scripts: objdiff: Ignore debug info when comparing

Message ID 1503453571-24705-1-git-send-email-yamada.masahiro@socionext.com
State New
Headers show

Commit Message

Masahiro Yamada Aug. 23, 2017, 1:59 a.m.
From: Stephen Boyd <stephen.boyd@linaro.org>

If the kernel is configured to be built with debug symbols, or
has bug tables, comparing files may not work if line numbers
change. This makes comparing object files with these options
harder to do. Let's strip out the debug info and drop the
__bug_table here so that we don't see false positives. There may
be other things to drop later, and it may be architecture
specific, but this works for me with my ARM64 build.

[ Import Linux commit: 65ba6fa439e7c3cbf97de9dce9e7a3390ae2638c ]

Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Reviewed-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/objdiff | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Tom Rini Aug. 26, 2017, 8:47 p.m. | #1
On Wed, Aug 23, 2017 at 10:59:31AM +0900, Masahiro Yamada wrote:

> From: Stephen Boyd <stephen.boyd@linaro.org>

> 

> If the kernel is configured to be built with debug symbols, or

> has bug tables, comparing files may not work if line numbers

> change. This makes comparing object files with these options

> harder to do. Let's strip out the debug info and drop the

> __bug_table here so that we don't see false positives. There may

> be other things to drop later, and it may be architecture

> specific, but this works for me with my ARM64 build.

> 

> [ Import Linux commit: 65ba6fa439e7c3cbf97de9dce9e7a3390ae2638c ]

> 

> Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>

> Reviewed-by: Jason Cooper <jason@lakedaemon.net>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>


Applied to u-boot/master, thanks!

-- 
Tom

Patch

diff --git a/scripts/objdiff b/scripts/objdiff
index 62e51dae2138..4fb5d6796893 100755
--- a/scripts/objdiff
+++ b/scripts/objdiff
@@ -57,13 +57,15 @@  get_output_dir() {
 do_objdump() {
 	dir=$(get_output_dir $1)
 	base=${1##*/}
+	stripped=$dir/${base%.o}.stripped
 	dis=$dir/${base%.o}.dis
 
 	[ ! -d "$dir" ] && mkdir -p $dir
 
 	# remove addresses for a cleaner diff
 	# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
-	$OBJDUMP -D $1 | sed "s/^[[:space:]]\+[0-9a-f]\+//" > $dis
+	$STRIP -g $1 -R __bug_table -R .note -R .comment -o $stripped
+	$OBJDUMP -D $stripped | sed -e "s/^[[:space:]]\+[0-9a-f]\+//" -e "s:^$stripped:$1:" > $dis
 }
 
 dorecord() {
@@ -73,6 +75,7 @@  dorecord() {
 
 	CMT="`git rev-parse --short HEAD`"
 
+	STRIP="${CROSS_COMPILE}strip"
 	OBJDUMP="${CROSS_COMPILE}objdump"
 
 	for d in $FILES; do