r317203 (current google3 now) is probably a better candidate now for llvm-next  since r316287 is too  close to r316199.

Yes, I was wondering about that; they just "released" that candidate late Thursday afternoon, and I had started working on picking/testing r316287 on Wednesday...

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb

commit e2844ff915c0f916d35b15a43f0d0ca873ecf5bb
Author: Caroline Tice <cmtice@google.com>
Date: Sat Nov 18 04:18:52 2017

Roll llvm-next to r317203

Upgrade llvm-next to r317203.

BUG= chromium:783836 
TEST=Successful trybot builds with kevin, nyan_big and falco.

Change-Id: Id335ea635a243bf60de85ad573d09e5f12671796
Reviewed-on: https://chromium-review.googlesource.com/764115
Commit-Ready: Caroline Tice <cmtice@chromium.org>
Tested-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Yunlian Jiang <yunlian@chromium.org>

[rename] https://crrev.com/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb/sys-devel/lld/lld-6.0_pre316199-r2.ebuild
[rename] https://crrev.com/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb/sys-devel/clang/clang-6.0_pre316199_p20171105-r1.ebuild
[rename] https://crrev.com/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb/sys-devel/llvm/llvm-6.0_pre316199_p20171105-r1.ebuild
[rename] https://crrev.com/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb/sys-devel/gcc/gcc-4.9.2-r171.ebuild
[add] https://crrev.com/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb/sys-devel/llvm/files/clang-6.0-enable-libgcc-with-compiler-rt.patch
[rename] https://crrev.com/e2844ff915c0f916d35b15a43f0d0ca873ecf5bb/sys-libs/compiler-rt/compiler-rt-6.0_pre316199-r1.ebuild

After upgrading llvm-next, we found two packages had build issues with a new warning.

Bug filed here:
ttps://bugs.chromium.org/p/chromium/issues/detail?id=787037

CL's created here:
https://chromium-review.googlesource.com/c/chromiumos/platform/audiotest/+/779063
https://chromium-review.googlesource.com/c/chromiumos/platform/gestures/+/779064

We also found a problem in the host package dev-libs/grpc (found in chromiumos-sdk, causing InitSdk stage to fail).  I filed this bug upstream, to get the bug in the code fixed:  https://github.com/grpc/grpc/issues/13597.

In the meantime, I patched the ebuild file for that package to disable the new warning (the warning is -Wunused-private-field).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/6a7a502e85a551833575d3d81acd665c896c0cdd

commit 6a7a502e85a551833575d3d81acd665c896c0cdd
Author: Caroline Tice <cmtice@google.com>
Date: Wed Dec 13 05:09:36 2017

LLVM: roll to next version r317203

Roll to tested llvm-next version r317203.

Text matrix:
https://docs.google.com/spreadsheets/d/1BMoyeYTrvEFb08MeBuJtX2fQ6CBuhkm_JHedt_gN2Qg/edit#gid=0

BUG= chromium:783836 
TEST=See test matrix.

Change-Id: I2ecdaef281d73a63bf368df2a853b46c09c5af88
Reviewed-on: https://chromium-review.googlesource.com/823077
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Tested-by: Caroline Tice <cmtice@chromium.org>
Trybot-Ready: Caroline Tice <cmtice@chromium.org>

[delete] https://crrev.com/8d9a29f4c428b4afe64305e7ae88a942bb1998ca/sys-devel/llvm/files/clang-5.0-enable-libgcc-with-compiler-rt.patch
[rename] https://crrev.com/6a7a502e85a551833575d3d81acd665c896c0cdd/sys-devel/llvm/llvm-6.0_pre317203_p20171212.ebuild
[rename] https://crrev.com/6a7a502e85a551833575d3d81acd665c896c0cdd/sys-devel/gcc/gcc-4.9.2-r174.ebuild
[rename] https://crrev.com/6a7a502e85a551833575d3d81acd665c896c0cdd/sys-libs/compiler-rt/compiler-rt-6.0_pre317203.ebuild
[rename] https://crrev.com/6a7a502e85a551833575d3d81acd665c896c0cdd/sys-devel/clang/clang-6.0_pre317203_p20171212.ebuild
[rename] https://crrev.com/6a7a502e85a551833575d3d81acd665c896c0cdd/sys-devel/lld/lld-6.0_pre317203.ebuild
[delete] https://crrev.com/8d9a29f4c428b4afe64305e7ae88a942bb1998ca/sys-devel/llvm/files/cherry/a312801e78a7627965158838eae1fb9a10487af7.patch
[delete] https://crrev.com/8d9a29f4c428b4afe64305e7ae88a942bb1998ca/sys-devel/llvm/files/cherry/d7958d5ac0c1e979dec35ea26a981532e094b5b2.patch
[delete] https://crrev.com/8d9a29f4c428b4afe64305e7ae88a942bb1998ca/sys-devel/llvm/files/cherry/b1bfcf247fd22246ea224ad2df241f25c63ea22e.patch
[delete] https://crrev.com/8d9a29f4c428b4afe64305e7ae88a942bb1998ca/sys-devel/llvm/files/cherry/697969187cd6d8ed03eabbe1198ee7892d872953.patch

