Clearer error message when parsing Android XML resource fails.

Clearer error message when parsing Android XML resource fails.

Previously, when generate_v14_compatible_resources.py encountered an
invalid XML file, it showed an error message that didn't tell which
file it was processing. E.g.:

  Traceback (most recent call last):
    ...
    File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 207, in parseFile
      parser.Parse(buffer, 0)
  ExpatError: unbound prefix: line 6, column 0

Now it also prints the name of the file that couldn't be parsed. E.g.

  Traceback (most recent call last):
    ...
    File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 207, in parseFile
      parser.Parse(buffer, 0)
  ExpatError: unbound prefix: line 6, column 0
  Failed to parse XML file: chrome/android/res/layout/my_layout.xml

Committed: https://crrev.com/fcd9c4769cdea951a67a4021a6d8b5f6bec79bbd
Cr-Commit-Position: refs/heads/master@{#302138}

[newt (away), 2014-10-30 06:49:14]

newt@chromium.org changed reviewers:
+ kkimlabs@chromium.org

[newt (away), 2014-10-30 06:49:15]

PTAL

[Kibeom Kim (inactive), 2014-10-30 07:07:39]

lgtm

Thanks for doing this!

https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
File build/android/gyp/generate_v14_compatible_resources.py (right):

https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
build/android/gyp/generate_v14_compatible_resources.py:73: traceback.print_exc()
Just a question: it looks this is a common practice among chromium python
scripts, but if we just want some additional information in addition to what it
reports already, wouldn't this be more natural?

1. printing the additional information first. (#74)
2. throwing the Exception we caught.

[Kibeom Kim (inactive), 2014-10-30 07:10:44]

https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
File build/android/gyp/generate_v14_compatible_resources.py (right):

https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
build/android/gyp/generate_v14_compatible_resources.py:73: traceback.print_exc()
On 2014/10/30 07:07:39, Kibeom Kim wrote:
> Just a question: it looks this is a common practice among chromium python
> scripts, but if we just want some additional information in addition to what
it
> reports already, wouldn't this be more natural?
> 
> 1. printing the additional information first. (#74)
> 2. throwing the Exception we caught.
> 

Though, having the most important message at the last line is much more
noticeable I guess.

[newt (away), 2014-10-30 16:22:17]

On 2014/10/30 07:10:44, Kibeom Kim wrote:
>
https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
> File build/android/gyp/generate_v14_compatible_resources.py (right):
> 
>
https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
> build/android/gyp/generate_v14_compatible_resources.py:73:
traceback.print_exc()
> On 2014/10/30 07:07:39, Kibeom Kim wrote:
> > Just a question: it looks this is a common practice among chromium python
> > scripts, but if we just want some additional information in addition to what
> it
> > reports already, wouldn't this be more natural?
> > 
> > 1. printing the additional information first. (#74)
> > 2. throwing the Exception we caught.
> > 
> 
> Though, having the most important message at the last line is much more
> noticeable I guess.

Yeah. My goal was to get the most important information grouped together at the
bottom. The downside of this method is that the code isn't as pretty and parse
errors can't be handled further up the stack (which we don't do anyway). I think
the current approach is probably best, though. Do you agree?

[Kibeom Kim (inactive), 2014-10-30 18:01:54]

On 2014/10/30 16:22:17, newt wrote:
> On 2014/10/30 07:10:44, Kibeom Kim wrote:
> >
>
https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
> > File build/android/gyp/generate_v14_compatible_resources.py (right):
> > 
> >
>
https://codereview.chromium.org/661433005/diff/1/build/android/gyp/generate_v...
> > build/android/gyp/generate_v14_compatible_resources.py:73:
> traceback.print_exc()
> > On 2014/10/30 07:07:39, Kibeom Kim wrote:
> > > Just a question: it looks this is a common practice among chromium python
> > > scripts, but if we just want some additional information in addition to
what
> > it
> > > reports already, wouldn't this be more natural?
> > > 
> > > 1. printing the additional information first. (#74)
> > > 2. throwing the Exception we caught.
> > > 
> > 
> > Though, having the most important message at the last line is much more
> > noticeable I guess.
> 
> Yeah. My goal was to get the most important information grouped together at
the
> bottom. The downside of this method is that the code isn't as pretty and parse
> errors can't be handled further up the stack (which we don't do anyway). I
think
> the current approach is probably best, though. Do you agree?

yeah I agree. Thanks!

[newt (away), 2014-10-30 18:49:02]

The CQ bit was checked by newt@chromium.org

[commit-bot: I haz the power, 2014-10-30 18:50:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/661433005/1

[commit-bot: I haz the power, 2014-10-30 19:56:06]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-30 19:57:05]

Patchset 1 (id:??) landed as
https://crrev.com/fcd9c4769cdea951a67a4021a6d8b5f6bec79bbd
Cr-Commit-Position: refs/heads/master@{#302138}