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
  ...

1 files changed, 66 insertions, 51 deletions

diff --git a/Makefile b/Makefile
index 3e4868a6498b..2c5d00ba537e 100644
--- a/Makefile
+++ b/Makefile
@@ -212,6 +212,13 @@ endif
 ifdef SUBDIRS
   $(warning ================= WARNING ================)
   $(warning 'SUBDIRS' will be removed after Linux 5.3)
+  $(warning )
+  $(warning If you are building an individual subdirectory)
+  $(warning in the kernel tree, you can do like this:)
+  $(warning $$ make path/to/dir/you/want/to/build/)
+  $(warning (Do not forget the trailing slash))
+  $(warning )
+  $(warning If you are building an external module,)
   $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
   $(warning ==========================================)
   KBUILD_EXTMOD ?= $(SUBDIRS)
@@ -221,9 +228,12 @@ ifeq ("$(origin M)", "command line")
   KBUILD_EXTMOD := $(M)
 endif
 
+export KBUILD_CHECKSRC KBUILD_EXTMOD
+
 ifeq ($(abs_srctree),$(abs_objtree))
         # building in the source tree
         srctree := .
+        building_out_of_srctree :=
 else
         ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
                 # building in a subdirectory of the source tree
@@ -231,22 +241,17 @@ else
         else
                 srctree := $(abs_srctree)
         endif
-
-        # TODO:
-        # KBUILD_SRC is only used to distinguish in-tree/out-of-tree build.
-        # Replace it with $(srctree) or something.
-        KBUILD_SRC := $(abs_srctree)
+        building_out_of_srctree := 1
 endif
 
-export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
+ifneq ($(KBUILD_ABS_SRCTREE),)
+srctree := $(abs_srctree)
+endif
 
 objtree         := .
-src             := $(srctree)
-obj             := $(objtree)
-
 VPATH           := $(srctree)
 
-export srctree objtree VPATH
+export building_out_of_srctree srctree objtree VPATH
 
 # To make sure we do not include .config for any of the *config targets
 # catch them early, and hand them over to scripts/kconfig/Makefile
@@ -262,7 +267,7 @@ old_version_h := include/linux/version.h
 clean-targets := %clean mrproper cleandocs
 no-dot-config-targets := $(clean-targets) \
                          cscope gtags TAGS tags help% %docs check% coccicheck \
-                         $(version_h) headers_% archheaders archscripts \
+                         $(version_h) headers headers_% archheaders archscripts \
                          %asm-generic kernelversion %src-pkg
 no-sync-config-targets := $(no-dot-config-targets) install %install \
                            kernelrelease
@@ -449,7 +454,7 @@ USERINCLUDE    := \
 LINUXINCLUDE    := \
                 -I$(srctree)/arch/$(SRCARCH)/include \
                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
-                $(if $(filter .,$(srctree)),,-I$(srctree)/include) \
+                $(if $(building_out_of_srctree),-I$(srctree)/include) \
                 -I$(objtree)/include \
                 $(USERINCLUDE)
 
@@ -510,7 +515,7 @@ PHONY += outputmakefile
 # At the same time when output Makefile generated, generate .gitignore to
 # ignore whole output directory
 outputmakefile:
-ifneq ($(srctree),.)
+ifdef building_out_of_srctree
         $(Q)ln -fsn $(srctree) source
         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
         $(Q)test -e .gitignore || \
@@ -527,7 +532,10 @@ endif
 ifneq ($(GCC_TOOLCHAIN),)
 CLANG_FLAGS     += --gcc-toolchain=$(GCC_TOOLCHAIN)
 endif
+ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
 CLANG_FLAGS     += -no-integrated-as
+endif
+CLANG_FLAGS     += -Werror=unknown-warning-option
 KBUILD_CFLAGS   += $(CLANG_FLAGS)
 KBUILD_AFLAGS   += $(CLANG_FLAGS)
 export CLANG_FLAGS
@@ -608,6 +616,7 @@ ifeq ($(KBUILD_EXTMOD),)
 init-y          := init/
 drivers-y       := drivers/ sound/
 drivers-$(CONFIG_SAMPLES) += samples/
+drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
 net-y           := net/
 libs-y          := lib/
 core-y          := usr/
@@ -1053,9 +1062,6 @@ vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
 
 targets := vmlinux
 
-# Some samples need headers_install.
-samples: headers_install
-
 # The actual objects are generated when descending,
 # make sure no implicit rule kicks in
 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
@@ -1096,12 +1102,12 @@ PHONY += prepare archprepare prepare1 prepare3
 # and if so do:
 # 1) Check that make has not been executed in the kernel src $(srctree)
 prepare3: include/config/kernel.release
-ifneq ($(srctree),.)
+ifdef building_out_of_srctree
         @$(kecho) '  Using $(srctree) as source for kernel'
         $(Q)if [ -f $(srctree)/.config -o \
                  -d $(srctree)/include/config -o \
                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
-                echo >&2 "  $(srctree) is not clean, please run 'make mrproper'"; \
+                echo >&2 "  $(srctree) is not clean, please run 'make ARCH=$(ARCH) mrproper'"; \
                 echo >&2 "  in the '$(srctree)' directory.";\
                 /bin/false; \
         fi;
@@ -1181,39 +1187,44 @@ headerdep:
 #Default location for installed headers
 export INSTALL_HDR_PATH = $(objtree)/usr
 