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/1bc9d550412ee4517cf2483e32586c527bdf0c5b

commit 1bc9d550412ee4517cf2483e32586c527bdf0c5b
Author: Manoj Gupta <manojgupta@google.com>
Date: Sun Dec 17 12:20:45 2017

generic_stages: temporarily ignore all target prebuilts.

This is a temporary CL.  Revert this CL once in has participated in
a green CQ run.  This process is documented at:

https://sites.google.com/a/google.com/chromeos/for-team-members/infrastructure/chromeos-admin/clear_binaries

BUG= chromium:783836 
TEST=Tested with bob-paladin (rebuilt packages). Unittests pass.

Change-Id: I1e769f71e78b9ce3dacbdeeb8d2351ad3d420f1f
Reviewed-on: https://chromium-review.googlesource.com/831232
Commit-Ready: Manoj Gupta <manojgupta@chromium.org>
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>

[modify] https://crrev.com/1bc9d550412ee4517cf2483e32586c527bdf0c5b/cbuildbot/config_dump.json
[modify] https://crrev.com/1bc9d550412ee4517cf2483e32586c527bdf0c5b/lib/sysroot_lib.py
[modify] https://crrev.com/1bc9d550412ee4517cf2483e32586c527bdf0c5b/cbuildbot/stages/build_stages_unittest.py
[modify] https://crrev.com/1bc9d550412ee4517cf2483e32586c527bdf0c5b/cbuildbot/stages/generic_stages.py
[modify] https://crrev.com/1bc9d550412ee4517cf2483e32586c527bdf0c5b/lib/config_lib.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/a76bad1cb99ea17ed7d04d93151ca35041318c72

commit a76bad1cb99ea17ed7d04d93151ca35041318c72
Author: Manoj Gupta <manojgupta@chromium.org>
Date: Sun Dec 17 22:30:43 2017

Revert "generic_stages: temporarily ignore all target prebuilts."

This reverts commit 1bc9d550412ee4517cf2483e32586c527bdf0c5b.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> generic_stages: temporarily ignore all target prebuilts.
>
> This is a temporary CL.  Revert this CL once in has participated in
> a green CQ run.  This process is documented at:
>
> https://sites.google.com/a/google.com/chromeos/for-team-members/infrastructure/chromeos-admin/clear_binaries
>
> BUG= chromium:783836 
> TEST=Tested with bob-paladin (rebuilt packages). Unittests pass.
>
> Change-Id: I1e769f71e78b9ce3dacbdeeb8d2351ad3d420f1f
> Reviewed-on: https://chromium-review.googlesource.com/831232
> Commit-Ready: Manoj Gupta <manojgupta@chromium.org>
> Tested-by: Manoj Gupta <manojgupta@chromium.org>
> Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>

Bug:  chromium:783836 
Change-Id: I7b3f2fbb65d6c1eacff07ef329a5ffc1a524f620
Reviewed-on: https://chromium-review.googlesource.com/831527
Commit-Ready: Manoj Gupta <manojgupta@chromium.org>
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>

[modify] https://crrev.com/a76bad1cb99ea17ed7d04d93151ca35041318c72/cbuildbot/config_dump.json
[modify] https://crrev.com/a76bad1cb99ea17ed7d04d93151ca35041318c72/lib/sysroot_lib.py
[modify] https://crrev.com/a76bad1cb99ea17ed7d04d93151ca35041318c72/cbuildbot/stages/build_stages_unittest.py
[modify] https://crrev.com/a76bad1cb99ea17ed7d04d93151ca35041318c72/cbuildbot/stages/generic_stages.py
[modify] https://crrev.com/a76bad1cb99ea17ed7d04d93151ca35041318c72/lib/config_lib.py

Roll is done. Closing.