogmXV
 PsDzsfUe9GsxgYexfozGX61rpd6JinzQKVyoDW3oTT54fbBxO3uDqT8kOBw72dPT
 9nkOxTzyb+UO0dpb/MhXLGkGcv8+lTA5ffVIKUx5UxKngRbukc3dxwVJgO4HmucK
 bwVQGD83D+/if5/JL9WtQRjDwFEn+IFmdv+3cAXkRo4IIS18LPZB1MJncTeWr8Z9
 HlkuDXlJOncUWCABGd1IKu1j0S2HpXV4qhqQXJ6PdfOvUPEaD9qgqEAjD5FxxyXF
 wpaV2MWya5i1FGwD5UKhi8hVnAFJyF0/w+enjiPwlmIbjdyEVXE=
 =6peY
 -----END PGP SIGNATURE-----

Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO updates from Kees Cook:
 "Clang Link Time Optimization.

  This is built on the work done preparing for LTO by arm64 folks,
  tracing folks, etc. This includes the core changes as well as the
  remaining pieces for arm64 (LTO has been the default build method on
  Android for about 3 years now, as it is the prerequisite for the
  Control Flow Integrity protections).

  While x86 LTO enablement is done, it depends on some pending objtool
  clean-ups. It's possible that I'll send a "part 2" pull request for
  LTO that includes x86 support.

  For merge log posterity, and as detailed in commit dc5723b02e
  ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
  build:

        make LLVM=1 LLVM_IAS=1 defconfig
        scripts/config -e LTO_CLANG_THIN
        make LLVM=1 LLVM_IAS=1

  (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
  and "ARCH=arm64" to the "make" command lines.)

  Summary:

   - Clang LTO build infrastructure and arm64-specific enablement (Sami
     Tolvanen)

   - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"

* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
  arm64: allow LTO to be selected
  arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
  arm64: vdso: disable LTO
  drivers/misc/lkdtm: disable LTO for rodata.o
  efi/libstub: disable LTO
  scripts/mod: disable LTO for empty.c
  modpost: lto: strip .lto from module names
  PCI: Fix PREL32 relocations for LTO
  init: lto: fix PREL32 relocations
  init: lto: ensure initcall ordering
  kbuild: lto: add a default list of used symbols
  kbuild: lto: merge module sections
  kbuild: lto: limit inlining
  kbuild: lto: fix module versioning
  kbuild: add support for Clang LTO
  tracing: move function tracer options to Kconfig
2021-02-23 09:28:51 -08:00

