Merge tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Clean up Makefiles and scripts

 - Improve clang support

 - Remove unneeded genhdr-y syntax

 - Remove unneeded cc-option-align macro

 - Introduce __cc-option macro and use it to fix x86 boot code compiler
   flags

* tag 'kbuild-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: improve comments on KBUILD_SRC
  x86/build: Specify stack alignment for clang
  x86/build: Use __cc-option for boot code compiler options
  kbuild: Add __cc-option macro
  kbuild: remove cc-option-align
  kbuild: replace genhdr-y with generated-y
  kbuild: clang: Disable 'address-of-packed-member' warning
  kbuild: remove duplicated arch/*/include/generated/uapi include path
  kbuild: speed up checksyscalls.sh
  kbuild: simplify silent build (-s) detection

1 files changed, 8 insertions, 16 deletions

diff --git a/Makefile b/Makefile
index d7cb0372bed9..faea0e37c2f2 100644
--- a/Makefile
+++ b/Makefile
@@ -84,17 +84,10 @@ endif
 # If the user is running make -s (silent mode), suppress echoing of
 # commands
 
-ifneq ($(filter 4.%,$(MAKE_VERSION)),)  # make-4
-ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),)
+ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
   quiet=silent_
   tools_silent=s
 endif
-else                                    # make-3.8x
-ifneq ($(filter s% -s%,$(MAKEFLAGS)),)
-  quiet=silent_
-  tools_silent=-s
-endif
-endif
 
 export quiet Q KBUILD_VERBOSE
 
@@ -113,8 +106,8 @@ export quiet Q KBUILD_VERBOSE
 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 # variable.
 
-# KBUILD_SRC is set on invocation of make in OBJ directory
-# KBUILD_SRC is not intended to be used by the regular user (for now)
+# KBUILD_SRC is not intended to be used by the regular user (for now),
+# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
 ifeq ($(KBUILD_SRC),)
 
 # OK, Make called in directory where kernel src resides
@@ -135,7 +128,6 @@ ifneq ($(words $(subst :, ,$(CURDIR))), 1)
 endif
 
 ifneq ($(KBUILD_OUTPUT),)
-# Invoke a second make in the output directory, passing relevant variables
 # check that the output directory actually exists
 saved-output := $(KBUILD_OUTPUT)
 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
@@ -148,6 +140,7 @@ PHONY += $(MAKECMDGOALS) sub-make
 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
         @:
 
+# Invoke a second make in the output directory, passing relevant variables
 sub-make:
         $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
         -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
@@ -303,7 +296,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 
 HOSTCC       = gcc
 HOSTCXX      = g++
-HOSTCFLAGS   = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
+HOSTCFLAGS   := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
 HOSTCXXFLAGS = -O2
 
 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
@@ -388,12 +381,10 @@ USERINCLUDE    := \
 # Needed to be compatible with the O= option
 LINUXINCLUDE    := \
                 -I$(srctree)/arch/$(hdr-arch)/include \
-                -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
                 -I$(objtree)/arch/$(hdr-arch)/include/generated \
                 $(if $(KBUILD_SRC), -I$(srctree)/include) \
-                -I$(objtree)/include
-
-LINUXINCLUDE    += $(filter-out $(LINUXINCLUDE),$(USERINCLUDE))
+                -I$(objtree)/include \
+                $(USERINCLUDE)
 
 KBUILD_CPPFLAGS := -D__KERNEL__
 
@@ -707,6 +698,7 @@ KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
+KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
 # Quiet clang warning: comparison of unsigned expression < 0 is always false
 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the