GN: Make file/dir resolving return errors.

GN: Make file/dir resolving return errors.

Previously GN would silently eat some types of errors when resolving files or directory names, leading to unexpected behavior.

This adds error checking to the resolution functions.

Committed: https://crrev.com/ff0986feacdae709a944b7cc6ee990b6cc304b76
Cr-Commit-Position: refs/heads/master@{#332697}

[brettw, 2015-06-03 20:55:16]

brettw@chromium.org changed reviewers:
+ scottmg@chromium.org

[brettw, 2015-06-03 20:56:15]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[brettw, 2015-06-03 20:56:43]

The CQ bit was unchecked by brettw@chromium.org

[brettw, 2015-06-03 20:56:57]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-06-03 20:58:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1155713006/20001

[scottmg, 2015-06-03 21:01:59]

lgtm

https://codereview.chromium.org/1155713006/diff/1/tools/gn/action_target_gene...
File tools/gn/action_target_generator.cc (right):

https://codereview.chromium.org/1155713006/diff/1/tools/gn/action_target_gene...
tools/gn/action_target_generator.cc:82: if (script_file.value().empty())
should this be err_.has_error()?

https://codereview.chromium.org/1155713006/diff/1/tools/gn/source_dir.cc
File tools/gn/source_dir.cc (right):

https://codereview.chromium.org/1155713006/diff/1/tools/gn/source_dir.cc#newc...
tools/gn/source_dir.cc:138: "You can't use empty strings as directoriers. "
"directories"

[commit-bot: I haz the power, 2015-06-03 21:08:33]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-03 21:08:33]

Dry run: Try jobs failed on following builders:
  linux_chromium_gn_chromeos_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_gn_dbg on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_gn_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[brettw, 2015-06-03 21:29:55]

The CQ bit was checked by brettw@chromium.org

[brettw, 2015-06-03 21:29:55]

The patchset sent to the CQ was uploaded after l-g-t-m from scottmg@chromium.org
Link to the patchset: https://codereview.chromium.org/1155713006/#ps60001
(title: " ")

[commit-bot: I haz the power, 2015-06-03 21:31:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1155713006/60001

[commit-bot: I haz the power, 2015-06-03 21:45:50]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-06-03 21:46:43]

Patchset 4 (id:??) landed as
https://crrev.com/ff0986feacdae709a944b7cc6ee990b6cc304b76
Cr-Commit-Position: refs/heads/master@{#332697}