Move goma/ccache logic to //build/toolchain/gcc_toolchain.gni

Move goma/ccache logic to //build/toolchain/gcc_toolchain.gni

Avoid logic duplication between linux/android/... toolchain definitions
that all did the same thing. This is helpful for further work with
compiler prefixes / wrappers, in particular for non-goma-users.

Some toolchains used the prefix on nm and objcopy calls, this was probably
wrong and no longer happens. The toolchains that used gcc_toolchain.gni
but did not manually setup goma/ccache opt out of the setting to avoid
large behavior changes.

BUG=

Committed: https://crrev.com/dfe796aa7deb3cb7c72dfdd294c73554b4e5c0c2
Cr-Commit-Position: refs/heads/master@{#350767}

[tsniatowski, 2015-09-24 09:48:10]

tsniatowski@opera.com changed reviewers:
+ brettw@chromium.org, dpranke@chromium.org

[tsniatowski, 2015-09-24 09:51:22]

PTAL. Background: I'm trying to get icecc running in gn without external setup,
and this is a related clanup that should be useful regardless of what comes of
the icecc work.

[Dirk Pranke, 2015-09-24 19:26:45]

seems reasonable. lgtm.

[tsniatowski, 2015-09-24 19:32:12]

The CQ bit was checked by tsniatowski@opera.com

[commit-bot: I haz the power, 2015-09-24 19:35:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1361403002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1361403002/1

[brettw, 2015-09-24 19:35:57]

lgtm

https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
File build/toolchain/gcc_toolchain.gni (right):

https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
build/toolchain/gcc_toolchain.gni:89: # Allow toolchains to avoid ccache/goma
explicitly
The phrasing of this comment seems weird to me, since I don't really see it as
opt-out. I'd say we don't need a comment here, but you should document the new
use_ccache and use_goma variables in the comment above the template above.

[tsniatowski, 2015-09-24 19:40:07]

The CQ bit was unchecked by tsniatowski@opera.com

[Dirk Pranke, 2015-09-24 19:41:08]

https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
File build/toolchain/gcc_toolchain.gni (right):

https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
build/toolchain/gcc_toolchain.gni:89: # Allow toolchains to avoid ccache/goma
explicitly
On 2015/09/24 19:35:56, brettw wrote:
> The phrasing of this comment seems weird to me, since I don't really see it as
> opt-out. I'd say we don't need a comment here, but you should document the new
> use_ccache and use_goma variables in the comment above the template above.

I'm not sure I understand you; we still want the command line arg use_goma to
override 
things for the default toolchains; are you suggesting that we should modify,
e.g., clang_x64's toolchain_args
to say use_goma = use_goma ?

[tsniatowski, 2015-09-24 19:48:27]

https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
File build/toolchain/gcc_toolchain.gni (right):

https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
build/toolchain/gcc_toolchain.gni:89: # Allow toolchains to avoid ccache/goma
explicitly
On 2015/09/24 19:41:08, Dirk Pranke wrote:
> On 2015/09/24 19:35:56, brettw wrote:
> > The phrasing of this comment seems weird to me, since I don't really see it
as
> > opt-out. I'd say we don't need a comment here, but you should document the
new
> > use_ccache and use_goma variables in the comment above the template above.
> 
> I'm not sure I understand you; we still want the command line arg use_goma to
> override 
> things for the default toolchains; are you suggesting that we should modify,
> e.g., clang_x64's toolchain_args
> to say use_goma = use_goma ?

This wouldn't do anything. As I understand it the setting would simply be better
documented as "Set to false to avoid using ccache/goma even if requested
globally" near where other invoker-settable variables are listed.

[tsniatowski, 2015-09-24 20:29:57]

On 2015/09/24 19:48:27, tsniatowski wrote:
>
https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
> File build/toolchain/gcc_toolchain.gni (right):
> 
>
https://codereview.chromium.org/1361403002/diff/1/build/toolchain/gcc_toolcha...
> build/toolchain/gcc_toolchain.gni:89: # Allow toolchains to avoid ccache/goma
> explicitly
> On 2015/09/24 19:41:08, Dirk Pranke wrote:
> > On 2015/09/24 19:35:56, brettw wrote:
> > > The phrasing of this comment seems weird to me, since I don't really see
it
> as
> > > opt-out. I'd say we don't need a comment here, but you should document the
> new
> > > use_ccache and use_goma variables in the comment above the template above.
> > 
> > I'm not sure I understand you; we still want the command line arg use_goma
to
> > override 
> > things for the default toolchains; are you suggesting that we should modify,
> > e.g., clang_x64's toolchain_args
> > to say use_goma = use_goma ?
> 
> This wouldn't do anything. As I understand it the setting would simply be
better
> documented as "Set to false to avoid using ccache/goma even if requested
> globally" near where other invoker-settable variables are listed.

brettw, better now?

[brettw, 2015-09-24 21:34:15]

lgtm

[tsniatowski, 2015-09-25 04:10:10]

The CQ bit was checked by tsniatowski@opera.com

[tsniatowski, 2015-09-25 04:10:10]

The patchset sent to the CQ was uploaded after l-g-t-m from dpranke@chromium.org
Link to the patchset: https://codereview.chromium.org/1361403002/#ps20001
(title: "move the invoker param docs")

[commit-bot: I haz the power, 2015-09-25 04:10:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1361403002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1361403002/20001

[commit-bot: I haz the power, 2015-09-25 04:43:54]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-25 04:44:45]

Patchset 2 (id:??) landed as
https://crrev.com/dfe796aa7deb3cb7c72dfdd294c73554b4e5c0c2
Cr-Commit-Position: refs/heads/master@{#350767}