Merge tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - remove headers_{install,check}_all targets

 - remove unreasonable 'depends on !UML' from CONFIG_SAMPLES

 - re-implement 'make headers_install' more cleanly

 - add new header-test-y syntax to compile-test headers

 - compile-test exported headers to ensure they are compilable in
   user-space

 - compile-test headers under include/ to ensure they are self-contained

 - remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value
   flags

 - add -Werror=unknown-warning-option for Clang

 - add 128-bit built-in types support to genksyms

 - fix missed rebuild of modules.builtin

 - propagate 'No space left on device' error in fixdep to Make

 - allow Clang to use its integrated assembler

 - improve some coccinelle scripts

 - add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute
   path for $(srctree).

 - do not ignore errors when compression utility is missing

 - misc cleanups

* tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits)
  kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix
  kbuild: Inform user to pass ARCH= for make mrproper
  kbuild: fix compression errors getting ignored
  kbuild: add a flag to force absolute path for srctree
  kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree
  kbuild: remove src and obj from the top Makefile
  scripts/tags.sh: remove unused environment variables from comments
  scripts/tags.sh: drop SUBARCH support for ARM
  kbuild: compile-test kernel headers to ensure they are self-contained
  kheaders: include only headers into kheaders_data.tar.xz
  kheaders: remove meaningless -R option of 'ls'
  kbuild: support header-test-pattern-y
  kbuild: do not create wrappers for header-test-y
  kbuild: compile-test exported headers to ensure they are self-contained
  init/Kconfig: add CONFIG_CC_CAN_LINK
  kallsyms: exclude kasan local symbols on s390
  kbuild: add more hints about SUBDIRS replacement
  coccinelle: api/stream_open: treat all wait_.*() calls as blocking
  coccinelle: put_device: Add a cast to an expression for an assignment
  coccinelle: put_device: Adjust a message construction
  ...

lib/Kconfig.debug

@@ -305,19 +305,26 @@ config DEBUG_FS
 
 	  If unsure, say N.
 
-config HEADERS_CHECK
-	bool "Run 'make headers_check' when building vmlinux"
+config HEADERS_INSTALL
+	bool "Install uapi headers to usr/include"
 	depends on !UML
 	help
-	  This option will extract the user-visible kernel headers whenever
-	  building the kernel, and will run basic sanity checks on them to
-	  ensure that exported files do not attempt to include files which
-	  were not exported, etc.
+	  This option will install uapi headers (headers exported to user-space)
+	  into the usr/include directory for use during the kernel build.
+	  This is unneeded for building the kernel itself, but needed for some
+	  user-space program samples. It is also needed by some features such
+	  as uapi header sanity checks.
+
+config HEADERS_CHECK
+	bool "Run sanity checks on uapi headers when building 'all'"
+	depends on HEADERS_INSTALL
+	help
+	  This option will run basic sanity checks on uapi headers when
+	  building the 'all' target, for example, ensure that they do not
+	  attempt to include files which were not exported, etc.
 
 	  If you're making modifications to header files which are
-	  relevant for userspace, say 'Y', and check the headers
-	  exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
-	  your build tree), to make sure they're suitable.
+	  relevant for userspace, say 'Y'.
 
 config OPTIMIZE_INLINING
 	bool "Allow compiler to uninline functions marked 'inline'"