kbuild: sync with Linux Kernel v3.15-rc1

This commit imports Kbuild-related updates
from v3.14 to v3.15-rc1.

 - commit 3d3d6b8474204b6819688c9800774d52d370a538
    kbuild: LLVMLinux: Adapt warnings for compilation with clang
 - commit 61163efae02040f66a95c8ed17f4407951ba58fa
    kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
 - commit 79192ca8ebd9a25c583aa46024a250fef1e7766f
    scripts: objdiff: detect object code changes between two commits
 - commit 1c9e70a55b088d97a59241744fe459409d0c3582
    kbuild: create a build directory automatically for out-of-tree build
 - commit a03fcb50e816a69acffb13b5e56db75063aeba8a
    kbuild: remove redundant '.*.cmd' pattern from make distclean
 - commit 13338935f1574a2dcd1c891461b0dcc42f8cff42
    kbuild: move "quote" to Kbuild.include to be consistent
 - commit bfdfaeae500a3b194b73b01e92a8034791a58b7f
    kbuild: specify build_docproc as a phony target
 - commit f4d4ffc03efc864645b990e1d579bbe1b8e358a4
    kbuild: dtbs_install: new make target
 - commit 1e64ff42ea3d8d2fc8aa71f9717b3c1cb6c2f893
    Kbuild, lto: Disable LTO for asm-offsets.c
 - commit ccbef1674a1579842c7dbdf554efca85d2cd245a
    Kbuild, lto: add ld-version and ld-ifversion macros
 - commit ae63b2d7bdd9bd66b88843be0daf8e37d8f0b574
    scripts/tags.sh: Ignore *.mod.c
 - commit e36aaea28972c57a32a3ba5365e61633739719b9
    kbuild: Fix silent builds with make-4

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

7 files changed, 227 insertions, 13 deletions

diff --git a/Makefile b/Makefile
index c91c10e..970a219 100644
--- a/Makefile
+++ b/Makefile
@@ -127,7 +127,7 @@ saved-output := $(KBUILD_OUTPUT)
 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
 								&& /bin/pwd)
 $(if $(KBUILD_OUTPUT),, \
-     $(error output directory "$(saved-output)" does not exist))
+     $(error failed to create output directory "$(saved-output)"))
 
 PHONY += $(MAKECMDGOALS) sub-make
 
@@ -205,7 +205,14 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	  else echo sh; fi ; fi)
 
 HOSTCC       = gcc
+HOSTCXX      = g++
 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
+HOSTCXXFLAGS = -O2
+
+ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
+HOSTCFLAGS  += -Wno-unused-value -Wno-unused-parameter \
+		-Wno-missing-field-initializers -fno-delete-null-pointer-checks
+endif
 
 ifeq ($(HOSTOS),cygwin)
 HOSTCFLAGS	+= -ansi
@@ -301,12 +308,26 @@ 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$(MAKEFLAGS))),)
+  quiet=silent_
+endif
+else					# make-3.8x
 ifneq ($(filter s% -s%,$(MAKEFLAGS)),)
   quiet=silent_
 endif
+endif
 
 export quiet Q KBUILD_VERBOSE
 
+ifneq ($(CC),)
+ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
+COMPILER := clang
+else
+COMPILER := gcc
+endif
+export COMPILER
+endif
 
 # Look for make include files relative to root of kernel src
 MAKEFLAGS += --include-dir=$(srctree)
@@ -368,8 +389,9 @@ export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_ve
 
 # Files to ignore in find ... statements
 
-RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS \
-		   -o -name .pc -o -name .hg -o -name .git \) -prune -o
+export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
+			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
+			  -prune -o
 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
 
@@ -523,6 +545,20 @@ endif
 
 KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
 
+ifeq ($(COMPILER),clang)
+KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
+KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
+KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
+KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
+KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
+# 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
+# source of a reference will be _MergedGlobals and not on of the whitelisted names.
+# See modpost pattern 2
+KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
+endif
+
 KBUILD_CFLAGS	+= -g
 # $(KBUILD_AFLAGS) sets -g, which causes gcc to pass a suitable -g<format>
 # option to the assembler.
@@ -1168,7 +1204,8 @@ CLOBBER_DIRS  += $(patsubst %,spl/%, $(filter-out Makefile, \
 CLOBBER_FILES += u-boot* MLO* SPL System.map nand_spl/u-boot*
 