487 lines
17 KiB
Text

# SPDX-License-Identifier: GPL-2.0
# Backward compatibility
asflags-y += $(EXTRA_AFLAGS)
ccflags-y += $(EXTRA_CFLAGS)
cppflags-y += $(EXTRA_CPPFLAGS)
ldflags-y += $(EXTRA_LDFLAGS)
ifneq ($(always),)
$(warning 'always' is deprecated. Please use 'always-y' instead)
always-y += $(always)
endif
ifneq ($(hostprogs-y),)
$(warning 'hostprogs-y' is deprecated. Please use 'hostprogs' instead)
hostprogs += $(hostprogs-y)
endif
ifneq ($(hostprogs-m),)
$(warning 'hostprogs-m' is deprecated. Please use 'hostprogs' instead)
hostprogs += $(hostprogs-m)
endif
# flags that take effect in current and sub directories
KBUILD_AFLAGS += $(subdir-asflags-y)
KBUILD_CFLAGS += $(subdir-ccflags-y)
# Figure out what we need to build from the various variables
# ===========================================================================
# When an object is listed to be built compiled-in and modular,
# only build the compiled-in version
obj-m := $(filter-out $(obj-y),$(obj-m))
# Libraries are always collected in one lib file.
# Filter out objects already built-in
lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
# Subdirectories we need to descend into
subdir-ym := $(sort $(subdir-y) $(subdir-m) \
$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
# Handle objects in subdirs:
# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
# foo/modules.order
# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
#
# Generate modules.order to determine modorder. Unfortunately, we don't have
# information about ordering between -y and -m subdirs. Just put -y's first.
ifdef need-modorder
obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
else
obj-m := $(filter-out %/, $(obj-m))
endif
ifdef need-builtin
obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
else
obj-y := $(filter-out %/, $(obj-y))
endif
# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))), $(m))))
multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))), $(m))))
multi-used := $(multi-used-y) $(multi-used-m)
# Replace multi-part objects by their individual parts,
# including built-in.a from subdirectories
real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))
always-y += $(always-m)
# hostprogs-always-y += foo
# ... is a shorthand for
# hostprogs += foo
# always-y += foo
hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
always-y += $(hostprogs-always-y) $(hostprogs-always-m)
# userprogs-always-y is likewise.
userprogs += $(userprogs-always-y) $(userprogs-always-m)
always-y += $(userprogs-always-y) $(userprogs-always-m)
# DTB
# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
extra-y += $(dtb-y)
extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
ifneq ($(CHECK_DTBS),)
extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
extra-y += $(patsubst %.dtbo,%.dt.yaml, $(dtb-y))
extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtbo,%.dt.yaml, $(dtb-))
endif
# Add subdir path
extra-y := $(addprefix $(obj)/,$(extra-y))
always-y := $(addprefix $(obj)/,$(always-y))
targets := $(addprefix $(obj)/,$(targets))
obj-m := $(addprefix $(obj)/,$(obj-m))
lib-y := $(addprefix $(obj)/,$(lib-y))
real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
# Finds the multi-part object the current object will be linked into.
# If the object belongs to two or more multi-part objects, list them all.
modname-multi = $(sort $(foreach m,$(multi-used),\
$(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=))))
__modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
modname = $(subst $(space),:,$(__modname))
modfile = $(addprefix $(obj)/,$(__modname))
# target with $(obj)/ and its suffix stripped
target-stem = $(basename $(patsubst $(obj)/%,%,$@))
# These flags are needed for modversions and compiling, so we define them here
# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
# end up in (or would, if it gets compiled in)
name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
name-fix = $(call stringify,$(call name-fix-token,$1))
basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
-D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
$(filter-out $(ccflags-remove-y), \
$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
$(CFLAGS_$(target-stem).o))
_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
$(filter-out $(asflags-remove-y), \
$(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
$(AFLAGS_$(target-stem).o))
_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
#
# Enable gcov profiling flags for a file, directory or for all files depending
# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
# (in this order)
#
ifeq ($(CONFIG_GCOV_KERNEL),y)
_c_flags += $(if $(patsubst n%,, \
$(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
$(CFLAGS_GCOV))
endif
#
# Enable address sanitizer flags for kernel except some files or directories
# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
#
ifeq ($(CONFIG_KASAN),y)
