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
  ...

scripts/Kbuild.include

@@ -79,8 +79,8 @@ endef
 # would try to directly execute the shell builtin 'command'. This workaround
 # should be kept for a long time since this issue was fixed only after the
 # GNU Make 4.2.1 release.
-cc-cross-prefix = $(firstword $(foreach c, $(filter-out -%, $(1)), \
-			$(if $(shell command -v $(c)gcc 2>/dev/null), $(c))))
+cc-cross-prefix = $(firstword $(foreach c, $(1), \
+			$(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
 
 # output directory for tests below
 TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
@@ -187,12 +187,6 @@ dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
 # $(Q)$(MAKE) $(clean)=dir
 clean := -f $(srctree)/scripts/Makefile.clean obj
 
-###
-# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
-# Usage:
-# $(Q)$(MAKE) $(hdr-inst)=dir
-hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
-
 # echo command.
 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 echo-cmd = $(if $($(quiet)cmd_$(1)),\
@@ -213,12 +207,12 @@ objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 # See Documentation/kbuild/makefiles.rst for more info
 
 ifneq ($(KBUILD_NOCMDDEP),1)
-# Check if both arguments are the same including their order. Result is empty
+# Check if both commands are the same including their order. Result is empty
 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
-arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
+cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
                          $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 else
-arg-check = $(if $(strip $(cmd_$@)),,1)
+cmd-check = $(if $(strip $(cmd_$@)),,1)
 endif
 
 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
@@ -231,15 +225,15 @@ make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1))))
 
 # Find any prerequisites that is newer than target or that does not exist.
 # PHONY targets skipped in both cases.
-any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
+any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^)
 
 # Execute command if command has changed or prerequisite(s) are updated.
-if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
+if_changed = $(if $(any-prereq)$(cmd-check),                                 \
 	$(cmd);                                                              \
 	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 
 # Execute the command and also postprocess generated .d dependencies file.
-if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)),$(cmd_and_fixdep),@:)
+if_changed_dep = $(if $(any-prereq)$(cmd-check),$(cmd_and_fixdep),@:)
 
 cmd_and_fixdep =                                                             \
 	$(cmd);                                                              \
@@ -249,7 +243,7 @@ cmd_and_fixdep =                                                             \
 # Usage: $(call if_changed_rule,foo)
 # Will check if $(cmd_foo) or any of the prerequisites changed,
 # and if so will execute $(rule_foo).
-if_changed_rule = $(if $(strip $(any-prereq) $(arg-check)),$(rule_$(1)),@:)
+if_changed_rule = $(if $(any-prereq)$(cmd-check),$(rule_$(1)),@:)
 
 ###
 # why - tell why a target got built
@@ -274,8 +268,8 @@ ifeq ($(KBUILD_VERBOSE),2)
 why =                                                                        \
     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
         $(if $(wildcard $@),                                                 \
-            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
-                $(if $(arg-check),                                           \
+            $(if $(any-prereq),- due to: $(any-prereq),                      \
+                $(if $(cmd-check),                                           \
                     $(if $(cmd_$@),- due to command line change,             \
                         $(if $(filter $@, $(targets)),                       \
                             - due to missing .cmd file,                      \