kbuild: Improve portability of some sed invocations

* Use BREs where EREs aren't necessary.
* Pass -E instead of -r to use EREs. This will be standardized in the
next POSIX revision[0]. GNU sed supports this since 4.2 (May 2009),
and busybox since 1.22.0 (Jan 2014).
* Use the [:space:] character class instead of ` \t` in bracket
expressions. In bracket expressions, POSIX says that <backslash> loses
its special meaning, so a conforming implementation cannot expand \t
to <tab>[1].
* In BREs, use interval expressions (\{n,m\}) instead of non-standard
features like \+ and \?.
* Use a loop instead of -s flag.

There are still plenty of other cases of non-standard sed invocations
(use of ERE features in BREs, in-place editing), but this fixes some
core ones.

[0] http://austingroupbugs.net/view.php?id=528
[1] http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05

Signed-off-by: Michael Forney <[e-mail]>
Signed-off-by: Masahiro Yamada <[e-mail]>

scripts/Kbuild.include

···
 	    $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;;        \
 	  boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;;            \
 	  *) echo "Don't know how to preprocess $(1)" >&2; false ;;          \
-	esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
+	esac | tr ";" "\n" | sed -n 's/^.*=== __KSYM_\(.*\) ===.*$$/KSYM_\1/p'
 
 cmd_and_fixdep =                                                             \
 	$(echo-cmd) $(cmd_$(1));                                             \

scripts/Makefile.build

···
 
 # List module undefined symbols (or empty line if not enabled)
 ifdef CONFIG_TRIM_UNUSED_KSYMS
-cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
+cmd_undef_syms = $(NM) $@ | sed -n 's/^  *U //p' | xargs echo
 else
 cmd_undef_syms = echo
 endif

scripts/adjust_autoksyms.sh

···
 
 EOT
 [ "$(ls -A "$MODVERDIR")" ] &&
-sed -ns -e '3{s/ /\n/g;/^$/!p;}' "$MODVERDIR"/*.mod | sort -u |
+for mod in "$MODVERDIR"/*.mod; do
+	sed -n -e '3{s/ /\n/g;/^$/!p;}' "$mod"
+done | sort -u |
 while read sym; do
 	if [ -n "$CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX" ]; then
 		sym="${sym#_}"

scripts/gen_initramfs_list.sh

···
 	source="$1"
 	if [ -f "$1" ]; then
 		${dep_list}header "$1"
-		is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\?/cpio/')"
+		is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\{0,1\}/cpio/')"
 		if [ $2 -eq 0 -a ${is_cpio} = "cpio" ]; then
 			cpio_file=$1
 			echo "$1" | grep -q '^.*\.cpio\..*' && is_cpio_compressed="compressed"

scripts/headers_install.sh

···
 for i in "$@"
 do
 	FILE="$(basename "$i")"
-	sed -r \
-		-e 's/([ \t(])(__user|__force|__iomem)[ \t]/\1/g' \
-		-e 's/__attribute_const__([ \t]|$)/\1/g' \
+	sed -E \
+		-e 's/([[:space:](])(__user|__force|__iomem)[[:space:]]/\1/g' \
+		-e 's/__attribute_const__([[:space:]]|$)/\1/g' \
 		-e 's@^#include <linux/compiler(|_types).h>@@' \
 		-e 's/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g' \
-		-e 's/(^|[ \t(])(inline|asm|volatile)([ \t(]|$)/\1__\2__\3/g' \
-		-e 's@#(ifndef|define|endif[ \t]*/[*])[ \t]*_UAPI@#\1 @' \
+		-e 's/(^|[[:space:](])(inline|asm|volatile)([[:space:](]|$)/\1__\2__\3/g' \
+		-e 's@#(ifndef|define|endif[[:space:]]*/[*])[[:space:]]*_UAPI@#\1 @' \
 		"$SRCDIR/$i" > "$OUTDIR/$FILE.sed" || exit 1
 	scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ "$OUTDIR/$FILE.sed" \
 		> "$OUTDIR/$FILE"