gen_build_files.sh is an order prerequisite only for autoconf.h

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

2 files changed, 21 insertions, 29 deletions

diff --git a/Makefile b/Makefile
index 87779d791..590512191 100644
--- a/Makefile
+++ b/Makefile
@@ -509,7 +509,7 @@ include $(srctree)/Makefile.flags
 # with it and forgot to run make oldconfig.
 # If kconfig.d is missing then we are probarly in a cleaned tree so
 # we execute the config step to be sure to catch updated Kconfig files
-include/autoconf.h: .kconfig.d .config gen_build_files
+include/autoconf.h: .kconfig.d .config | gen_build_files
 	$(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
 
 else
diff --git a/scripts/gen_build_files.sh b/scripts/gen_build_files.sh
index 647c7daf7..a98f509ce 100755
--- a/scripts/gen_build_files.sh
+++ b/scripts/gen_build_files.sh
@@ -11,20 +11,19 @@ srctree="$1"
 src="$srctree/include/applets.src.h"
 dst="include/applets.h"
 s=`sed -n 's@^//applet:@@p' -- "$srctree"/*/*.c "$srctree"/*/*/*.c`
-echo "/* DO NOT EDIT. This file is generated from applets.src.h */" >"$dst.$$.tmp"
+old=`cat "$dst" 2>/dev/null`
 # Why "IFS='' read -r REPLY"??
 # This atrocity is needed to read lines without mangling.
 # IFS='' prevents whitespace trimming,
 # -r suppresses backslash handling.
+new=`echo "/* DO NOT EDIT. This file is generated from applets.src.h */"
 while IFS='' read -r REPLY; do
 	test x"$REPLY" = x"INSERT" && REPLY="$s"
 	printf "%s\n" "$REPLY"
-done <"$src" >>"$dst.$$.tmp"
-if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
-	rm -- "$dst.$$.tmp"
-else
+done <"$src"`
+if test x"$new" != x"$old"; then
 	echo "  GEN     $dst"
-	mv -- "$dst.$$.tmp" "$dst"
+	printf "%s\n" "$new" >"$dst"
 fi
 
 # (Re)generate include/usage.h
@@ -35,20 +34,15 @@ dst="include/usage.h"
 # with space or tab
 # (note: we need to use \\\\ because of ``)
 s=`sed -n -e 's@^//usage:\([ \t].*\)$@\1 \\\\@p' -e 's@^//usage:\([^ \t].*\)$@\n\1 \\\\@p' -- "$srctree"/*/*.c "$srctree"/*/*/*.c`
-echo "/* DO NOT EDIT. This file is generated from usage.src.h */" >"$dst.$$.tmp"
-# Why "IFS='' read -r REPLY"??
-# This atrocity is needed to read lines without mangling.
-# IFS='' prevents whitespace trimming,
-# -r suppresses backslash handling.
+old=`cat "$dst" 2>/dev/null`
+new=`echo "/* DO NOT EDIT. This file is generated from usage.src.h */"
 while IFS='' read -r REPLY; do
 	test x"$REPLY" = x"INSERT" && REPLY="$s"
 	printf "%s\n" "$REPLY"
-done <"$src" >>"$dst.$$.tmp"
-if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
-	rm -- "$dst.$$.tmp"
-else
+done <"$src"`
+if test x"$new" != x"$old"; then
 	echo "  GEN     $dst"
-	mv -- "$dst.$$.tmp" "$dst"
+	printf "%s\n" "$new" >"$dst"
 fi
 
 # (Re)generate */Kbuild and */Config.in
@@ -61,16 +55,15 @@ find -type d | while read -r d; do
 
 		s=`sed -n 's@^//kbuild:@@p' -- "$srctree/$d"/*.c`
 
-		echo "# DO NOT EDIT. This file is generated from Kbuild.src" >"$dst.$$.tmp"
+		old=`cat "$dst" 2>/dev/null`
+		new=`echo "# DO NOT EDIT. This file is generated from Kbuild.src"
 		while IFS='' read -r REPLY; do
 			test x"$REPLY" = x"INSERT" && REPLY="$s"
 			printf "%s\n" "$REPLY"
-		done <"$src" >>"$dst.$$.tmp"
-		if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
-			rm -- "$dst.$$.tmp"
-		else
+		done <"$src"`
+		if test x"$new" != x"$old"; then
 			echo "  GEN     $dst"
-			mv -- "$dst.$$.tmp" "$dst"
+			printf "%s\n" "$new" >"$dst"
 		fi
 	fi
 
@@ -81,16 +74,15 @@ find -type d | while read -r d; do
 
 		s=`sed -n 's@^//config:@@p' -- "$srctree/$d"/*.c`
 
-		echo "# DO NOT EDIT. This file is generated from Config.src" >"$dst.$$.tmp"
+		old=`cat "$dst" 2>/dev/null`
+		new=`echo "# DO NOT EDIT. This file is generated from Config.src"
 		while IFS='' read -r REPLY; do
 			test x"$REPLY" = x"INSERT" && REPLY="$s"
 			printf "%s\n" "$REPLY"
-		done <"$src" >>"$dst.$$.tmp"
-		if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
-			rm -- "$dst.$$.tmp"
-		else
+		done <"$src"`
+		if test x"$new" != x"$old"; then
 			echo "  GEN     $dst"
-			mv -- "$dst.$$.tmp" "$dst"
+			printf "%s\n" "$new" >"$dst"
 		fi
 	fi
 done