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

scripts/Kbuild.include

@@ -108,6 +108,11 @@ as-option = $(call try-run,\
 as-instr = $(call try-run,\
 	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
 
+# __cc-option
+# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
+__cc-option = $(call try-run,\
+	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
+
 # Do not attempt to build with gcc plugins during cc-option tests.
 # (And this uses delayed resolution so the flags will be up to date.)
 CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
@@ -115,19 +120,19 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
 # cc-option
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
-cc-option = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+cc-option = $(call __cc-option, $(CC),\
+	$(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2))
+
+# hostcc-option
+# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
+hostcc-option = $(call __cc-option, $(HOSTCC),\
+	$(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
 	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
-# cc-option-align
-# Prefix align with either -falign or -malign
-cc-option-align = $(subst -functions=0,,\
-	$(call cc-option,-falign-functions=0,-malign-functions=0))
-
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 cc-disable-warning = $(call try-run,\

scripts/Makefile.asm-generic

@@ -15,7 +15,7 @@ _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
 
 # Stale wrappers when the corresponding files are removed from generic-y
 # need removing.
-generated-y   := $(generic-y) $(genhdr-y) $(generated-y)
+generated-y   := $(generic-y) $(generated-y)
 all-files     := $(patsubst %, $(obj)/%, $(generated-y))
 old-headers   := $(wildcard $(obj)/*.h)
 unwanted      := $(filter-out $(all-files),$(old-headers))

scripts/Makefile.host

@@ -20,12 +20,6 @@
 # Will compile qconf as a C++ program, and menu as a C program.
 # They are linked as C++ code to the executable qconf
 
-# hostcc-option
-# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
-
-hostcc-option = $(call try-run,\
-	$(HOSTCC) $(HOSTCFLAGS) $(HOST_EXTRACFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
-
 __hostprogs := $(sort $(hostprogs-y) $(hostprogs-m))
 host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m))
 host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m))

scripts/checksyscalls.sh

@@ -202,15 +202,12 @@ EOF
 }
 
 syscall_list() {
-    grep '^[0-9]' "$1" | sort -n | (
+    grep '^[0-9]' "$1" | sort -n |
 	while read nr abi name entry ; do
-	    cat <<EOF
-#if !defined(__NR_${name}) && !defined(__IGNORE_${name})
-#warning syscall ${name} not implemented
-#endif
-EOF
+		echo "#if !defined(__NR_${name}) && !defined(__IGNORE_${name})"
+		echo "#warning syscall ${name} not implemented"
+		echo "#endif"
 	done
-    )
 }
 
 (ignore_list && syscall_list $(dirname $0)/../arch/x86/entry/syscalls/syscall_32.tbl) | \