Coroutine use after free on Clang 12.

[zoecarver]

Bugzilla Link	50499
Version	12.0
OS	All
CC	@adrianimboden,@zygoloid

Extended Description

Starting with Clang 12, the address sanitizers fail because of a use-after-free any time get_return_object returns something that is not the parent object and the parent object is not empty. Here's a reproducer: https://godbolt.org/z/6Gfv3xG9o

Refs https://reviews.llvm.org/D103196 where this came up.

[ChuanqiXu9]

This problem comes from that the GRO shouldn't live in the frame. We might add a special attribute for GRO to tell the middle end that it shouldn't be put on the frame.

[llvmbot]

@llvm/issue-subscribers-coroutines

| | | | --- | --- | | Bugzilla Link | [50499](https://llvm.org/bz50499) | | Version | 12.0 | | OS | All | | CC | @adrianimboden,@zygoloid |

Extended Description

Starting with Clang 12, the address sanitizers fail because of a use-after-free any time get_return_object returns something that is not the parent object and the parent object is not empty. Here's a reproducer: https://godbolt.org/z/6Gfv3xG9o

Refs https://reviews.llvm.org/D103196 where this came up.