 # Directories & files removed with 'make mrproper'
-MRPROPER_DIRS  += include/config include/generated
+MRPROPER_DIRS  += include/config include/generated          \
+                  .tmp_objdiff
 MRPROPER_FILES += .config .config.old \
 		  tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
 		  include/config.h include/config.mk
@@ -1234,8 +1271,8 @@ distclean: mrproper
 	@find $(srctree) $(RCS_FIND_IGNORE) \
 		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
 		-o -name '*.bak' -o -name '#*#' -o -name '.*.orig' \
-		-o -name '.*.rej' -o -name '*.pyc' \
-		-o -name '*%' -o -name '.*.cmd' -o -name 'core' \) \
+		-o -name '.*.rej' -o -name '*%' -o -name 'core' \
+		-o -name '*.pyc' \) \
 		-type f -print | xargs rm -f
 
 backup:
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 6504571..c664e39 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -3,6 +3,7 @@
 
 # Convenient variables
 comma   := ,
+quote   := "
 squote  := '
 empty   :=
 space   := $(empty) $(empty)
@@ -161,6 +162,15 @@ ld-option = $(call try-run,\
 # Important: no spaces around options
 ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
 
+# ld-version
+# Usage: $(call ld-version)
+# Note this is mainly for HJ Lu's 3 number binutil versions
+ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
+
+# ld-ifversion
+# Usage:  $(call ld-ifversion, -ge, 22252, y)
+ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3))
+
 ######
 
 ###
diff --git a/scripts/Makefile b/scripts/Makefile
index 242e3a0..68c998e 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -9,7 +9,7 @@ hostprogs-y += docproc
 
 # These targets are used internally to avoid "is up to date" messages
 PHONY += build_docproc
-build_docproc: scripts/docproc
+build_docproc: $(obj)/docproc
 	@:
 
 # Let clean descend into subdirs
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 36346fd..6416c1a 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -90,12 +90,22 @@ warning-  := $(empty)
 warning-1 := -Wextra -Wunused -Wno-unused-parameter
 warning-1 += -Wmissing-declarations
 warning-1 += -Wmissing-format-attribute
-warning-1 += -Wmissing-prototypes
+warning-1 += $(call cc-option, -Wmissing-prototypes)
 warning-1 += -Wold-style-definition
 warning-1 += $(call cc-option, -Wmissing-include-dirs)
 warning-1 += $(call cc-option, -Wunused-but-set-variable)
 warning-1 += $(call cc-disable-warning, missing-field-initializers)
 
+# Clang
+warning-1 += $(call cc-disable-warning, initializer-overrides)
+warning-1 += $(call cc-disable-warning, unused-value)
+warning-1 += $(call cc-disable-warning, format)
+warning-1 += $(call cc-disable-warning, unknown-warning-option)
+warning-1 += $(call cc-disable-warning, sign-compare)
+warning-1 += $(call cc-disable-warning, format-zero-length)
+warning-1 += $(call cc-disable-warning, uninitialized)
+warning-1 += $(call cc-option, -fcatch-undefined-behavior)
+
 warning-2 := -Waggregate-return
 warning-2 += -Wcast-align
 warning-2 += -Wdisabled-optimization
@@ -225,7 +235,7 @@ $(multi-objs-y:.o=.s)   : modname = $(modname-multi)
 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
 
 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
-cmd_cc_s_c       = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
+cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
 
 $(obj)/%.s: $(src)/%.c FORCE
 	$(call if_changed_dep,cc_s_c)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index d568fde..a04439d 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -273,6 +273,18 @@ $(obj)/%.dtb: $(src)/%.dts FORCE
 
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 
+# Helper targets for Installing DTBs into the boot directory
+quiet_cmd_dtb_install =	INSTALL $<
+      cmd_dtb_install =	cp $< $(2)
+
+_dtbinst_pre_:
+	$(Q)if [ -d $(INSTALL_DTBS_PATH).old ]; then rm -rf $(INSTALL_DTBS_PATH).old; fi
+	$(Q)if [ -d $(INSTALL_DTBS_PATH) ]; then mv $(INSTALL_DTBS_PATH) $(INSTALL_DTBS_PATH).old; fi
+	$(Q)mkdir -p $(INSTALL_DTBS_PATH)
+
+%.dtb_dtbinst_: $(obj)/%.dtb _dtbinst_pre_
+	$(call cmd,dtb_install,$(INSTALL_DTBS_PATH))
+
 # Bzip2
 # ---------------------------------------------------------------------------
 
