Self-hosting failure in ARM again

Folks,

It seems we got the same issue with Clang alignment as before:

http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-selfhost/builds/3025
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-selfhost-neon/builds/485
http://lab.llvm.org:8011/builders/clang-cmake-thumbv7-a15-full-sh/builds/118

Commits between 231213 and 231255.

There are a few issues that could have brought it:
* Seth's changes to Clang (unlikely)
* Michael's changes to DAGCombiner (likely)
* David's generic changes in LLVM (unlikely)

I'll be bisecting this like I did earlier, but I'd like to keep you
guys posted of the potential reverts, since this is not jut breaking
tests, but breaking Clang self-hosting (which cost us weeks during the
release).

Ahmed,

You have a better idea what the real problem is. I think maybe we
should bump its priority up again, or this will keep popping every
month.

Did you file a bug?

cheers,
--renato

Hi Renato,

I think it's a different issue this time.

The bots (not only ARM, btw) are getting an FE failure in compiling Support/CommandLine.cpp.
Since some of David's in this range were to CommandLine.h, they appear to me to be the more likely culprits. In particular, r231221 touched ~basic_parser(), which is what we seem to be breaking on.

Apologize in advance in case it IS my DAGCombine change. :slight_smile:
  Michael

The bots (not only ARM, btw) are getting an FE failure in compiling Support/CommandLine.cpp.
Since some of David's in this range were to CommandLine.h, they appear to me to be the more likely culprits. In particular, r231221 touched ~basic_parser(), which is what we seem to be breaking on.

I see, we may have two issues at hand.

Apologize in advance in case it IS my DAGCombine change. :slight_smile:

No worries, that's a Clang issue, or at least it was last time, where
the structures are not aligned correctly.

I'll report back once I have a culprit. :slight_smile:

cheers,
--renato

Folks,

It seems we got the same issue with Clang alignment as before:

http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-selfhost/builds/3025
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-selfhost-neon/builds/485
http://lab.llvm.org:8011/builders/clang-cmake-thumbv7-a15-full-sh/builds/118

Hmm, are these actually alignment-related? They all seem to be the
same assert failing:

    Assertion `(!DD->isTrivial() || DD->hasAttr<DLLExportAttr>()) &&
"Should not emit dtor epilogue for non-exported trivial dtor!"'
failed.

I'm tempted to say the CommandLine changes triggered some clang bug?

Commits between 231213 and 231255.

There are a few issues that could have brought it:
* Seth's changes to Clang (unlikely)
* Michael's changes to DAGCombiner (likely)
* David's generic changes in LLVM (unlikely)

I'll be bisecting this like I did earlier, but I'd like to keep you
guys posted of the potential reverts, since this is not jut breaking
tests, but breaking Clang self-hosting (which cost us weeks during the
release).

Ahmed,

You have a better idea what the real problem is. I think maybe we
should bump its priority up again, or this will keep popping every
month.

Did you file a bug?

Yep, http://llvm.org/bugs/show_bug.cgi?id=22728

Good luck with the bisecting!

-Ahmed