tree b37320b5095626dcf571877d4bbafa22ebb042e7
parent ea63c6c08d533fb6e13df508495f9be6d9064033
author brettw <brettw@chromium.org> 1485305395 -0800
committer Commit bot <commit-bot@chromium.org> 1485305395 +0000

Display override values in GN args help.

Previously "gn args --list" would display the default value only. Now that we
have default_args in the .gn file, there are more places for the values to come
from and this is confusing (because the default value isn't necessarily what
you get).

This change makes --list display both the current value and the default value,
and the locations of the definitions for each. So when default_args apply, you
can see where the value is set. The same applies to args set in the args.gn
file for a build. It looks like this:

  is_debug
      Current value = false
        From //.gn:15
      Overridden from the default = true
        From //build/config/BUILDCONFIG.gn:154

The short mode --list --short has changed to list the current value rather than
the default.

Some obsolete help text was updated and some unused Args functions were removed.

BUG=684169,416139

Review-Url: https://codereview.chromium.org/2651023004
Cr-Original-Commit-Position: refs/heads/master@{#445883}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 9257ae440105ca90bd219517782cf55258fc830c