-# If we do an all arch process set dst to include/arch-$(SRCARCH)
-hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
+quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
+      cmd_headers_install = \
+        mkdir -p $(INSTALL_HDR_PATH); \
+        rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
+        usr/include $(INSTALL_HDR_PATH)
 
-PHONY += archheaders archscripts
+PHONY += headers_install
+headers_install: headers
+        $(call cmd,headers_install)
 
-PHONY += __headers
-__headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
-        $(Q)$(MAKE) $(build)=scripts build_unifdef
+PHONY += archheaders archscripts
 
-PHONY += headers_install_all
-headers_install_all:
-        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
+hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
 
-PHONY += headers_install
-headers_install: __headers
+PHONY += headers
+headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
         $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
           $(error Headers not exportable for the $(SRCARCH) architecture))
-        $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
-        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
-
-PHONY += headers_check_all
-headers_check_all: headers_install_all
-        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
+        $(Q)$(MAKE) $(hdr-inst)=include/uapi
+        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
 
 PHONY += headers_check
-headers_check: headers_install
-        $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
-        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
+headers_check: headers
+        $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
+        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
+
+ifdef CONFIG_HEADERS_INSTALL
+prepare: headers
+endif
 
 ifdef CONFIG_HEADERS_CHECK
 all: headers_check
 endif
 
+PHONY += scripts_unifdef
+scripts_unifdef: scripts_basic
+        $(Q)$(MAKE) $(build)=scripts scripts/unifdef
+
 # ---------------------------------------------------------------------------
 # Kernel selftest
 
@@ -1283,18 +1294,24 @@ all: modules
 # using awk while concatenating to the final file.
 
 PHONY += modules
-modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
-        $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
+modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
         @$(kecho) '  Building modules, stage 2.';
         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
 
-modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
-        $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
+modules.order: $(vmlinux-dirs)
+        $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(vmlinux-dirs)) > $@
+
+modbuiltin-dirs := $(addprefix _modbuiltin_, $(vmlinux-dirs))
 
-%/modules.builtin: include/config/auto.conf include/config/tristate.conf
-        $(Q)$(MAKE) $(modbuiltin)=$*
+modules.builtin: $(modbuiltin-dirs)
+        $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(vmlinux-dirs)) > $@
 
+PHONY += $(modbuiltin-dirs)
+# tristate.conf is not included from this Makefile. Add it as a prerequisite
+# here to make it self-healing in case somebody accidentally removes it.
+$(modbuiltin-dirs): include/config/tristate.conf
+        $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
 
 # Target to prepare building external modules
 PHONY += modules_prepare
@@ -1360,7 +1377,7 @@ CLEAN_DIRS  += $(MODVERDIR) include/ksym
 CLEAN_FILES += modules.builtin.modinfo
 
 # Directories & files removed with 'make mrproper'
-MRPROPER_DIRS  += include/config usr/include include/generated          \
+MRPROPER_DIRS  += include/config include/generated          \
                   arch/$(SRCARCH)/include/generated .tmp_objdiff
 MRPROPER_FILES += .config .config.old .version \
                   Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
@@ -1551,7 +1568,7 @@ $(DOC_TARGETS): scripts_basic FORCE
 # ---------------------------------------------------------------------------
 
 PHONY += scripts_gdb
-scripts_gdb: prepare
+scripts_gdb: prepare0
         $(Q)$(MAKE) $(build)=scripts/gdb
         $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
 
@@ -1698,7 +1715,7 @@ CHECKSTACK_ARCH := $(ARCH)
 endif
 checkstack:
         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
-        $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
+        $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
 
 kernelrelease:
         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
@@ -1717,11 +1734,11 @@ endif
 
 tools/: FORCE
         $(Q)mkdir -p $(objtree)/tools
-        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
+        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
 
 tools/%: FORCE
         $(Q)mkdir -p $(objtree)/tools
-        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
+        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
 
 # Single targets
 # ---------------------------------------------------------------------------
@@ -1755,8 +1772,6 @@ build-dir = $(patsubst %/,%,$(dir $(build-target)))
 PHONY += /
 /: ./
 
-# Make sure the latest headers are built for Documentation
-Documentation/ samples/: headers_install
 %/: prepare FORCE
         $(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)