Commit 1e9ed936 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 

Pull Kbuild updates from Masahiro Yamada:

 - Remove the global -isystem compiler flag, which was made possible by
   the introduction of <linux/stdarg.h>

 - Improve the Kconfig help to print the location in the top menu level

 - Fix "FORCE prerequisite is missing" build warning for sparc

 - Add new build targets, tarzst-pkg and perf-tarzst-src-pkg, which
   generate a zstd-compressed tarball

 - Prevent gen_init_cpio tool from generating a corrupted cpio when
   KBUILD_BUILD_TIMESTAMP is set to 2106-02-07 or later

 - Misc cleanups

* tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
  kbuild: use more subdir- for visiting subdirectories while cleaning
  sh: remove meaningless archclean line
  initramfs: Check timestamp to prevent broken cpio archive
  kbuild: split DEBUG_CFLAGS out to scripts/Makefile.debug
  gen_init_cpio: add static const qualifiers
  kbuild: Add make tarzst-pkg build option
  scripts: update the comments of kallsyms support
  sparc: Add missing "FORCE" target when using if_changed
  kconfig: refactor conf_touch_dep()
  kconfig: refactor conf_write_dep()
  kconfig: refactor conf_write_autoconf()
  kconfig: add conf_get_autoheader_name()
  kconfig: move sym_escape_string_value() to confdata.c
  kconfig: refactor listnewconfig code
  kconfig: refactor conf_write_symbol()
  kconfig: refactor conf_write_heading()
  kconfig: remove 'const' from the return type of sym_escape_string_value()
  kconfig: rename a variable in the lexer to a clearer name
  kconfig: narrow the scope of variables in the lexer
  kconfig: Create links to main menu items in search
  ...
parents 67b7e1f2 8212f898

Documentation/kbuild/makefiles.rst

+2 −15
Original line number Diff line number Diff line
@@ -1050,22 +1050,9 @@ is not sufficient this sometimes needs to be explicit. 
The above assignment instructs kbuild to descend down in the

directory compressed/ when "make clean" is executed.



To support the clean infrastructure in the Makefiles that build the

final bootimage there is an optional target named archclean:



	Example::



		#arch/x86/Makefile

		archclean:

			$(Q)$(MAKE) $(clean)=arch/x86/boot



When "make clean" is executed, make will descend down in arch/x86/boot,

and clean as usual. The Makefile located in arch/x86/boot/ may use

the subdir- trick to descend further down.



Note 1: arch/$(SRCARCH)/Makefile cannot use "subdir-", because that file is

included in the top level makefile, and the kbuild infrastructure

is not operational at that point.

included in the top level makefile. Instead, arch/$(SRCARCH)/Kbuild can use

"subdir-".



Note 2: All directories listed in core-y, libs-y, drivers-y and net-y will

be visited during "make clean".

Makefile

+2 −39
Original line number Diff line number Diff line
@@ -850,44 +850,6 @@ ifdef CONFIG_ZERO_CALL_USED_REGS 
KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr

endif



DEBUG_CFLAGS	:=



ifdef CONFIG_DEBUG_INFO



ifdef CONFIG_DEBUG_INFO_SPLIT

DEBUG_CFLAGS	+= -gsplit-dwarf

else

DEBUG_CFLAGS	+= -g

endif



ifndef CONFIG_AS_IS_LLVM

KBUILD_AFLAGS	+= -Wa,-gdwarf-2

endif



ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT

dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4

dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5

DEBUG_CFLAGS	+= -gdwarf-$(dwarf-version-y)

endif



ifdef CONFIG_DEBUG_INFO_REDUCED

DEBUG_CFLAGS	+= -fno-var-tracking

ifdef CONFIG_CC_IS_GCC

DEBUG_CFLAGS	+= -femit-struct-debug-baseonly

endif

endif



ifdef CONFIG_DEBUG_INFO_COMPRESSED

DEBUG_CFLAGS	+= -gz=zlib

KBUILD_AFLAGS	+= -gz=zlib

KBUILD_LDFLAGS	+= --compress-debug-sections=zlib

endif



endif # CONFIG_DEBUG_INFO



KBUILD_CFLAGS += $(DEBUG_CFLAGS)

export DEBUG_CFLAGS



ifdef CONFIG_FUNCTION_TRACER

ifdef CONFIG_FTRACE_MCOUNT_USE_CC

  CC_FLAGS_FTRACE	+= -mrecord-mcount
@@ -984,7 +946,7 @@ KBUILD_CFLAGS += -falign-functions=64 
endif



# arch Makefile may override CC so keep this after arch Makefile is included

NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)

NOSTDINC_FLAGS += -nostdinc



# warn about C99 declaration after statement

KBUILD_CFLAGS += -Wdeclaration-after-statement
@@ -1051,6 +1013,7 @@ KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) 


# include additional Makefiles when needed

include-y			:= scripts/Makefile.extrawarn

include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug

include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan

include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan

include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan

arch/alpha/Kbuild

+3 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

obj-y			+= kernel/ mm/

obj-$(CONFIG_MATHEMU)	+= math-emu/



# for cleaning

subdir- += boot

arch/alpha/Makefile

+0 −3
Original line number Diff line number Diff line
@@ -55,9 +55,6 @@ $(boot)/vmlinux.gz: vmlinux 
bootimage bootpfile bootpzfile: vmlinux

	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@



archclean:

	$(Q)$(MAKE) $(clean)=$(boot)



archheaders:

	$(Q)$(MAKE) $(build)=arch/alpha/kernel/syscalls all

arch/arc/Kbuild

+3 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

obj-y += kernel/

obj-y += mm/



# for cleaning

subdir- += boot