Skip COFF timestamp difference.

Skip COFF timestamp difference.

Current deps diffs shows lots of files differs only first certain bytes on Windows.  They are COFF timestamp difference, and we do not usually need to check.  Let me skip showing them.

BUG=314403
Committed: https://crrev.com/968e61838c000ee1850cfa8850dcfe4e51087265
Cr-Commit-Position: refs/heads/master@{#417179}

[Yoshisato Yanagisawa, 2016-09-02 09:10:18]

Description was changed from

==========
Skip COFF timestamp difference.

BUG=314403
==========

to

==========
Skip COFF timestamp difference.

Current deps diffs shows lots of files differs only first certain bytes on
Windows.  They are COFF timestamp difference, and we do not usually need to
check.  Let me skip showing them.

BUG=314403
==========

[Yoshisato Yanagisawa, 2016-09-02 09:10:35]

yyanagisawa@chromium.org changed reviewers:
+ dpranke@chromium.org, maruel@chromium.org

[M-A Ruel, 2016-09-02 16:30:26]

https://codereview.chromium.org/2303063003/diff/20001/tools/determinism/compa...
File tools/determinism/compare_build_artifacts.py (right):

https://codereview.chromium.org/2303063003/diff/20001/tools/determinism/compa...
tools/determinism/compare_build_artifacts.py:563: if (sys.platform == 'win32'
and
This code belongs to binary_diff(); should passlist the allowed extentions.

[Dirk Pranke, 2016-09-02 16:53:19]

I defer to maruel@ here.

[Yoshisato Yanagisawa, 2016-09-05 02:44:25]

https://codereview.chromium.org/2303063003/diff/20001/tools/determinism/compa...
File tools/determinism/compare_build_artifacts.py (right):

https://codereview.chromium.org/2303063003/diff/20001/tools/determinism/compa...
tools/determinism/compare_build_artifacts.py:563: if (sys.platform == 'win32'
and
On 2016/09/02 16:30:26, M-A Ruel wrote:
> This code belongs to binary_diff(); should passlist the allowed extentions.

I cannot catch what you mean exactly but I guess you might saying that doing
this kinds of check in diff_binary instead of here, right?

Let me revise the code like so.

[M-A Ruel, 2016-09-06 15:35:54]

https://codereview.chromium.org/2303063003/diff/40001/tools/determinism/compa...
File tools/determinism/compare_build_artifacts.py (right):

https://codereview.chromium.org/2303063003/diff/40001/tools/determinism/compa...
tools/determinism/compare_build_artifacts.py:448: lhs_data = [l for l in
lhs_header]
Replace the lines 448-452 with:
return lhs_data[4:8] != rhs_data[4:8]

[Yoshisato Yanagisawa, 2016-09-07 01:50:28]

https://codereview.chromium.org/2303063003/diff/40001/tools/determinism/compa...
File tools/determinism/compare_build_artifacts.py (right):

https://codereview.chromium.org/2303063003/diff/40001/tools/determinism/compa...
tools/determinism/compare_build_artifacts.py:448: lhs_data = [l for l in
lhs_header]
On 2016/09/06 15:35:54, M-A Ruel wrote:
> Replace the lines 448-452 with:
> return lhs_data[4:8] != rhs_data[4:8]

I would basically change the code like so but let me do more than that.

I think callee should have knowledge of local information, and when I write a
function like this, we might need to think lhs_header and rhs_header are
arbitrary COFF header.  Then, I made this like general purpose function to
return True on timestamps in COFF header only differs.

However, we actually needs first 8 bytes, and we do not check anything else,
this function is overkill.  However expecting first 8 bytes of the file might
not be so trivial.

Let me merge this function to the caller, and only checks first 8 bytes, and
only skips first 8 bytes if timestamps are different.

[M-A Ruel, 2016-09-07 18:45:40]

lgtm

[Yoshisato Yanagisawa, 2016-09-08 01:20:07]

The CQ bit was checked by yyanagisawa@chromium.org

[commit-bot: I haz the power, 2016-09-08 01:20:29]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-08 03:36:46]

Description was changed from

==========
Skip COFF timestamp difference.

Current deps diffs shows lots of files differs only first certain bytes on
Windows.  They are COFF timestamp difference, and we do not usually need to
check.  Let me skip showing them.

BUG=314403
==========

to

==========
Skip COFF timestamp difference.

Current deps diffs shows lots of files differs only first certain bytes on
Windows.  They are COFF timestamp difference, and we do not usually need to
check.  Let me skip showing them.

BUG=314403
==========

[commit-bot: I haz the power, 2016-09-08 03:36:47]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-09-08 03:40:21]

Description was changed from

==========
Skip COFF timestamp difference.

Current deps diffs shows lots of files differs only first certain bytes on
Windows.  They are COFF timestamp difference, and we do not usually need to
check.  Let me skip showing them.

BUG=314403
==========

to

==========
Skip COFF timestamp difference.

Current deps diffs shows lots of files differs only first certain bytes on
Windows.  They are COFF timestamp difference, and we do not usually need to
check.  Let me skip showing them.

BUG=314403

Committed: https://crrev.com/968e61838c000ee1850cfa8850dcfe4e51087265
Cr-Commit-Position: refs/heads/master@{#417179}
==========

[commit-bot: I haz the power, 2016-09-08 03:40:22]

Patchset 4 (id:??) landed as
https://crrev.com/968e61838c000ee1850cfa8850dcfe4e51087265
Cr-Commit-Position: refs/heads/master@{#417179}