ifneq ($(CONFIG_KASAN_HW_TAGS),y)
_c_flags += $(if $(patsubst n%,, \
$(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
endif
endif
ifeq ($(CONFIG_UBSAN),y)
_c_flags += $(if $(patsubst n%,, \
$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
$(CFLAGS_UBSAN))
endif
ifeq ($(CONFIG_KCOV),y)
_c_flags += $(if $(patsubst n%,, \
$(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
$(CFLAGS_KCOV))
endif
#
# Enable KCSAN flags except some files or directories we don't want to check
# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
#
ifeq ($(CONFIG_KCSAN),y)
_c_flags += $(if $(patsubst n%,, \
$(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
$(CFLAGS_KCSAN))
endif
# $(srctree)/$(src) for including checkin headers from generated source files
# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
ifdef building_out_of_srctree
_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
endif
endif
part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
quiet_modtag = $(if $(part-of-module),[M], )
modkern_cflags = \
$(if $(part-of-module), \
$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
modkern_aflags = $(if $(part-of-module), \
$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
-include $(srctree)/include/linux/compiler_types.h \
$(_c_flags) $(modkern_cflags) \
$(basename_flags) $(modname_flags)
a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
$(_a_flags) $(modkern_aflags)
cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
$(_cpp_flags)
ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
$(addprefix -I,$(DTC_INCLUDE)) \
-undef -D__DTS__
# Useful for describing the dependency of composite objects
# Usage:
# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
define multi_depend
$(foreach m, $(notdir $1), \
$(eval $(obj)/$m: \
$(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
endef
quiet_cmd_copy = COPY $@
cmd_copy = cp $< $@
# Shipped files
# ===========================================================================
quiet_cmd_shipped = SHIPPED $@
cmd_shipped = cat $< > $@
$(obj)/%: $(src)/%_shipped
$(call cmd,shipped)
# Commands useful for building a boot image
# ===========================================================================
#
# Use as following:
#
# target: source(s) FORCE
# $(if_changed,ld/objcopy/gzip)
#
# and add target to extra-y so that we know we have to
# read in the saved command line
# Linking
# ---------------------------------------------------------------------------
quiet_cmd_ld = LD $@
cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
# Archive
# ---------------------------------------------------------------------------
quiet_cmd_ar = AR $@
cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
# Objcopy
# ---------------------------------------------------------------------------
quiet_cmd_objcopy = OBJCOPY $@
cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
# Gzip
# ---------------------------------------------------------------------------
quiet_cmd_gzip = GZIP $@
cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
# DTC
# ---------------------------------------------------------------------------
DTC ?= $(objtree)/scripts/dtc/dtc
DTC_FLAGS += -Wno-interrupt_provider
# Disable noisy checks by default
ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
DTC_FLAGS += -Wno-unit_address_vs_reg \
-Wno-unit_address_format \
-Wno-avoid_unnecessary_addr_size \
-Wno-alias_paths \
-Wno-graph_child_address \
-Wno-simple_bus_reg \
-Wno-unique_unit_address \
-Wno-pci_device_reg
endif
ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
DTC_FLAGS += -Wnode_name_chars_strict \
-Wproperty_name_chars_strict \
-Winterrupt_provider
endif
DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
# Generate an assembly file to wrap the output of the device tree compiler
quiet_cmd_dt_S_dtb= DTB $@
cmd_dt_S_dtb= \
{ \
echo '\#include <asm-generic/vmlinux.lds.h>'; \
echo '.section .dtb.init.rodata,"a"'; \
echo '.balign STRUCT_ALIGNMENT'; \
echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
echo '__dtb_$(subst -,_,$(*F))_begin:'; \
echo '.incbin "$<" '; \
echo '__dtb_$(subst -,_,$(*F))_end:'; \
echo '.global __dtb_$(subst -,_,$(*F))_end'; \
echo '.balign STRUCT_ALIGNMENT'; \
} > $@
$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
$(call if_changed,dt_S_dtb)
quiet_cmd_dtc = DTC $@
cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
$(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
-d $(depfile).dtc.tmp $(dtc-tmp) ; \
cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
$(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
$(call if_changed_dep,dtc)
$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
$(call if_changed_dep,dtc)
DT_CHECKER ?= dt-validate
DT_BINDING_DIR := Documentation/devicetree/bindings
# DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile
DT_TMP_SCHEMA ?= $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
