[libcxx-commits] [PATCH] D72543: [libcxxabi] Insert padding in __cxa_exception struct for compatibility

John McCall via Phabricator via libcxx-commits libcxx-commits at lists.llvm.org
Thu Jan 16 14:34:15 PST 2020


rjmccall added a comment.

In D72543#1825150 <https://reviews.llvm.org/D72543#1825150>, @smeenai wrote:

> From spelunking through history, it looks like D33030 <https://reviews.llvm.org/D33030> tried to solve the same problem, and then rL319123 <https://reviews.llvm.org/rL319123> undid that solution and came up with a different one to solve the same underlying issue. rL319123 <https://reviews.llvm.org/rL319123> is still in place; does it need to be adjusted for the change in this diff?


It looks like those patches were attempts to ensure adequate alignment of the exception object given the absence of an alignment attribute on the `_Unwind_Exception` type itself.  rL319123 <https://reviews.llvm.org/rL319123> became inadequate after `_Unwind_Exception` became an aligned type because that change still affected the layout of the C++ exception types.  What we're fixing here is essentially the same problem that was introduced by D33030 <https://reviews.llvm.org/D33030>.

> Additionally, is this something that should be picked to 10.0 after it's committed?

I think this should be put in 10.0, yes.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72543/new/

https://reviews.llvm.org/D72543





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