Merge tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32

 - ensure to rebuild all objects when the compiler is upgraded

 - exclude system headers from dependency tracking and fixdep processing

 - fix potential bit-size mismatch between the kernel and BPF user-mode
   helper

 - add the new syntax 'userprogs' to build user-space programs for the
   target architecture (the same arch as the kernel)

 - compile user-space sample code under samples/ for the target arch
   instead of the host arch

 - make headers_install fail if a CONFIG option is leaked to user-space

 - sanitize the output format of scripts/checkstack.pl

 - handle ARM 'push' instruction in scripts/checkstack.pl

 - error out before modpost if a module name conflict is found

 - error out when multiple directories are passed to M= because this
   feature is broken for a long time

 - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info

 - a lot of cleanups of modpost

 - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
   second pass of modpost

 - do not run the second pass of modpost if nothing in modules is
   updated

 - install modules.builtin(.modinfo) by 'make install' as well as by
   'make modules_install' because it is useful even when
   CONFIG_MODULES=n

 - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
   to allow users to use alternatives such as pigz, pbzip2, etc.

* tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits)
  kbuild: add variables for compression tools
  Makefile: install modules.builtin even if CONFIG_MODULES=n
  mksysmap: Fix the mismatch of '.L' symbols in System.map
  kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS
  modpost: change elf_info->size to size_t
  modpost: remove is_vmlinux() helper
  modpost: strip .o from modname before calling new_module()
  modpost: set have_vmlinux in new_module()
  modpost: remove mod->skip struct member
  modpost: add mod->is_vmlinux struct member
  modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
  modpost: remove mod->is_dot_o struct member
  modpost: move -d option in scripts/Makefile.modpost
  modpost: remove -s option
  modpost: remove get_next_text() and make {grab,release_}file static
  modpost: use read_text_file() and get_line() for reading text files
  modpost: avoid false-positive file open error
  modpost: fix potential mmap'ed file overrun in get_src_version()
  modpost: add read_text_file() and get_line() helpers
  modpost: do not call get_modinfo() for vmlinux(.o)
  ...

2 files changed, 28 insertions, 4 deletions

diff --git a/init/Kconfig b/init/Kconfig
index b5294bcba61d..58a4b705c1c2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -8,8 +8,25 @@ config DEFCONFIG_LIST
 	default "/boot/config-$(shell,uname -r)"
 	default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"
 
+config CC_VERSION_TEXT
+	string
+	default "$(CC_VERSION_TEXT)"
+	help
+	  This is used in unclear ways:
+
+	  - Re-run Kconfig when the compiler is updated
+	    The 'default' property references the environment variable,
+	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
+	    When the compiler is updated, Kconfig will be invoked.
+
+	  - Ensure full rebuild when the compier is updated
+	    include/linux/kconfig.h contains this option in the comment line so
+	    fixdep adds include/config/cc/version/text.h into the auto-generated
+	    dependency. When the compiler is updated, syncconfig will touch it
+	    and then every file will be rebuilt.
+
 config CC_IS_GCC
-	def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)
+	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q gcc)
 
 config GCC_VERSION
 	int
@@ -21,7 +38,7 @@ config LD_VERSION
 	default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)
 
 config CC_IS_CLANG
-	def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
+	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang)
 
 config LD_IS_LLD
 	def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD)
@@ -31,7 +48,14 @@ config CLANG_VERSION
 	default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
 
 config CC_CAN_LINK
-	def_bool $(success,$(srctree)/scripts/cc-can-link.sh $(CC))
+	bool
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(m64-flag)) if 64BIT
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(m32-flag))
+
+config CC_CAN_LINK_STATIC
+	bool
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) -static $(m64-flag)) if 64BIT
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) -static $(m32-flag))
 
 config CC_HAS_ASM_GOTO
 	def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
diff --git a/init/Makefile b/init/Makefile
index d45e967483b2..57499b1ff471 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -35,4 +35,4 @@ include/generated/compile.h: FORCE
 	@$($(quiet)chk_compile.h)
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@	\
 	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)"	\
-	"$(CONFIG_PREEMPT_RT)" "$(CC)" "$(LD)"
+	"$(CONFIG_PREEMPT_RT)" $(CONFIG_CC_VERSION_TEXT) "$(LD)"