quiet_cmd_dtb_check = CHECK $@
cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@
define rule_dtc
$(call cmd_and_fixdep,dtc)
$(call cmd,dtb_check)
endef
$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
$(call if_changed_rule,dtc,yaml)
dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
# Bzip2
# ---------------------------------------------------------------------------
# Bzip2 and LZMA do not include size in file... so we have to fake that;
# append the size as a 32-bit littleendian number as gzip does.
size_append = printf $(shell \
dec_size=0; \
for F in $(real-prereqs); do \
fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
dec_size=$$(expr $$dec_size + $$fsize); \
done; \
printf "%08x\n" $$dec_size | \
sed 's/\(..\)/\1 /g' | { \
read ch0 ch1 ch2 ch3; \
for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
printf '%s%03o' '\\' $$((0x$$ch)); \
done; \
} \
)
quiet_cmd_bzip2 = BZIP2 $@
cmd_bzip2 = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
# Lzma
# ---------------------------------------------------------------------------
quiet_cmd_lzma = LZMA $@
cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
quiet_cmd_lzo = LZO $@
cmd_lzo = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
quiet_cmd_lz4 = LZ4 $@
cmd_lz4 = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
$(size_append); } > $@
# U-Boot mkimage
# ---------------------------------------------------------------------------
MKIMAGE := $(srctree)/scripts/mkuboot.sh
# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
# the number of overrides in arch makefiles
UIMAGE_ARCH ?= $(SRCARCH)
UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
UIMAGE_OPTS-y ?=
UIMAGE_TYPE ?= kernel
UIMAGE_LOADADDR ?= arch_must_set_this
UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
quiet_cmd_uimage = UIMAGE $@
cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
-T $(UIMAGE_TYPE) \
-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
-n $(UIMAGE_NAME) -d $< $@
# XZ
# ---------------------------------------------------------------------------
# Use xzkern to compress the kernel image and xzmisc to compress other things.
#
# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
# of the kernel decompressor. A BCJ filter is used if it is available for
# the target architecture. xzkern also appends uncompressed size of the data
# using size_append. The .xz format has the size information available at
# the end of the file too, but it's in more complex format and it's good to
# avoid changing the part of the boot code that reads the uncompressed size.
# Note that the bytes added by size_append will make the xz tool think that
# the file is corrupt. This is expected.
#
# xzmisc doesn't use size_append, so it can be used to create normal .xz
# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
# big dictionary would increase the memory usage too much in the multi-call
# decompression mode. A BCJ filter isn't used either.
quiet_cmd_xzkern = XZKERN $@
cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
$(size_append); } > $@
quiet_cmd_xzmisc = XZMISC $@
cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
# ZSTD
# ---------------------------------------------------------------------------
# Appends the uncompressed size of the data using size_append. The .zst
# format has the size information available at the beginning of the file too,
# but it's in a more complex format and it's good to avoid changing the part
# of the boot code that reads the uncompressed size.
#
# Note that the bytes added by size_append will make the zstd tool think that
# the file is corrupt. This is expected.
#
# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
# single pass, so zstd doesn't need to allocate a window buffer. When streaming
# decompression is used, like initramfs decompression, zstd22 should likely not
# be used because it would require zstd to allocate a 128 MB buffer.
quiet_cmd_zstd = ZSTD $@
cmd_zstd = { cat $(real-prereqs) | $(ZSTD) -19; $(size_append); } > $@
quiet_cmd_zstd22 = ZSTD22 $@
cmd_zstd22 = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
# ASM offsets
# ---------------------------------------------------------------------------
# Default sed regexp - multiline due to syntax constraints
#
# Use [:space:] because LLVM's integrated assembler inserts <tab> around
# the .ascii directive whereas GCC keeps the <space> as-is.
define sed-offsets
's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
/^->/{s:->#\(.*\):/* \1 */:; \
s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
s:->::; p;}'
endef
# Use filechk to avoid rebuilds when a header changes, but the resulting file
# does not
define filechk_offsets
echo "#ifndef $2"; \
echo "#define $2"; \
echo "/*"; \
echo " * DO NOT MODIFY."; \
echo " *"; \
echo " * This file was generated by Kbuild"; \
echo " */"; \
echo ""; \
sed -ne $(sed-offsets) < $<; \
echo ""; \
echo "#endif"
endef