make it possible to keep Config/Kbuild snippets in *.c files

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

scripts/gen_build_files.sh

@@ -0,0 +1,55 @@
+#!/bin/sh
+
+test $# -ge 2 || exit 1
+
+# cd to objtree
+cd "$2" || exit 1
+
+srctree="$1"
+
+find -type d \
+| while read; do
+    d="$REPLY"
+
+    src="$srctree/$d/Kbuild.src"
+    dst="$d/Kbuild"
+    if test -f "$src"; then
+	echo "  CHK     $dst"
+
+	s=`grep -h '^//kbuild:' "$srctree/$d"/*.c | sed 's^//kbuild:^^'`
+	while read; do
+	    test x"$REPLY" = x"INSERT" && REPLY="$s"
+	    printf "%s\n" "$REPLY"
+	done <"$src" >"$dst.$$.tmp"
+
+	if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
+	    rm "$dst.$$.tmp"
+	else
+	    echo "  GEN     $dst"
+	    mv "$dst.$$.tmp" "$dst"
+	fi
+    fi
+
+    src="$srctree/$d/Config.src"
+    dst="$d/Config.in"
+    if test -f "$src"; then
+	echo "  CHK     $dst"
+
+	s=`grep -h '^//config:' "$srctree/$d"/*.c | sed 's^//config:^^'`
+	while read; do
+	    test x"$REPLY" = x"INSERT" && REPLY="$s"
+	    printf "%s\n" "$REPLY"
+	done <"$src" >"$dst.$$.tmp"
+
+	if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
+	    rm "$dst.$$.tmp"
+	else
+	    echo "  GEN     $dst"
+	    mv "$dst.$$.tmp" "$dst"
+	fi
+    fi
+
+done
+
+# Last read failed. This is normal. Don't exit with its error code:
+exit 0