Thanks Nico!

The next roll will have to deal with the prototype change in PPCallbacks::InclusionDirective:
https://chromium-review.googlesource.com/c/chromium/src/+/1054445

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ed11385d70dda5f5b41a080bce5cb1fc854217b4

commit ed11385d70dda5f5b41a080bce5cb1fc854217b4
Author: Reid Kleckner <rnk@google.com>
Date: Thu May 10 20:44:13 2018

Attempt to fix Clang ToT bots after upstream r332021

PPCallbacks::InclusionDirective now takes an extra
SrcMgr::CharacteristicKind parameter.

TBR=thakis@chromium.org
NOTRY=True

Bug:  841908 
Change-Id: I34557d16829d34687fbdfdb0ee885b2ab2b75a3e
Reviewed-on: https://chromium-review.googlesource.com/1054445
Reviewed-by: Reid Kleckner <rnk@chromium.org>
Commit-Queue: Reid Kleckner <rnk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557662}
[modify] https://crrev.com/ed11385d70dda5f5b41a080bce5cb1fc854217b4/tools/clang/translation_unit/TranslationUnitGenerator.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/14f716226f9251edfc34b268d74bbb2f89570ed9

commit 14f716226f9251edfc34b268d74bbb2f89570ed9
Author: Reid Kleckner <rnk@google.com>
Date: Thu May 10 21:04:03 2018

Speculative fix 2 for Clang ToT bots after upstream r332021

Add a missing 'clang::' namespace qualifier.

TBR=thakis@chromium.org
NOTRY=True
BUG= 841908 

Change-Id: I60e48efbfd92017a3802e9f74d77a9ddcb307b27
Reviewed-on: https://chromium-review.googlesource.com/1054527
Reviewed-by: Reid Kleckner <rnk@chromium.org>
Commit-Queue: Reid Kleckner <rnk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557670}
[modify] https://crrev.com/14f716226f9251edfc34b268d74bbb2f89570ed9/tools/clang/translation_unit/TranslationUnitGenerator.cpp

r332059 for lld vtable ICF ( bug 838449  too -- still want to wait on https://reviews.llvm.org/D46672 or the proposed simpler replacement)

Glancing across the ToT waterfall, I think all the redness is non-blocking. It all looks like Chromium issues, not LLVM issues, like Nico says, after we get the pdata/xdata fix in we should roll. The roll needs to remove the LLVM_FORCE_HEAD_REVISION ifdefs from TranslationUnitGenerator.cpp, of course.

The pdata/xdata fix in https://reviews.llvm.org/D46672 landed as r332169. 

The main ToT bot redness is  crbug.com/842166  which IIUC is on the Chromium side, so I'll try packaging:

https://chromium-review.googlesource.com/c/chromium/src/+/1056991

I suppose we want https://reviews.llvm.org/D46786 for  crbug.com/838449  too, but packaging to see where we're at still makes sense.

Trying one here: https://chromium-review.googlesource.com/c/chromium/src/+/1056991

Rolling past r332273 should get us the rest of  issue 838449 .

The asan test failures look legitimate. Suspecting r332033 as it seems to have something to do with asan and thread startup.

It doesn't appear to be that or another suspect, r331936, so I kicked off a bisect.

Bisection pointed to r331953 as the culprit.

Looking...

r332319 should fix timeouts in ASAN tests

stack-use-after-return looks like a valid report

Trying r332335: https://chromium-review.googlesource.com/c/chromium/src/+/1059112

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8d82617244fbf3bc10293b4de466213f8e177faf

commit 8d82617244fbf3bc10293b4de466213f8e177faf
Author: Hans Wennborg <hans@chromium.org>
Date: Wed May 16 06:54:59 2018

Roll Clang 331747:332335

Bug:  841908 
Change-Id: I56888161ac202a68dbbe21f760b2a76371c6a7fc
Reviewed-on: https://chromium-review.googlesource.com/1059112
Reviewed-by: Peter Collingbourne <pcc@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559001}
[modify] https://crrev.com/8d82617244fbf3bc10293b4de466213f8e177faf/tools/clang/scripts/update.py
[modify] https://crrev.com/8d82617244fbf3bc10293b4de466213f8e177faf/tools/clang/translation_unit/TranslationUnitGenerator.cpp

This appears to be sticking.

Next roll:  issue 844392