Display override values in GN args help.

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-Commit-Position: refs/heads/master@{#445883}
Committed: https://chromium.googlesource.com/chromium/src/+/9257ae440105ca90bd219517782cf55258fc830c

[brettw, 2017-01-24 19:22:16]

Fix

[brettw, 2017-01-24 19:22:28]

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

[brettw, 2017-01-24 19:24:07]

Description was changed from

==========
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.

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
==========

to

==========
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
==========

[brettw, 2017-01-24 19:24:20]

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

[commit-bot: I haz the power, 2017-01-24 19:25:07]

Dry run: 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, 2017-01-24 19:52:17]

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

[commit-bot: I haz the power, 2017-01-24 19:52:18]

Dry run: This issue passed the CQ dry run.

[scottmg, 2017-01-24 21:02:56]

lgtm

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/args.h
File tools/gn/args.h (right):

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/args.h#newcode30
tools/gn/args.h:30: ValueWithOverride(const Value& def_val);
Should probably have an operator= implementation to go with the copy
constructor.

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/command_args.cc
File tools/gn/command_args.cc (right):

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/command_args.c...
tools/gn/command_args.cc:132: // Override present, print bot it and the default.
bot -> both

[brettw, 2017-01-24 21:34:08]

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/args.h
File tools/gn/args.h (right):

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/args.h#newcode30
tools/gn/args.h:30: ValueWithOverride(const Value& def_val);
On 2017/01/24 21:02:55, scottmg wrote:
> Should probably have an operator= implementation to go with the copy
> constructor.

This isn't a copy constructor.

[scottmg, 2017-01-24 21:41:37]

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/args.h
File tools/gn/args.h (right):

https://codereview.chromium.org/2651023004/diff/20001/tools/gn/args.h#newcode30
tools/gn/args.h:30: ValueWithOverride(const Value& def_val);
On 2017/01/24 21:34:08, brettw (ping after 24h) wrote:
> On 2017/01/24 21:02:55, scottmg wrote:
> > Should probably have an operator= implementation to go with the copy
> > constructor.
> 
> This isn't a copy constructor.

Doh! Sorry.

(I assume map needs to copy, so you can't DISALLOW... right?)

[brettw, 2017-01-25 00:19:31]

Spellinc

[brettw, 2017-01-25 00:19:32]

The CQ bit was checked by brettw@chromium.org

[brettw, 2017-01-25 00:19:33]

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/2651023004/#ps40001
(title: "Spellinc")

[commit-bot: I haz the power, 2017-01-25 00:20:58]

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, 2017-01-25 00:50:00]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1485303572816280,
"parent_rev": "f4ada3dbe43cc265a5008bab02bc1ab9098deb31", "commit_rev":
"9257ae440105ca90bd219517782cf55258fc830c"}

[commit-bot: I haz the power, 2017-01-25 00:50:46]

Description was changed from

==========
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
==========

to

==========
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-Commit-Position: refs/heads/master@{#445883}
Committed:
https://chromium.googlesource.com/chromium/src/+/9257ae440105ca90bd219517782c...
==========

[commit-bot: I haz the power, 2017-01-25 00:50:51]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/9257ae440105ca90bd219517782c...