Fix a subtle proguard incremental build error

Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and the bug potentially only
happens in this case.

Committed: https://crrev.com/20b2c575c5ca4b674de21261151af412e9959047
Cr-Commit-Position: refs/heads/master@{#430890}

[tsniatowski, 2016-11-08 10:37:25]

Description was changed from

==========
Fix a subtle proguard incremental build error

I encountered  a confusing incremental build failure where proguard
would read and write to the same file accidentally, failing hard.
Happened after I switched the build config from not using proguard
(so the output jar was a gn copy hardlink) to using proguard.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and this potentially only
happens in this case. Worth fixing anyway I believe.
==========

to

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and this potentially only
happens in this case.
==========

[tsniatowski, 2016-11-08 10:37:26]

tsniatowski@opera.com changed reviewers:
+ jbudorick@chromium.org

[tsniatowski, 2016-11-08 10:37:39]

On 2016/11/08 10:37:26, tsniatowski wrote:
> mailto:tsniatowski@opera.com changed reviewers:
> + mailto:jbudorick@chromium.org

PTAL

[jbudorick, 2016-11-08 14:32:12]

lgtm w/ nit

Subtle indeed. Thanks for the patch!

https://codereview.chromium.org/2485663003/diff/1/build/android/gyp/proguard.py
File build/android/gyp/proguard.py (right):

https://codereview.chromium.org/2485663003/diff/1/build/android/gyp/proguard....
build/android/gyp/proguard.py:77: if out_inode and \
nit: please use parentheses instead of a trailing \ for continuation lines.

[tsniatowski, 2016-11-09 07:23:06]

Description was changed from

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and this potentially only
happens in this case.
==========

to

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and the bug potentially only
happens in this case.
==========

[tsniatowski, 2016-11-09 07:23:31]

The CQ bit was checked by tsniatowski@opera.com

[tsniatowski, 2016-11-09 07:23:31]

The patchset sent to the CQ was uploaded after l-g-t-m from
jbudorick@chromium.org
Link to the patchset: https://codereview.chromium.org/2485663003/#ps20001
(title: "slash to paren")

[commit-bot: I haz the power, 2016-11-09 07:23:47]

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, 2016-11-09 08:23:10]

Description was changed from

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and the bug potentially only
happens in this case.
==========

to

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and the bug potentially only
happens in this case.
==========

[commit-bot: I haz the power, 2016-11-09 08:23:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-11-09 08:24:56]

Description was changed from

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and the bug potentially only
happens in this case.
==========

to

==========
Fix a subtle proguard incremental build error

Prevent a confusing incremental build failure where proguard would
read and write to the same file accidentally, failing hard. Can
happen after switching the build from not using proguard, where the
output jar is a gn-copy hardlink to the input jar, to using proguard,
where the output is written to by a script reading from the input jar.

Fix by checking if the output is not a hardlink to the input in the
wrapper script.

NB. The build normally uses proguard on an apk, but makes it possible
to try and only proguard a single jar, and the bug potentially only
happens in this case.

Committed: https://crrev.com/20b2c575c5ca4b674de21261151af412e9959047
Cr-Commit-Position: refs/heads/master@{#430890}
==========

[commit-bot: I haz the power, 2016-11-09 08:24:57]

Patchset 2 (id:??) landed as
https://crrev.com/20b2c575c5ca4b674de21261151af412e9959047
Cr-Commit-Position: refs/heads/master@{#430890}