@@ -367,7 +379,3 @@ quiet_cmd_xzmisc = XZMISC  $@
 cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
 	xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
 	(rm -f $@ ; false)
-
-# misc stuff
-# ---------------------------------------------------------------------------
-quote:="
diff --git a/scripts/ld-version.sh b/scripts/ld-version.sh
new file mode 100755
index 0000000..198580d
--- /dev/null
+++ b/scripts/ld-version.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/awk -f
+# extract linker version number from stdin and turn into single number
+	{
+	gsub(".*)", "");
+	split($1,a, ".");
+	print a[1]*10000000 + a[2]*100000 + a[3]*10000 + a[4]*100 + a[5];
+	exit
+	}
diff --git a/scripts/objdiff b/scripts/objdiff
new file mode 100755
index 0000000..b3e4f10
--- /dev/null
+++ b/scripts/objdiff
@@ -0,0 +1,141 @@
+#!/bin/bash
+
+# objdiff - a small script for validating that a commit or series of commits
+# didn't change object code.
+#
+# Copyright 2014, Jason Cooper <jason@lakedaemon.net>
+#
+# Licensed under the terms of the GNU GPL version 2
+
+# usage example:
+#
+# $ git checkout COMMIT_A
+# $ <your fancy build command here>
+# $ ./scripts/objdiff record path/to/*.o
+#
+# $ git checkout COMMIT_B
+# $ <your fancy build command here>
+# $ ./scripts/objdiff record path/to/*.o
+#
+# $ ./scripts/objdiff diff COMMIT_A COMMIT_B
+# $
+
+# And to clean up (everything is in .tmp_objdiff/*)
+# $ ./scripts/objdiff clean all
+#
+# Note: 'make mrproper' will also remove .tmp_objdiff
+
+GIT_DIR="`git rev-parse --git-dir`"
+
+if [ -d "$GIT_DIR" ]; then
+	TMPD="${GIT_DIR%git}tmp_objdiff"
+
+	[ -d "$TMPD" ] || mkdir "$TMPD"
+else
+	echo "ERROR: git directory not found."
+	exit 1
+fi
+
+usage() {
+	echo "Usage: $0 <command> <args>"
+	echo "  record    <list of object files>"
+	echo "  diff      <commitA> <commitB>"
+	echo "  clean     all | <commit>"
+	exit 1
+}
+
+dorecord() {
+	[ $# -eq 0 ] && usage
+
+	FILES="$*"
+
+	CMT="`git rev-parse --short HEAD`"
+
+	OBJDUMP="${CROSS_COMPILE}objdump"
+	OBJDIFFD="$TMPD/$CMT"
+
+	[ ! -d "$OBJDIFFD" ] && mkdir -p "$OBJDIFFD"
+
+	for f in $FILES; do
+		dn="${f%/*}"
+		bn="${f##*/}"
+
+		[ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
+
+		# remove addresses for a more clear diff
+		# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
+		$OBJDUMP -D "$f" | sed "s/^[[:space:]]\+[0-9a-f]\+//" \
+			>"$OBJDIFFD/$dn/$bn"
+	done
+}
+
+dodiff() {
+	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
+
+	if [ $# -eq 0 ]; then
+		SRC="`git rev-parse --short HEAD^`"
+		DST="`git rev-parse --short HEAD`"
+	else
+		SRC="`git rev-parse --short $1`"
+		DST="`git rev-parse --short $2`"
+	fi
+
+	DIFF="`which colordiff`"
+
+	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
+		DIFF="`which diff`"
+	fi
+
+	SRCD="$TMPD/$SRC"
+	DSTD="$TMPD/$DST"
+
+	if [ ! -d "$SRCD" ]; then
+		echo "ERROR: $SRCD doesn't exist"
+		exit 1
+	fi
+
+	if [ ! -d "$DSTD" ]; then
+		echo "ERROR: $DSTD doesn't exist"
+		exit 1
+	fi
+
+	$DIFF -Nurd $SRCD $DSTD
+}
+
+doclean() {
+	[ $# -eq 0 ] && usage
+	[ $# -gt 1 ] && usage
+
+	if [ "x$1" = "xall" ]; then
+		rm -rf $TMPD/*
+	else
+		CMT="`git rev-parse --short $1`"
+
+		if [ -d "$TMPD/$CMT" ]; then
+			rm -rf $TMPD/$CMT
+		else
+			echo "$CMT not found"
+		fi
+	fi
+}
+
+[ $# -eq 0 ] &&	usage
+
+case "$1" in
+	record)
+		shift
+		dorecord $*
+		;;
+	diff)
+		shift
+		dodiff $*
+		;;
+	clean)
+		shift
+		doclean $*
+		;;
+	*)
+		echo "Unrecognized command '$1'"
+		exit 1
+		;;
+esac