Win/GN: Make no_exception config explicit.

Win/GN: Make no_exception config explicit.

This allows other code to remove the define for no exceptions. Only
necessary for compiling dEQP with Clang on Windows currently.

BUG=None
R=brettw@chromium.org,dpranke@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

[Jamie Madill, 2016-08-04 14:05:47]

Brett or Dirk, PTAL. This should align the code with how it works on Linux.
Necessary to get dEQP compiling on Win/Clang.

[Dirk Pranke, 2016-08-04 15:53:12]

this seems plausible to me, but since it's a change to BUILDCONFIG.gn, brettw@
needs to review it.

[brettw, 2016-08-04 22:28:25]

In principle this is OK but I think we need to do a little cleanup.

Posix already has a no_exceptions config added by default. This was separate
because there was no corresponding Windows one. We should unify these so there
is one "no exceptions" config applied for all platforms, and there is one way to
remove it (and hence enable exceptions).

So we probably want a
  //build/config/compiler:no_exceptions
block and to unify all the logic in there for the different platforms.

https://codereview.chromium.org/2214743002/diff/20001/build/config/win/BUILD.gn
File build/config/win/BUILD.gn (right):

https://codereview.chromium.org/2214743002/diff/20001/build/config/win/BUILD....
build/config/win/BUILD.gn:159: # This should go in :runtime_library.
This comment doesn't make sense to me.

[Jamie Madill, 2016-08-16 20:49:11]

Thanks for the review Brett. I'm actually a bit new to this so I wonder if you
could tell me how I should get the right posix/gcc/win/etc config applied to the
shared no_exceptions config? Is there a prior config example I could follow?

[brettw, 2016-08-16 21:14:04]

On 2016/08/16 20:49:11, Jamie Madill wrote:
> Thanks for the review Brett. I'm actually a bit new to this so I wonder if you
> could tell me how I should get the right posix/gcc/win/etc config applied to
the
> shared no_exceptions config? Is there a prior config example I could follow?

Here's what I'm thinking:

We should make one config, say //build/config/compiler:no_exceptions.

Copy the logic from //build/config/gcc:no_exceptions to there under a is_posix
block. Delete the old one.

Update the reference in BUILDCONFIG.gn to point to the new one (this can be
unconditional now), and update everybody that references it (probably only a
couple).

Add your code in as is_win block in the new config.

[Jamie Madill, 2016-08-17 18:19:11]

Description was changed from

==========
Win/GN: Make no_exception config explicit.

This allows other code to remove the define for no exceptions. Only
necessary for compiling dEQP with Clang on Windows currently.

BUG=None
R=brettw@chromium.org,dpranke@chromium.org
==========

to

==========
Win/GN: Make no_exception config explicit.

This allows other code to remove the define for no exceptions. Only
necessary for compiling dEQP with Clang on Windows currently.

BUG=None
R=brettw@chromium.org,dpranke@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

[Jamie Madill, 2016-08-17 18:22:36]

Brett, PTAL. I wasn't able to remove the gcc config, because two projects Chrome
depends on use this config. I'll have to add a proxy config, change them, then
remove the config after we roll them both. Can you let me know if this CL looks
like the right way to start?

[brettw, 2016-08-31 17:01:20]

https://codereview.chromium.org/2214743002/diff/60001/build/config/compiler/B...
File build/config/compiler/BUILD.gn (right):

https://codereview.chromium.org/2214743002/diff/60001/build/config/compiler/B...
build/config/compiler/BUILD.gn:1149: # Allows turning exceptions on or off.
Can this comment be a little more precise? This will disable exceptions when
applied, which are normally enabled in C++.

https://codereview.chromium.org/2214743002/diff/60001/build/config/gcc/BUILD.gn
File build/config/gcc/BUILD.gn (right):

https://codereview.chromium.org/2214743002/diff/60001/build/config/gcc/BUILD....
build/config/gcc/BUILD.gn:120: # TODO(jmadill): Remove this when ANGLE and
libc++ don't depend on it.
I don't see how leaving this here helps ANGLE. It excepts to be able to remove
this from the list of default configs (removing something that isn't there is an
error), but you already removed it. Keeping this config here unreferenced
doesn't help those cases.

I don't know how much ANGLE needs this specific thing. If they can tolerate this
being wrong for a day, we should keep the reference in the default configs to
this one, but make this one empty. This way the GN angle code will run but it
will temporarily have no exceptions until it's updated to the shared one.

If that's not possible, we may need a 3-way patch. For a tricky case in the
past, I make a new .gni file in build somewhere with a bool set to false,
updated the other repo to key it's behavior off of the bool,  waited for a roll,
then update the behavior and flipped the bool, then removed everything.

[Dirk Pranke, 2017-07-14 00:21:03]

Rietveld CL cleanup time ...

It looks like this never landed; is this still relevant / desirable?

[Jamie Madill, 2017-07-14 16:04:26]

On 2017/07/14 00:21:03, Dirk Pranke wrote:
> Rietveld CL cleanup time ...
> 
> It looks like this never landed; is this still relevant / desirable?

Yeah, it's on my backlog of issues to attend to.